pittengk

DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited.

The words “he,” “him,” “his,” “man,” and “men,” whenused in this publication, represent both the masculine andfeminine genders unless otherwise specifically stated.

You may recommend changes to this manual to improve it.Key your comments to the page and line of text in which thechanges are recommended. Give reasons for each commentto help understand and evaluate it. Send comments to:Commandant, United States Army Infantry School, ATTN:ATSH-B-ID, Fort Benning, Georgia 31905.

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FM 90-5

CHAPTER 1

The Jungle Environment

Section I. GENERAL

This chapter introduces jungle environ-ments—where they are found and what theyare like. Later chapters build on thisinformation, providing guidance on fightingand living in the jungle.

Field Marshal Slim’s words reflect theimage of the jungle most armies carry intojungle warfare. At first, the jungle seems tobe very hostile, but the hostility wanes astroops learn more about the jungle environ-ment.

Jungles, in their various forms, arecommon in tropical areas of the world—mainly Southeast Asia, Africa, and LatinAmerica.

“To our men. . . the jungle was astrange, fearsome place; moving andfighting in it were a nightmare. We weretoo ready to classify jungle as'impenetratable' . . . To us it appearedonly as an obstacle to movement; to theJapanese it was a welcome means ofconcealed maneuver and suprise . . .The Japanese reaped the deservedreward . . . we paid the penalty.”

–Field Marshall Slim, Victor inBurma, World War II (Concerningthe dark, early days of the BurmaCampaign)

CONTENTS

SECTION PAGE

I. General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1II. Climate and Weather. . . . . . . . . . . . . . . . . . 1-2Ill. Terrain and Vegetation . . . . . . . . . . . . . . . 1-3

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—FM 90-5

Section II. CLIMATE AND WEATHER

The climate in jungles varies withlocation. Close to the equator, all seasons arenearly alike, with rains throughout the year;farther from the equator, especially in Indiaand Southeast Asia, jungles have distinctwet (monsoon) and dry seasons. Both zoneshave high temperatures (averaging 78 to 95+degrees Fahrenheit), heavy rainfall (as muchas 1,000 centimeters [400+ inches] annually),and high humidity (90 percent) throughoutthe year.

Severe weather also has an impact ontactical operations in the jungle. The specificeffects of weather on operations arediscussed throughout this manual.

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Section III. TERRAIN AND VEGETATION

TYPES OF JUNGLESThe jungle environment includes

densely forested areas, grasslands, cul-tivated areas, and swamps. Jungles areclassified as primary or secondary junglesbased on the terrain and vegetation.

PRIMARY JUNGLES

These are tropical forests. Depending onthe type of trees growing in these forests,primary jungles are classified either astropical rain forests or as deciduous forests.

Tropical Rain Forests. These consistmostly of large trees whose branches spreadand lock together to form canopies. Thesecanopies, which can exist at two or threedifferent levels, may form as low as 10 metersfrom the ground. The canopies preventsunlight from reaching the ground, causing alack of undergrowth on the jungle floor.Extensive above-ground root systems andhanging vines are common. Theseconditions, combined with a wet and soggysurface, make vehicular traffic difficult. Footmovement is easier in tropical rain foreststhan in other types of jungle. Except wherefelled trees or construction make a gap in thecanopy of the rain forest, observation fromthe air is nearly impossible. Groundobservation is generally limited to about 50meters (55 yards).

Deciduous Forests. These are found insemitropical zones where there are both wetand dry seasons. In the wet season, trees arefully leaved; in the dry season, much of thefoliage dies. Trees are generally less dense indeciduous forests than in rain forests. Thisallows more rain and sunlight to filter to theground, producing thick undergrowth. In thewet season, with the trees in full leaf,observation both from the air and on the

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– FM 90-5

ground is limited. Movement is more difficultthan in the rain forest. In the dry season,however, both observation and trafficabilityimprove.

SECONDARY JUNGLES

These are found at the edge of the rainforest and the deciduous forest, and in areaswhere jungles have been cleared andabandoned. Secondary jungles appear whenthe ground has been repeatedly exposed tosunlight. These areas are typicallyovergrown with weeds, grasses, thorns,ferns, canes, and shrubs. Foot movement isextremely slow and difficult. Vegetation mayreach to a height of 2 meters. This will limitobservation to the front to only a few meters.

COMMON JUNGLE FEATURES

SWAMPS

These are common to all low jungle areaswhere there is water and poor drainage.There are two basic types of swamps—mangrove and palm.

Mangrove Swamps. These are found incoastal areas wherever tides influence waterflow. The mangrove is a shrub-like tree whichgrows 1 to 5 meters high. These trees havetangled root systems, both above and belowthe water level, which restrict movement tofoot or small boats. Observation in mangroveswamps, both on the ground and from the air,is poor. Concealment is excellent.

Palm Swamps. These exist in both salt andfresh water areas. Like movement in themangrove swamps, movement through palmswamps is mostly restricted to foot(sometimes small boats). Vehicular traffic isnearly impossible except after extensive roadconstruction by engineers. Observation andfields-of-fire are very limited. Concealment

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from both air and ground observation isexcellent.

SAVANNA

This is a broad, open jungle grassland inwhich trees are scarce. The thick grass isbroad-bladed and grows 1 to 5 meters high.Movement in the savanna is generally easierthan in other types of jungle areas, especiallyfor vehicles. The sharp-edged, dense grassand extreme heat make foot movement a slowand tiring process. Depending on the heightof the grass, ground observation may varyfrom poor to good. Concealment from airobservation is poor for both troops andvehicles.

BAMBOO

This grows in clumps of varying size injungles throughout the tropics. Large standsof bamboo are excellent obstacles for wheeledor tracked vehicles. Troop movementthrough bamboo is slow, exhausting, andnoisy. Troops should bypass bamboo standsif possible.

CULTIVATED AREAS

These exist in jungles throughout thetropics and range from large, well-plannedand well-managed farms and plantations tosmall tracts cultivated by individualfarmers. There are three general types ofcultivated areas—rice paddies, plantations,and small farms.

Rice Paddies. These are flat, flooded fieldsin which rice is grown. Flooding of the fieldsis controlled by a network of dikes andirrigation ditches which make movement byvehicles difficult even when the fields aredry. Concealment is poor in rice paddies.Cover is limited to the dikes, and then onlyfrom ground fire. Observation and fields offire are excellent. Foot movement is poorwhen the fields are wet because soldiers must

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— FM 90-5

wade through water about 1/2 meter (2 feet)deep and soft mud. When the fields are dry,foot movement becomes easier. The dikes,about 2 to 3 meters tall, are the only obstacles.

Plantations. These are large farms orestates where tree crops, such as rubber andcoconut, are grown. They are usuallycarefully planned and free of undergrowth(like a well-tended park). Movement throughplantations is generally easy. Observationalong the rows of trees is generally good.Concealment and cover can be found behindthe trees, but soldiers moving down the culti-vated rows are exposed.

Small Farms. These exist throughout thetropics. These small cultivated areas areusually hastily planned. After 1 or 2 years’use, they usually are abandoned, leavingbehind a small open area which turns intosecondary jungle. Movement through theseareas may be difficult due to fallen trees andscrub brush.

Generally, observation and fields-of-fireare less restricted in cultivated areas than inuncultivated jungles. However, much of thenatural cover and concealment are removedby cultivation, and troops will be moreexposed in these areas.

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FM 90-5

CHAPTER 2

Life in the Jungle

Section I. GENERALSoldiers must understand that the

environment affects everyone. The degree towhich soldiers are trained to live and fight inharsh environments will determine theirunit's success or failure.

“Jungle fighting is not new to USsoldiers, nor does the enemy have amonopoly on jungle know-how. USunits adapted well to jungle fighting,and when we operated against theNorth Vietnamese Army along theCambodian border we found that theyhad as much difficulty operating in thearea as we did. The prisoners wecaptured were, as a rule, undernour-ished, emaciated, and sick with malaria.They stated that almost everyone intheir unit had malaria, and many haddied from it.”

Report, 25th Infantry Division,Republic of Vietnam

jungle must learn that the most importantthing is to keep their heads and calmly thinkout any situation.

Many of the stories written about out-of-the-way jungle places were written by writerswho went there in search of adventure ratherthan facts. Practically without exception,these authors exaggerated or invented manyof the thrilling experiences they relate. Thesethrillers are often a product of the author’simagination and are not facts.

Most Americans, especially those raisedin cities, are far removed from their pioneerancestors, and have lost the knack of takingcare of themselves under all conditions. Itwould be foolish to say that, without propertraining, they would be in no danger if lost inthe jungles of Southeast Asia, SouthAmerica, or some Pacific island. On the otherhand, they would be in just as much danger iflost in the mountains of westernPennsylvania or in other undevelopedregions of our own country. The onlydifference would be that a man is less likely topanic when he is lost in his homeland thanwhen he is lost abroad.

There is very little to fear from the jungleenvironment. Fear itself can be an enemy.Soldiers must be taught to control their fearof the jungle. A man overcome with fear is oflittle value in any situation. Soldiers in a

CONTENTSSECTION PAGE

I . General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1II. Jungle Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2III. Jungle Survival . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10

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–FM 90-5

Section II. JUNGLE HAZARDS

EFFECT OF CLIMATE

The discomforts of tropical climates areoften exaggerated, but it is true that the heatis more persistent. In regions where the aircontains a lot of moisture, the effect of theheat may seem worse than the sametemperature in a dry climate. Many peopleexperienced in jungle operations feel that theheat and discomfort in some US cities in thesummertime are worse than the climate inthe jungle.

Strange as it may seem, there may bemore suffering from cold in the tropics thanfrom the heat. Of course, very lowtemperatures do not occur, but chilly daysand nights are common. In some jungles,in winter months, the nights are cold enoughto require a wool blanket or poncho liner forsleeping.

Rainfall in many parts of the tropics ismuch greater than that in most areas of thetemperate zones. Tropical downpoursusually are followed by clear skies, and inmost places the rains are predictable atcertain times of the day. Except in thoseareas where rainfall may be continuousduring the rainy season, there are not manydays when the sun does not shine part of thetime.

People who live in the tropics usuallyplan their activities so that they are able tostay under shelter during the rainy andhotter portions of the day. After becomingused to it, most tropical dwellers prefer theconstant climate of the torrid zones to thefrequent weather changes in colder climates.

INSECTS

Malaria-carrying mosquitoes areprobably the most harmful of the tropicalinsects. Soldiers can contract malaria ifproper precautions are not taken.

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Mosquitoes are most prevalent early atnight and just before dawn. Soldiers must beespecially cautious at these times. Malaria ismore common in populated areas than inuninhabited jungle, so soldiers must also beespecially cautious when operating aroundvillages. Mud packs applied to mosquito bitesoffer some relief from itching.

Wasps and bees may be common in someplaces, but they will rarely attack unless theirnests are disturbed. When a nest is disturbed,the troops must leave the area and reassem-ble at the last rally point. In case of stings,mud packs are helpful. In some areas, thereare tiny bees, called sweatbees, which maycollect on exposed parts of the body duringdry weather, especially if the body issweating freely. They are annoying butstingless and will leave when sweating hascompletely stopped, or they may be scrapedoff with the hand.

The larger centipedes and scorpions caninflict stings which are painful but not fatal.They like dark places, so it is alwaysadvisable to shake out blankets beforesleeping at night, and to make sure beforedressing that they are not hidden in clothingor shoes. Spiders are commonly found in thejungle. Their bites may be painful, but arerarely serious. Ants can be dangerous toinjured men lying on the ground and unableto move. Wounded soldiers should be placedin an area free of ants.

In Southeast Asian jungles, the rice-borer moth of the lowlands collects aroundlights in great numbers during certainseasons. It is a small, plain-colored mothwith a pair of tiny black spots on the wings. Itshould never be brushed off roughly, as thesmall barbed hairs of its body may be ground

into the skin. This causes a sore, much like aburn, that often takes weeks to heal.

LEECHESLeeches are common in many jungle

areas, particularly throughout most of theSouthwest Pacific, Southeast Asia, and theMalay Peninsula. They are found in swampyareas, streams, and moist jungle country.They are not poisonous, but their bites maybecome infected if not cared for properly. Thesmall wound that they cause may provide apoint of entry for the germs which causetropical ulcers or “jungle sores.” Soldiersoperating in the jungle should watch forleeches on the body and brush them off beforethey have had time to bite. When they havetaken hold, they should not be pulled offforcibly because part of the leech may remainin the skin. Leeches will release themselves iftouched with insect repellent, a moist piece oftobacco, the burning end of a cigarette, a coalfrom a fire, or a few drops of alcohol.

Straps wrapped around the lower part ofthe legs (“leech straps”) will prevent leechesfrom crawling up the legs and into the crotcharea. Trousers should be securely tucked intothe boots.

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— FM 90-5

SNAKESA soldier in the jungle probably will see

very few snakes. When he does see one, thesnake most likely will be making every effortto escape.

If a soldier should accidently step on asnake or otherwise disturb a snake, it willprobably attempt to bite. The chances of thishappening to soldiers traveling along trailsor waterways are remote if soldiers are alert

and careful. Most jungle areas pose less of asnakebite danger than do the uninhabitedareas of New Mexico, Florida, or Texas. Thisdoes not mean that soldiers should becareless about the possibility of snakebites,but ordinary precautions against them areenough. Soldiers should be particularlywatchful when clearing ground.

Treat all snakebites as poisonous.

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FM 90-5—–

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–FM 90-5

CROCODILES ANDCAYMANS

Crocodiles and caymans are meat-eating share of crocodiles, but there are fewreptiles which live in tropical areas. authenticated cases of crocodiles actually“Crocodile-infested rivers and swamps” is a attacking humans. Caymans, found in Southcatch-phrase often found in stories about the and Central America, are not likely to attacktropics. Asian jungles certainly have their unless provoked.

WILD ANIMAL

In Africa, where lions, leopards, andother flesh-eating animals abound, they areprotected from hunters by local laws and liveon large preserves. In areas where the beastsare not protected, they are shy and seldomseen. When encountered, they will attempt toescape. All large animals can be dangerous ifcornered or suddenly startled at closequarters. This is especially true of femaleswith young. In the jungles of Sumatra, Bali,Borneo, Southeast Asia, and Burma there aretigers, leopards, elephants, and buffalo.Latin America’s jungles have the jaguar.Ordinarily, these will not attack a manunless they are cornered or wounded.

Certain jungle animals, such as waterbuffalo and elephants, have been domes-ticated by the local people. Soldiers shouldalso avoid these animals. They may appear

tame, but this tameness extends only topeople the animals are familar with.

POISONOUSVEGETATION

Another area of danger is that ofpoisonous plants and trees. For example,nettles, particularly tree nettles, are one ofthe dangerous items of vegetation. Thesenettles have a severe stinging that willquickly educate the victim to recognize theplant. There are ringas trees in Malaysiawhich affect some people in much the sameway as poison oak. The poison ivy and poisonsumac of the continental US can cause manyof the same type troubles that may beexperienced in the jungle. The danger frompoisonous plants in the woods of the USeastern seaboard is similar to that of the

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FM 90-5—

tropics. Thorny thickets, such as rattan,should be avoided as one would avoid ablackberry patch.

Some of the dangers associated withpoisonous vegetation can be avoided bykeeping sleeves down and wearing gloveswhen practical.

HEALTH ANDHYGIENE

The climate in tropical areas and theabsence of sanitation facilities increase thechance that soldiers may contract a disease.Disease is fought with good sanitationpractices and preventive medicine. In pastwars, diseases accounted for a significantlyhigh percentage of casualties.

WATERBORNE DISEASES

Water is vital in the jungle and is usuallyeasy to find. However, water from naturalsources should be considered contaminated.Water purification procedures must betaught to all soldiers. Germs of seriousdiseases, like dysentery, are found in impurewater. Other waterborne diseases, such asblood fluke, are caused by exposure of anopen sore to impure water.

Soldiers can prevent waterbornediseases by:

Obtaining drinking water fromapproved engineer water points.

Using rainwater; however, rainwatershould be collected after it has beenraining at least 15 to 30 minutes. Thislessens the chances of impurity beingwashed from the jungle canopy intothe water container. Even then thewater should be purified.

Insuring that all drinking water ispurified.

Not swimming or bathing in untreatedwater.

Keeping the body fully clothed whencrossing water obstacles.

FUNGUS DISEASES

These diseases are caused by poorpersonal health practices. The jungleenvironment promotes fungus and bacterialdiseases of the skin and warm waterimmersion skin diseases. Bacteria and fungiare tiny plants which multiply fast under thehot, moist conditions of the jungle. Sweat-soaked skin invites fungus attack. The

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— FM 90-5

following are common skin diseases that arecaused by long periods of wetness of the skin:

Warm Water Immersion Foot. Thisdisease occurs usually where there are manycreeks, streams, and canals to cross, with dryground in between. The bottoms of the feetbecome white, wrinkled, and tender. Walkingbecomes painful.

Chafing. This disease occurs when soldiersmust often wade through water up to theirwaists, and the trousers stay wet for hours.The crotch area becomes red and painful toeven the lightest touch.

Most skin diseases are treated by lettingthe skin dry.

HEAT INJURIES

These result from high temperatures,high humidity, lack of air circulation, andphysical exertion. All soldiers must betrained to prevent heat disorders.

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FM 90-5—

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— FM 90-5

they attack, a small force should be able todisperse them.

NOTE: For more details, see FM 21-10 forfield hygiene and sanitation, and FM 21-11for first aid for soldiers.

NATIVESLike all other regions of the world, the

jungle also has its native inhabitants.Soldiers should be aware that some of thesenative tribes can be hostile if not treatedproperly.

There may be occasions, however, whenhostile tribes attack without provacation. If

Section III. JUNGLE SURVIVAL

FOODFood of some type is always available in toads and salamanders, have glands on the

the jungle—in fact, there is hardly a place in skin which should be removed before theirthe world where food cannot be secured from meat is eaten. Fruits, flowers, buds, leaves,plants and animals. All animals, birds, bark, and often tubers (fleshy plant roots)reptiles, and many kinds of insects of the may be eaten. Fruits eaten by birds andjungle are edible. Some animals, such as monkeys usually may be eaten by man.

Meats that can be The following types offound in most jungles in- fruits and nuts are common Vegetables found include: in jungle areas: most jungles include:

Wild fowl Bananas Wild

Wild cattle Coconutsraspberries Taro *

Nakarika Yam *Wild pig Oranges and

lemons Yucca *Freshwater fish * Papaya

Navele nutsSaltwater fish

Hearts of palm trees

Breadfruit MangoesFresh-water crawfish

*These items must be cooked before eating.

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FM 90-5 –

There are various means of preparingand preserving food found in the jungle. Fish,for example, can be cleaned and wrapped inwild banana leaves. This bundle is then tiedwith string made from bark, placed on ahastily constructed wood griddle, androasted thoroughly until done. Anothermethod is to roast the bundle of fishunderneath a pile of red-hot stones.

Other meats can be roasted in a hollowsection of bamboo, about 60 centimeters (2feet) long. Meat cooked in this manner willnot spoil for three or four days if left insidethe bamboo stick and sealed.

Yams, taros, yuccas, and wild bananascan be cooked in coals. They taste somewhatlike potatoes. Palm hearts can make arefreshing salad, and papaya a deliciousdessert.

SHELTERJungle shelters are used to protect

personnel and equipment from the harshelements of the jungle. Shelters are necessarywhile sleeping, planning operations, andprotecting sensitive equipment.

When selecting shelter, leadersshould:

Choose high ground, away fromswamps and dry river beds

Avoid trails, game tracks, or villages(See app E for more on shelters.)

NAVIGATIONNavigation in thick jungle areas is

difficult even for the most experiencednavigators. Soldiers navigating in the junglemust use various aids. The compass is anobvious aid, but a soldier would never be ableto move very fast in the jungle if he had toconstantly move along a magnetic azimuth.

Movement along a terrain feature, such as aridgeline, is easier but can be extremelydangerous when establishing a pattern ofconsistency. A soldier must trust thecompass, map, and pace count. A soldiershould not keep his eyes riveted on thecompass; however, it should be used as acheck.

The shadows caused by the sun are aneasily observed and accurate aid to direction.Allowances must be made for the gradualdisplacement of the shadows as the sunmoves across the sky.

Other aids to maintaining directioninclude prominent objects, the course ofrivers, prevailing winds, the stars, and themoon. (See app B for more on navigation.)

OBSERVATION

All movements of animals and men aremarked by tracks and signs. Soldiers mustlearn to read signs left in soft ground, instreambeds, on roads and trails, and nearwatering places and salt licks. Animalsseldom move without a reason; a few freshtracks supply information about their maker,his direction, and probable intentions.

Animals avoid man. The animals, theirtracks, and their behavior can revealwhether or not men are in the area. Junglefighters can listen to the cries of animals andlearn to recognize their alarm calls.

The ability to track and to recognizesigns in the jungle are valuable skills.Throughout the soldier’s time in the jungle,he should practice these skills. (See app B formore on tracking.)

CLOTHING AND EQUIPMENTBefore deploying for jungle operations,

troops are issued special uniforms andequipment. Some of these items are:

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—FM 90-5

JUNGLE FATIGUES

These fatigues are lighter and fasterdrying than standard fatigues. To providethe best ventilation, the uniform should fitloosely. It should never be starched.

JUNGLE BOOTS

These boots are lighter and faster dryingthan all-leather boots. Their cleated soles willmaintain footing on steep, slippery slopes.The ventilating insoles should be washed in

INSECT (MOSQUITO) BAR

The insect (mosquito) bar or net shouldbe used any time soldiers sleep in the jungle.Even if conditions do not allow a shelter, thebar can be hung inside the fighting positionor from trees or brush. No part of the bodyshould touch the insect net when it is hung,because mosquitoes can bite through thenetting. The bar should be tucked or laidloosely, not staked down. Although this pieceof equipment is very light, it can be bulky ifnot folded properly. It should be folded inside

warm, soapy water when the situation allows. the poncho as tightly as possible.

C L O T H I N G A N D E Q U I P M E N T

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CHAPTER 3

Preparation and Training to Deploy to Jungle Areas

Section I. GENERAL

Chapters 1 and 2 describe the jungle This chapter lists the factors to beenvironment. Since many soldiers are considered when preparing for jungle opera-unaccustomed to such an environment, they tions and presents training tips for con-must make preparations before conducting ducting jungle training.jungle operations.

Section II. FACTORS TO BE CONSIDEREDWHEN PREPARING FOR

JUNGLE OPERATIONS

When a unit is alerted for training oractual combat operations in a jungleenvironment, the commander must firstconsider the following:

Where will the unit be training oroperating?

What are the climatic and terrainconditions of the objective area?

How much time does the unit haveto prepare?

Will the unit be taking its ownequipment?

Does any of the unit’s equipment re-quire modification (including camou-flage painting)?

What special equipment does theunit require?

Does the unit have any junglewarfare instructors, soldiers with jungleexperience, or linguists?

What available training areas haveclimate and terrain resembling theobjective area?

What training assistance is avail-able? Outside instructors? Trainingaids?

What type operations are to beconducted—conventional or counter-guerrilla?

CONTENTSSECTION PAGE

I. General . . . . . . . . . . . . . . . . . . . . . . . . 3-1

II. Factors to be Considered whenPreparing for Jungle Operations . . 3-1

Ill. Training Tips . . . . . . . . . . . . . . . . 3-2

Does higher headquarters havespecial standing operating procedures(SOP) for jungle war?

Are all soldiers physically fit?

What information is availableabout the enemy?

What information is availableabout local civilians and allied forces inthe objective area?

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—FM 90-5

Once these questions have beenanswered, the commander can develop aprogram to prepare his unit to operate in thejungle.

The idea that a unit is technically andtactically proficient is only a small part of a

Section III. TRAINING TIPS

Units committed to jungle operationsmay have to fight as soon as they arrive inthe operational area. Commanders mustmake the best use of the preparation timeavailable. Measures which commandersshould consider include:

Making use of time in garrison. Certainjungle subjects can be taught usingclassroom instruction. This training shouldbegin as soon as possible, so that time injungle training areas can be devoted to moreadvanced techniques.

Integrating individual training into unittraining exercises. Rather than devote fieldtraining time to the individual skills requiredto live in the jungle, these skills should beintroduced early in classes, and thenpracticed during unit training exercises.

Making use of local training areas.

unit’s preparation. Emphasis should beplaced on the mental, physical, andpsychological aspects of operating in ajungle environment. The key to overcomingthese problems lies with the unit chain ofcommand in their efforts to develop a “will towin” as well as “will to train to win.”

resemble jungle terrain, some jungletechniques can be introduced in them. Thiswill provide a training base which can beexpanded when the unit deploys to its jungletraining or operational areas. In addition,physical training should begin in the localtraining area as early as possible beforedeployment.

Although these training areas may not

The following lists can be used as a guide to subjects that should be covered:

INDIVIDUAL TRAINING

Common Subjects: Staff and Leader Subjects:

Jungle environment and acclimation Jungle maintenance and supply techniques

Living in the jungle Jungle terrain appreciation

Survival, evasion, and escape Enemy order of battle and tactics

Camouflage and concealment Airmobile techniques

Tracking

Operational area orientation Specialist Subjects:

Jungle navigation Language

Equipment recognition Demolitions

Enemy orientation Field expedient antennas

Physical conditioning Medevac techniques

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UNIT TRAINING

Movement

Obstacles and Barriers

Scouting, Surveillance, Patrolling, and Tracking

Air Defense

Adjustment and Conduct of Fires

Immediate Action Drill

Communications

Jungle Operations:

Ambush/counterambush

Raid

Attack

Defense

Infiltration

Airmobile operations

Waterborne operations

River crossing

Road clearing

FIRE TEAM AND CREWMEMBERS

Identification and Marking of Mines and Booby-traps

Working with Helicopters

Weapons Training

ACCLIMATIONThe first priority in preparation for

jungle warfare is acclimation (gettingaccustomed to jungle climate). Troops whoare not conditioned properly will not performjungle warfare tasks reliably. Differentpeople become acclimated to hot weather atdifferent rates, but the following methodscan be used in most units.

Exercise is the best method foracclimation, because troops in good physicalcondition will adapt easily to new climates. A7- to 14-day conditioning period should besufficient for most soldiers. Exercises shouldbe moderately strenuous at the beginning,and become more demanding each day.Troops from warm climates will adapt fasterthan troops deploying from colder climates.Physical training in heated gymnasiumsprior to deployment will also ease theacclimation process.

Leaders must be alert for symptoms ofheat disorders during the acclimation period.

SURVIVAL, EVASION, ANDESCAPE

Convincing a soldier that he will survivealone in the jungle will go a long way inbuilding his self-confidence. FM 21-76contains details on survival, evasion, andescape training.

SWIMMINGSwimming is also a vital skill for the

jungle fighter. Falling into a jungle pool orriver can be a terrible experience, especiallyfor a nonswimmer. All troops should be“drown proofed” as shown in FM 21-20. Unitsshould identify their strong swimmers forlifeguard training and other more difficultswimming tasks.

CAMOUFLAGE ANDCONCEALMENT

Training to conceal soldiers andequipment from ground and air observationis equally important to combat, combatsupport, and combat service support units.Proper use of camouflage will help to make upfor an enemy’s superior knowledge of thejungle area. Appendix E contains in-formation about jungle camouflage and con-cealment techniques.

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JUNGLE LIVING

Following a short period of classroominstruction, soldiers should experience jungleliving conditions in the field. This trainingcan be incorporated into other unit training.

Subjects which should be stressedinclude:

Heat disorders

Survival

First aid

Health, hygiene, and field sanitation

Proper wearing of clothing

Use of equipment in a jungle environ-ment

Prevention and treatment of snake-bites and insect bites

During this period of training, use ofgarrison facilities should be kept to aminimum. Supplies should be brought to thefield rather than the unit returning to the rearfor them. Soldiers should learn to live withoutunnecessary personal comforts.

Land navigation should be practicedusing jungle movement techniques. (Seeapp B.)

TARGET AREA ORIENTATION

Classes on the host country should stressthose facts which apply to operations.

3-4

Subjects could include:

Terrain appreciation

Cl imate

Population and culture

Language (phrase books may beissued)

Road, railroad, and canal system

Standards of conduct for US Armypersonnel

Allied armed forces

Reasons for US involvement

JUNGLE TACTICS

Chapter 5 describes tactics common tojungle fighting. These tactics should betaught first to leaders down to squad level.The leaders then train their own units. Stressshould be placed on small unit tactics and _operations with Army aviation. Since nightoperations, especially ambushes, arecommon in jungle fighting, units shouldemphasize night training.

MOVEMENTUnits should train in tactical marches.

Training should emphasize:

Breaching of obstacles

Scouting, patrolling, and tracking

Off-road movement over ruggedterrain

Air defense and counterambush drills

WEAPONS TRAINING

Most jungle fighting takes place at closerange. Soldiers should be trained in “quick

FM 90-5—

fire,” as outlined in chapter 8, FM 23-9Advanced training should be conducted on a“jungle range.” On this range, soldiers movedown a trail and engage pop-up and movingtargets which appear suddenly at closerange. Targets are operated by an assistanton signals from a lane grader. Targets shouldbe exposed for 3 to 6 seconds. Only 2 or 3rounds should be fired at each target. At alater stage, boobytraps and obstacles can beemplaced on the trail.

INTELLIGENCE

Soldiers should be trained in specificintelligence subjects.

These include:

Enemy organization and tactics

Equipment recognition

National markings

Sound or signature recognition

This last subject is particularlyimportant in jungle operations, becausesoldiers will more often hear weapons firingthan see them. If captured enemy weapons

and equipment are available, they should beused as aids in this training.

MAINTENANCE ANDLOGISTICS

Chapter 6 describes some of the jungle’seffects on equipment. Operators need to learntechniques to keep their equipment opera-tional.

Subjects to be covered include:

Effects of climate on equipment

Jungle operational techniques

Preventive maintenance

Recovery and repair techniques

Staff members and leaders shouldreceive familiarization training on thesetechniques in order to supervise theoperators. In addition, staff and leadersshould learn those special supplyrequirements and procedures in theoperational area. They should also be fa-miliar with the capabilities of those logisticalunits supporting the force.

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CHAPTER 4

The Threat in Jungle Areas

Section I. GENERAL

The jungle is an environment which spectrum from lightly armed guerrillas allstretches in a broad belt around the tropical the way to conventional forces.areas of the world. Each of these areas has itsown military, political, and economic This chapter describes the main featuresconditions. As a result, it is impossible to of guerrilla and conventional forces as theydescribe one threat which applies to all are found in the jungle, and briefly outlinesjungle areas. Potential enemies which US the types of potential threat forces in variousforces might face in the jungle run the jungle regions.

Section II. GUERRILLA FORCES

WHAT GUERRILLAS ARE The basic guerrilla organization is athree- to five-man cell. These cells are capable

Guerrillas are irregular forces. They of independent action. They also can benormally constitute the military faction of a brought together for larger operations andpolitical resistance or a subversive move- dispersed later. Guerrillas are organized intoment. These forces engage in unconventional cells for two reasons. One is for security. Theoperations in order to undermine the power of fewer the people who can identify members ofan established government or to take a guerrilla force, the better the chances arepolitical control away from other factions. that it will survive. The second reason is forTheir goal is normally to establish a new support. Guerrillas must live off the land to agovernment, often according to a radical large degree, and small cells are easier topolitical philosophy. support in this manner.

C O N T E N T S

SECTION PAGE

I. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

II. Guerrilla Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

III. Conventional Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

IV. Potential Enemies in Three Jungle Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 -8

V. Weapons Used by Potential Jungle Enemies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 4-9

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—FM 90-5

HOW GUERRILLAS FIGHTGuerrillas are usually weaker than

conventional forces in terms of totalresources. For that reason, guerrillas will notattempt to overwhelm large units of theiropponents in combat. They will instead try toinflict as much damage as possible inlightning actions, withdrawing before theopposing forces can react. Guerrillas aremost effective when they strike widelyseparated targets over a long period of time.This type of action will confuse, demoralize,and frustrate their opponents.

Typical missions which guerrillasconduct to accomplish their goalsinclude:

Destroying or damaging vital installa-tions, equipment, or supplies

Capturing supplies, equipment, or keygovernmental or military personnel

Diverting government forces fromother operations

Creating confusion and weakeninggovernment morale

These missions are not normallyaccomplished by the use of conventionalattacks and defenses. Instead, guerrillas relyon speed, surprise, and security. Guerrillaoperations include raids, ambushes, miningand boobytrapping, and sniping.

Targets are selected by the guerrillabased on an analysis of how much theelimination of the target will disrupt thegovernment, what the effect on the populacewill be, the risk of being killed or captured,and the amount of weapons or supplies whichcan be seized. This analysis calls for timelyintelligence, which is gained by activepatrolling.

The retention of the initiative is the key tosuccess in guerrilla operations. Guerrillasrely on their ability to strike where they areleast expected, at points where thegovernment forces are least prepared. If theguerrillas lose the initiative, and are forced toreact to the operations of conventional forces,their effectiveness is greatly reduced.

Guerrillas are not normally organized orequipped for stand-and-fight type defensiveoperations. They prefer to defend themselvesby moving, by dispersing into small groups,or by diverting the opponent’s attention whilethey withdraw. Whenever possible, theseoperations are accomplished by offensiveoperations against the opponent’s flank orrear. If the government forces persist in theirattack, the guerrillas are prepared todisengage to keep their freedom of action. Ifforced to disperse into small groups, theguerrilla forces become less effective untilthey regroup to resume offensive operations.

One of the most important needs ofguerrilla forces is support. This support cancome from a number of sources. Food, forexample, can be stolen or supplied bypolitical sympathizers. Weapons can begathered from raids on governmentinstallations. A foreign power may providesecret training, and shipments of food,weapons, ammunition, and equipment. If theguerrillas can be cut off from these sources ofsupport, they will be much less effective.

To protect their operations, jungleguerrillas will normally establish bases fromwhich they can operate. These bases will bein remote areas. The bases will be secured bya combination of guerrilla outposts and by agrapevine intelligence network establishedby political sympathizers. Although theymay be difficult to find, there will normallybe concealed routes into the bases, from

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which the guerrillas have access to their with government policies. If the people aretargets and sources of support. apathetic or passively hostile to their

GUERRILLA STRENGTHS government, the guerrillas will seek to

AND WEAKNESSESdevelop this feeling into a popular base ofsupport. If no such feeling exists among the

Guerrillas operate most effectively in people, it will be much harder for guerrillas tocountries where the people are discontented set up operations.

Section III. CONVENTIONAL FORCES

TYPES OF CONVENTIONALFORCES IN THE JUNGLE

Conventional forces committed to jungleoperations can perform any one of a numberof missions. The lowest level of involvementis the use of conventional forces to advise andassist native guerrilla or paramilitary forces,teaching them either how to fight or how tooperate sophisticated equipment. A higherlevel of involvement is the use ofconventional forces as a military cadre inunits which are composed of native forces.Finally, the highest level of involvement is

the operation of conventional forces in aconventional role, fighting major battles inthe jungle.

Conventional jungle enemies may comefrom a number of places. It is possible thatUS forces committed to jungle operations willfight native conventional forces. It is alsopossible that US forces will fightconventional forces brought in from asponsoring hostile power. In either case,

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—FM 90-5

most potential jungle enemies are infantryforces, supported with artillery, mortars, andarmored vehicles, organized along the linesof Soviet forces. These forces may also have acapability to conduct tactical air (TACAIR)operations and nuclear, biological, chemical(NBC) warfare. They may be equipped withweapons and equipment that are ageneration or two older than those found inmore modern armies.

HOW CONVENTIONALFORCES FIGHTIN THE JUNGLE

The way in which a potential conven-tional threat army fights in the jungledepends on the terrain, the combatexperience of that army, and the degree towhich it models itself after the forces of asponsoring power.

Jungle enemies have also used deception

A jungle enemy can be expected to beskilled in the art of camouflage, the chiefmeans he has to evade his opponent’s fire-power. Camouflage will be for him a way oflife. He will probably use bunkers andtunnels as protective survival measures. Toslow opposing forces, he may use obstacles,

mines, and boobytraps. He will move oncovered and concealed routes, usingdarkness to conceal most of his operations.He will probably depend heavily on streamsand rivers to provide concealed routes ofmovement and drinking water.

He can be expected to remove allintelligence indicators from the battlefield.He will go to great lengths to remove hisdead, wounded, weapons, and even expendedcartridges from the battlefield. He will try toleave no information relating to order ofbattle, strength, dispositions, or intentions.

“We captured numerous enemydocuments which either condemned orcommended certain units for the policeof the battle field.”

—Report, 25th Infantry Division,Kontum Province, Republic ofVietnam

means, such as explosive bullets andfirecrackers, to mislead US units as to thesize and disposition of the forces opposingthem. Communications deception andjamming have also been used by jungleenemies against opponents.

Since the US Army is noted foremploying an abundance of firepower, jungleenemies in the past have preferred to engageUS units at extremely close range. At times, itis impossible for US commanders to use theirsupporting indirect fires without takingfriendly casualties. The specific effects thatthis technique has on offensive and defensiveoperations will be discussed later. In general,however, the US ground commander mustoperate in such a manner that all his firesupport can always be used effectively.

Jungle enemies can be expected to trainhard to use the jungle to their advantage. In

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the offense, for example, they use the thickfoliage to infiltrate positions and eliminatecommand posts (CP), key weapons, and vitalfacilities. These operations are conducted totake away their opponent’s advantages incommand and control, fire support, andlogistical means. The intent is to put theirforces on a more equal footing with theiropponents. This situation can be exploited bya force with superior knowledge of theterrain.

When forced to defend, these forces willquite often prepare elaborate defensivepositions, well camouflaged and concealed.In addition, defenders may use snipers,boobytraps, and ambushes to delay, create asense of confusion and insecurity, and causethe attacker to surrender the initiative.

It is also possible that US forcescommitted to jungle operations will fight

Warsaw Pact forces, probably members ofairborne divisions. Although these troopswill have newer and more sophisticatedweapons than some of the troops native tojungle areas, they probably will not befamiliar with the local terrain and may not bewell trained in jungle operations.

STRENGTHS ANDWEAKNESSES OFCONVENTIONAL

JUNGLE ENEMIES

Much of a conventional jungle enemy’seffectiveness depends on familiarity with theterrain. In general, this means that armiesnative to a battlefield area will be moreeffective than forces from outside. Even ifthese outside forces have a greater amount offirepower than the native forces, the lack ofterrain familiarity may limit their ability touse that firepower.

Weaknesses of potential conven- Strengths of potential conventionaltional jungle enemies will probably jungle enemies will probably include:include:

Larger units, much more difficult toAdequate firepower for conventionalattacks and defense

Bigger targets for close-air support orartillery

Knowledge of the terrain and area

Well-trained and disciplined soldiers

More difficulty in evading detection

Less information from local

sympathizers

Independence from local support

HOW THE THREAT DEFENDS

The threat defense is a temporary firepower. His defense will be cleverly andmeasure, adopted only when necessary. This carefully prepared.does not imply, however, that the threat de-fense consists of half measures or that he is A typical jungle enemy defensiveunskilled in defense techniques. Jungle position consists of a complex series of earthenemies will use every trick possible to and timber bunkers, spider holes, andsurvive against massive amounts of tunnels. These are positioned to achieve

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— FM 90-5

mutual support. Bunkers are built low tomake them more difficult to see and engageby fire. They are well camouflaged—even thefields-of-fire may be cut from the waist down,so that they will be unnoticeable to astanding man. Weapons positions areplanned to provide interlocking fires—lethaleven during limited visibility. Boobytrapsand obstacles are integrated into the defenseto slow, demoralize, and confuse the attacker.

The jungle threat’s concept of the defenseis to trap the attacker by allowing him tomove into prepared fields-of-fire. Fire isopened at extremely close range, sometimesat 50 meters or less. This is done for tworeasons—first, to bring fires to bear from allsides, and, second, to force the attacker toremove himself before he can call forsupporting fires.

While the key part of the jungle threat’sdefense is automatic weapons positions inbunkers, the enemy will also put snipers inthe trees. In this way, the attacker cannotdevote his full attention to the bunkers,because he must also deal with the snipers.

If the attacker is too strong, the junglethreat will attempt to withdraw over routesthat have been planned and scouted to makethe withdrawal as rapid as possible. Stay-behind ambushes, snipers, mines, andobstacles are used to slow the attacker.

HOW THECONVENTIONALENEMY ATTACKS

Attack is the preferred form of combat forpotential jungle enemies. Because most ofthese forces expect to have a disadvantage infirepower and technology when fighting USforces, most of them have developed specialtechniques to help make up the differencethrough surprise. They may, for example,probe a defensive position until the defender

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reveals the location of his key weapons.These weapons are then eliminated byinfiltrators before the main attack. They mayuse firecrackers to create a diversion,drawing the defender’s fire and deceivinghim as to the size of the attacking force. Theymay infiltrate the defense to eliminatecommand posts, mortars, or artillery units.

"Decoy the Americans from onedirection by smoke, firing, or shouting.Then attack him from an unexpecteddirection.”

Threat units will avoid attackingprepared defenses when possible. They preferto attack a weak point, using the jungle,weather, and their own special training asmuch as possible. Sapper squads arespecially trained to infiltrate minefields andobstacles in order to neutralize key positionsor create a gap in the defense. The enemymay also isolate a position, so that theiropponents will be tied down in trying torelieve it, or they may conduct raids todisrupt operations and lower the defender’smorale. Darkness, poor weather, and rough

—Captured Japanese Document, terrain will be used to conceal theseWorld War II operations.

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— FM 90-5

A commander should never assume thatany jungle area is impassable to a well-trained jungle enemy. Experience has shownthat such enemies are very adept at usingextremely difficult terrain effectively asavenues of approach.

"Use fog and rain to catch theAmericans off guard. Make an assaultsuddenly, from positions which theAmericans believe unapproachable,such as cliffs, rivers, and jungles. ”

—Captured Japanese Document,World War II

Although the jungle enemy attacksswiftly, his attacks are planned in minutedetail. If he is allowed to attack according to

plan, the jungle enemy is an effective force. Ifthe defender can interrupt even a minor partof the plan, the enemy will have difficulty inadjusting, and the attack will probably fail.This aspect of enemy operations places ahigh premium on the struggle for theinitiative at all levels.

If the defending force can be pushed outof its positions and forced to retreat, thejungle enemy will probably make every effortto maintain contact through pursuit. He willharass the rear guard, at the same timesending forces to outrun and cut off theretreating force. He will then try to destroythe retreating force by ambush orencirclement.

Section IV. POTENTIAL ENEMIES INTHREE JUNGLE REGIONS

It is impossible to describe one junglethreat which applies to all areas of the world.There are, however, certain characteristics ofpotential threat forces that are peculiar tospecific jungle regions.

LATIN AMERICAThe most likely threat the US forces may

face in Latin American jungles are insurgentmovements. These movements aim at theoverthrow of a wealthy ruling class to installa new regime. The US is often viewed by theinsurgents as an ally of the government, andUS facilities and institutions are oftentargets for these movements.

The military faction of these insurgentmovements consists of guerrilla forcessimilar to those described earlier. They areorganized into small cells, are lightly armed,and are capable of concentrating for actsagainst major facilities and then dispersingafter the operation. Although their ultimateobjective will often be the establishment ofcontrol over the urban areas, they may usethe jungle to provide a concealed and secure

base of operations. The support of the localpeople is very important to their survival.

At the time US forces are committed tofight in Latin American areas, guerrillaforces are likely to be augmented withmilitary aid and personnel from othersponsoring countries in the region. Theseforces may perform any one of a number ofroles: advisors, guerrilla cadre, or limitedconventional combat. Logistical andintelligence support may also come fromthese forces.

SUBSAHARAN AFRICA

The conflicts in this region since WorldWar II have been waged by insurgent groupsagainst perceived vestiges of colonialism orimperialism. Most of these colonialist andimperialist institutions are connected in theminds of the insurgents with the WesternEuropean powers. As a result, the instabilityin some areas of this region has provided atempting target for provocation. To makematters more complicated, many of theconflicting factions are also struggling

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among themselves, due to political or ancienttribal differences. This in turn creates evenmore regional turmoil, and an even greatervulnerability for exploitation.

Conflicting factions in SubsaharanAfrica consist primarily of guerrilla groups.These guerrillas, however, are often moreheavily armed than Latin Americanguerrillas for two reasons. First, these groupshave mortars, artillery, and recoillessweapons from national army formationswhich have been defeated or disbanded.Second, external powers have backed theirfavorite factions by supplying arms,ammunition, and equipment. For the mostpart, these guerrillas subsist by acquiringfood and supplies from the countryside.

Foreign involvement in these guerrillamovements has consisted of advisors andcadre from sponsoring nations. Should USforces ever fight in this region, it is likely thatthey will encounter troops foreign to thenation. In addition, there is also a possibility that Warsaw Pact troops, primarily airborneor tactical aviation units, would becommitted to such a region to fight UStroops.

SOUTHEAST ASIA

In many respects, the potential threatarray in Southeast Asia is the mostcomplicated of any jungle region. There areactive guerrilla movements in most

Southeast Asian countries as well as tribaland cultural conflicts. There is a goodpossibility of foreign support or intervention.

The unique development in this regionhas been the rise of a regional power. Sincethe end of US involvement in Southeast Asia,this power has developed a potent con-ventional force, using equipment capturedfrom the US and its allies or suppliedby communist countries. More than anyother potential threat native in a jungleregion, it possesses the ability for sustainedconventional operations against any USforces which might be deployed in the area.Its capabilities span the range fromclandestine guerrilla operations to large-scale conventional attacks, supported bytanks, motorized units, artillery, andaviation.

Because there are already strong forcesin this region, the probability of involvementof large numbers of world power forces is notgreat. There is a good possibility, however,that US troops committed in these areasmight encounter weapons and equipmentsupplied by a world power. They might alsoencounter advisors from world powers thatinstruct and aid the native forces in the use ofsophisticated equipment.

Finally, of all the regions discussed thusfar, the chemical warfare threat willprobably be greatest for US forcesconducting operations in Southeast Asia.

Section V. WEAPONS USED BY POTENTIALJUNGLE ENEMIES

Although potential jungle enemy forces the weapons’ characteristics and knowvary widely from region to region, there are where the weapons are found in typicalcertain types of weapons which are communist forces organizations.commonly found in jungle countries. USforces should become familiar with these Although guerrilla forces do not have thebasic types of weapons in order to be able to same type of organizational structure asrecognize them on the jungle battlefield. conventional forces, they too will probablyThey should also have a basic knowledge of carry many of these weapons.

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— FM 90-5

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4-11

—FM 90-5

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4-13

—FM 90-5

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—FM 90-5

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FM 90-5

CHAPTER 5

Tactical Operations

Section I. GENERAL

This chapter deals with tacticaloperations in the jungle. Before reading thismaterial, soldiers should be familiar with theappropriate level of basic tactics in:

FM 7-8, The Infantry Platoon andSquad (Infantry, Airborne, AirAssault, Ranger).

FM 7-10, The Infantry Rifle Company.

FM 7-20, The Infantry Battalion(Infantry, Airborne, Air Assault,Ranger).

FM 90-4, Airmobile Operations.

FM 100-5, Operations.

Although jungle operations are con-ducted according to the basic guides con-tained in these manuals, there are specialtechniques which help to insure success inthe jungle. These techniques result from therestricted maneuver, slow tempo, closecombat, and limited visibility commonlyfound in the jungle.

Combat in the jungle is characterizedby long periods of developing the situationand looking for the enemy; and short pe-riods of violent, and sometimes unexpected,combat.

To meet these conditions, unitsmust have:

Aggressive intelligence-gatheringprocedures

Disciplined soldiers

Solid SOPS proven in training andupdated on a continuous basis

Aggressive and tough-mindedleadership

These four points must be emphasizedwhen a unit is engaged in jungle operations.The need for discipline is evident when oneconsiders the extended periods of looking,often fruitlessly, for the enemy. When contactis made, maximum advantage can only beachieved through aggressive and violentaction predicated upon solid SOPs.Aggressive leadership at the small-unit(squad and platoon) level is the one elementthat ties together the discipline and thetraining.

CHARACTERISTICS OFTHE JUNGLE BATTLEFIELD

The thick foliage and rugged terrain ofmost jungles limit fields of fire and speed ofmovement.

SECTION CONTENTS PAGEI. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

II. Reconnaissance, Surveillance, and Security Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8III. Offensive Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10IV. Defensive Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15V. Retrograde . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24VI. Other Combat Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24

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— FM 90-5

These terrain characteristics makejungle fighting different from fighting onmore open terrain. To be effective junglefighters, soldiers must learn to use thesecharacteristics to their advantage. Potentialjungle enemies train to exploit the jungle; somust the US Army.

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FM 90-5—

CHARACTERISTICS OFJUNGLE OPERATIONS

The aspects of terrain and enemydiscussed above result in fewer set-piecebattles. Rather than conventional attacksconducted against conventional defenses,jungle battles are more often ambushes,raids, and meeting engagements. Battles arenot fought for high ground as frequently asconventional battles. Orientation is on theenemy rather than on the terrain. Hills in thejungle are often too thickly vegetated topermit observation and fire, and therefore donot always qualify as key terrain. In thejungle, roads, rivers and streams, fordingsites, and landing zones are more likely to bekey terrain features.

The frequency of ambushes, raids, andmeeting engagements makes it veryimportant that units in the jungle practiceimmediate action drills. In the junglefirefight, the side which initiates contact andgains fire superiority in the first few secondswill normally have a decisive advantage.

CONTROL

Command and control are difficult in thejungle. The thick foliage allows leaders to seeand control only a portion of their units.

To cope with this problem,commanders and leaders must:

Plan their operations carefully

Issue mission type orders

Insure that each soldier understandshis part of the mission

In addition, the thick jungle foliage andheavy monsoon rains often weaken radiosignals, making communications difficult.To reduce the effects of the problem, use of thehelicopter as a command and control vehicleis recommended. In that the heavy monsoonrains may not allow helicopters to always fly,

an alternate means of command and controlmust be planned for.

FLEXIBILITY

While an appreciation of battlefieldcharacteristics, jungle enemies, and char-acteristics of jungle operations is useful,flexibility is important to any leader involvedin jungle operations. Successful operationsrequire an extraordinary command adapt-ability—sometimes, a departure fromorthodox thinking in favor of new and oftenuntried procedures. Soldiers must learn tolive with the jungle and adapt to its initiallyapparent disadvantages. Having done this,the unit can concentrate on the use ofconcealment, covered movement, andsurprise.

SECURITY AND INTELLIGENCE

Commanders must stress effectivesecurity measures and aggressiveintelligence-gathering techniques to preventbeing surprised. The key is to give thefront-line soldier an appreciation of thethings to look for. Food remnants and fecescan indicate how long ago an enemy unitoccupied an area. Captured documents,equipment, and weapons may provide orderof battle information and an idea of theenemy’s logistical situation. Even anammunition crate may yield a lot numberand packing date. From this an intelligencespecialist may be able to trace the enemyunit’s place in the order of battle.

In the past, US forces operating in junglewarfare have generally been augmented bynative scouts, attached down to platoon level.These scouts were auxiliaries, paid by theunit they supported from a fund establishedby higher headquarters for that purpose.Scouts familiar with the terrain and the enemycan be an extremely valuable asset. Localsecurity regulations should provide guidance

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—FM 90-5

as to what friendly information can be given photography are not as effective because ofto scouts. the concealment of the foliage.

Surveillance, target acquisition, and The local populace is one of the mostnight observation (STANO) devices, valuable intelligence sources. Whetherespecially infrared, starlight scopes, and hostile, friendly, or indifferent, the peopleunattended ground sensors, are quite can provide information which, wheneffective in gathering information about processed, will help complete the intelligencetroop movements in the jungle. Radars and picture.

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Security prevents the enemy fromgaining intelligence on US units. Activesecurity measures, such as patrolling and theuse of observation posts (OP), helps preventUS units from being ambushed or attackedby surprise. These measures do not lessen theneed for passive security. Camouflage andnoise and light discipline conceal US forcesfrom enemy observation. To prevent beingtracked by the enemy, bivouacs and trailsmust be policed. Odor discipline is also asecurity measure. The enemy can follow suchodors as heat tabs, cigarette smoke, deo-dorant, and C rations.

TROOP-LEADINGPROCEDURES FOR

JUNGLE OPERATIONS

STANDING OPERATINGPROCEDURES

A unit’s jungle operations SOP shouldinclude actions which the unit does on aroutine basis or actions that are earned outessentially the same way each time they aredone. Examples of such actions includeorganizing for combat, resupply, bivouacand shelter preparation, movementtechniques, and battle drill. Use of SOPs willsave planning time.

PLANNING USE OF TIME

A unit planning for jungle combatfollows the same planning sequence as inany other type of combat operation. Inplanning the use of available time, leadersmust consider that many tasks in the jungletake more time than the same tasks in otherenvironments. More time must be allowed formovement and security. This means thatunits may have to begin movements earlierin order to accomplish their missions withina specified time. This may leave less time forplanning and preparation.

AIR MOVEMENT PREPARATION

If the unit is to be inserted by helicopter,the commander should go through the pre-paratory steps outlined in FM 90-4.

INSPECTION

Prior to beginning a misssion, unitleaders should inspect their troops toinsure that:

They have all their needed equipment

They have no unnecessary equipment

Weapons are cleaned, lubricated, andzeroed

Equipment and weapons are inworking order

Everyone understands his job and theunit’s SOP

CONTROL OF EQUIPMENT

Those troops who carry extra equipmentshould not be allowed to discard it. CapturedUS equipment has been used by jungleenemies in the past. In Southeast Asia and inthe Pacific, recovered equipment was a majorsource of enemy supply.

SUPERVISION

Supervision must continue throughoutthe conduct of the operation. As the troopsbecome tired after long periods of marchingor digging in, they will tend to get lax andignore good security habits. This is anespecially common trend if they have notbeen in contact for a few days. Tightsupervision is a must to insure that securitypatrols and OPs are dispatched and doingtheir jobs; that troops remain alert; and thatfire, noise, and light discipline are notrelaxed.

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JUNGLE MOVEMENT

PLANNING AND ROUTE SELECTIONBefore conducting a move in the jungle,

leaders should make a map and aerial photo-graph reconnaissance. This reconnaissancewill indicate possible danger areas,obstacles, and roads or clearings suitable forresupply.

In planning the route, leaders shouldconsider the following:

Lines of drift, such as ridgelines,are easy to guide on because they avoidstreams and gullies and because they areusually less vegetated.

Danger areas, such as streambedsand draws, are usually more thicklyvegetated. They offer excellent conceal-

ment, but travel along them is slow anddifficult.

Roads and trails should beavoided. Although they are easy to moveon, they offer little concealment. Theseare the areas most likely to be underenemy observation. They are easy toambush and are very likely to be mined orboobytrapped.

MOVEMENT TECHNIQUESUnits moving in the jungle should

normally use the jungle movementtechnique, but may use traveling overwatchand bounding overwatch when necessary.The file formation should be avoided in allbut the most thickly vegetated areas.

To effectively use the junglemovement technique, certain keyfactors must be understood. They in-clude the following:

Only the platoon should employ Each squad maintains an azimuththis movement technique. and pace.

The lead fire team of the leadsquad is always in a wedge (modified). Immediate action drill (SOP) is

The support elements may moveessential.

with the headquarters element or beattached to a squad(s) depending upon This technique is most effectivelikely threats. during daylight movement.

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FM 90-5—

This movement technique is basicallycharacterized as a formation of multiplecolumns which are mutually supporting.

5 - 7

— FM 90-5

In traveling overwatch, the lead elementperforms the mission of point security, withtroops from the rest of the unit performingrear and flank security. When contact isimminent, the unit moves into boundingoverwatch. Bounds, as terrain allows, arenormally 50 meters or less.

SECURITY

The thick foliage makes ambush aconstant danger. Point, flank, and rearsecurity teams will help keep a force frombeing ambushed. These teams must be farenough away from the main body that if theymake contact the whole force will not beengaged. They should not be so far away,however, that they cannot be supported.These security elements must be alert tosigns of the enemy, and should carry as lighta load as possible so they are able tomaneuver. Security duties should be rotatedoften to avoid fatigue. Scout dogs may also beused with the security element. These dogsoften detect the enemy before he is detected

by humans. The jungle heat is hard on them,however, and they must be rested frequently.

If contact is broken between elements orindividuals, the rear element should remainin position. Those in front should return toestablish contact.

HALTSUnits should plan halts on terrain which

lends itself to all-round defense. During shorthalts, soldiers drop to one knee and faceoutward, their weapons at the ready. If thehalt occurs at a trail crossing, securityelements are sent out along the trail. Thesecurity element remains in place until theunit clears the crossing. During longer halts,units establish a perimeter defense. They runsecurity patrols around their positions, andemploy Claymore mines and early warningdevices. Before an overnight halt, unitsshould stop while there is still enoughdaylight to establish a secure perimeterdefense, prepare ambushes, and dispatchpatrols as necessary. If halted units areseparated, connecting patrols should be runperiodically to detect enemy infiltration.

Section II. RECONNAISSANCE, SURVEILLANCE,AND SECURITY OPERATIONS

RECONNAISSANCEReconnaissance operations are always

important in jungle warfare. Many offensiveoperations in the jungle take on the aspects ofa reconnaissance operation during theirearly stages. This is because the success ofoffense in the jungle depends on ability tofind the enemy. The excellent concealmentfound in the jungle enables the enemy tooperate unobserved both by day and night.Extensive patrolling is necessary to obtaininformation on his locations, strength, anddisposition.

Reconnaissance is a responsibility of allleaders during jungle operations. Units with

the capability to conduct reconnaissanceshould conduct frequent short patrols duringthe conduct of normal missions. Thesepatrols should be coordinated with higherand adjacent units. In some situations,reconnaissance may become the primaryobjective of a major jungle operation.

Planning for a jungle reconnaissanceshould be thorough and well coordinated.Coordination with higher and adjacentheadquarters will help insure maximumresults from each patrol and eliminateduplication of effort. Radio is the primarymeans used to control reconnaissance

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FM 90-5 –

operations. Each reconnaissance patrol mustbe prepared to make contact, develop thesituation, and report to its controllingheadquarters.

GROUNDRECONNAISSANCE

In the jungle, these operations areaccomplished by means of OPs and long- orshort-range reconnaissance patrols. Thevalue of OPs is somewhat reduced in thejungle because of the limited visibility. OPsare most effective when used along trails,roads, and streams to detect enemymovement. (Although OPs in other areasmay not provide much useful information onthe enemy, they still are effective inproviding early warning.) Reconnaissancepatrols in the jungle are normally squad-size.These patrols move in a manner to takeadvantage of natural concealment, andavoid becoming engaged with the enemy.The use of helicopters increases the depthbehind enemy lines that such patrols can beemployed. For further details on recon-naissance patrols, see section VI.

VISUAL RECONNAISSANCEFrom the air, key terrain features can

often be identified and the enemy detected inareas where there are gaps in the junglecanopy. Aerial photographs are importantsources of information because photographinterpretation can disclose hidden enemycamps not visible to the air observer.Photographs can also be used to locatehelicopter landing zones. Decoy reconnais-sance flights can be used to confuse ordeceive the enemy about upcoming opera-tions.

RECONNAISSANCE-IN-FORCEThis method may be used to gather

intelligence which cannot be gained by anyother reconnaissance means. Examples ofsuch intelligence include the enemy com-

mander’s plan for committing his reserves, orthe trails used by a guerrilla force.

The commander conducting thereconnaissance-in-force will normallyorganize his unit into a number ofreconnoitering forces. These reconnoiteringforces conduct movements to contact, hastyor deliberate attacks, raids, reconnaissance,or patrols. Once the unit makes contact withthe enemy, the commander must react on theintelligence gained. He must be prepared toexploit success or, if necessary, extricate theforces.

The size of the unit that conducts areconnaissance-in-force depends on thenature of the intelligence to be gained and thechance that the reconnoitering force willhave to fight on unfavorable terms. Forexample, if a battalion commander wants tofind out how an enemy commander willcommit his reserve, he may conduct areconnaissance-in-force with his companiesconducting limited objective attacks. If, onthe other hand, a commander wants to findthe routes used by a number of small guerrillagroups, the reconnaissance-in-force missionmay be assigned to a company, which in turnwill have its platoons conduct movements tocontact.

RECONNAISSANCE-BY-FIRE

When using this method, the force fireson suspected enemy positions to cause theenemy to disclose his position by moving orreturning fire. Reconnaissance-by-fire risksthe loss of surprise. Its most effective use inthe jungle is to find the flanks or gaps inenemy lines. Reconnaissance-by-fire fromattack helicopters will often reveal thelocation of well-concealed enemy troops.Likewise, a reconnaissance-by-fire fromarmored vehicles firing into a wood line,either while moving crosscountry or along aroad, can neutralize an enemy ambush.When using reconnaissance-by-fire,

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—FM 90-5

commanders must consider the difficulties ofammunition resupply in the jungle.

SURVEILLANCE

Surveillance operations in the jungleinclude using all techniques for establishinga continuous, thorough watch of thebattlefield. This watch must be establishedboth over large jungle areas and at selectedkey points such as trails, streams, andclearings. Surveillance operations areusually planned to support other missions.

GROUND SURVEILLANCERADARS

These radars are best employed in thosejungle areas where vegetation and terrain donot restrict line of sight. Night observationdevices are also useful in such areas duringperiods of darkness. Unattended groundsensors, which are not affected by poor lineof sight, are very useful in watching specifickey areas. These electronic devices areaffected by poor weather and are difficult tomove in thickly forested areas. As a result,the use of manned OPs in jungle areas shouldalways be planned.

AIR SURVEILLANCE

Surveillance of jungle areas from the airis most effective when pilots are familiarwith ground operations and can recognizechanges from normal patterns. Repeatedflights by the same crews will attain thislevel of familiarity. In addition to visualsurveillance, photographic coverage of anarea can assist the surveillance effort. Side-

looking airborne radar (SLAR) is not veryeffective in thick foliage, but can be used forsurveillance along roads, trails, or streams.Likewise, infrared detection devices arelimited by fog, clouds, rain, and vegetation.Airborne personnel detector devices(sniffers) were developed during the Vietnamwar to detect human odors. These devices areextremely effective in detecting base campsof nonmechanized forces, but are limited byfog, rain, and windy conditions.

SECURITY OPERATIONS

Security must be a primary part of alljungle operations; therefore, specific securitymeasures are covered as they apply to otheroperations throughout this chapter.Compared with operations in other types ofterrain, security measures in the jungle mustbe intensified because of the poor observationand difficulties of control and movement.Operations must be slower than normal, andsecurity forces must be closer to the unitssecured in order to provide adequate securityin the jungle. Because it provides all-roundsecurity, the perimeter defense will be thedefensive technique used most often by unitsoperating independently in the jungle.

The “stand-to” is an important securitytechnique in jungle fighting. When a unitstands-to, all of its soldiers don their fightingloads and occupy their fighting positions.The unit is 100 percent alert and ready tofight an attacking enemy. Stand-toprocedures differ from unit to unit, butcommon stand-to times are before first light,before last light, before helicopter resupply,and before movement.

Section III. OFFENSIVE OPERATIONS

SPECIAL FACTORSThe purpose and fundamentals of the

offense as outlined in field manuals for other

5-10

environments generally apply as well tooffensive operations in the jungle.

FM 90-5–

There are, however, factors whichrequire the use of special offensivetechniques:

Thick foliage makes it difficult forleaders to control their soldiers or todetect the enemy

Fire support is difficult to observe andadjust

Momentum and speed are difficult tomaintain

FUNDAMENTALSOF THE

JUNGLE OFFENSEWhen considering the use of special

offensive techniques, commanders mustremember that some offensive fundamentalsacquire a new significance in the jungle.

Probably the most important and mostdifficult of these fundamentals is the require-ment to see the battlefield. Above all else, theattacker must know the battlefield. As aresult, he relies heavily on security patrols,information provided by air and groundreconnaissance, and proper movement tech-niques.

Key to effective operations in junglewarfare is the fundamental of using weaponsystems to their best advantage. In additionto organic weapons, the ground commandermust closely coordinate the employment ofthe supporting weapons available to him.The dense foliage found in some jungles mayprevent heavy weapons from moving directlywith the infantry. In those cases, TACAIRsupport and helicopter weapons must makeup the difference. TOWs and Dragons, on theother hand, are of limited use in most jungleenvironments. The soldiers that man theseweapons may be more effective as securityforces or as reinforcements for maneuver

elements. The primary jungle weapons areindividual infantry small arms, supported bymachineguns and mortars.

To concentrate overwhelming combatpower against enemy weakness in jungleoperations, the attacker must be able to bringup other elements quickly to support anelement that is engaged. In determining howfar he can separate his subordinate units, thecommander must consider the factors ofmission, enemy, terrain and weather, andtroops and time available (METT). Theseparation may be expressed in time or indistance. The ability to provide mutualsupport must not be overlooked. Gapsbetween units should be covered by scoutsand connecting patrols. Targets should beplanned along the unit’s route so that sup-porting fires can be responsive. The use ofhelicopters will permit even more rapidconcentration of forces and provideadditional firepower (chap 6).

The jungle also increases the difficulty ofefforts to provide continuous support. Thekey is constant planning, coordination, andmaximum use of helicopters. Fires must beplanned along the attack route so that theycan be delivered in the shortest amount oftime. Procedures for calling attackhelicopters must be standardized andrehearsed. Likewise, combat service supportmust be timely and responsive. Ammunitionand water must be loaded on pallets in thetrains so that they can be brought forward assoon as needed.

CONDUCT OF THEJUNGLE OFFENSE

Because it is so hard to gather intelli-gence, jungle offensive tactics must becharacterized by continuous reconnaissance.A unit attacking without timely informationon the location of the enemy may subject itselements to enemy ambush without being

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—FM 90-5

able to support them. In such a situation,they may be defeated in detail.

“It is a situation that too frequentlyoccurs in the Vietnam fighting. Theforward element, losing men andbecoming pinned down, compromisesthe position of all others. What hasstarted out as an attack loses all formand deteriorates into a costly rescueact."

Successful jungle attacks usuallycombine dispersion and concentration. Forexample, a rifle company may move out in adispersed formation so that it can find theenemy. Once contact is made, its platoonsclose on the enemy from all directions. In thisway, they move to support each other anddestroy the enemy.

Operations are enemy-oriented, notterrain-oriented. Wherever the enemy isfound, that is where he should be destroyed.

–S.L.A. Marshall, BIRD If he is allowed to escape, he will only have tobe found again, with all the risks involved.

MOVEMENT TO CONTACTAND HASTY ATTACK

These two forms of combat are discussedtogether since they account for the majorityof combat actions in the jungle. Thesuccessful follow-on action to movement tocontact is a violently executed hasty attack.This action capitalizes on the advantage ofsurprise and the confusion prevalent in thejungle. Movement to contact in the junglediffers little from the general conceptdescribed in FM 7-20. The decision to employsingle or multiple columns may depend solelyon terrain and foliage considerations.

For companies and battalions, multiplecolumns are a sound movement practicebecause this formation provides morefirepower to the front and because it is easierto deploy troops from two or three columnsthan from one file. In order to speed updeployment, units should develop andrehearse SOPs and immediate action drills.Troops should try to maintain a distance offive to seven paces between men, but mustmaintain visual contact. All-round defenseand security measures must be maintainedthroughout movement.

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FM 90-5–

Once contact with the enemy is made, theunit’s first action is to build up a large volumeof fire. The commander then assesses thesituation and deploys his unit to overrun theenemy’s positions while they are stillsuppressed. In this way, he seizes theinitiative. There should be no delay in thetroops’ movement from the march formationinto assault formation. Security elementsprotect the rear and prevent the enemy’scounterattack. These forces may be used laterto exploit a success, but should not becommitted until the commander under-stands the situation.

The slowness of jungle maneuver makesa rapid call for supporting indirect fireimportant. Upon making contact, fires on theenemy should be immediately requested andadjusted from planned targets. To receiveeffective and timely fire support, accurateand continuous land navigation isnecessary. Means for controlling attackhelicopters are also important; this includesboth radio and visual means. Adjustmenttechniques should be established by SOP.

Supporting fires and TACAIR or attackhelicopters can place fires on suspectedwithdrawal routes, placing further pressureon the enemy. The success of the hasty attackdepends to a large degree on the unit’svigorous execution of unit SOPs and theleadership of the squad and platoon leaders.

As the situation is developed and anenemy position is located, a violent assaultshould be made over the enemy’s position.Soldiers stay on the alert for hidden enemypositions, snipers in the trees, and tunnelsthrough which the enemy might move toattack the attacker’s rear. This thoroughtechnique will also provide enoughinformation of the enemy and security topermit the commander to use his reserveforce for exploitation, if needed.

The assault should be made using fireand maneuver. Soldiers should cover each

other, moving by crawls and short rushes.Fire should be well-aimed shots and shortbursts of automatic fire.

In such a fast-moving situation, it mightbe possible, for example, for a platoon toreceive a fragmentary order (FRAGO), moveto a pickup zone (PZ), and conduct an airassault to an objective. In this case, theplanning might take place on the PZ or evenin the vicinity of the objective rally point(ORP).

After the objective is seized, it must besecured immediately with a hasty perimeter,OPs, and early warning devices. This is todetect and repel an enemy counterattack or toallow the attacker to prepare to continue theattack.

THE DELIBERATEATTACK

Based on information gained fromreconnaissance and other sources, thecommander may formulate a plan to attack alarger objective using a deliberate attack.Jungle terrain favors reduced distances andintervals between troops and units, and thedeployment from movement to attackformation as far forward as possible. Inthickly vegetated terrain, the use of some ofthe same control techniques used in a nightattack may be required.

Fire support is as essential in the jungleas in other types of terrain. Unsupportedtroops are likely to incur heavy casualtieswhen attacking jungle positions, especiallyconsidering the difficulties of employingorganic weapons. Targets must bepinpointed by reconnaissance, and firesmust be adjusted within very close range ofattacking troops. During the assault, thesesupporting fires must continue until shiftedby the assaulting commander. They are thenadjusted onto targets which will assist theprogress of attacking forces by blocking

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—FM 90-5

enemy counterattacks or withdrawal. Due topoor observation, indirect fire may have to beadjusted by sound (see app I).

Assaulting troops move over theobjective using aggressive fire andmovement to overcome enemy resistance.Assaulting troops again must be alert tosnipers, mines and boobytraps, hiddenpositions, and tunnels which would permitthe enemy to maneuver into the rear ofattacking forces. Assaulting platoons andsquads move in a single direction, with firesconcentrated on enemy positions as they arelocated. Attacking elements must adjusttheir progress using base elements and phaselines. Smoke may be used to screen the flanksof the penetration from enemy observationand reduce his ability to deliver effectivefires. Once an initial penetration is secured, itis exploited until the objective is taken.

After the objective is overrun, it must besecured immediately with a hasty perimeter,OPs, and early warning devices to detect andrepel an enemy counterattack or to allow the

attacker to prepare to continue the attack (seeIV).

INFILTRATIONJungle areas are ideal for infiltration.

Dense vegetation and rugged terrain limitthe enemy’s ability to detect movement. As atechnique to move through the enemy’s posi-tions, infiltration can be used with otheroffensive maneuvers to gain an advantage inthe jungle. Although jungle infiltrations arenormally conducted on foot, under certaincircumstances helicopters or watercraft maybe used.

Infiltrations are normally difficult tocontrol. Chances for success are better iftroops are well trained, well briefed, and wellrehearsed. Roads, trails, and streams shouldbe avoided because they will normally beunder enemy surveillance. Movement bystealth is normally slow and exhausting.Phase lines (PL), infiltration routes, andadequate communications must be used tocontrol the operation and to coordinate fireswith movement.

EXPLOITATIONAND PURSUIT

Local successes should be exploited as attack helicopters may also be used to blocksoon as possible to cut off the retreat of escape routes. Tanks may be used alongisolated enemy forces. Airmobile troops are trails or roads or in less dense areas ifmost effective to block enemy retreat in the properly secured with infantry. Duringjungle. They can also disrupt and harass exploitations, rear areas must be securedenemy reserve, logistical, and command against the actions of bypassed oroperations. Artillery, TACAIR support, and infiltrating enemy.

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FM 90-5—

Pursuit operations in the jungle shouldbe conducted to maintain contact with theenemy. The precautions required to secureagainst ambush can slow pursuit operationsconsiderably. Because attacking troopsbecome more fatigued than defending troops,pursuit operations should be conducted usingtroops from the reserve. As is the case withmost jungle offensive operations, airmobileforces, air cavalry, and attack helicopterscan be used very effectively in pursuitoperations.

ATTACK AGAINSTA FORTIFIED POSITION

As mentioned earlier, jungle enemieshave often used strongly fortified defensivepositions to protect themselves from theeffects of US firepower. If it is necessary toattack such a position, troops will probablyencounter bunkers, barbed wire, mines, andboobytraps. The enemy will often have to beburned or blasted out of such positions. Theseoperations will require attacks on a narrowfront, great amounts of firepower, andlimited objective attacks.

Fortified enemy positions in dense jungleare often so well concealed that troops are notaware of their presence until they havephysically encountered them. In these cases,the best course of action is usually to adjustforward dispositions enough to allow use ofsupporting indirect fires, to deploy additionalforces to block possible withdrawal routes,and then to maneuver under the cover ofsupporting fires to defeat the fortifications indetail.

Maximum use of combat intelligence isrequired when attacking fortified areas.Aerial photographs, electronic intelligence,interrogation of prisoners of war (PW), andaggressive patrolling are all means ofgaining the required information. Patrolsalso keep the enemy off balance and limit theenemy’s ability to patrol.

In addition, combat engineer, and spe-cial weapons (such as flame) and equipmentshould be attached to the maneuver forces toassist in destroying the fortifications.

Destruction of the enemy in those typesof positions takes a lot of time and effort.Other means should be used as much aspossible. Here is a technique that provedsuccessful in the past:

“The use of CS riot control gas couldnot be overlooked... On one occasion, abattalion made a night attack with gasmasks following an aerial CS attack. Ahelicopter made several low passes onthe windward side of the area anddispersed about 250 CS grenades. Thiswas followed by 20 minutes of artilleryfire, about half of which was VT fuzefired into the enemy positions. Behind awalking barrage of artillery fire, onecompany assaulted, and, once inside theobjective, flareships lit up the area.Eighteen enemy were killed, whi!e nocasualties were suffered by the friendlytroops.”

—Report, 25th Infantry Division,Duang Nhgai Province, Republicof Vietnam

Section IV. DEFENSIVE OPERATIONS

SPECIAL FACTORSThe purpose and fundamentals of the

defense as outlined in field manuals for otherenvironments also apply to defensiveoperations in the jungle.

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—FM 90-5

There are, however, certain factorswhich require the use of special tech-niques:

Thick foliage makes it difficult todetect the approach of an attackingenemy

Slowness of jungle movement makesit difficult to react to an enemy threat

Limited visibility between defensivepositions

Limited fields of fire

Psychological impact of fighting in astrange environment

FUNDAMENTALSOF THE

JUNGLE DEFENSEAs in the offense, jungle defensive

operations are based on the same funda-mentals used in other area operations. Someof these fundamentals acquire a specialsignificance in the jungle.

To succeed in the jungle defense, acommander must understand the enemyand see the battlefield. The enemy willprobably be expert in using the environmentto his advantage, and the defender mustunderstand enemy techniques. To counterthe threat of infiltration, the defender mustemploy all-round defense and all surveillancemeans available. No amount of electronicmeans can eliminate the need for frequentpatrolling.

The defender must exploit everyadvantage that he has, particularly theabundant concealment provided by thefoliage and the weather. A force whichremains concealed may disrupt an enemy’sattack by using surprise fire from hidden

5-16

locations. Though not as common as in othertypes of terrain, features which lendthemselves to the defense, such as rivers,gorges, and ridges, should be used if theydominate likely avenues of approach. Thedefender must appreciate the defensivecharacteristics of the terrain and environ-ment.

The defender must maximize the effec-tiveness of key weapons, which in the jungleare infantry small arms, mortars, andartillery. The poor trafficability alsoincreases the importance of attackhelicopters and TACAIR.

In planning to concentrate combatpower at critical times and places, thedefender must first plan the massing ofsmall-arms fire. Since fields-of-fire will belimited, positions must be placed closetogether for mutual support. To move troopsand weapons rapidly to supplementary oralternate positions, it maybe necessary to cutpaths through the bush. Units shouldrehearse these maneuvers.

As in the offense, the problem ofproviding continuous support is to a largedegree solved by effective communicationsand the use of helicopters.

PLAN OF THEJUNGLE DEFENSE

Planning for the jungle defense shouldprovide for a covering force area, a mainbattle area, and a rear area. Forces in eacharea must be provided fire support. Obstaclesare planned to improve the natural defensivestrength of the terrain. Plans are alsoformulated for counterattacks. The followingfactors should be considered when planningfor the jungle defense:

Day and night in jungle regions areeach roughly 12 hours long. Nights,

FM 90-5—

especially under jungle canopies, areextremely dark. Defensive preparationsshould begin at least 2 hours before night-fall.

The heat and humidity will fatiguetroops rapidly.

Tropical rain will flood positionsunless they are adequately drained. Duringthe rainy season, defensive positions shouldbe dug on high ground, if possible.

Because jungle terrain favors infiltra-tion, the use of starlight scopes, OPs, and

After the commander organizes theground and secures the area to be defended,he then positions his Dragons, if they can beused effectively, and machineguns andclears fields of fire. Leaders must insure thattroops do not cut too much vegetation. Inorder to be mutually supporting, positionswill be closer together than on other types ofterrain. In addition to attaining mutualsupport, this helps prevent enemyinfiltration. Mines and obstacles should beemplaced where they are covered by friendlyfires. These should be located beyond handgrenade throwing range of the defensive

early warning devices is very important. positions.

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—FM 90-5

SECURITY

Since enemy tactics, jungle terrain, andbad weather favor attacks conducted bystealth, security should be the leader’s firstconcern. OPs, early warning devices,ambushes, and patrols are all measureswhich will prevent a unit from beingsurprised. Patrols must be planned accordingto an irregular schedule. A system ofrecognition signals must be used to preventthe engagement of friendly units.

NOTE: If mechanical ambushes are used,units should stop patrolling in that area, andshould provide some means, such ascommunications wire, to guide OP personneland prevent them from straying into themechanical ambush.

DEFENSIVE FORMATIONS

The basic defensive technique in thejungle is the perimeter defense. Two othervery effective defensive techniques for jungleoperations are the triangle and “Y”formations (see app J). Whether a unit isoperating independently or as part of a largerdefensive position, it must be prepared todefend itself against an attack from anydirection. Initially, these formations will beformed by platoons or by companies. Largerunits should position their companies indepth to provide all-round defense. Alert andaggressive patrols and OPs will defeatenemy attempts to infiltrate betweenpositions. Later, if time permits, platoon andcompany formations can be connected withfighting positions and trenches. Even then,however, companies and platoons must beprepared for all-round defense.

PRIORITY OF WORK

Units in the defense must pay particularattention to their priority of work. Since moresecurity measures must be taken thannormal, fewer troops will be available to

prepare defensive positions at any one time.Positions should be prepared andcamouflaged as in any other situation.Overhead cover should be prepared usingstrong wood and sandbags. Claymore minesand trip flares should be emplaced in front ofthe defensive positions. Fields of fire shouldbe cut low, leaving enough foliage so as not toreveal the location of the defensive position(app E).

To counter enemy reconnaissanceefforts, units should shift the positions ofmachineguns after dark. After a few days,the entire unit’s position should be changed.If a unit remains in position for a longerperiod of time, it is more likely to bereconnoitered by the enemy and subject toattack.

COMMAND AND CONTROL

Command and control are extremelydifficult in the jungle defense. Commandersmust place great emphasis on planning,coordination, and small-unit leadership.Decentralized control is important to insurethat subordinate units can react to multiplethreats. Aggressive leadership at the small-unit level is necessary in fighting off isolatedassaults at close range. Alternate com-munications means must be establishedwherever possible. An example might be acommunications system using wire as theprimary means, radio as the secondarymeans, and pyrotechnics for certainprearranged signals.

Defensive targets for artillery andmortars should be planned on stream andtrail junctions, and any other likely enemyavenues of approach. Artillery and mortarfire should also be used to cover the manyareas of dead space found in jungle terrain. Itis also a good idea to confirm the location ofthe defense on the ground by using artillery

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FM 90-5—

marking missions integrated intoregistration missions. Signals for theemployment of TACAIR and attackhelicopters, both day and night, and formedevac and resupply helicopters must alsobe planned.

CONDUCT OF THEJUNGLE DEFENSE

There are occasions when a unit willhave to establish a defense with minimumplanning time. This normally occurs whenan attack is stalled, at dusk when the unit isstill in contact with the enemy and no nightattack is planned, or when an intermediateobjective must be secured before continuingthe attack. These situations are moredangerous in the jungle than in other areasbecause of the dense foliage and the closenessof the enemy.

The normal course of action in thesecases is to establish a perimeter defense.Dragons, if they can be used effectively, andmachineguns are positioned immediatelywhere they have the best fields of fire. Assoon as possible, OPs and other local securitymeasures are established. Frontages aresmaller than in other types of terrain,especially at night, to guard against enemyinfiltration. Indirect fires are registered andfighting positions are dug as soon aspossible.

Once these actions have been completed,steps are taken to improve the defense. Aprimary consideration in improving adefense is to expand the perimeter to gain“working room. ” This may require limitedattacks, massed artillery and mortar fire, orclose-in machinegun fire to force the enemyto withdraw. If the position will be occupiedfor a long time, it should be made as strong aspossible.

This may be done as follows:

A small reserve is formed as soon aspossible to react to enemy threats

Local security is pushed forward

Counterattack plans are developed

Wire communications are establishedand pyrotechnic signals planned

Machineguns are employed singly inorder to cover as many enemyapproaches as possible

If troops remain in a defensive positionfor a long time, they must not becomecomplacent. Leaders must inspect weapons,positions, and the cleanliness of troops. Theymust also develop plans for alerts, feeding,maintenance, and bathing. These activitiesmust be scheduled according to a randompattern so that the enemy cannot takeadvantage of a set routine.

An alert system must be established, sothat a portion of the defensive force is alwaysawake. Although the poor observation injungles favors the enemy’s attack at anytime, the early hours of the morning affordhim the greatest chance of surprise unlesspositive alert measures are taken. All troopsshould stand-to before dawn.

The jungle enemy will try to probe aposition to locate the flanks of positions andkey weapons. Soldiers must not give awaytheir positions by premature firing.Claymores and hand grenades should beused to engage these probes. When probed,riflemen near machineguns should fire, notthe machinegunners. Machinegunners mustuse their pistols for self-defense instead oftheir machineguns. When the enemy attacks,he will try to isolate friendly positions anddestroy them one at a time. Well-planned,mutually supporting fires will prevent this.

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FM 90-5

COUNTERATTACKIf enemy forces penetrate a position, a support the counterattack. If they leave their

counterattack is the best way to expel them. positions while the enemy is being expelled,Troops in the area of the penetration must they increase the chance that they will be hitstay in their positions and continue to fire to with friendly fires.

THE BATTALIONCOMBAT BASE

When engaged in tactical operations inthe jungle, elements of the battalion willoften establish a base for command and con-trol and fire support resources, protected by aperimeter defense. These resources are calledthe battalion combat base.

The location of the perimeterdefense to defend the battalion combatbase will depend upon the:

Forces available to defend the combatbase

Ability to support subordinate unitswith indirect fire

Defensibility of terrain

Ability to communicate with sub-ordinate units

Prior to establishing the battalioncombat base, the commander should conduct

a reconnaissance to determine thedefensibility of the terrain. He also plansforces required for the defense. While thedefense must be capable of defeating thelargest attack which the enemy is likely toconduct, it must use the minimum forcesnecessary. The combat support company,reinforced as necessary with an attachedinfantry platoon, is the largest force that isrealistically available for preparing anddefending the perimeter. To use a larger forcewould probably leave insufficient forces tofight the more important combat. Since someelements, such as the antitank platoon of thecombat support company, may not beemployed effectively in the jungle, they willoften be available for use in the perimeterdefense. The battalion commander willnormally designate the combat supportcompany or headquarters and headquarterscompany commander to be the battalioncombat base commander and will have himtake charge of the construction and execu-tion of the perimeter defense.

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FM 90-5—

Forces normally under control of thebattalion combat base commanderinclude:

The antitank platoon

A Redeye section, if attached (both toman the perimeter and to provide anti-aircraft fire)

The heavy mortar platoon (both toman the perimeter and provide firesupport)

A rifle platoon, if provided for theperimeter defense

The scout platoon is normally used forpatrolling or screening missions, rather thanbeing used in manning the combat baseperimeter.

During construction of the perimeterdefense, it is vulnerable to enemy attack.Consequently, it is imperative to completethe perimeter defense as quickly as possibleand to provide maximum security duringconstruction.

The threat of infiltration attacks must beemphasized. The enemy may not be able toconduct large scale attacks on fortifiedpositions, but he may be capable ofdisrupting operations by infiltrating one- ortwo-man teams through the perimeter toplace explosive devices on command andcontrol facilities, artillery pieces or mortars,or ammunition storage areas. This infiltra-tion is often preceded by a deceptive attack orprobe by ground forces. Troops in theperimeter must maintain constant security,using early warning systems and continuouspatrolling. Starlight scopes, OPs, unattendedground sensors, and tripflares are also used.Wire obstacles should be used to keepinfiltrators out of critical facilities.

A battalion combat base may have toremain in place for a long time. Continuous

firing of mortars and landing of helicoptersmakes concealing its location very difficult.These two factors make it necessary toharden the perimeter defense. Overheadcover and sandbagged bunkers must beprovided for all fighting positions. Thetactical operations center (TOC) andCP should have similar protection and mayalso be dug underground. Mortars andartillery pieces should be dug in or fortifiedwith sandbags.

ORGANIZATION OFTHE DEFENSE

A reserve for the defense may beconstituted from attachments, such asengineers (if available), or from off-shiftpersonnel from TOC and CP elements. Thisreserve will react to enemy attacks, and willreinforce the defense or counterattack. Theymust be rehearsed on signals and actionsuntil they become proficient. Mortars areemployed to provide close-in fire support.Artillery pieces can provide direct fire butprobably will not be able to provide indirectfire support of the perimeter. Hence, theperimeter should be located within range ofother artillery and mortar units foradditional protection.

The battalion combat base commanderassigns sectors to subordinate platoons,insuring that likely avenues of approach aredominated by Dragons, machineguns, andartillery in direct fire role, if possible. He thenplans indirect fires. The commander specifiespoints at which adjoining platoons mustcoordinate. The platoon leader selects eachposition and designates the personnel to manit.

The platoon leader must insure that hehas complete coverage throughout his sectorto deal with not only a mass attack but alsoinfiltration of small elements.

Once the positions are selected, theplatoon leader insures that a priority of workis adhered to.

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—FM 90-5

EXAMPLE OF PRIORITIES OF WORK

Work should be accomplished in the following steps, consistent with thetactical situation and the availability of resources.

Step 1: Air assault/ground assault seizes the site.

Immediate security established to includeOPs.

Area swept for boobytraps.

Mortars laid.

Step 11: Communications established.

CP set up.

Position of TOC dug in.

Selected TOC personnel displaced toperimeter defense.

Step Ill: Perimeter positions established.

Fields of fire cleared.

Reserve force established.

Wire to all positions.

Step IV: Barriers and obstacles placed aroundperimeter defense.

Early warning devices emplaced.

Security/ambush patrol plans established.

Final protective fire (FPF) fired in.

Positions sustained.

Positions are hardened with overhead cover.

All other positions improved.

More fields of fire cleared.

Landing zone enlarged.

Latrine, generators, and ammunition supplypoint (ASP) established.

NOTE: Throughout work, camouflage mustbe applied.

Step V:

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FM 90-5—

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–FM 90-5

SECTION V. RETROGRADE

Retrograde operations are conducted inmuch the same manner as the defense, withthe additional requirement to gain a mobilityadvantage over the enemy. This is done bytaking measures to increase the mobility ofthe unit conducting the retrograde(reconnaissance and preparation of routes,use of helicopters, etc.), and by takingmeasures to decrease the mobility of theenemy (ambushes, artillery fires, mines, wireobstacles, etc.).

WITHDRAWL

Withdrawals may be conducted underenemy pressure or not under enemy pressureas explained in FM 7-8 and FM 7-10. Becauseof the cover and concealment provided by thejungle, a withdrawal under enemy pressuremay be conducted using deception in muchthe same manner as a withdrawal not underenemy pressure. The ruggedness of theterrain and the strength of the attackingenemy are key factors in this type ofoperation. Routes, assembly areas, and newpositions must be thoroughly reconnoitered.They may also be marked if such markingdoes not compromise security. Denselyvegetated areas will require increased use ofguides. Control in such areas is very difficult;

therefore, leadership, planning, andrehearsal are crucial.

"I will never again tell my platoon towithdraw - especially in the jungle -without telling it where to go. I had ahell of a time getting them together. ”

—Platoon Leader, New Guinea,World War II

Unattended ground sensors employedalong likely enemy avenues of approach canbe used to provide information on enemymovement and activities. This informationcan in turn be used to place fires on theenemy.

DELAY

The delay in sector is normally the mostfrequently used type of retrograde in thejungle. Ambushes may be used to halt theenemy’s pursuit, and can aid the main bodyin breaking contact along the delay route.Mechanical ambushes, wire obstacles, andminefield will also delay the enemy. In thejungle, the delay is normally conducted inseveral phases: defense, withdrawal underpressure, breaking contact, and movement toand occupation of new positions where thedefense starts again. As in the withdrawal,units should reconnoiter and clear routes tothe rear.

Section VI. OTHER COMBAT OPERATIONS

Patrols, raids, and ambushes are nor- One jungle myth that was popular bothreally used more often in the jungle than in during World War II and the Vietnam Warmore open terrain. The jungle permits small was that “the night belongs to the enemy. ”units to move undetected during reconnais- The enemy has no better night vision orsance patrols and achieve surprise when stealth than do trained US soldiers. He willconducting raids and ambushes. These are often use the night as a means to avoid USsmall-unit operations. They depend heavily firepower, but with the proper use of patrols,on the skill and stealth of infantry platoons raids, and ambushes, this problem can beand squads, and are demanding operations. eliminated.

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FM 90-5—

"On any given night in Vietnam,American soldiers staged hundreds ofambushes, for the ambush is one of theoldest and most effective militarymeans of hampering the enemy’snighttime exploits.”

—J.A. Cash, Seven Firefights inVietnam

Successful jungle patrols, raids, andambushes result from detailed planning,intensive training, and constant rehearsal.Troops must be alert. A unit which hasmoved cross-country through the jungle untillate in the afternoon will not be in a conditionto succeed if it has to go out on ambush thatnight. Commanders must realize that suchoperations require time to prepare, train, andrest.

The basic techniques for patrols, raids,and ambushes can be found in chapter 5, FM7-8. Specific techniques which are effective injungle operations are described below.

PATROLSA patrol is a detachment sent out by a

larger unit to conduct a combat orreconnaissance operation. The operationitself is also called a patrol. The mission toconduct a patrol may be given to a fire team,squad, platoon, or company. The leader of thedetachment conducting a patrol is referred toas the patrol leader.

CATEGORIES OF PATROLS

The planned action at the objectivedetermines the patrol’s category. There aretwo categories of patrols:

Combat (ambush, raid, or security)Patrol. This patrol provides security andharasses, destroys, or captures enemy troops,

equipment, and installations. A combatpatrol also collects and reports information,whether related to its mission or not.

Reconnaissance (area or zone) Patrol.This patrol collects information or confirmsor disproves the accuracy of information pre-viously gained.

Regardless of the category of thepatrol, there are four key principles tosuccessful patrolling. These are:

Detailed planning.

Thorough reconnaissance.

Positive control.

All-round security.

ORGANIZATION FOR A PATROL

The patrol leader decides what elementsand teams are needed for his patrol, selectsmen or units for these elements and teams,and decides what weapons and equipmentare needed. He should, however, use his unit’snormal organization (squads and platoons)and chain of command (squad and platoonleaders) as much as possible to meet theseneeds. For example, a combat patrol may beorganized like this: the companyheadquarters is the patrol headquarters; the1st platoon is the assault element; the 2dplatoon is the security element; and the 3dplatoon and weapons platoon make up thesupport element.

GENERAL ORGANIZATIONA patrol generally consists of a patrol

headquarters and the elements needed for themission.

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–FM 90-5

Patrol Headquarters. The headquarters(HQ) of a company-size patrol normallyconsists of the same number of men as aregular company headquarters. However,regardless of a patrol’s size, its leader tailorsthe headquarters to meet mission needs. Thepatrol headquarters has the sameresponsibilities as any other commandelement.

Reconnaissance Patrol. In an areareconnaissance (recon), a patrol has a recon-naissance element and a security element. Ina zone reconnaissance, a patrol has severalreconnaissance elements. Each one providesits own security.

Combat Patrol. A combat patrol normallyhas an assault element, a security element,and a support element. At times, the supportelement may be omitted by combining it withthe assault element.

In general, jungle terrain affordsexcellent concealment, provides some cover,and hinders enemy observation andmovement. During rainy periods, the soundof movement is less obvious. Wet ground andwet vegetation also muffle noise. All of thesefactors favor the patrolling unit.

On the other hand, the difficulties ofmovement and control and the ease withwhich the enemy can infiltrate friendly unitsare disadvantages to units patrolling in thejungle. These factors can best be overcome bytraining and discipline.

Silence, in both voice and movement, isessential at all times during a jungle patrol.With practice, it is possible to move steadily,deliberately, and carefully through thejungle, parting the undergrowth instead ofcrashing through it or cutting through it withmachetes. Troops should avoid walking ondry leaves, sticks, rotten wood, or anythingthat would make noise. Machetes should beused to cut trails only as a last resort. Talkingshould be done in a whisper, and arm-and-

5-26

hand signals should be used wheneverpossible.

Trails should be avoided. Patrols shouldmake every effort to hide signs of movement,especially when moving through untraveledterritory or near enemy positions.

Some techniques which may beused include:

Requiring all troops to wear boots thathave the same pattern on their soles.

Requiring troops to carry only themission essentials, and do not letthem litter.

Cautioning troops to avoid smallsaplings, when going up hill. Theshaking of overhead branches can beseen and heard at a distance.

Requiring troops to keep off trails. Ifnecessary to monitor or guide on atrail, patrols should move parallel tothe trail and not on it.

Native scouts are valuable in patrollingbecause they are often very familiar with theterrain. Patrol leaders must realize, however,that a scout’s function is only to showdirection and provide information. He shouldnever lead the patrol. The correct position of ascout is with the patrol leader, so that theleader can make decisions based on thescout’s advice.

RAIDRaids in the jungle environment must be

keyed to reliable intelligence. The actions ofthe raiding unit must be decisive and rapid inorder to catch an elusive jungle enemy. Araid’s success depends on good intelligenceand a sound plan.

Jungles favor raid operations. Theexcellent concealment enables skilledraiding patrols to operate deep in enemyterritory. Platoon-sized units are best suited

FM 90-5—

to jungle raids. Supporting artillery firesshould be planned, but due to difficulties ofcontrol, timing, and communications, jungleraids may be executed without artillerysupport. Surprise is a key ingredient of asuccessful raid.

Raids that require deep penetration intoenemy-held areas are best executed byestablishing a patrol base in the general areaof the final objective. From there,reconnaissance patrols can be sent to scoutenemy positions while the remainder of theforce completes its preparations for the raid.Helicopters and watercraft are effectivemeans of transporting a raiding force rapidlyto the vicinity of its objective withoutdepleting their physical strength in adifficult march.

AMBUSHESThe ambush is more important, more

effective, and more frequently used in junglefighting than in any other type of combat.Jungle terrain provides many opportunitiesfor a well-concealed force to gain surprise.Surprise is essential for a successful ambush.

Destruction of enemy forces is theprimary purpose of most ambushes, but otherbenefits result from a well-executed ambushprogram.

These benefits include:

Disruption of enemy operations,since troops become reluctant to moveand fight in areas where ambushes arefrequent.

Capture of prisoners andequipment which may yield intelligencedata.

Capture of supplies, thusincreasing combat effectiveness at theexpense of the enemy. In someinstances, this is the primary source ofsupplies for guerrilla forces.

More than in any other type of terrain,jungle ambushes require high standards ofdiscipline. Soldiers on an ambush must beprepared to remain in the same position forhours at a time, without being able to sleep,talk, or smoke. They must endure insects andresist the desire to make any quick moves toswat or brush the insects away. All theserequire extensive training to develop thepatience and self-discipline required.

The location for an ambush should bechosen after a careful analysis of the terrain,using maps, aerial photographs, andpersonal reconnaissance. The site chosenmust contribute to the surprise of theambush. Many times the selection of a site forsurprise alone will be more effective thanattempting to ambush from a site which is inother respects tactically sound but at whichthe enemy is sure to be suspicious. Coveredroutes of approach and withdrawal, goodfields of fire, and canalization of the enemyare characteristics of a good site. The siteshould always be reconnoitered andapproached from the rear.

In no other operation is camouflage moreimportant than in the ambush. Weaponsshould fire through screens of undisturbed,living foliage. Spoilage resulting from thepreparation of positions must be removedfrom sight. There can be no unnecessarynoise or movement. If reliefs are used, theyshould be scheduled so that only a few menmove at any one time. One or two menmoving are harder to detect than an entirerelief moving at once.

DEFENSE AGAINSTAMBUSH

Since ambushes are more frequent andeffective in the jungle than in any other typeof terrain, a unit moving through the junglemust take all possible measures to reduce itsvulnerability to ambush. The most effectivemeans of countering an ambush is to detect it

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–FM 90-5

before entering the kill zone. This, however, planning, and counterambush drills are alsois not always possible. important antiambush techniques.

Mounted troops are very vulnerable toDismounted troops have an advantage jungle ambushes, especially where the

over mounted troops in avoiding ambushes foliage grows up to the edge of a road.because they do not have to move on roads or Ambush of vehicular columns traditionallytrails. Commanders of dismounted units has been a primary tactic of jungle enemies.should make a map and aerial photograph As a result, traffic in jungle areas must bereconnaissance to detect likely ambush sites tightly controlled and kept to a minimum. Alland plan routes which avoid them. During vehicles should have armed riders. Armoredmovement, security to the front, rear, and vehicles should escort convoys, and trafficflanks should be maintained at all times. information should be carefully guarded.Alert troops, good noise discipline, and well- Fire planning and route selection andrehearsed signals are other means which will reconnaissance are important for mountedreduce the chances of ambush. Accurate land troops as well as for dismounted troopsnavigation, continuous fire support (app M, FM 7-8).

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FM 90-5—

COUNTERAMBUSHMEASURES

Troops must also be trained in counter-ambush measures. The key is early detectionfollowed by reflex-type counteraction, a highvolume of return fire, and relentless pursuit.The most effective counterambush measuresare well-rehearsed immediate action drills.Every soldier must know exactly what he issupposed to do.

Dismounted troops should react to anambush immediately, firing into theambushers without orders. Building andretaining fire superiority is the best initialdefense against an ambush. If a patrol findsitself in an enemy ambush, it must get out ofthe kill zone immediately. It must take thefollowing immediate actions:

Troops in the kill zone, without order orsignal, immediately return fire, and quicklymove out of the kill zone by the safest way.(There is no set way to do this; it must be eachsoldier’s decision for his situation. ) Smoke

grenades can help conceal the troops in thekill zone.

Troops not in the kill zone fire to supportthe withdrawal of the troops in the kill zone.

If a dismounted patrol is ambushed, itshould attempt to break contact andreorganize in the last designated rally point.

Mounted troops who are ambushedshould attempt to drive rapidly out of the killzone. Vehicles approaching the kill zoneshould stop so they do not enter it. Troopsshould then dismount and maneuver todestroy the ambush.

In any case, the rapid call for supportingartillery and mortar fire will help theambushed force to gain fire superiority andwill assist the maneuver to destroy theambush.

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FM 90-5

CHAPTER 6

Helicopter, Armor, Mechanized Infantry,And Combat Support Operations

Section I. GENERAL

In the jungle, infantry battalions are the This chapter outlines those techniquesheart of both the offense and the defense. which are most effective in supportingThese battalions are normally supported by a infantry engaged in jungle operations.mixture of helicopter, armor, artillery, airdefense, engineer, and other units.

Sect ion I I . Hel icopters

HELICOPTERROLES

The helicopter is a combat system that is borne fire, reconnaissance, air assault, andunaffected by the poor trafficability of jungle command control in the jungle. For resupplyareas. As a result, it has become a vital part of and medical evacuation, see chapter 7.US jungle operations. US forces have usedhelicopters in the jungle successfully for In all of these operations, bad weatherheliborne fire, reconnaissance, air assault, and enemy air defense are major con-command and control, resupply, and medical siderations in the jungle as they would beevacuation. This section will discuss heli- anywhere else.

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—FM 90-5

Heliborne fire is provided by the attackhelicopter unit.

The attack helicopter unit performsthree basic missions:

Overwatch and security

Engagement of targets located byground elements

Independent target engagements

Attack helicopters in an overwatch andsecurity role protect other assets, such asother helicopters or convoys. Attackhelicopters in the heliborne fire role canaugment the fires of units fighting on theground. In jungle operations, they maybe theonly additional means of fire available.Finally, attack helicopters may acquire andengage targets independent of any otheroperations.

HELICOPTER ARMAMENT

Although the Cobra, AH 1S, armed withthe TOW, has become the standard USattack helicopter, the nature of the typicaljungle enemy and the terrain make the 2.75-inch rocket (HE) a more useful weaponagainst known point positions. The

2.75-inch rocket, 7.62-mm“Flechette”minigun and 40-mm grenade launcher, alsoon the attack helicopter, are extremelyeffective against dismounted troops.

COMMUNICATIONSThe most important consideration when

using attack helicopters to augment the fireof ground troops is communications. Bothradio and visual communications meansmust be established and maintained. Radiocommunications are used to pass targetinformation from the ground commander tothe helicopter. Visual communications areused to mark the location of friendly troops.Common daytime signals are a smoke

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FM 90-5—

grenade, a panel, and a mirror. A flashlight,a strobe light, and a chemical light stick areeffective for signaling at night.

COMMUNICATION WITHATTACK HELICOPTERS

While the helicopters are en route to thetarget area, a member of the attack helicopterteam will contact the ground commanderover the radio. At this time, the groundcommander must transmit target handoffinformation.

TYPICAL EXCHANGE OF TARGET HANDOFF INFORMATION

IDENTIFICATION Helicopter: — “55T7 this is 24J6. ”

Ground Commander: — “24J6 this is 5517. ”

Ground Commander “I am pinned down by an estimatedENEMY INFORMATION enemy company. I am receiving

AK-47, RPD, and RPG fires.”

Ground Commander: “I am in a perimeter defense. There isOWN SITUATION no artillery impacting at this time. I

will mark my location with smoke. ”

Helicopter “I’m about 30 seconds from yourreported location. Pop a smokegrenade.”

Ground Commander: — “WILCO.”VISUAL IDENTIFICATION Helicopter: — “I identify yellow smoke.”

Ground commander “Roger, yellow smoke. Enemy is atazimuth 120 degrees from yellowsmoke, estimated distance 200meters. ”

COORDINATION Helicopter: “Roger, I’ll make my run fromnortheast to southwest.”

R E C O N N A I S S A N C EReconnaissance missions are normally

given to air cavalry. Air cavalry troops andsquadrons are equipped with attackhelicopters, scout helicopters, and utilityhelicopters. The air cavalry troop isorganized with a troop headquarters,aeroscout platoon, aeroweapons platoon,

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–FM 90-5

aeroreconnaissance platoon, and serviceplatoon. The troop is task organized forspecific reconnaissance missions.

The aeroscouts use terrain flying whilelooking for signs of the enemy. Attackhelicopters from the aeroweapons platoonsupport them and engage targets as they areacquired. If a thickly vegetated area cannotbe reconnoitered from the air, theaeroreconnaissance platoon can be insertedon the ground by the utility helicopters.

AIRMOBILE OPERATIONSThis employment of air cavalry is

effective in the jungle. The informationgathered can be rapidly processed intointelligence. This in turn can be used to plantimely commitment of troops into the area.

Airmobile operations in the jungle arethe most rapid means of concentratingcombat power at a critical time and place onthe ground. The doctrine for airmobileoperations is found in FM 90-4, and it isgenerally applicable to jungle operations.

Special considerations in jungleoperations include:

Utility helicopters will not be ableto lift the same size Ioads that they can inmore temperate areas. Sometimes thismay result in as few as 5 soldiers persortie for UH-1H and 19 soldiers forUH-60.

Radio and visual communicationsbetween ground and air are vital toinsure proper coordination. The thickjungle foliage will often make this moredifficult than in other types of terrain.

There maybe few suitable landingzones (LZ). Most landing zones will beonly large enough to support one or twohelicopters at a time.

Units may have to be resuppliedtotally by air.

One of the most common uses of thehelicopter in jungle operations is commandand control. Command and control (C&C)helicopters are specially outfitted with radioswhich allow communications with elementson the ground, supporting artillery, and otheraircraft. These helicopters also have seats inthem arranged so that commanders, S3s,and fire support coordinators (FSCOORD)can talk to each other and perform theirrespective functions. Such helicopters arenormally available to command groupsdown to and including infantry battalionlevel.

To use the C&C helicopter ef-fectively, a commander should exploitits unique capabilities:

The helicopter’s speed enables acommander to influence the action inwidely separated areas.

The helicopter’s powerful radiosand f l ight a l t i tude permit thecommander to communicate moreeffectively and reliably than he could onthe ground.

The unrestricted observation fromthe air allows the commander to see theterrain better, adjust fires moreaccurately, and control attackhelicopters more effectively than hecould on the ground.

When used for a commander’sreconnaissance, the C&C helicopter is asignificant help in planning operations.Likewise, a battalion commander whotakes his company commanders in theC&C helicopter to issue an operationorder (OPORD) can use the terrain belowas a reference— like a readymadesandtable.

The C&C helicopter can be one of thejungle commander’s greatest assets. It can

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FM 90-5—

also be abused. The keys to its effective useare a few common sense considerations.

The helicopter cannot become asubstitute for command presence on theground. (A commander cannot merely flyover a unit and be satisfied that he knows itssituation. The view from the air often gives adistorted picture of conditions on theground.)

The helicopter should not interfere withground operations. (If a unit has to devotetime to cutting an LZ every day for a visitfrom the commander, it will get little elsedone.)

The helicopter must not violate aground unit’s security. (A helicopter

hovering overhead soon reveals the locationof a unit on the ground. )

The helicopter must not intrude on aground unit’s internal radio nets. (Thehelicopter’s radios are more powerful, andwill interfere with the ground commander’sability to control his own unit.)

The helicopter is vulnerable to groundfire. (Although the nature of the air defensethreat will be different in every conflict, nocommander can expect to survive if hemaintains a stationary position anytime inthe vicinity of ground contact or orbits athigh altitudes. The helicopter is extremelyvulnerable to small-arms fire and heat-seeking missiles.)

Section III. ARMOR OPERATIONSIN THE JUNGLE

Up to this point, this chapter has covered different in the jungle than that on moreinfantry tactics in the jungle. Armor may open terrain. Instead of rapid envelop-also play a role on the jungle battlefield. ments and deep penetrations, tanks pri-Because the tank’s mobility is greatly marily provide fire support for infantry inrestricted on jungle terrain, its role is jungle fighting.

Tanks can perform the following missions in the jungle:

Support attacking infantry. In the Support infantry in retrograde opera-meeting engagement, they move to tions.the point of contact to provide directfire support. Secure convoys and protect lines of

communications and key facilities.

Provide heavy fire support in the Attack or defend against enemydefense and conduct counterattacks. armor.

TACTICAL OPERATIONSOFFENSIVE OPERATIONS

In the movement to contact, infantry will distances between the forces, but the tanksnormally lead, supported by tanks from should be close enough to the infantry to beoverwatch positions whenever the terrain able to move forward quickly to providepermits. Terrain and vegetation will dictate immediate fire support.

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–FM 90-5

In a meeting engagement or attack, once positions from which they can support thethe infantry makes contact, tanks move to infantry.

Tanks can fire their machineguns andmain guns using high explosive antitank(HEAT) and antipersonnel rounds to destroyor suppress the enemy, clear jungle foliage,and destroy fortified positions.

Should the enemy have armor, the tankscan more effectively attack the enemy armorthan can the TOW or Dragon antitankguided missile because the tank gun canbetter fire through the jungle foliage.

When terrain permits, infantry can fixthe enemy, while tanks create a penetrationto split the enemy defense. The tanks andinfantry can then destroy the severed forces.

DEFENSIVE OPERATIONS

Tanks are used in the jungle defense asthey are used in any other environment. Theyadd greatly to close defensive firepower andserve as a mobile counterattack force.

6-6

In the position defense, tanks shouldbe positioned to:

Block possible armor or motorizedpenetrations

Move quickly to fill gaps in thedefense

Provide antiarmor fire

Tanks in the jungle defense arevulnerable to infiltrators; consequently, all-round security and close coordination withinfantry are essential.

Hurricane fencing should be erected as ascreen in the defensive position to providestand-off against enemy use of rocket-propelled grenades (RPG) and antitankguided missiles (ATGM).

RETROGRADETanks can support retrograde operations

in much the same way as in the defense.Contrary to general practice, in jungle

FM 90-5—

retrograde operations tanks will oftendisengage first, covered by the infantry.

LIMITATIONSRESTRICTIONS ON USE OF ARMOR

Vegetation. Densely forested areas, wheretree trunks are close and heavy above-groundroot systems exist, may make movementdifficult. Thick stands of bamboo may slowor even stop tanks.

Topography. Many jungles exist in ruggedmountainous areas which will impede tanks.Swamps, coastal river basins, and otherareas intersected by waterways poseobstacles to tanks because of their soft soiland frequent deep channels.

Weather. Rainy seasons (monsoons) causerivers and streams to rise and becomeunfoldable. Heavy rains may also causedamage to roads.

TECHNIQUES TO OVERCOMEARMOR RESTRICTIONS

All of these factors limit but do notexclude the use of tanks.

A commander can overcome thoselimitations by using these techniques:

Know the terrain. Know where tankscan travel. Avoid areas which areobviously impassable.

Know the weather. What were recentconditions? What is expected? Whateffect will these conditions have onthe use of tanks?

Move dismounted infantry in front oftanks on unfamiliar and heavilyvegetated terrain. They can check andverify conditions, act as guides, andprovide security.

TIPS FOR MOVEMENTIN THE JUNGLE

Jungle conditions vary greatly fromplace to place and season to season.

Here are some movement tips whichapply to most jungle areas:

Red silt soils tend to break downquickly when wet. They may support asingle tracked vehicle but may becomeuntrafficable with heavy use.

Inundated areas containing yel-lowish reeds and cloudy water usuallyhave bottoms too soft to support tanks.

Rice fields, in the dry season, areusually trafficable to tanks and person-nel carriers. During the rainy season,they may be untrafficable. Fields withstanding water in the wet season mayhave a bottom too soft to move on; thosecontaining clear water and greenvegetation usually are on firm groundand are trafficable. One technique fordetermining if rice fields are trafficable is“poling.” Using this technique, troopsprecede tanks across the field they areto cross, sinking poles (1 to 1 1/2 inchesin diameter, with flat ends) into theground. If the poles cannot be sunk, thefield is usually firm enough to cross.

River and stream bottoms usuallyare untrafficable. The armored vehiclelaunched bridge (AVLB) can span 17meters (57 feet) and is more thanadequate for most stream crossing. Caremust be taken to insure that theshoulders of the banks can support theAVLB while tanks cross. When the AVLBis not avilable, perforated steel plankscan be used to provide a firm surface onwhich tanks can ford small streams.

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–FM 90-5

Section IV. MECHANIZED INFANTRYMechanized infantry units are able to

provide a commander fighting in a jungleenvironment a greater flexibility than thatafforded by nonmechanized infantry.Mechanized infantry may be employed as amounted force, a dismounted force, orairmobile infantry.

CAPABILITIES

OFFENSIVEIn offensive operations, mechanized

infantry may conduct the followingoffensive actions:

Movements to contact

Attacks-hasty or deliberate

Reconnaissance-in-force

DEFENSIVE

In defensive operations, mecha-nized infantry may be used:

In a strongpoint defense

As part of a linear defense

To establish a perimeter defense

OTHER OPERATIONS

Mechanized infantry units, espe-cially when formed into tank-infantrycompany teams, may also be used inother operations such as:

Route clearance and security

Convoy escort

Reserve of a higher headquarters(either for offensive or defensiveoperations)

Raids

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FM 90-5—

CONSIDERATIONSFOR

E M P L O Y M E N TAs mechanized infantry may be used in

different ways, the precise mission it isassigned must be weighed against itsstrengths and weaknesses in a jungleenvironment.

STRENGTHS WEAKNESSES

Quick reaction over distances. Trafficability. When used as aThe unit has its own transportation mounted force, mechanized infantryimmediately available, and considerable units may be limited in the scope of theirfirepower to accompany it. In savanna or operations by the terrain in which theyon firm but lightly vegetated ground, are employed.mechanized infantry is able to move

Noise. The operating noise of theconsiderable distances in a relativelyshort period of time. tracked vehicles limits the ability of

Firepower. A mechanized infan-mechanized infantry units to achievesurprise while moving.

try force has greater firepower thanother infantry units. The carrier’s caliber Logistics requirements. Mecha-.50 machinegun can be used to nized infantry units increase logistics

strengthen defenses or provide requirements, because of increasedovermatching fires. petroleum, oils and lubricants (POL)

Large load capacity. The ar-consumption; greater repair partsrequirements; more frequent recovery

mored personnel carrier (A PC) provides operations; and larger maintenancemechanized infantry units larger capa- requirements.city to carry food, water, and ammuni-tion than other units.

Communications. A mechanizedinfantry unit has a communications

advantage because of both the numberand types of radios it uses.

Disposition of M113 APC when troopsare dismounted. When employing mecha-nized infantry as an airmobile force or asdismounted infantry, consideration must begiven to the disposition of the M113 APCs. Itis usually advisable for a driver to remainwith each vehicle. In addition, some in-fantrymen may have to provide security for

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–FM 90-5

the carriers and thus will not be able to fightwith the dismounted element.

MECHANIZED OFFENSIVEOPERATIONS IN

A JUNGLE ENVIROMENTThe offensive operations that mecha-

nized infantry units are most likely to con-duct in a jungle environment are movementto contact and reconnaissance-in-force.

A movement to contact is used to gain orregain contact with the enemy, and todevelop a situation. It serves as the first stageof operations against an enemy force whichhas not been located, and normally ends in ameeting engagement.

A reconnaissance-in-force is employed toforce the enemy to react so that friendlyelements can develop information about theenemy by discovering his location,disposition, and intent. It is used when othermeans of gaining information about theenemy are not available.

Hasty and deliberate attacks areconducted in much the same manner as theyare in conventional terrain. The techniques,however, may differ due to the jungleenvironment, especially the strictapplication of control measures incontrolling maneuver elements in the thickjungle vegetation. Also, an attack willnormally be conducted on a more narrowfront due to limited visibility.

MOUNTED MOVEMENTHasty and deliberate attacks are

conducted in much the same manner as theyare in conventional terrain. The techniques,however, may differ due to the jungle en-vironment.

When moving in the jungle, either cross-country or along roads, it is best to move inmultiple columns onpossible. The leadpreceded by an aerial

6-10

as broad a front aselements should beroute reconnaissance.

Indirect fire support must be closelycoordinated and instantly available, ascontact is often violent and without warning.TACAIR and attack helicopters provideanother responsive means to react to enemycontact.

DISMOUNTED MOVEMENT(APC ACCOMPANYING)

When in contact or contact is antici-pated the troops dismount and fight on foot.The caliber .50 machinegun on the APC canprovide fire support maneuveringelements.

RECONNAISSANCE BY FIREMovement in the jungle carries with it

the prospect of ambush at any time.Reconnaissance by fire is a technique thatcan be used to decrease this danger. In thistechnique, lead elements engage suspected orlikely enemy locations with automaticweapons as the unit moves. The enemy isthen made to move or return fire. When con-sidering a reconnaissance by fire, thecommander should realize that it uses a lot ofammunition and reveals his location to theenemy. Reconnaissance by fire is not anexcuse for indiscriminate fire by individuals.

MOVEMENT TO CONTACTMounted movement to contact in the

jungle is characterized by deliberate use oftraveling overwatch and bounding over-watch. The overwatch positions will be closerthan in other areas, due to the vegetation andterrain. Contact with the enemy will usuallybe made at close range (within 200 meters);therefore, automatic weapons should be keptwell forward. Frontal, flank, and rearsecurity may be established mounted, butmore often should be provided by dismountedelements. The security elements should berotated frequently to prevent fatigue.

RECONNAISSANCE-IN-FORCEWhen conducting a reconnaissance-in-

force, a mechanized infantry unit may have

FM 90-5–

lead elements conduct a mounted movementto contact. At likely ambush sites along theroute, however, these elements mustdismount and patrol. These patrols arenormally conducted by a platoon’s maneuverelement. The earner teams, usually with twomen in each, should overwatch the maneuverelement. They can be called forward whenrequired.

DELIBERATE ATTACKS

Deliberate attacks in the jungle areusually conducted dismounted, with M113ssupporting the attacking elements. Caremust be exercised to insure that themaneuvering infantry does not mask thesupporting fires during the assault. Theassault can be preceded by artillerypreparation and use of close air support.

MECHANIZED INFANTRYDEFENSIVE OPERATIONS

IN A JUNGLE ENVIROMENTMechanized infantry units are a formid-

able force when defending. The mostcommon types of defensive operations theymight participate in are forming a defensiveperimeter, establishing a strongpoint, ortaking part in a position defense.

DEFENSIVE PERIMETERSDefensive perimeters may be established

at any time but are normally used duringperiods of limited visibility to increase thesecurity of the force and to allow time formaintenance and rest. The perimeter is ahasty defense technique. It is usually only atemporary arrangement and is movedfrequently. A perimeter is not orientedagainst a particular enemy force, but takesadvantage of terrain to obtain the greatestsecurity possible.

Establishment of a Perimeter. An M113leaves a track that is difficult to hide andeasy to follow. Therefore, a mechanizedinfantry perimeter is difficult to conceal.

Consideration should be given to theplacement of ambushes along the back trackpath leading into the perimeter. Theperimeter is very similar to that used by dis-mounted infantry but it is adjusted toaccommodate the tracked vehicles. It is bestto have a quartering party precede the unitbut this may not be possible in all cases. Aunit SOP should be the basis for specifyingthe establishment of a defensive perimeter.M113s may be used to clear fields of firewhere they are capable of doing so. (An APCis capable of clearing considerable brush in ashort period ot time. ) The M113s are thenparked in a circle, wagon train style, facingout. Individual fighting positions areprepared in front of the parked vehicles. Dis-mounted observation posts (OP) and ambushpatrols are sent out. These elements may useClaymore mines and early warning devices.The caliber .50 machineguns may bedismounted or remain on the M113s but aremanned at all times. When the soldiers areallowed to sleep, they should be in or close tofighting positions in order to be nearoverhead protection. Ramps should normallybe raised, with access to the M113 throughthe troop door, in order to provide protectionto the crew from indirect fire.

Defense of a Perimeter. An enemy groundattack against a perimeter defense maybe bya surprise assault or be preceded bypreparatory fires. The unit shouldcontinually have all the automatic weaponsmanned and ready to fire, but care must betaken to insure patrols and OPs are backwithin the perimeter before machinegunFPLs are fired. M113s should not be movedduring a night attack on a defensive position,except under emergency conditions, due tothe danger of injuring prone friendly troops.

STRONGPOINT DEFENSE

A strongpoint is a defensive positionwhich is fortified as extensively as time and

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–FM 90-5

materials permit. It is normally located on aterrain feature critical to the defense.Individual fighting positions should beprepared with overhead cover. The M113sshould be placed in hull defilade positions,which are formed by natural terrain featuresor dug by a bulldozer. Each position shouldbe deep enough to protect the vehicle. Thecaliber .50 machinegun may be dismountedor remain on the vehicle. If it remains on thevehicle, the position should allow the caliber.50 machinegun to attain grazing fire. Ifmaterials are on hand and time is available,a chain link fence may be emplaced 10 to 15meters in front of each M113 position to causepremature detonation of antitank rounds.Each squad’s position and OP should belinked with the platoon leader in a telephonehot-loop, with radio used as an alternatemeans of communication.

SUGGESTED DEFENSIVETECHNIQUES FOR

MECHANIZED INFANTRY UNITS

Each M113 can carry a large amount ofequipment. The mechanized unit should takeadvantage of this by habitually carryingequipment to aid in preparing defensivepositions.

This equipment may include:

Concertina and barbed wire

Engineer stakes

Pierced steel planking

Sandbags

Chain saws

Pioneer tools

Hurricane fencing (RPG/ATGMscreen)

Night vision devices

M60 machineguns should be dismountedwherever possible and placed in preparedpositions. The caliber .50 machinegun maybe used either mounted or dismounted. Itshould be dismounted when the terrainprevents the gunner from getting a suitablemounted firing position. During mountedmovement, the caliber .50 machinegunshould be manned by the track commanderand the M60 machinegun manned in thecargo hatch. (See FM 7-7.)

OTHER MECHANIZEDOPERATIONS

When operating in the jungle, mecha-nized infantry units may be given missionswhich they would not normally perform inother types of terrain. Such missions requirespecial planning and coordination beforeand during the conduct of the mission.

ROUTE CLEARANCE AND SECURITYThese operations are conducted when a

route has been closed or unused. They areusually conducted so that supply activitiesmay occur, but should not be confused withconvoy escort operations, which requiredifferent tactics and techniques. Routesecurity and clearance operations areoriented on a specific route and thesurrounding areas, to insure that vehicularoperations are not interrupted along thatroute.

Route clearance operations are con-ducted to eliminate the enemy along the roadand to remove any explosives which mayhave been placed there. Whenever possible,route clearance is a combined arms effortinvolving as a minimum the use of armor,infantry, engineers, artillery, and Armyaviation. Route clearance involvesdeliberate, detailed, and coordinated actionswhich are slow. The route must often bewalked by mine-sweep teams, and the areasadjoining the route must be cleared by

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FM 90-5—

dismounted infantry. During route clearanceoperations, the mechanized infantryelements normally provide security forces forthe combat engineer mine-sweep teams. Theinfantry is also used to clear the areas oneither side of the road.

Route security missions are charac-terized by continuous activity to prevent theenemy from cutting the route or ambushingelements using it.

Patrolling is the key to route security,day and night. Patrols should be dispatchedso there is no pattern. Patrols are usuallysquad-sized and are assigned specific areasof responsibility. They may at times movemounted but dismount where appropriate.These areas of responsibility should extendto 1 kilometer each side of a route, for themission is to prevent enemy mining orambushes. A reserve force should becentrally located to be able to react in anydirection.

Bridges or large culverts along roads areprime locations for enemy demolitions andambushes. They must be kept clear andintact. A good way to do this is to ambushnear them at night, and patrol from themduring the day. Night observation devicesshould be used in ambush operations.

CONVOY MOVEMENTS

Coordination must take place before andduring a convoy movement. Each patrolmust know the time of entry and time of exitof each convoy, the numbers and types ofvehicles, and whether the convoy has anarmed escort. Just prior to the convoy’sapproach, the security patrols intensifypatrolling the areas immediately next to theroad, and assume security positions alongthe known or suspected enemy avenues ofapproach. The convoy commander shouldhave each patrol leader’s callsign andfrequency, and notify him when he isentering and leaving the area.

The elimination of the enemy is the re-sponsibility of the unit through which theconvoy is passing. If the convoy makescontact with the enemy, it should get out ofthe contact area as quickly as possible. Theconvoy commander will call the appropriatepatrol leader or area commander and informhim of the contact. It is the area commander’sresponsibility to relieve the convoy, reinforcefriendly elements, and coordinate indirectfire or air support. The convoy, or its escort,fires on ambush locations until they can getout of the kill zone.

Convoy Escort. The purpose of amechanized infantry convoy escort is tomove with and secure a convoy. The convoycommander establishes the route, check-points, fire coordination, and communica-tions. He supervises rehearsal of actions oncontact. He also identifies critical loads in theconvoy and priorities for cross-loading. Theconvoy commander and escort shouldoperate on a common radio frequency. Cross-loading spreads critical cargo in more thanone vehicle. Convoys can use aerialreconnaissance aircraft as a part of theescort.

The mechanized infantry in their M113sand tanks, if available, both lead and followthe convoy. Wherever possible, the M113swill travel in pairs. If tanks are present, theynormally lead the M113s. Communicationsamong all convoy elements are essential. Theconvoy will travel according to the rate of theslowest vehicle.

The suppression and elimination ofhostile fire is the responsibility of the escortcommander. His first priority is to preservethe convoy and its contents. Upon beingengaged by the enemy, the convoy will speedup to get out of the kill zone. Accompanyingmechanized infantry and armor will assaultby fire first, and maneuver as necessary. Anyactivity other than in the immediate areamust be coordinated with the commander inwhose area the ambush occurs, particularly

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—FM 90-5

if indirect fires or pursuit becomes neces-sary.

TANK-INFANTRY TEAMS

Tanks and mechanized infantry areoften restricted by jungle terrain, but wherethey can be employed, they complement eachother well. For this reason, mechanizedinfantry and armored units are often teamed.The two most common uses of tank-infantryteams in the jungle are for movements tocontact and for convoy escorts.

Each must know how the other operatesand the characteristics of all weaponssystems. The tankers must always knowwhere dismounted infantrymen are and theinfantry must protect the tanks from close-inenemy attack.

VEHICLE RECOVERY

Mechanized infantry’s primary advan-tage is its ability to move rapidly as com-pared to nonmechanized infantry. Thisoften will be curtailed by jungle terrain.Every effort must be made to prevent M113sfrom becoming stuck or sustainingmechanical malfunctions that render theminoperative. The two most commonoccurrences are throwing a track and gettingstuck in mud. The easiest way to preventeither is to precede each M 113 with a groundguide.

If an M113 becomes stuck, the primaryrecovery vehicle is the M578 vehicle trackretriever (VTR). One is assigned to eachcompany. It is equipped with a crane andboom, chains, and various other equipment,and it is usually located in the companytrains. It should be escorted to and from arecovery site as it is not a combat vehicle.Every effort should be made to recovervehicles by using another M113 before theM578 is used, unless an M578 is immediatelyavailable. The M578 should be moved onlywhen needed because it has less traffic-ability than the M113, weighs more, and is

wider, which make movement in the jungledifficult for the M578.

Thrown Tracks. An M113 usually throws atrack when the track is broken or detachedfrom the drive sprockets. Repair timedepends on a number of variables but usuallyvaries from 45 minutes to 4 hours. The bestpreventive for thrown tracks is maintenanceand good driving techniques. These involvekeeping the track in good repair and underproper tension, the drive sprockets turned orchanged, and supervising the drivers.

Mired M113s. Despite the M113s ability tomove over most terrain, getting stuck in mudis not uncommon, especially when operatingnear rice fields or in areas of high rainfall. Inthese circumstances, ground guides are oflittle help. Infantry squads must developexpertise in expedient recovery methods.Each M113 should carry tow cables and alsochains. Since M578s will not always beavailable, the squad must know how torecover the vehicle without VTR support. Insuch instances, other M113s pulling intandem may be necessary. A tank is evenbetter because it is much heavier than anM113, is more powerful, and generally hasgreater traction, except in mud.

LOAD PLANS FOR THE M113

Load plans are designed to standardizeloading of equipment and supplies andevacuation of priority items if the M113 isrendered inoperable. The plans further serveto standardize operations within a unit. Loadplanning requires a reverse sequence—thatis, items that are used infrequently and areless critical to the mission than others areloaded first. Items that are used on a dailybasis and are essential to missionaccomplishment must be readily available.When planning loads, consideration mustalso be given to maintenance. For example,radios should be easy to get to, and the enginecompartment should not be blocked. The loadplan diagram should also establish a

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FM 90-5—

numerical or alphabetical priority ofequipment and supplies.

Section V. COMBAT SUPPORTRIFLE COMPANY

MORTAR SECTIONThe rifle company’s mortar section’s

mission is to provide close and continuousindirect fire support to the company. Wheretrafficable road networks are available, themortar section can displace to perform itsmissions while mounted. It may, however,have problems in the jungle environment dueto a limited number of suitable firingpositions, as a result of heavy rains andrestricted overhead clearance. The use ofchain saws and demolitions may benecessary to obtain mask and overheadclearance. It also may be possible to fire frompositions on or near roads and trails.

When the company operates in terrainwhere vehicles cannot go, several difficultiessurface. Moving a dismounted mortar sectionin rugged jungle terrain with all of itsweapons components and ammunition isdifficult. The infantry platoon can be taskedto assist; however, this will severely hampertheir ability to maneuver. If the mortar fire isabsolutely essential to the company’s schemeof maneuver, then consideration should begiven to the employment of only one mortar.Also, consideration should be given to thedisplacement of mortars by helicopter.

Ideally, the rifle platoons will operate with-in range of the mortars. Resupply is providedby vehicle or helicopter. If the company is op-erating within range of a 4 .2-inch mortar pla-toon or an artillery battery, then considera-tion may be given to using the mortar sectionas infantry. This will allow the companymore operating flexibility and considerablylighten the soldier’s fighting load.

FIELD ARTILLERYThe mission of the field artillery is to

provide close and continuous indirect fire

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–FM 90-5

support; destroy, neutralize, or suppress theenemy indirect fire; and coordinate allsupporting fires. A jungle environment posesunique challenges to both maneuver andfield artillery commanders by restrictingmovement, observation, fields of fire,communications, and target acquisition.

Jungle battles are characterized bylimited visibility and close combat. Thepreponderance of fire support is employeddanger-close, and must be carefully

centers (FDC) and adjacent maneuver units.Adjustment is frequently conducted usingcreeping techniques and sometimes by sound.

The following factors must be consideredwhen employing field artillery in a jungleenvironment.

MUNITIONS EFFECTS

Heavy vegetation degrades the effects ofall types of munitions. More firepower oralternative fuze action is normally required

coordinated with supporting fire direction to achieve effective results.

The following guidance is offeredwhen requesting or selecting shell-fuzecombinations:

Proximity (VT) fuzed rounds lose the desired method of attack. Also,much of their effect in tree canopies or superquick fuzes should not be used inother thickly vegetated areas by muddy or water covered terrain, such asexploding above or high in the treetops. swamps or paddies. The effects of

superquick fuzed HE ammunition will be

Delay fuzes give better effects in sharply reduced as blast and shell

heavy vegetation. fragments will be directed upward.

Delay fuze can penetrate thick

Time fuzed rounds also tend to canopies. The fuze triggers in the

lose some effect, in the jungle by treetops, and detonates the round in the

exploding in tree canopies, due to the air at a lower level. However, when used

fuze impact function. Time fuzes, against troops in inundated areas or

however, can be extremely effective areas with soft, boggy soil conditions

when used for close, defensive fires (300 and no canopy to trigger the fuze

to 900 meters) with high-explosive (HE) overhead, delay rounds will bury

munitions. themselves in the ground, losing theirantipersonnel effect.

Superquick fuzing is useful in Improved conventional munitionsopen, lightly vegetated, or secondary (lCM) should not be used in thick foliagegrowth areas. Rounds may explode too and water-filled rice paddies. The ICMsoon in high, thick tree canopies, and like submunitions may hang up in heavytime fuzes, lose most of the shell’s foliage or fall undetonated to the ground,effect. In low canopy jungles, however, creating a hazardous area, or they mayairbursts can increase casualty-causing submerge in water, rendering themeffects. As the tree canopy is thinned out ineffective. Appropriately fuzed HEby bursting munitions, a switch to VT or rounds should be substituted for ICM, astime fuze maybe required if airbursts are necessary.

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FM 90-5–

Rearward protection for individualfighting positions must be provided whenmanning a perimeter around an artillery unit(105-mm) which has beehive ammunition.Infantrymen must also be advised of thesignals for firing antipersonnel (beehive)munitions and periodically see a demon-stration of effects to insure understandingand compliance.

The heat and humidity of tropical areasspeeds the deterioration of all types ofammunition. Further, ammunition packingmaterials and subcomponents are alsosubject to more rapid deterioration andrequire protection.

This protection should include:

Adequate shelter and ventilation forammunition.

Rotating stocks. The first-in should bethe first fired.

OBSERVATION

Ground observation is limited, and aerialobservation may be more advantageous. Allavailable air assets, proficient in observedfire procedures, to include USAF, should beused when priorities and level of risk/advantage are favorable. Limited visibilitymight also make it difficult for groundobservers to locate themselves and otherfriendly units. Determining location by oneof the indirect fire means may be necessary.Marking rounds may be fired. In severe casesadjustment is possible by sound.

POSITIONING

Positioning of artillery pieces may poseproblems due to soft soil, lack of overheadclearance, and piece masking by trees andterrain. When operating in unfamiliar areas,the battery commander’s reconnaissance isimportant. Construction of prefabricatedfiring platforms, in accordance with FM 5-15,

may be necessary when operating in low-lying areas or near bodies of water. In an areawhere no suitable firing positions are knownto exist, an engineer representative shouldaccompany the battery reconnaissanceparty. The engineer can provide invaluableexpertise when a firing position must becarved out of the jungle or selected on poorterrain.

MOBILITY

The mobility of field artillery units maybe impaired by bad weather, lack of roads, orpoor terrain trafficability conditions. If roadsare used for movement, proper preparationsmust be made. Roadsides may lack adequateroom for firing positions during roadmovements. Road movement requiresground security forces, supporting artillery,and helicopter or USAF cover to maintainclear routes and provide protection and firesupport. If roads are too restrictive, artilleryunits must be well trained in airmobileoperations as this may become their primarymode of transportation in a jungle environ-ment. Engineer support may be required toclear and maintain roads and to prepareadequate LZs.

SURVEY

Line-of-sight limitations severelyhamper survey operations. Target areasurvey may be virtually impossible. Radar,celestial observation, simultaneousobservation, hasty survey, and observedfiring charts should be used to help offset theprobable lack of survey. Firing positionsshould receive the highest priority in surveyplanning.

COMMUNICATION

Radio relays and elevated antennas areoften required to overcome line-of-sightcommunications restrictions. Cross-countrywire can be laid by helicopter, but speciallytrained and equipped crews are required.

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–FM 90-5

PLANNING ANDCOORDINATION

Jungle battles are normally verydecentralized, but fire support planning andcoordination must be centralized.

Since movement is difficult, fire supportmay be restricted by the inability to quicklymove mortars or artillery so that they canprovide continuous coverage. Advanceplanning and continuous situationmonitoring are necessary to avoid suchdifficulties.

Observed fires are coordinated routinely.Unobserved fires require particular attentionto protect friendly units because of theobserver’s difficulty in accurately locatinghimself and targets. All indirect fires must becoordinated by fire support officers at alllevels. Fire support officers must constantlymonitor the location of supported maneuverunits to be capable of providing rapidclearance when required.

BATTERY DEFENSE

When the enemy situation is vague orsignificant enemy guerrilla activity ispresent, artillery units can be collocated withor provided security by elements of aninfantry battalion. Additional security isneeded because of the artillery’s limitedcapability for self-defense in the face of adetermined enemy attack. The artillery unit’scapabilities will also enhance the maneuverunit’s defense. When the infantry unitprovides security, this permits the battery tofulfill its primary mission of fire support.

The star formation of howitzers isoptimal for all-round defensive coverage.However, due to terrain restrictions, a lazy Wor variation thereof may be utilized.

Additional security in the form of firesupport must be planned for and provided byadjacent artillery and mortar units. Thisadditional fire support should be planned onand around unit positions with both HE and

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FM 90-5

illumination. Once in position, the battery’showitzers, FDC, and TOC form an innerperimeter; the infantry occupies the outerperimeter. Each howitzer will be assigned asector for direct fire. Each howitzer sectionchief will make a range card. It will includedata necessary to engage targets within hisassigned sector.

Each howitzer should have beehive

detonating and time fuzes allocated forbattery defense. Battery defense can beimproved by collocating one 81-mm mortarwith the battery. The mortar can provideclose-in illumination and close indirectfire (within 70 meters of its own position). Assoon as possible, howitzer positions shouldbe parapeted, vital installations dugin, and fighting and sleeping positions

(105-mm only) and/or HE, with point prepared.

SPLIT BATTERY ORPLATOON OPERATIONS

In order to provide artillery coverage to defensive fires. If firing positions are tooseparated maneuver elements, the battery widely separated, mutual support and themay have to operate in a split battery or inplatoon configurations. If split, the firingelements should be located within maximumrange so that both elements can mass fires onthe most important targets. Each firingposition should be laid out so that each guncan support another gun’s position withdirect fire, and so located that other artilleryunits can provide supporting indirect

massing of fires will not be possible.Fractional battery operations have a majordisadvantage of reducing the number ofbattery personnel who can be used for batterydefense. Augmentation with at least aninfantry platoon at each location becomesessential. Separated firing elements shouldbe collocated with a maneuver battalion’sdefensive position. The battery commander

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- F M 9 0 - 5

will probably go where the greatest threatexists or with the larger part of the battery.The executive officer will command the otherelements of the battery. The communicationsassets of the battery will be distributed sothat each element can monitor and transmiton at least two frequencies. For sustainedfractional battery operations, the FDCsection must be augmented with additionalpersonnel. This can be done when batterypersonnel are cross-trained. Split techniquesshould be avoided where possible as theyviolate the critical principle of mass andresult in drastic reductions in effectiveness.

STRONGPOINT

If it is anticipated that a battery will be inone position for an extended period of time,the position should be hardened to offerprotection from direct and indirect fire. Inorder to prepare the position, adequatematerials must be provided, and the batterycommander must work closely with theengineers and the maneuver unitcommander. If possible, a position should beselected near a usable road to facilitate themovement of heavy engineer equipment,supplies, and ammunition to the position.However, if the strongpoint is accessible onlyby air, the time needed to construct thestrongpoint will be greatly increased. Theinitial construction efforts will be directed

toward the construction of a defensibletactical position by nightfall of the first day.

The following must be completedfirst:

■ Fighting positions with overheadcover

■ Howitzer positions with parapets andoverhead cover for ammunition

■ Tactical wire emplaced and Claymoremines positioned

■ FDC and TOC positions dug in withoverhead cover

■ Range cards and defense plans made

The firing unit should occupy theposition in a formation which provides6400-mil coverage and optimal battery de-fense. As the perimeter is expanded, anyvegetation which presents site-to-crest prob-lems must be cleared. As soon as the peri-meter has been improved, construction effortsare centered on the howitzers. Howitzer posi-tions are reinforced with trail logs, erosioncontrol, powder pits, and revetment of theinside and top of the parapet, using logs orammunition boxes and sandbags. Sandbagsalone can be used to parapet the howitzer, inwhich case, 1,500 to 2,000 sandbags for eachparapet are needed.

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FM 90-5-

Larger caliber weapons will requirespecial assistance from supporting engi-neers.

NAVAL GUNFIRE

Naval gunfire, along with close airsupport, is employed in amphibiousoperations prior to the landing of artilleryunits. After maneuver and artillery elementsare established ashore, US Navy ships canprovide reinforcing artillery support injungle areas near the coast. Destroyers orsmaller inshore fire support ships may beable to provide support along large junglerivers.

When a unit is conducting operationswithin range of naval gunfire, a navalgunfire liaison officer will normally belocated in the nearest fire support coordina-tion center. He will arrange for ground andaerial observers for the maneuver units. Ifthese are not available, forward observerscan adjust the ship’s fires. The call-for-fireand adjustment procedures for naval gunfireare basically the same as for artillerysupport. (See FM 6-40 for details.)

NOTE: Naval gunfire provides low trajectory

ordnance. This might be a problem in heavilyforested jungle areas because the projectilemay strike tall trees, detonating prematurely

over friendly troops.

TACTICALAIR SUPPORT

The roles of TACAIR forces are the samein the jungle as elsewhere. In the jungle,where contacts are often unplanned, theseaircraft offer another source of responsivecombat support. Heavily armed fighter-bombers may be able to engage targets closerto friendly troops than can artillery.

are

FORWARD AIR CONTROLLERS

Airborne forward air controllers (FAC)more effective than ground FACs in

densely vegetated areas because they have abroader view of the battlefield. The airborneFAC usually can see the target area better forcontrolling aerial delivery of munitions. Allmeans must be used to mark friendly andenemy locations—smoke, mirrors, andpanels. Fires already being delivered canalso be used to mark targets. As is true withother aerial systems, the air defense threat isa primary consideration when usingairborne FACs.

MUNITIONS

The munitions used vary with the typevegetation and terrain. Unfinned napalmand cluster bomb units may lose much oftheir effect if they detonate in the thickcanopy of primary jungle. Finned napalm, onthe other hand, is more stable and accurateand may be used as close as 160 meters tofriendly troops in more open areas. The “hardbombs” range in size from 250 to 3,000pounds and can be used in primary jungle.The FAC will advise danger-close distances.Another weapon, the 20-mm cannon, can bebrought in as close as 25 meters from troopsunder cover or 200 meters from exposedtroops.

AIRCRAFT

The A-10 aircraft is particularly wellsuited to operate in the jungle. It flies slowenough so that the pilot can see his targets. Itcan also remain in the area for a long time.The A-10 can employ any of the Air Force’sclose air support munitions, and is fitted withthe 30-mm cannon, which is especially wellsuited for ground support. Safetyconsiderations for the 30-mm cannon are thesame as for the 20-mm cannon.

When requesting TACAIR, the requestershould specify the type terrain andvegetation it will be targeted on. This willhelp the Air Force decide what type ofordnance and fuzing to employ.

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—FM 90-5

AIR DEFENSEAND AIR DEFENSE

ARTILLERY

Jungles normally provide good con-cealment from the air. This may reduce airdefense requirements. Thickly vegetatedareas increase the effectiveness of passive airdefense measures, such as camouflage anddispersion. Exposed areas, such as clearings,roads, or river crossings, and facilities wheretroops tend to concentrate, such as supplypoints and headquarters, will require airdefense artillery (ADA) protection.

The jungle affects ADA mobility,maintenance, and communications in thesame way as it affects other combat supportresources. In addition, target acquisition ismore difficult, and radars are less effective.ADA gunners may not be able to see enemyaircraft until they fly over their position.Reaction times will be short, and manyengagements will take place after crossover.

PRIORITY FOR AIR DEFENSE

The jungle concealment afforded tomaneuver forces decreases the likelihoodthat enemy air will attack them. Thus, it ismore likely that air attacks will be directedagainst base complexes, airfields, andlogistical facilities. These areas willnormally receive first priority for air defensein jungle operations.

HAWKS

Hawk battalions will normally beassigned general support missions for thedefense of critical assets, such as basecomplexes, airfields, port facilities, and linesof communications. As much as possible.Hawk coverage will be extended over theareas in which maneuver forces areoperating. To guard against attack by aninfiltrating enemy, Hawk elements may belocated within base complexes. While thisreduces the security problems, it may

sacrifice some of the Hawk’s early engage-ment capability. Radars may have to bemounted on towers or berms to be effective.

CHAPARRAL/VULCANChaparral/Vulcan battalions in the

jungle can be used in a similar manner toHawk battalions. In addition, Vulcans canbe used to protect convoys from both air andground attack. Chaparrals may be pre-positioned to protect traffic at critical points.When used in this manner, Chaparral/Vulcan units in the jungle are normallyattached to the maneuver units they support.Chaparral/Vulcan positions which afford360-degree coverage and long-range fields-of-fire will be hard to find. Chaparral/Vulcanunits may have to clear trees and shrubs tohave adequate firing positions.

REDEYE AND STINGERRedeye and Stinger will cover maneuver

units when they are crossing open areas,such as rice paddies or rivers. Redeye andStinger gunners will also find it hard to findpositions which offer 360-degree coverageand long-range fields of fire, and may alsohave to clear trees and shrubs for adequatefiring positions. These positions should onlybe occupied long enough to fire because theyare easily detected from the air. Redeyes andStingers defending convoys on jungle roadsshould be positioned within and move withthe convoys. Redeyes and Stingers in jungleoperations are normally attached to the unitsthey support.

ENGINEERS

Engineers “open up” the jungle. Roadbuilding and repair; installation, port, andairfield building; and river crossing

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FM 90-5–

operations are continuous tasks for theengineers.

Like most other type supporting units,engineers do their jobs much the same in thejungle as anywhere else. But, also like othertype units, they have special considerationsto deal with.

ROADS

Road construction in the jungle isusually affected by (1) poor drainage andheavy rainfall, and (2) poor subgradefoundation.

These problems can be dealt withby:

■ Avoiding low ground for road con-struction

■ Laying long sections of pontoonbridging, corduroy, or chespaling roadthrough low swampy ground

■ making roads wider, which thins theoverhead foliage, so the sun can getthrough to dry them out

■ Using subgrade materials to supportheavy traffic (See TM 5-330 fordetails.)

AIRFIELDS

Construction of LZs, helipads, andairstrips in remote areas are also importantengineer tasks in the jungle. To accomplishthese tasks, engineers are inserted into thearea to be cleared. Using demolitions andtools, they make an initial clearance of treesand underbrush. For large jobs, follow-onengineers with heavy equipment are broughtin to finish the work.

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—FM 90-5

Another problem is protecting thesurface of these sites from erosion in therainy season, and protecting aircraft fromdust in the dry season. Steel matting, T17membrane (a tough rubberized fabric), orPeneprime (oil surfacing) are all materialswhich will keep the dust down on jungle LZs.

PRIMARY SUPPORT

Engineers support the infantry in thejungle primarily by clearing the way for themovement of friendly forces (mobility) whileimpeding the movement of the enemy(countermobility). Both of these types ofsupport enhance the third area of engineersupport—survivability.

Some specific ways engineers canhelp in all three areas are:

Mobility. Improving or buildinglines of communications and helpingmove troops and supplies acrossbarriers—particularly water obstacles.

Countermobi l i ty . Creat ingobstacles to support the defense;removing them to assist in the offense.

Survivability. Constructingstrongpoints and assisting in theconstruction of other defensivepositions.

It is also essential that the infantrysupport the engineers. Engineers are ex-tremely vulnerable during constructionactivities and need infantry protection to dotheir jobs.

COMBAT SUPPORTCOMPANY lN A

JUNGLE ENVIRONMENT

The infantry battalion has its own directand indirect fire support, reconnaissance/security, and communications section. Their

6-24

effective employment is critical to thecommander’s ability to mass his combatpower against the enemy. All of the battal-ion’s combat support elements except thecommunications platoon are assigned to thecombat support company.

The combat support company com-mander has a unique role in that he:

Is a special staff officer, makingrecommendations on the employment ofhis elements to the battalion commander

Retains command responsibilityfor the platoons and sections of thecompany even though he normally losesoperational control in a tactical environ-ment (He still supports them logisticallyand administratively unless the platoonsor sections are attached to a riflecompany. )

May become the battalion combatbase commander (See battalion combatbase, chapter 5.)

May be used as a maneuverelement commander

The battalion commander mustdetermine how to use the combat supportcompany elements through a thoroughexamination of the battalion’s mission andthe combat support company’s state oftraining. Only then can he select theappropriate role for the combat supportcompany commander and his unit.

If and when the combat supportcompany commander becomes a maneuverelement commander, the commander ofheadquarters and headquarters companymust assume the responsibility ofcommanding the combat base. In addition,soldiersessentialreplacesoldiers.antitank

must be taken from the leastjobs in the battalion trains to

the combat support companyNormally, the scout platoon, theplatoon, and the battalion reserve

FM 90-5—

element would be formed into a maneuverelement.

FUNCTIONS OFTHE SCOUT PLATOON

The mission of the scout platoon is toperform reconnaissance, provide limitedsecurity, and assist in controlling thebattalion’s movement. The scout platoon isnormally employed as a unit under battalioncontrol. However, under certain conditions itmay be attached to another unit or operate asa separate element with an area of operationsof its own. Generally, under all three of theseconditions, it is the primary mission of thescout platoon to find the enemy. In a jungleenvironment it normally performs route,zone, and area reconnaissance. The scoutplatoon has a limited capability to conductsecurity operations, to provide early warningof enemy maneuver, and to deny the enemyinformation concerning the battaliondisposition and movements. The primarysecurity mission for the scout platoon is the

screen. A screen is a series of OPs from whichenemy movement can be observed. Whenvegetation allows good observation, OPs arelocated on high ground and patrols are onlyused for local security around the OP. Whenobservation ranges are very short, the OPsmay have to be moved to the lower areas.Patrols between OPs are required to detectenemy movement. The distances betweenOPs may be extremely long so they must bealert for signs of enemy infiltration.

FUNCTIONS OF THEANTITANK PLATOON

primary mission of the antitankis to destroy enemy tanks. Its

Theplatoonsecondary missions are to engage othervehicles, crew-served weapons, fortifiedpositions, and other point-type targets.Against an enemy with no tanks, or interrain which does not permit the use of long-range antitank weapons, the antitankplatoon may be used as a rifle platoon.

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FM 90-5

CHAPTER 7

Combat Service Support

Section I. GENERAL

Combat service support elements in ajungle environment retain the same basicmissions and capabilities as in otherenvironments. However, they must makeadjustments due to terrain, weather, andvegetation.

Jungle operations subject personnel andequipment to effects not found in otherenvironments. Trafficability and securityproblems, discussed in other chapters, oftenaffect combat service support elements asmuch as maneuver forces.

The lack of an extensive all-weathertransportation network in many jungle areasmakes the mission of support units moredifficult. Transportation difficulties maydictate that maneuver units be resupplied byair, pack animals, or human portage.

US Army forces in the jungle willnormally operate at the end of a long line of

communication. Cargo space must not bewasted on unessential items. Transportationpriority must be given to essential materials,and support areas must not become crowdedwith comfort items.

Jungle combat operations are char-acterized by ambushes and infiltration. Thesecurity threat caused by infiltrators willrequire that lines of communication bepatrolled frequently and convoys be escorted.Consequently, it is essential that combatservice support is performed as far forwardas the tactical situation permits. This notonly improves response time, but reducesroad movement and allows the combatservice support elements to take advantageof the security offered by combat units.

The heat and humidity of jungle areasalso have harmful effects on men andequipment.

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–FM 90-5

Weapons tend to rust quickly, and must Electrical connections corrode quickly.be cleaned and oiled more frequently than inmost other areas. Lenses and dials become quickly fogged

with internal moisture.Canvas items rot and rubber deteriorates

much faster than in more temperate areas. Troops drink more water, requiringgreater water purification and transport

Battery life is shorter than is normal. means.

Section II. LOGISTICS

TRAINS

The variations of terrain, weather, andvegetation in the jungle affect theorganizing, positioning, and securing ofcombat service support.

EFFECTS OF THE JUNGLEON OPERATING THE TRAINS

Organizing the trains is often simplifiedin the jungle. Because of the terrain, aerialresupply will usually be common practice.The responsiveness provided by aerialresupply requires fewer supplies stockpiled inthe combat trains. Thus, combat trainsconsisting of medics, a maintenance element,and small amounts of C rations, ammunition,and lubricants may be the only requirement.The remainder of the logistical assets will be

located in the field trains, to include:petroleum, oils, and lubricants (POL); mostvehicles; stockpiled ammunition and otherordnance items; the aid station; rations;maintenance contact teams; and, whenavailable, water purification facilities.

Trains should be far enough forward torespond quickly to troop needs, yet farenough to the rear to have minimumexposure to the enemy. The jungle offersexcellent sites for concealment, defilade, anddispersion. Since most resupply is done byair, the combat trains may often be lo-cated with the field trains in the brigadetrains area. Thus, they can be a greaterdistance to the rear than normal. All trainsshould be located near LZs. Field,

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FM 90-5

combat, and company trains should also belocated close to a road, river, or trail whichmay be used as an alternate method ofresupply. If none of these are available, LZsand supply routes may have to beconstructed.

Securing the trains area is a majorproblem in the jungle. Infiltration of enemyunits into rear areas is highly probable. Inthe defense, the trains should be locatedwithin a reserve unit defensive perimeter(see IV, chap 5). In the offense, the trainspersonnel normally have to provide theirown security. If other forces are available—for example, the reserve—they are integratedinto this security plan.

Frequent displacement of the trains isoften required, either to evade enemyinfiltration or to keep up with combatelements. The combat trains usually movewith the combat elements when theydisplace. They can move independently ofthe forward combat elements if a unit isprovided to secure them. The field trains willnormally displace when the brigade trainsdisplace.

RESUPPLYING UNITSAirlift is key to jungle resupply opera-

tions to include movement of supplies toattacking or defending units. Returning air-craft should be used to evacuate casualties.

Since the combat trains in a jungleenvironment are smaller yet less mobile thanin more open terrain, most of the class III(POL) and V (ammunition) will be stocked inthe field trains. The helicopter can providetimely resupply when ammunition, POL,etc., are not stored in the combat trains.These supplies can often be moved morequickly by air (helicopter or airdropped byparachute) from the field trains thanoverland from combat trains. The normalmethod in the jungle is to deliver suppliesdirectly to forward companies (unit dis-tribution).

SECURITY OFSUPPLY ROUTES

A special security problem exists whensupplies are not moved by air. Enemyambushes and mines are a constant threat onground supply routes. The following actionsmay be taken to minimize the threat tosupply routes.

Commanders should locate fire sup-port elements, command posts, and defen-sive positions near supply routes. Sub-ordinate units can then conduct clearing androute security operations. Each unit shouldbe given an area to clear and secure.Maneuver units should operate on the flanksof the route to guard against ambush.

7-3

—FM 90-5

Infantry, armor, and engineer elementscan organize mine-clearing teams whichmethodically search for and clear mines,bodytraps, and roadblocks. Engineers withmine detectors and probes sweep the road.The infantry and tanks provide securityagainst ambush. Any mines detected aremarked and either deactivated or blown inplace.

Working behind the mine-clearingteams, dump trucks fill holes in the road withgravel. Other engineer teams replaceculverts, repair bridges and streamcrossings, and clear vegetation back from theedge of the road.

The road-clearing process is repeatedeach morning before traffic starts to move.The enemy may replace removed minesduring the night.

Security against ambush and attack isprovided mainly by patrols to either flank ofthe route to discover enemy forces before theycan get into position to launch an ambush.These patrols should range as far out aspossible to reduce the danger of the mainbody being ambushed. Routes should bepatrolled at irregular intervals throughoutthe day and night.

Clearing the vegetation back from theroad’s edge will also help to prevent ambush,but may be a very large undertaking. It alsoincreases the enemy’s difficulty of miningthe road, and facilitates friendly aerialobservation and airmobile operations alongthe road.

Airborne artillery observers, forward aircontrollers, attack helicopters, and aircavalry reconnaissance increase the securityby flying reconnaissance and surveillancemissions.

At night, counterambush patrols shouldbe sent out. Scout dogs are very useful tothese patrols in detecting the enemy.

7-4

As additional security on the supply route,STANO devices should be emplaced to detectenemy movement at critical points along theroute.

Bridges are vulnerable links in anysupply route. They must be protected. A staticsecurity post may be required to secure thebridge against attack by guerrillas orinfiltrators. Static security posts are bestorganized in a perimeter defense. The size ofthe defending force depends on the mission,the size and characteristics of the hostileforce, and the importance of the bridge to themission. Such posts in remote areas will belarger than those nearer supporting forces.The parent unit must be prepared tocounterattack with reserves to assist eachpost.

It will usually be necessary to formarmed convoys, escorted by armed vehiclesfrom a military police, cavalry, or maneuverunit. At least one helicopter should fly aheadof the main body to give early warning ofambushes or evidence of hasty mining and provide additional communicationscapability. On-call fires should be planned onlikely ambush sites. Convoys should not bescheduled at regular intervals.

If ambushed, the escort vehicles shouldimmediately return fire. The cargo vehiclesshould be moved out of the kill zone asrapidly as possible. Attack helicopters andtrailing combat vehicles can then maneuverto destroy the ambush.

CLASSES OFS U P P L Y

CLASS I(SUBSISTENCE ITEMS)

Nonperishable canned, dried, ordehydrated items primarily should be usedwhen the unit is not actively engaged incombat. This requires kitchen facilities,except for refrigeration. Rations (individual

FM 90-5—

combat meal, long-range patrol, or smalldetachment rations) normally will be issuedto units actively engaged in combat. Thenumber of rations earned by the individualsoldier should be determined by such factorsas weight, how and in what quantities foodcan be brought forward, when resupply willbe conducted, and the estimated duration ofthe operation. Hot meals should be servedwhen the combat situation allows. Theseshould be prepared in the field trains and de-livered by helicopter. Feeding is usuallyaccomplished during the day because of thedanger and difficulty of movement at nightand the possibility of enemy ambush or nightattack.

CLASS II(INDIVIDUAL EQUIPMENTAND GENERAL SUPPLIES)

In a tropical environment, rapiddeterioration is a primary consideration inclass II supply. Issue clothing, particularlycombat boots and socks, lasts a very shorttime. Normal wear and tear on clothing mayrequire a resupply every 5 to 6 days. Class IIresupply can be a major morale builder. ClassII requirements should be estimated well inadvance and special provisions should bemade for timely resupply. At battalion level,limited emergency supplies of assortedcombat boots, socks, uniforms, and similaritems of short wear periods should be stockedin the field trains.

CLASS III (POL)

The supply of class III items does notinitially present a great problem, asrelatively few vehicles will be forward duringthe operation. However, aviation fuel will berequired in large amounts. Units mustestablish class III distribution points forvehicles and aircraft, as required, in the fieldtrains. Tank trucks will be used as farforward as possible. Collapsible fuel drumscan be brought forward by helicopter. Units

must take care to insure that diesel and motorgasoline fuel drums are available andmarked. When circumstances permit the useof tracked vehicles, planning must includeadditional POL since tracked vehiclesnormally have a high fuel consumption ratewhen operating in rugged terrain. Additionallubricants for weapons will also be requireddue to the greater requirement for cleaningand protection.

CLASS IV(CONSTRUCTION MATERIALS)

Barrier material and special equipmentis extremely bulky and heavy. The use oflarge amounts of it for defensive positionswill create transportation problems. Heavylift helicopters are the most practical meansto move these items.

CLASS V(AMMUNITION)

Because of weight and bulk involved,resupply of ammunition and explosivespresents a difficult problem. The nature ofthe terrain and climate in the junglemagnifies the problems in ammunitionstorage. Steep terrain should be avoidedwhen selecting suitable sites for storage.Level, firm ground may become too soft inheavy rain. Rain and intense heat combine tospeed the deterioration of containers andammunition, especially if it is taken out of thepacking material. To counteract theseconditions, adequate dunnage, shelter, andventilation must be used. Ammunition in thefield trains should be left in packingmaterials until ready for use. Frequentchecks should be made for deterioration ofpacking material.

When the ammunition is unpacked andtaken to the field, it is more susceptible torain, heat, and humidity. Therefore, as ageneral rule, ammunition which is not usedwithin two weeks should be exchanged fornew ammunition. While in the field, however,

7-5

-FM90-5

CLASS IX(REPAIR PARTS)

measures must be taken so that ammunitionis never exposed needlessly to the weather. Itshould be carried in ammunition pouches orcontainers and protected when stored inpositions.

CLASS VI(PERSONAL DEMAND ITEMS)

Such items as soap, cigarettes, candy,etc., are important morale builders. Theyshould be supplied on a regular basis.

CLASS VII(MAJOR END ITEMS)

Storage areas must be designed toprotect these items from the jungleenvironment. Weapons, vehicles, and otheritems in storage must be inspected morefrequently than in other environments.Protective lubricants must be maintained onall surfaces that can rust.

Operational readiness of all storedequipment must be insured by frequentinspections and maintenance. Commandersshould turn in those items for which theyhave no need in the jungle. When major enditems are not in use, they are stored ormaintained in rear areas.

CLASS VIII(MEDICAL SUPPLIES)

Because the heat and high humidity cancause deterioration of certain medicalmaterials and medicines (for example,penicillin, hydrocortisone liquids, sulfaliquids), frequent resupply and replacementof these items may be required. There willalso be a priority need for refrigerationequipment to store class VIII supplies. Therewill be an increased requirement forantiseptic material because the high heatand humidity increase the incidence ofinfection in wounds.

Equipment parts that deteriorate or wearout faster in the jungle environment must bedetermined. Prescribed load list (PLL) mustreflect the increased turnover of these parts.

CLASS X(NONMILITARY ITEMS)

These items, for example, agriculturaltools and equipment, are not required for theconduct of conventional combat operationsin the jungle; however, they are veryimportant in the conduct of civil-militaryoperations. These items should not bestocked unless a unit is actively participatingin a civil-military operation.

OTHER SUPPLIESMaps exposed to humid jungle air

quickly deteriorate. A greater stockage ofmaps will be required than in otherenvironments.

Water is critical in the jungle. Water must be obtained from the divisional waterpoints using battalion transportation orpurified by units themselves in the field.There is a greater demand for waterpurification tablets and water points. Unitsshould also carry a greater number of lysterbags and other water containers. Closesupervision should be exercised to insure thatsoldiers do not drink unpurified water.

The lack of suitable landing zones makeswater resupply extremely difficult if the air-craft cannot land. Numerous techniqueshave been tried in dropping water throughthe jungle canopy, for example, free drop,parachute. However, they have met with onlylimited success and for the most part are im-practical. The following water resupplytechnique has proven to be extremelysuccessful. Water should be placed in eithercollapsible 5-gallon containers or in 2-quartcontainers. These containers should beplaced inside lightweight, portable

7-6

FM 90-5-

containers, that is, rucksacks or duffel bags,which a soldier can quickly move off the DZ.No more than 10 gallons of water (80 pounds)should be placed in each bag for lowering.The bags will be lowered from a helicopter byuse of the equipment belay system.

transportation facilities are poor in mostjungle areas and cannot handle heavymilitary traffic without extensive im-provements. An air line of communicationcan eliminate many of the problems as-sociated with surface movement.

Equipment needed for platoon-sizeelement to supply water by helicopter,using collapsible containers and theEquipment Belay System:

Two 120-foot climbing ropes.

Eleven snap links.

Three 12-foot utility ropes (slingropes).

One doughnut ring or similaranchoring device.

One rappel D-bag.

Eight 5-gallon containers and fourduffel bags.

MAINTENANCEMaintenance organizations function

essentially the same as in other operations.The high humidity and temperatureprevalent in jungle areas will increasemaintenance requirements. Preventivemaintenance on any item affected bymoisture and heat is extremely important.Emphasis must be placed on on-sitemaintenance and the use of aircraft totransport maintenance contact teams andrepair parts to unit level. To respond to theneed for responsive maintenance support,the number of repair parts for immediatedirect exchange must be increased.

TRANSPORTATIONUnits fighting in the jungle should

consider all types of transportation. Surface

HUMAN PORTAGE

This is a basic means of moving suppliesand equipment in jungle operations. At best,this method is slow, laborious, andinefficient. Yet, in certain extreme situations,it may be the only method available.

WHEELED AND TRACKEDVEHICLES

Wheeled vehicles are normally restrictedto roads and wider trails, and even these mayprove impassable during heavy rains.Sometimes, goods must be transported bycross loading from wheeled to trackedvehicles. For example, large wheeled vehiclesmove the supplies as far forward as possible,where they are transloaded to trackedvehicles which move them cross-country. Inrugged terrain, the supplies may have to befurther transloaded to pack animals ornative supply bearers.

7-7

–FM 90-5

INLAND WATERWAYS

These channels are a very importantpart of a transport system, especially inremote areas. Large rivers often allow smallships and large boats to penetrate severalhundred miles inland. Where smallerstreams branch out, a unit may establishtransfer points for the transloading of cargointo smaller watercraft. A river that isnormally very shallow during the dry seasonwill be deeper during the rainy season,permitting travel by larger craft.

A unit should establish supply pointshigh enough above the level of the water toprevent damage in the event of flash flood.

FIXED-WING TRANSPORTAIRCRAFT

These aircraft can usually operate atgreater distances without refueling thancargo helicopters. However, use of fixed-wingaircraft to airland supplies requires morelanding strips than may be present.Construction and maintenance of airfields injungles is a difficult engineer task, but opensavanna may be large enough and firmenough to use as an airstrip.

Airdrop of supplies is an alternative toairlanding Airdrop by parachute is a rapidmeans of delivery and makes deliveries toisolated units possible without furthertransloading.

Disadvantages include the dispersion ofsupplies and the possibility of lost cargo inthe jungle canopy, vulnerability to localenemy air defense, and requirement for atleast local friendly air superiority.

A variation of airdrop by parachute is thelow altitude parachute extraction system(LAPES). The parachute is used to pull theload from the rear ramp of an aircraft flyingat a reduced speed just a few feet off theground. LAPES solves dispersion and treehangup problems, allowing use of the smallerdrop zones more common in jungle areas.However, fragile equipment might notsurvive this type of drop. In areas where theaircraft can make a low-level approach, suchas savannas, LAPES may be a valuableresupply technique. It is used with C-130aircraft only.

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FM 90-5-

The container parachute delivery systemprovides single pass delivery of from 1 to 16individually rigged A-21 containers into asmall drop zone (DZ) at altitudes of 500 to 600feet.

When using this system, selection of aDZ is critical to accurate delivery of thebundles. The nature of jungle terrain and thesmall DZs do not allow for accurate deliveryof bundles. The DZ must be at least a 400-meter by 400-meter area. A straight stretch ofroad or a large field visible from the air maybe used. If an open ground area cannot belocated, the next step is to try to make thedrop in a river, lake, or ocean. If dropped inthe water, bundles must be rigged withadequate buoyancy (empty water cans will

preplanned and executed immediately uponcompletion of the drop.

Another method which can be used forsmall loads of some sturdy types of suppliesand equipment is the free drop. Here, the loadis simply dropped, without parachute, from alow-flying aircraft.

Helicopters are very effective in thistechnique because they can hover low over aunit and drop the supplies exactly wheredesired. Because helicopters are vulnerableto small-arms fire, however, the unit on theground must take adequate securitymeasures. It should establish a perimeterdefense around the area over which thehelicopter will hover, and it should conductpatrols prior to the resupply to insure that the

do). Recovery of the - bundles must be - surrounding area is cleared of enemy.

MEDICALO P E R A T I O N S

Medical support in jungle operations terrain and vegetation. The manner in whichfollows the basic principles of military medical units support tactical operations willmedicine, but medical treatment and depend on the employment of the supportedevacuation will often be complicated by the unit and the type of jungle in which they areextended distances and inaccessibility due to operating. The relatively high incidence of

7-9

–FM 90-5

disability caused by heat, humidity, andinsect-borne diseases will require increasedemphasis on health and sanitationmeasures.

The evacuation of wounded in junglewarfare presents numerous problems.Because of the prevalence of rapidlydebilitating tropical diseases and thelikelihood of quick infection of wounds in thejungle, speedy evacuation is vital. Unitsmust use all available methods to augmentorganic medical evacuation means. Thesemay include tracked vehicles, pack animals,watercraft, helicopters, and litter bearers.Ground medical evacuation in the jungle willnormally be along supply routes, as they areusually given all possible protection from theenemy.

The difficulties of overland medicalevacuation in jungle operations emphasizethe advantages of air evacuation. Whenweather, aircraft availability, and friendlyair superiority permit their use, helicopters

transportation for casualties. The reductionof time between injury and treatmentincreases the chance of survival and raisesmorale. A helicopter equipped with a cablehoist system can evacuate casualties fromthick jungle vegetation where no landingzones are available.

In some remote and densely foliagedjungles, the only means of evacuation maybeby litter. This is a slow and exhausting taskrequiring well-conditioned soldiers to carrythe litters. At best, litter teams can carry

provide fast, comfortabe, and efficient

patients only a fewrough jungle terrainrelief.

There are severalrugged terrain, thebasket litter offers

hundred meters overbefore needing rest or

types of litters. In verymountain-type metalmost security to the

patient. However, it is bulky to carry evenduring normal operations. The standardfolding litter or field expedient variationsmade of cloth and poles are less bulky and getthe job done just as well if patients are movedwith great care.

Litter hauls should be as short aspossible. Medical facilities should be as closeas practicable to the troops.

P E R S O N N E LMA NAGEMENT

C O N S I D E R A T I O N S

REPLACEMENTS

The jungle may appear as a fearsomeplace to the uninitiated. Individualreplacements may doubt their ability to copewith tropical diseases; heat; oppressivehumidity; entangling close vegetation; theconstant threat of ambush and close combat;wildlife; and periodic isolation from supportelements. Commanders must realize that these are natural fears and must provide aperiod for acclimation and psychologicaladjustment. All new arrivals must receive acomplete orientation on the unit, its mission,and the enemy, and be trained in the routinesof jungle living, working, and fighting.

GRAVE REGISTRATION

Direct support for the recovery,identification, and evacuation of deceasedpersonnel will normally be available in thejungle. However, the hot and humid climatepresents special problems, and it isimportant that the remains of the dead beremoved rapidly to prevent theirdeterioration. This may have profound effecton troop morale. Hasty burials should beconducted as a last resort. Grave sites shouldbe marked clearly and reported.

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FM 90-5

APPENDIX A

R e f e r e n c e s

FIELD MANUALS (FM)

3-10

5-15

5-20

5-31

5-36

6-20 (HTF)

6-40

6-50

7-7 (HTF)

7-8 (HTF)

7-10 (HTF)

7-20 (HTF)

8-35

19-40

20-12

20-32

20-33

21-10

21-11

21-20

21-26

21-30

Employment of Chemical Agents

Field Fortifications

Camouflage

Boobytraps (U)

Route Reconnaissance and Classification

Fire Support in Combined Arms Operations

Field Artillery Cannon Gunnery

The Field Artillery Cannon Battery

The Mechanized Infantry Platoon and Squad

The Infantry Platoon and Squad (Infantry, Airborne, AirAssault, Ranger)

The Infantry Rifle Company

The Infantry Battalion (Infantry, Airborne, Air Assault,Ranger)

Evacuation of the Sick and Wounded

Enemy Prisoners of War, Civilian Internees, and DetainedPersons

Amphibious Embarkation

Mine/Countermine Operations

Combat Flame Operations

Field Hygiene and Sanitation

First Aid for Soldiers

Physical Readiness Training

Map Reading

Military Symbols

at the Company Level

A-1

– FM 90-5

21-31

21-40

21-60

21-75

21-76

23-9

23-90

24-18

24-20

24-21

29-51

30-5

30-10

44-1 (HTF)

44-3 (HTF)

57-38

71-1 (HTF)

71-2 (HTF)

90-2 (HTF)

90-4 (HTF)

90-6 (HTF)

Topographic Symbols

NBC (Nuclear, Biological, and Chemical) Defense

Visual Signals

Combat Training of the Individual Soldier and Patrolling

Survival, Evasion, and Escape Manual

M16A1 Rifle and Rifle Marksmanship

81-mm Mortar

Field Radio Techniques

Field Wire and Field Cable Techniques

Tactical Multichannel Radio Communications Techniques

Division Supply and Field Service Operations

Combat Intelligence

Military Geographical Intelligence (Terrain)

US Army Air Defense Artillery Employment

Air Defense Artillery Employment: Chaparral/Vulcan

Pathfinder Operations

Tank and Mechanized Infantry Company Team

The Tank and Mechanized Infantry Battalion Task Force

Tactical Deception

Airmobile Operations

Mountain Operations

90-10(HTF)

Military Operations on Urbanized Terrain (MOUT)

90-13(HTF)

River Crossing Operations

100-5(HTF)

Operations

100-20 Low Intensity Conflict

A-2

FM 90-5-

TECHNICAL MANUALS (TM)

3-240

5-277

5-312

9 - 1 3 0 0 - 2 0 5

10-1670-262-12_

11-666

Field Behavior of Chemical, Biological, and RadiologicalAgents

Bailey Bridge

Military Fixed Bridges

Ammunition and Explosive Standards

Operator’s and Organizational Maintenance Manual(Including Repair Parts and Special Tool Lists) forPersonnel Stabo Extraction System and Cargo andPersonnel Lowering Device

Antennas and Radio Propagation

A-3

FM 90-5

APPENDIX B

N a v i g a t i o n a n d T r a c k i n g

S e c t i o n I . G E N E R A L

This appendix assumes that the reader jects, the reader should refer to FM 21-26.already knows the basics of map reading andland navigation. For a review of these sub-

S e c t i o n I I . J U N G L E N A V I G A T I O N

Navigating in the jungle can be difficultfor those troops not accustomed to it. Thisappendix outlines techniques which havebeen used successfully in jungle navigation.With training and practice, troops should beable to use these techniques to navigate ineven the thickest jungle.

NAVIGATION TOOLS

MAPS

Because of the isolation of many jungles,the rugged ground, and the presence of the

canopy, topographic survey is difficult and isdone mainly from the air. Therefore,although maps of jungle areas generallydepict the larger features (hill, ridges, largerstreams, etc.) fairly accurately, some smallerterrain features (gullies, small or intermit-tent streams, small swamps, etc.), which areactually on the ground, may not appear onthe map. Also, many older maps are inac-curate. So, before going into the jungle,commanders and staff should bring theirmaps up to date.

B-1

– FM 90-5

COMPASS

No one should move in the jungle withouta compass. It should be tied to the clothing bya string or bootlace. The three most commonmethods used to follow the readings of acompass are:

Sighting along the desired azimuth. Thecompass man notes an object to the front(usually a tree or bush) that is on line with theproper azimuth and moves to that object.This is not a good method in the jungle astrees and bushes tend to look very muchalike.

Holding the compass at waist level andwalking in the direction of a setazimuth. This is a good method for thejungle. The compass man sets the compassfor night use with the long luminous lineplaced over the luminous north arrow and thedesired azimuth under the black index line.There is a natural tendency to drift either leftor right using this method. Jungle navi-gators must learn their own tendencies andallow for this drift.

Sighting along the desired azimuth andguiding a man forward until he is on linewith the azimuth. The unit then moves tothe man and repeats the process. This is themost accurate method to use in the jungleduring daylight hours, but it is slow. In thismethod, the compass man cannot mistakethe aiming point and is free to release thecompass on its string and use both handsduring movement to the next aiming point.

The keys to navigation are maintainingthe right direction and knowing the distancetraveled. Skill with the compass (acquiredthrough practice) takes care of the firstrequirement. Ways of knowing the distancetraveled include checking natural featureswith the map, knowing the rate of movement,and pacing.

CHECKING FEATURES

Major recognizable features (hills, rivers,changes in the type of vegetation) should benoted as they are reached and then identifiedon the map. Jungle navigators must BECAUTIOUS ABOUT TRAILS—the trail onthe ground may not be the one on the map.

RATE OF MOVEMENT

Speed will vary with the physicalcondition of the troops, the load they carry,the danger of enemy contact, and the typeof jungle growth. The normal error is tooverestimate the distance traveled. Thefollowing can be used as a rough guide to themaximum distance covered in 1 hour duringdaylight.

lDAYLIGHT MOVEMENT

lMAXIMUM

TYPE TERRAIN DISTANCE(in metersper hour)

TROPICAL RAIN 1,000FOREST

DECIDUOUS FOR- 500EST, SECONDARYJUNGLE, TALLGRASS

SWAMPS 100 TO 300

RICE PADDIES 800(WET)

RICE PADDIES 2,000(DRY)

PLANTATIONS 2,000

TRAILS 1,500

PACING

In thick jungle, this is the best way ofmeasuring distance. It is the only method

B-2

FM 90-5-

which lets the soldier know how far he has accurate, soldiers must practice pacing overtraveled. With this information, he can different types of terrain. Each soldier shouldestimate where he is at any given time- make a PERSONAL PACE TABLE like thissomething that must be known to call for o n e -indirect fire support in a hurry. To be

At least two men in each independent company commander in matters of naviga-group should be compass men, and three or tion. When in doubt, the commander shouldfour should be keeping a pace count. The do a resection, using artillery marking roundsartillery fire support team (FIST) chief as outlined in FM 21-26, paragraph 10.should keep an accurate fix on his location,as should the platoon forward observers NOTE: Jungle foliage will often require that(FO). He can be a great help to the rifle artillery marking rounds be sensed by sound.

B-3

- FM 90-5

To locate a position by resection, thegeneral location must be known. Whitephosphorus rounds (airbursts) are thencalled on two widely separated grids whichare not on terrain features like the one theunit is occupying and which are a safedistance from the estimated location. A backazimuth to each of these rounds is taken andplotted on the map. The point where theyintersect is the observer’s approximatelocation.

LOCATION OFAN OBJECTIVE

In open terrain, an error in navigationcan be easily corrected by orienting onterrain features which are often visible froma long distance. In thick jungle, however, it ispossible to be within 50 meters of a terrainfeature and still not see it. Here are twomethods which can aid in navigation.

OFFSET METHOD

This method is useful in reaching anobjective that is not large or not on readilyidentifiable terrain but is on a linear feature,such as a road, stream, or ridge. The unitplans a route following an azimuth which is afew degrees to the left or right of the objective.The unit then follows the azimuth to thatterrain feature. Thus, when the unit reachesthe terrain feature, the members know theobjective is to their right or left, and theterrain feature provides a point of referencefor movement to the objective.

ATTACK METHOD

This method is used when moving to anobjective not on a linear feature. An easilyrecognizable terrain feature is chosen asclose as possible to the objective. The unitthen moves to that feature. Once there, theunit follows the proper azimuth and movesthe estimated distance to get to the objective.

B-4

F M 9 0 - 5 -

WHAT TO DO IF LOST

Do not panic. Few soldiers have everbeen permanently lost in the jungle,although many have taken longer to reachtheir destination than they should.

Disoriented navigators should try toanswer these questions. (If there are othernavigators in the group, they all should talkit over.)

What was the last known location?

Did the unit go too far and pass theobjective? (They should compare estimates oftime and distance traveled.)

Does the terrain look the way itshould? (They should compare thesurroundings with the map.)

What features in the area will help tofix the unit’s location? (They should try tofind these features.)

If the unit is unable to locate itselfusing these techniques, the leader can call foran air or artillery orienting round. However,this may cause a loss of security, particularlyif the unit is moving by stealth.

An airspot can usually be obtained fromArmy or Air Force aircraft. The pilot can becontacted and guided to the general locationby radio. A mirror, smoke, panels, or someother signal can be shown to the pilot. He willbe able to determine the unit’s location andreport it to them.

This, also, is a loss of security and shouldonly be a last resort.

NIGHT MOVEMENT

The principles for navigation at nightare the same as those for day movement. Theproblem in night movement is one of control,not navigation. In clear weather, throughsparse vegetation and under a bright moon, aunit can move almost as fast by night as byday. If the sky is overcast, vegetation is thick,

or there is little or no moon, movement will beslow and hard to control. The followingpoints can assist a unit during nightmovement.

Attach luminous tape to the back of eachsoldier’s headgear. Two strips, side by side,each about the size of a lieutenant’s bar, arerecommended. The two strips aid depthperception and reduce the hypnotic effectthat one strip can cause.

When there is no light at all, distancebetween soldiers should be reduced. Whennecessary to prevent breaks in contact, eachsoldier should hold on to the belt or the packof the man in front of him.

The leading man should carry a longstick to probe for sudden dropoffs orobstacles.

In limited visibility conditions, listeningmay become more important to security thanobserving. A unit which hears a strangenoise should halt and listen for at least 1minute. If the noise is repeated or cannot beidentified, patrols should be sent out toinvestigate. Smell, likewise, can be anindication of enemy presence in an area.

All available night vision devices shouldbe used.

NAVIGATIONAL TIPS

Trust the map and compass, butunderstand the map’s possible short-comings. Use the compass bezel ring,especially during night navigation.

Break brush. Do not move on trails orroads.

Plan the move, and use the plan.

Do not get frustrated. If in doubt, stopand think back over the route.Practice leads to confidence.

B-5

- FM 90-5

Sect ion I I I . TRACKING

Visual tracking is following the paths of Tracking is important in coun- men or animals by the signs they leave, terguerrills operations where it is oftenprimarily on the ground or vegetation. Scent difficult to locate the enemy. Guerrillas whotracking is following men or animals by the conduct raids and ambushes will normallyodors they leave. return to their bases as quickly as possible.

Well-developed tracking skills will help unitsPractice in tracking is required to to maintain contact with the enemy.

achieve and maintain a high standard ofskill. Because of the excellent natural con-cealment the jungle offers, all soldiers should SIGNSbe familiar with the general techniques ofvisual tracking to enable them to detect the Men or animals moving through junglepresence of a concealed enemy, to follow the areas leave signs of their passage.enemy, to locate and avoid mines or booby- Some examples of these signs aretraps, and to give early warning of ambush. listed below.

TRACKING POINTS

SAVANNA ROCKY GROUND

NOTE:If the grass is high, above 3 feet, Small stones and rocks are movedtrails are easy to follow because the aside or rolled over when walked on. Thegrass is knocked down and normally soil is also disturbed, leaving a distinctstays down for several days. If the grass variation in color and an impression. Ifis short, it springs back in a shorter the soil is wet, the underside of thelength of time. stones will be much darker in color than

Grass that is tramped down will the top when moved.

point in the direction that the person or If the stone is brittle, it will chipanimal is traveling.

Grass will show a contrast in colorand crumble when walked on. A lightpatch will appear where the stone is

with the surrounding undergrowth when broken and the chips normally remainpressed down. near the broken stone.

If the grass is wet with dew, the Stones on a loose or soft surfacemissing dew will show a trail where aperson or an animal has traveled.

are pressed into the ground when walked

Mud or soil from boots mayupon. This leaves either a ridge aroundthe edge of the stone where it has forced

appear on some of the grass. the dirt out, ora hole where the stone has

If new vegetation is showing been pushed below the surface of the

through a track, the track is old. ground.

In very short grass (12 inches or Where moss is growing on rocksless) a boot will damage the grass near or stones, a boot or hand will scrape offthe ground and a footprint can be found. some of the moss.

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FM 90-5—

TRACKING POINTS CONTINUED

PRIMARY JUNGLES SECONDARY JUNGLE

NOTE: Within rain forests and deciduous Broken branches and twigs.forests, there are many ways to track.This terrain includes undergrowth, live Leaves knocked off bushes and

and dead leaves and trees, streams with trees.

muddy or sandy banks, and moss on the Branches bent in the direction offorest floor and on rocks, which makes travel.tracking easier.

Disturbed leaves on the forest Footprints.floor, when wet, show up a darker color Tunnels made through vegetation.when disturbed.

Dead leaves are brittle and will Broken spiderwebs.

crack or break under pressure of a person Pieces of clothing caught on thewalking on them. The same is true of dry sharp edges of bushes.twigs.

Where the undergrowth is thick,especially on the edges of the forest,green leaves of the bushes that have RIVERS, STREAMS,been pushed aside and twisted will show MARSHES, AND SWAMPSthe underside of the leaf—this side islighter in color than the upper surface. To Footprints on the banks and infind this sort of trail, the tracker mustlook through the jungle instead of

shallow water.

directly at it. Mud stirred up and discoloring the

Boot impressions may be left onwater.

fallen and rotting trees. Rocks splashed with water in a

Marks may be left on the sides ofquietly running stream.

logs lying across the path. Water on the ground at a point of

Roots running across a path may exit.

show signs that something has moved Mud on grass or other vegetationthrough the area. near the edge of the water.

Broken spiderwebs across a pathindicate that something has movedthrough the area.

D E C E P T I O NThe enemy may use any of the following

methods to deceive or discourage trackers.They may, at times, mislead an experiencedtracker.

B-7

- FM 90-5

These deceptions include:

Walking backwards. The heel marktends to be deeper than that of the ballof the foot. The pace is shorter.

More than one person stepping in thesame tracks.

Walking in streams.

Splitting up into small groups.

Walking along fallen trees or steppingfrom rock to rock.

Covering tracks with leaves.

B-8

FM 90-5

APPENDIX C

J u n g l e O b s t a c l e s

Sect ion I . GENERAL

Units operating in the jungle will have to land. This appendix covers the skills requiredcross many obstacles. The most difficult to perform these tasks.obstacles will be streams and cliffs. Inaddition, units operating in the jungle will Before learning these skills, however,frequently have to insert or extract soldiers soldiers must be familiar with ropes andand units in places where helicopters cannot knots.

S e c t i o n I I . C H A R A C T E R I S T I C S A N D U S EO F E Q U I P M E N T

ROPES AND KNOTS

TYPES OF ROPE

Nylon. Nylon rope is most commonly used inclimbing and rappelling. The rope is seven-sixteenths of an inch in diameter and isissued in 120-foot lengths. Its dry breakingstrength averages 3,840 pounds (plus orminus 5 percent). Strength is reduced byabout 20 percent when the rope is wet. It willalso stretch about one-third of its lengthwhen wet. Nylon sling (utility) ropes arecommonly prepared by a unit in 12-footlengths from older ropes that are no longer

Vegetable Fiber. This is readily availablein jungle areas as it is made primarily fromthe fibers of tropical plants.

Manila rope is made from the fibers ofthe leaves of a banana tree. The lighter thecolor of the rope, the better the quality. Thisrope is superior to nylon rope for suspensiontraverses and rope bridges because it does notstretch as much as nylon, and it is not

used for climbing or rappelling. weakened when wet.

SECTION CONTENTS PAGE

I General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

Il. Characteristics and Use of Equipment . . . . . . . . . . . . . .C-l

Ill. Moving Down Hills and Cliffs. . . . . . . . . . . . . . . . . . . . . . . . . . . .. C-4

IV Moving by Helicopter. . . . . . . . . . . . . . . . C-6

V. Moving Across Water Obstacles . . . . . . . . . . . . . . . .C-13

C-1

–FM 90-5

The breaking strength and safe loadcapacity (respectively) for the sizes ofmanila rope most often used by jungletroops are:

1 -inch-diameter rope-9,000 pounds/2,250 pounds

1 /2-inch-diameter rope-3,650 pounds/660 pounds

Hemp rope is made from the fibers of thehemp plant. This is the strongest of the fiberropes. It is usually soaked in tar to preservethe rope from damage caused by dampness,but this tar tends to reduce the rope’sstrength. Also, because of its greater weight,tarred hemp is not practical for use byinfantry troops.

NOTE: The breaking strength of a rope isalways greater than its safe working capacity.The difference is a “safety factor. ” Individualropes can vary greatly in minimum breakingstrength. Even though a rope may not breakunder this load, the fibers are stretchedbeyond their elastic limit. Thereafter thestrength of the rope is permanently reduced.Exposure, wear, use, and bending decrease arope’s strength over a period of time. Thisshould be allowed for in estimating thestrength of a used rope. The strength of a ropethat is slung over a hook or contains a knot isreduced by about 30 percent; sharp bendsover corners will cut strength by 50 percent;sand or grit between the fibers will quickly cutthe fibers, and sharply drop the overallstrength of the rope.

CARE OF A ROPE

Clean a muddy rope by washing it inwater, but not in salt water.

Do not pull a rope oversharp edges. Placelayers of heavy cloth or grass between therope and any sharp edge to prevent thecutting of fibers.

Do not drag a rope through sand and dirt,or step on it, or drive over it.

Keep a rope dry. If it gets wet, dry it assoon as possible to prevent rotting. (Amildewed rope will have a musty odor andinner fibers will have a dark, stained look.)

Do not leave a rope knotted or tightlystretched any longer than needed.

Never splice a climbing or rappellingrope.

Inspect a rope often, both the outside andthe inside. Untwist a few strands at different points to open the rope to check the inside.

Melted nylon and dark streaks indicateburns. Nylon rope burns when it rubs againstother nylon ropes. Nylon ropes should neverbe tied in such away that there is rope-to-ropefriction.

Dirt and sawdust-like material inside therope indicates damage.

A rope should be checked at a number ofdifferent places—any weak point in itweakens the entire rope.

Whenever any unsafe conditions arefound in a rope, it should be destroyed or cutup in short pieces. This w-ill prevent use of therope for hoisting. The short pieces can beused for toggle ropes and for other purposeswhich do not involve load bearingoperations.

C-2

FM 90-5-

c-3

—FM 90-5

Section III . MOVING DOWNH I L L S A N D C L I F F S

R A P P E L L I N G

Rappelling is a means to move quicklydown very steep hills and cliffs. Rappellinginvolves sliding down a rope which has beenanchored around a firm object (anchor point)such as a tree, projecting rock, or piton.

HASTY RAPPEL

The hasty rappel is a fast, easy way to getdown a moderately steep slope or cliff. Asoldier must wear a shirt to do a hasty rappel.

C-4

FM 90-5

SEAT-HIP RAPPEL

The seat-hip rappel is a fast method In this rappel, friction is taken up by aof getting down a steep hill or cliff, and snaplink inserted in a rappel seat fastenedit is also used to rappel from helicopters. to the body.

C-5

–FM 90-5

Section IV. MOVING BY HELICOPTER

RAPPELLING FROMHELICOPTERS

In the jungle, there are many placeswhere the vegetation or the ruggedness of theterrain will not permit a helicopter to land.Therefore, it maybe necessary to rappel froma helicopter to get on the ground. Specialequipment is required to rappel fromhelicopters. There are no safe fieldexpedients. The following paragraphsdescribe the equipment and procedure used inrappelling from helicopters and furnishinformation on other extraction means.

EQUIPMENT

The donut ring is the primary anchoringdevice (anchor point) inside a helicopter. Thefloating safety ring is the secondary anchorpoint. The donut ring consists of a 12-inchsolid ring of ½-inch cold-rolled steel cable;seven parachute static line snap hooks; four½-inch U-bolts; and 12 inches of chain or½-inch cable. Instructions for making adonut ring and a floating safety ring arefound in FM 57-38.

The log coil helps the double rappellingrope fall clear of the aircraft. To prepare it,start with the running end of the rope and coilthe rope evenly and tightly around the log.Use a log approximately 2 to 3 inches indiameter and 16 to 24 inches long.

C-6

A system that has proven to be almostideal for rope deployment in helicopter rappeloperations is that of the rope deploymentbag. The rope deployment bag is issue as acomponent of the Stabo extraction systemThe ropes are prepared in the normal rappelconfiguration and stretched to full lengthThe D-bag is placed at the loose ends ofrope opposite the snaplinks. After insurthat all rubber bands are present allstowing lines of the D-bag, a bight is formedin the two runnings ends of the rappel ropesand then placed in the center retainer bandjust above the stow pocket. The rope is thenfolded and stowed in the retainer bandsworking from side to side of the D-bag, whilemaking sure that folds do not extend pasteither side of the D-bag. Six to eight folds ofrope are placed in each retainer band,working towards the top of the D-bag. Oncethe top of the bag is reached, a bight is formedin the climbing ropes 24 inches below the firstsnaplink and stowed in the top centerretainer band. After the D-bag is inspected,the bag is rolled, going from bottom to top,leaving the snaplinks exposed. Tape is usedto secure the top flap of the bag.

PROCEDURES

The rappelling rope is connected to thedonut ring and the floating safety ring, in thefollowing order, and in the manner described.

FM 90-5-

C-7

–FM 90-5

To rappel from a helicopter.

Hook into the rope, as in the seat-hiprappel, upon entering the helicopter. Sit onthe floor, keeping the brake hand firmly inthe small of the back.

Place the rope in lap.

Upon the command, “GET READY,”look toward the donut ring and pull on therope to check the anchor point connection.Check the rappel seat and snaplink to insurethat the rope is properly inserted. Conduct afinal visual inspection of the hookup.

Upon the command, “SIT IN THEDOOR,” swing the feet out to the helicopterskid, keeping the brake on.

Upon the command, “DROP ROPE,”drop the rope with the guide hand, insuringthat the rope does not fall between the cargocompartment and the skid and that the ropeis not tangled or fouled.

Upon the command, “POSITION,”using the guide hand to assist, pivot 180degrees on the helicopter and skid bar. Facethe inside of the helicopter. Spread the feetshoulder-width apart; lock the knees; andbend forward at the waist, forming an “L”body position.

Upon the command, “Go,” flex theknees and jump backward, letting the roperun through both the brake hand and theguide hand. Descend 5 to 10 meters at a time,looking at the ground over the brake hand.Keep the feet together and legs straight,while maintaining the “L” body position.

Upon reaching the ground, back all theway out of the rope and move quickly awayfrom beneath the helicopter.

OTHER MEANS OF ENTERINGAND LEAVING HELICOPTERS

The troop ladder is a good method forlarger groups to enter or leave an area where

C-8

FM 90-5-

the helicopter cannot land. Installation of theladder is an aviation responsibility. The crewchief will control the number of troops on theladder. Only five or six troops will be allowedon the ladder at a time.

Use the legs for climbing and de-scending; the arms for stability and holdingthe ladder close to the body.

If possible, each soldier, and especiallythose carrying heavy loads, should tie arappel seat with a snaplink attached beforeascending. Then, if he becomes tired, he can“snap in,” avoiding the chance of a fall.

When going down a ladder, the firstsoldier on the ground steadies the ladder forthe remaining troops. When climbing up aladder, the soldier designated to hold theladder steady is the last one up the ladder. Ifthe helicopter starts going up before everyoneis loaded, the soldier holding the ladder onthe ground should release it at once.

When on the ladder, remain calm at alltimes. If the helicopter should start settling tothe ground, stay calm, watch the ground, andstay on the ladder until reaching the ground.

Once on the ground, move from under-neath the helicopter.

The jungle penetrator is a metal seatrescue assembly attached to a winch on ahelicopter. The seats remain folded when thedevice is being lowered. The seats areunfolded when the device is on the ground. Aconical nose allows it to penetrate the junglefoliage. One to three soldiers (two is astandard load) can be placed on it. Nylonstraps are placed under the arms of thesoldier(s) to be hoisted. The device lifts thesoldier(s) into the helicopter.

C-9

–FM 90-5

OTHER EXTRACTION MEANS

Other means which can be used forextraction of troops where landing zones (LZ)

are not available include such devices as thepersonnel Stabo extraction system, theMaguire rig, the Palmer rig, or the jungleoperations extraction system (JOES).

STABO SYSTEM

This system provides a means for rapidpickup of soldiers by helicopter from areaswhere the helicopter cannot land. The systemconsists of the personnel harness, thebridle, the suspension rope, the safety rope,and the deployment bag.

As the pickup process is initiated, thehelicopter hovers over the pickup zone at

C-10

FM 90-5

altitudes up to 150 feet. A member of thehelicopter crew drops the extraction systemdeployment bag from the left door of thehelicopter. (A maximum of three units maybe connected and dropped simultaneously.)As the deployment bag descends, thesuspension rope deploys until the bagreaches the ground. The soldier to beextracted then attaches the bridle snaphooks

and tight the soldier notifies the helicopter byradio or hand signals that liftoff may begin.The helicopter then lifts the soldier from thearea and, carrying him suspended beneaththe helicopter, moves to an area where a safelanding can be made. The helicopter thenlowers the suspended soldier to the ground,lands nearby, and allows him to board thehelicopter. For details on employing this

to the lift V-rings on his harness. After system, consult TM 10-1670-262-12.insuring that the leg straps are connected

C-1 1

–FM 90-5

PALMER RIGThis rig is constructed with the 120-foot

nylon rope and two 12-foot nylon sling ropes.One end of the 120-foot rope is secured to thedonut ring. The running end of the 120-footrope is tied with an end of the rope bowlineknot at the end of the rope. One of the 12-footsling ropes is tied 3 feet above the bowlinewith a Prusik knot, and the loose ends are tiedoff with a square knot to form a loop. Therider uses the remaining sling rope to form arappel seat. He then fastens a snaplink to therappel seat and the bowline knot; places hisarms up and through the upper loop; and isextracted. The Palmer rig is relatively safeand may be used when evacuating woundedpersonnel.

MAGUIRE RIG

This rig is also simple and easy toconstruct. It is made with an 8-foot by 2-inchpiece of nylon webbing sewn together at theends to form a loop containing a D-ring. A smaller slip loop (wrist loop) is sewn 12inches down from the top of the larger loop.During extraction, the rider simply sits in theseat of the large loop. He then places his wristin the slip loop and tightens the loop,insuring that he does not fall from the largerloop during extraction.

JUNGLE OPERATIONSEXTRACTION SYSTEM

This system was developed after carefulevaluation of the three previously mentionedsystems, while considering those items ofequipment available to the individualsoldier. The JOES can be quickly constructedfrom components readily available from thesupply system. The individual soldierrequires very little (10 to 15 minutes) trainingin what he will be required to do if he needs tobe extracted, and only a maximum of 5minutes is required for him to actuallyprepare for extraction.

C-12

FM 90-5-

CONSTRUCTION OF A JOES FOR TWO INDIVIDUALS

Material needed:

Anchor system for helicopter Three military snaplinks,(donut ring).

Two 12-foot utility ropes.

Two 120-foot rappel ropes. One deployment system.

Once all equipment has beenthoroughly inspected, the JOES isprepared in the following manner.

Lay out both 120-foot rappel approximately 12 inches in diameter,ropes side by side. Any excess over 6 inches should be

taped to help eliminate confusion duringMove to one end and, taking both hook up.

ropes as one, tie a round turn and twohalf-hitches around a snaplink Approximately 18 inches from theapproximately 5 feet from the end. top of the bowline knot toward the fixed

end of the rope, take one end of a 12-footFrom the first knot, move 18 utility rope and tie a Prusik knot and a

inches toward the short end of the rope bowline with a half-hitch around oneand tie another round turn and two half- 1 20-foot rappel rope.hitches around another snaplink. Tapeany excess rope. This now becomes the On the same rope, using the otherfixed end of the rope and will be attached end of the 12-foot utility rope, tie the

to the anchor system in the helicopter. same knot directly below the first.

Repeat steps 5 and 6 with anotherMove to the working end of the sling rope on the other 120-foot rappel

rope and, taking both ropes as one, tie a rope.bowline with a half-hitch. The loopsformed by this bowline should be Pack JOES in D-bag.

Each individual who is to be extracted snaplink into one loop at the end of the ropemust have a 12-foot utility rope and a snap- bowline, and places the loop formed by one oflink. If the individual does not have theseitems, they can be dropped to him with theJOES. The individual to be extracted makesa rappel seat out of the 12-foot utility rope andinstalls the snaplink as if he were going tomake a rappel.

When JOES is dropped, he and his buddymove to the bag. Each individual hooks his

the 12-foot utility ropes over his shouldersand under his armpits. He and his buddy stayas far back from the helicopter as practicaluntil it starts to lift up, and as tension is puton the rope, they move forward until they aredirectly underneath it and linked up withother personnel. All soldiers should link upby holding onto the adjacent person’sequipment.

C-13

– FM 90-5

Section V. MOVING ACROSSWATER OBSTACLES

CROSSING RIVERSAND STREAMS

There are several expedient ways to crossrivers and streams. The ways used in anysituation depends on the width and depth ofthe water, the speed of the current, the timeand equipment available, and the friendlyand enemy situation.

There is always a possibility ofequipment failure. For this reason, everysoldier should be able to swim. In all watercrossings several strong swimmers should bestationed either at the water’s edge or, ifpossible, in midstream to help anyone whogets into trouble.

If a soldier accidentally falls into thewater, he should swim with the current to thenearer bank. Swimming against the currentis dangerous because the swimmer is quicklyexhausted by the force of the current.

FORDING

A good site to ford a stream hasthese characteristics:

Good concealment on both banks.

Few large rocks in the river bed.(Submerged large rocks are usuallyslippery and make it difficult tomaintain footing.)

Shallow water or a sandbar in themiddle of the stream. Troops may restor regain their footing on thesesandbars.

Low banks to make entry and exiteasier. High banks normally meandeep water. Deep water near the farshore is especially dangerous as thesoldiers may be tired and less able toget out.

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FM 90-5-

A unit should cross at an angle againstthe current. Each soldier should keep his feetwide apart and drag his legs through thewater, not lift them, so that the current willnot throw him off balance. Poles can be usedto probe in front of the troops to help find deepholes and maintain footing.

FLOATING AIDS

For deeper streams which have littlecurrent, soldiers can use a number of floatingaids such as the following:

The standard air mattress

TrousersNOTE: Trousers must be soaked inwater before using.

Canteen safety belt

Poncho life beltWater wings

Poncho brush raft

Australian poncho raftLog rafts

C-15

— FM 90-5

C-16

FM 90-5-

When launching any poncho raft orleaving the water with it, take care not todrag it on the ground as this will causepunctures or tears.

C-17

– FM 90-5

ROPE BRIDGES

For crossing streams and small riversquickly, rope bridges offer a suitabletemporary system, especially when there is astrong current. Because of the stretch factorof nylon ropes, they should not be used tocross gaps of more than 20 meters. For largergaps, manila rope should be used.

C-18

FM 90-5-

In order to erect a rope bridge, the first at point A. Take the other end of the linething to be done is to get one end of the rope upstream as far as it will go. Then, tie a slingacross the stream. This task can be rope around the waist of a strong swimmerfrustrating when there is a strong current. To and, using a snaplink, attach the line to him.get the rope across, anchor one end of a rope He should swim diagonally downstream tothat is at least double the width of the stream the far bank, pulling the rope across.

One-Rope Bridge. A one-rope bridge can be construct. The bridge is constructed the sameconstructed either above water level or at regardless of the level.water level. The leader must decide which to

C-19

–FM 90-5

Crossing Method above WaterLevel. Use one of the following methods.

Commando crawl. Lie on the top of therope with the instep of the right foot hookedon the rope. Let the left leg hang to maintainbalance. Pull across with the hands andarms, at the same time pushing on the ropewith the right foot. (For safety, each soldierties a rappel seat and hooks the snaplink tothe rope bridge.)

Monkey crawl. Hang suspended belowthe rope, holding the rope with the hands andcrossing the knees over the top of the rope.Pull with the hands and push with the legs.(For safety, each soldier ties a rappel seat andhooks the snaplink to the rope bridge.) This isthe safest and the best way to cross the one-rope bridge.

Crossing Method at Water Level.Hold onto the rope with both hands, faceupstream, and walk into the water. Cross thebridge by sliding and pulling the handsalong the rope. (For safety, each soldier ties asling rope around his waist, leaving aworking end of about 3 to 4 feet. He ties abowline in the working end and attaches asnaplink to the loop. He then hooks thesnaplink to the rope bridge.)

To recover the rope, the last soldier untiesthe rope, ties it around his waist and, after allslack is taken up, is pulled across.

Two-rope bridge. Construction of thisbridge is similar to that of the one-ropebridge, except two ropes, a hand rope and afoot rope, are used. These ropes are spacedabout 1.5 meters apart vertically at theanchor points. (For added safety, makesnaplink attachments to the hand and footropes from a rope tied around the waist. Moveacross the bridge using the snaplink to allowthe safety rope to slide.) To keep the ropes a

C-20

FM 90-5 –

uniform distance apart as men cross,spreader ropes should be tied between the tworopes every 15 feet. A sling rope is used andtied to each bridge rope with a round turn andtwo half-hitches.

OTHER CROSSING MEANS

Suspension traverses, bridges, andcableways can be used to move large

numbers of soldiers or heavy equipmentover wide rivers and ravines, or up anddown cliffs in a short period of time. Be-cause heavy or bulky material or equipmentis needed to construct these expedients,their use is practical only if the neededitems can be transported to the site by airor surface means (watercraft, pack animals,etc.).

C-21

FM 90-5

APPENDIX D

W a t e r b o r n e O p e r a t i o n s

Sect ion I . GENERAL

MIDDLE SECTOR(CENTRAL VALLEY)

The inland waterways and junglecoastal or delta regions are land environ-ments dominated by water routes. There maybe one or more major waterways and anextensive network of smaller waterways.Usable roads are scarce, and cross-countrymovement is extremely difficult. Thefollowing describes jungle waterways.

UPPER SECTOR(HEADWATERS)

The headwaters of a waterway areusually formed in a mountainous region. Theheadwaters consist of numerous tributarieswhich merge to form a river system as thewater flows down to the valley. Headwatersare characterized by waterfalls, rapids, andvariations in water depth, all of whichrestrict the use of watercraft.

When the waterway reaches the centralvalley, it has formed a broad river which isusually navigable for great distances inland.This river is usually fed by numeroustributaries. In those jungles where there aredefinite dry and rainy seasons, many of thetributaries found during the rainy seasonmay not exist during the dry season. Theriver in the valley is wide, slow, and oftenmeanders. During periods of heavy rainfall,the course of the river may change. Thejungle vegetation grows up along the river-banks to form an almost solid wall. Thebanks of the river are often steep andslippery. Many of the navigable tributariesfeeding the major river will often be com-pletely overgrown with vegetation andcontain obstacles such as fallen trees.

D-1

–FM 90-5

LOW SECTOR(DELTA)

When the river reaches the low coastal change speed or reverse with the tide in aarea, it spreads over a flat, alluvial plain and predictable manner. Bottoms of thebecomes a number of river tributaries (small tributaries normally slope up to a crest or barstreams or channels spreading fanlike from at the river’s mouth. In some instances, onlythe main channel) disbursing a great amount watercraft with a draft (that part of the craftof sediment into a gulf, bay, or ocean. under water) of 1 to 2 meters will be able toUsually, there are many large and small tidal cross the crest or bar at high tide.streams and channels, whose current may

Sect ion II . PREPARING FORO P E R A T I O N S

W A T E R B O R N ECOMBAT OPERATIONS

The fundamentals and tactics applicablein conventional ground operations apply inwaterborne operations. However, specialorganization, equipment, and techniques arerequired when ground forces are supportedby Navy ships and craft. The waterborneforce should be employed with all availablemodes of transportation to seek out anddestroy the enemy and his installations. Oneportion of the force may enter the area bywatercraft; another may enter by helicopters;still another may enter the area by movingoverland. All units then maneuver to attackthe enemy. All available fire support shouldbe used in the operation: close air support,attack helicopters, waterborne and land-based artillery, and naval gunfire. Specialconsiderations in the conduct of junglewaterborne operations include the following:

The heavy vegetation along the banksof inland waterways offers excellentconcealment and enhances the effectiveness

D-2

of ambushes against watercraft. Therefore,counterambush measures must be planned inconjunction with all water movements.Steep, slippery river banks coupled withdense vegetation often make committing thewaterborne force in a coordinated assaultlanding extremely difficult.

Security measures during the move-ment phase along a jungle waterway includeproper watercraft formations, constantwater patrolling, and air observation, whenpossible. Fire support to include mortar,artillery, close air support, and availablenaval gunfire must be preplanned for allwater movements.

Intelligence is critical along junglewaterways. While aerial reconnaissanceyields a considerable amount of information,it will have to be supplemented by recon-naissance by boat, especially in areas wheretributaries are overgrown by vegetation.

FM 90-5-

S e c t i o n I I I . U S I N G J U N G L E W A T E R W A Y SSMALL BOAT HANDLINGThe use of inland and coastal waterways carrying capacity of units which normally

can add flexibility, surprise, and speed to operate dismounted. Thus, every combattactical operations in jungle areas. Use of leader should be familiar with the tacticalthese waterways will also increase the load- and technical aspects of small boat handling.

D-3

—FM 90-5

ORGANIZATION

Boats may be powered by outboardmotors, paddles, or oars. The mission,availability, and the river itself dictate themethod of propulsion to be used.

Motors are noisy. On the other hand,they provide speed, reduce fatigue, and freepersonnel for security missions. The noiseform motors can be heard for distances of 500to 1,000 meters by day and up to 5,000 metersat night (sound carries better in the quieter,cooler night air). Provided the craft is notseen and the motor does not change pitch,however, it is difficult to estimate thedirection of the sound and exactly how faraway it is. Bearing these factors in mind,troops may be able to disguise a movement bydeceptive tactics such as having other craftwork the area. Stopping the motor whentraveling downstream will also aid thesecurity of movement.

Paddling is a slow and tiring process, butit is quieter than using motors. (With plastic,wooden, or metal craft, paddles may need tobe wrapped with cloth to reduce noise whenthe paddles strike the craft.)

Before a waterborne operation, eachperson in a boat is assigned a specific boatposition and a corresponding number. (Thisis the long count method of organization. )

NOTE: The unit, normally a squad, that usesthe RB-15 for transportation actuallycomprises the crew that operates it. All othersthat do not operate the boat are passengers.

First, the crewmembers are assignedtheir positions. Next, the passengers areassigned their positions. When using an RB-15, for example, the crewmembers areassigned positions 1 through 11, and thepassengers are assigned positions 12through 15. One person is designated as theboat commander (normally the coxswain).Two persons are designated as a navigator-observer team.

For operational purposes, the crew isorganized into pairs. Passengers are notnumbered in this method. (This is the shortcount method of organization.) When usingthe RB-15, for example, the crewmembers (inpairs) are assigned to operational positions 1through 5.

D-4

FM 90-5-

Crew duties:

The coxswain is responsible for thecontrol of the boat and action of thecrew. He supervises the loading, lash-ing, and distribution of equipment, Healso maintains the course and speedof the boat.

■ The number 1 paddler (long countm e t h o d ) i s t h e o b s e r v e r a n d i sresponsible for the storage and use ofthe bowline.

The number 2 paddler (long countmethod) is responsible for setting thestroke.

■ All paddlers are responsible forloading and lashing the equipment intheir respective compartment.

PREPARATION OFPERSONNEL AND

EQUIPMENT

Each crewmember and passenger mustwear a life preserver.

The load-carrying equipment harness isworn unbuckled at the waist.

The rifle is slung outside of thelifepreserver, opposite the outboard side, withthe muzzle down.

Crew-served weapons, radios, ammuni-tion, and other bulk equipment are lashedsecurely to the boat to prevent loss if the boatshould overturn.

Radios, batteries, and unboxed am-munition are waterproofed.

Hot weapons are cooled prior to beingplaced in the boat to prevent damage to theboat or injury to personnel.

Pointed objects are padded to preventpuncture of the boat.

The most effective equipment-lashingsystem that has been developed is the RB-15lashing system. This system is quick andeasy to install, requires no special equipment,and prevents loss of equipment in the eventthe craft is capsized. It also allows the craft tobe easily righted.

The equipment needed in thislashing system is:

Ten sling ropes-

■ Three for capsize lines.

One for securing the M60.

■ Six for rigging the RB-15.

Nine snaplinks-

■ Two for securing the M60.

■ Four for securing rucksacks.

■ Three for the center line.

The average squad can fully rig and lashan RB- 15, using this system, inapproximately 15 minutes.

D-5

– FM 90-5

I

I

I

C O M M A N D S“short Count, count off. ” Crew counts off “Long count, count off. ” Crew counts off

their positions by pairs, for example, 1,2,3,4, their positions by individuals, for example, 1,5, coxswain (RB-15). 2, 3, 4, 5, 6, 7, 8, 9, 10, coxswain (RB-15).

D-6

FM 90-5—

“Boat stations. ” Crew takes position “High carry, mo[e” (used for longalong side of boat. distance moves overland).

D-7

—FM 90-5

“Lower the boat, move. ” Crew lowers theboat gently to the ground using carryinghandles.

“Give way together. “Crew paddles to thefront, with Number 2 setting the stroke forthe rest of the crew.

“Hold. “ Entire crew keeps paddlesmotionless in the water, thereby stopping theboat.

“Hold left (right). ” Left crewmembershold, right crewmembers continue withprevious command.

“Back paddle. ” Entire crew paddlesbackward. This action propels the boat to therear.

“Back paddle left (right). ” Left crew-members back paddle causing the boat toturn left, right crewmembers continue withprevious command.

“Rest paddles. ” Crewmembers placepaddles on their laps with blades outboard.This command may be given to pairs, i.e.,“Number 1‘s rest paddles. ”

LAUNCHING AND LANDING

When launching, the crew maintains afirm grip on the boat until they are inside theboat; similarly, when landing, they hold ontothe boat until it is completely out of the water.

The crew stays as low as possible whenentering and leaving the boat to avoidcapsizing it.

Crewmembers can load or unload a boateither by individuals or in pairs. They loadand unload a boat by individuals at steepriver banks and along shoreline where thewater is deep near the shore. They also loador unload from or into a larger vessel such asa landing craft, mechanized (LCM), byindividuals.

D-8

The crewmembers load or unloadindividually according to their number in thelong count method. The coxswain directsthem by saying, “One in (out), two in (out), ”etc.

The crewmembers load and unload a boat in pairs when at shallow waterriverbanks. They load or unload in pairsaccording to their number in the short countmethod. The coxswain directs them bysaying, “Ones in (out), twos in (out), ” etc.

FM 90-5—

HELOCASTINGHelocasting is an excellent method for

deploying troops and equipment in anyterrain in which water courses exist. Thistechnique involves a CH-47 helicopter, a 15-man rubber boat (RB-15), and a squad. TheRB-15 is loaded with the squad’s rucksacks,crew-served weapons, radios, and otherheavy mission-essential items. All thisequipment is kept in the RB-15 by a lashingsystem. At the desired time, the RB-15 ispushed off the ramp and into the water. Thesquad follows it, exiting the CH-47 in twocolumns off the tailgate. Drop speed is 20-25knots and drop altitude is 10-20 feet. Thewater should have little or no current andshould be free of all obstacles, including sea-weed and stumps, and be at least 15 feet deep.

The only preparation necessary for theCH-47 is that two lengths of rollers must beinstalled in the center of the tailgate. The tworearward set of seats on each side of the CH-47must be raised to fit the RB-15 inside.Personnel wear fatigues (boots unbloused,shirts out, sleeves rolled down, top buttonfastened), load-carrying equipment, and anindividual life preserver. The individualweapon is tied to the individual in such amanner that it can be raised overhead whenthe individual exits the CH-47.

The RB-15 lashing system is used inrigging and lashing the rubber boat with therespective equipment. The boat is placed onthe roller system and moved into the CH-47,bow first. On signal, it is pushed out by thecastmaster and coxswain or RB-15commander. Once the RB-15 is in the water,the squad follows it. The first man to the boatmakes a quick inspection for damage andaccountability of equipment, frees thepaddles, and starts paddling the boat towardthe rest of the squad. If the boat capsizes, itcan be easily righted using standard drills.

This technique can be used without theRB-15 to cast scouts along a riverbank. They

would swim to a designated shore or to adesignated point to conduct their mission.

RB-15 helocasting is also an effectivemeans of resupplying a company operatingalong a water obstacle. Over 1,000 pounds ofrations, ammunition, and supplies can beplaced in each boat.

D-9

–FM 90-5

RIVER MOVEMENT

RIVER CHARACTERISTICS

A bend is a turn in the river course.

A reach is a straight portion of river between two bends.

A slough (pronounced slue) is a dead end branch from ariver, It is normally quite deep and can be distinguishedfrom the true river by its lack of current.

Dead water is a part of the river, due to erosion andchanges in the river course, that has no currents. Deadwater is characterized by excessive snags and debris.

An island is usually a tear-shaped mass of land in themain current of the river. Upstream portions of islandsusually catch debris and should be avoided.

CURRENT

The current in a narrow part of a reach is normally fasterthan in a wider portion. The current is fastest on theoutside of a curve; the sandbars and shallow water arefound on the inside of the curve.

Sandbars are located at those points where a tributaryfeeds into the main body of a river or stream.

D-10

FM 90-5

NAVIGATION

There are two acceptable methods ofriver navigation.

Checkpoint and General Route Method.This method is used when the landing site ismarked by a well-defined terrain feature andthe waterway does not have many branchesand tributaries. The navigator uses a stripmap, with the route drawn on it, and looks forprominent checkpoints along the way. It isbest used during daylight hours and for shortdistances. Except for those periods when thenavigator is right at a checkpoint, thismethod is not completely accurate. It is,however, the easiest means of river navi-gation.

D-11

–FM 90-5

Navigator-Observer Method. This is themost accurate means of river navigation andcan be used effectively in all light conditions.

The navigator is positioned in the centerof the boat and does not paddle. During hoursof darkness, he uses his flashlight under aponcho to check his map.

The navigator keeps his map andcompass oriented at all times.

The navigator keeps the observerinformed of the configuration of the river byannouncing bends, sloughs, reaches, andstream junctions as shown on his map.

The observer compares this informationwith the bends, sloughs, reaches, and streamjunctions he actually sees. When these areconfirmed the navigator notes the boat’slocation on his map.

as shown on his map. The observer confirmsthese with actual compass readings.

The navigator announces only oneconfiguration at a time to the observer anddoes not announce another until the first isconfirmed and noted.

At night, a strip map drawn on clearacetate backed with luminous tape may beused instead of a map. It should be to scale ora schematic. It should show all curves andthe azimuth and distance of all reaches. Itshould also show terrain features, streams,junctions, and sloughs.

TACTICAL MOVEMENT

The techniques of tactical rivermovement are very similar to those employedon land. As on land, movement techniquesdepend primarily on the likelihood of enemycontact and must be based on the concepts of

The navigator also keeps the observer traveling, traveling overwatch, and bound-informed of the general azimuths of reaches ing overwatch.

D-12

FM 90-5–

Distances between elements will varydepending upon observation, range ofweapons, and means of communication used.Each boat must maintain visual contact withthe boat to its front.

Boats move close to the shoreline, takingadvantage of the natural concealment.

When bends in the river deny observa-tion, a unit sends a reconnaissance teamashore to reconnoiter the river beyond thebend. When the reconnaissance teamdetermines that the area is clear, it signalsthe boats to move forward.

Troops in the boats are assigned specificsectors in which to observe and fire.

One person is appointed in each boat asan air guard. If an enemy aircraft is sighted,the boats immediately move close to shore forconcealment. Troops sit quietly in the boatsuntil all is clear. If the aircraft makes a firingpass, the unit beaches the boats and takes theappropriate defensive actions for an airattack.

Actions taken on enemy contactresemble those taken ashore. The elementscaught in the enemy’s fire return fire, beachthe boats, seek cover, and continue to fire.Other elements beach their boats andmaneuver ashore to destroy the enemy. Whena patrol is inserted by boat, the landing sitemust be secured before all elements of thepatrol disembark. A suggested technique is tohave the lead boat unload its personnel at thelanding site while the other boats cover themfrom a distance. After the site is secured, theother boats are landed on signal. After theboats have landed, the crews either hide theboats or have them removed from the area. Ineither case, the crews remove any signs ofactivity on the landing site.

D-13

—FM 90-5

D-14

FM 90-5–

D-15

FM 90-5

Fighting

APPENDIX E

Positions and Shelters

Section I. GENERAL

Although jungles have excellent con- as fighting positions, jungle shelters providecealment, the jungle fighter must still shelter from the elements and make life in theprepare fighting positions to get as much jungle more comfortable and healthful.cover as possible. Although not as important

Section II. PREPARING POSITIONSAND SHELTERS

FIGHTING POSITIONS

A jungle fighting position should providecover, permit effective engagement of theenemy, and blend in with its surroundings.Swamps and low areas should be avoidedbecause they normally do not afford goodfields of fire and are too wet to permit thedigging of fighting positions.

PROTECTION FROM ENEMY FIREA good fighting position provides

protection from direct small-arms fire andindirect fire fragmentation. Protection from

small-arms fire is provided by frontal cover.Natural frontal cover (trees, rocks, logs,rubble, etc.) is best as long as it is strongenough to stop bullets. Natural cover blendswith the surroundings; therefore, it is hardfor the enemy to identify positions. It maybenecessary, however, to use the dirt from thehole to build frontal cover when naturalfrontal cover is not available. Frontal covermust be wide enough to provide room for twosoldiers, thick enough (at least 46 centimeters[18 inches] of dirt) to stop enemy small-arms

CONTENTS

SECTION PAGE

I . General . . . . . . . . . . . . . . . . . . . . . .E-1

I I . Preparing Positions and Shelters .E-1 . . . . . . . . . . . . .

E-1

—FM 90-5

fire, high enough to cover the heads of the against the effects of indirect fire that burstssoldiers firing from behind it, and far enough to the flanks or rear of the position andin front of the hole to provide room for elbow against the effects of friendly supportingrests and sector stakes. weapons located in the rear.

Protection from indirect fire fragmenta- To conceal the fighting position, troopstion is gained by getting the soldiers below should take advantage of the jungle’s naturalground level and by building overhead cover. cover. They should use large fallen orThe logs cut to build overhead cover must be standing trees and depressions in thestrong. Soft wood will collapse when struck ground, and work to improve upon theby shell fragments. natural cover provided. Some logs, such as

palm tree logs, are too soft to stop bullets. IfTo insure complete protection for forced to use soft wood in building cover, a 10-

fighting positions, it is necessary to build inch layer of dirt or sandbags will have to beflank and rear cover. This cover protects added to the protection provided by the wood.

When positions are constructed, all live plants—the moist soil will help theseartificial cover must be camouflaged to blend plants survive.in with the surrounding terrain so it cannotbe detected by the enemy. Camouflage should All positions should provide for drainagebe kept fresh-dead or rotting vegetation will during tropical rainstorms. The floor of thegive away positions. Troops can transplant position should slope from the center of the

E-2

FM 90-5–

position toward the grenade sumps. This isimportant during the rainy season to avoidimmersion foot.

If time permits, an elevated floor stand ofsaplings can be built so that soldiers do nothave to stand in mud or water. Grenadesumps must remain clear.

Jungle soils are soft and erode quicklyduring the rainy season. Revetments willprevent the walls of a position from cavingin. The stakes should be driven all the wayinto the ground, once the anchor lines areattached. They must then be concealed sothat they cannot be confused with the firingstakes.

E-3

—FM 90-5

OBSERVATION AND FIELD OF FIRE

Soldiers should clear away only what isabsolutely necessary, in order to retain asmuch natural concealment as possible. Inproperly constructed positions, the soldier’seyes and weapon will be at ground level. Inthis way, the soldier is concealed from theenemy, is protected by cover, but still candetect any approaching enemy. If a smalltree is in a soldier’s field of fire, it should notbe chopped down completely. Only thebranches that deny observation should beremoved. The cuttings on the tree should bedarkened with mud. Overly cleared areas orfresh, improperly concealed cuttings are easyto spot.

CONCEALMENT FROMENEMY AIR OBSERVATION

Positions should be placed under thejungle canopy for its natural concealmentfrom air observation. If this is not possible,positions should be covered with camouflagenets or with expedient covers of looselywoven vines and branches.

For more detailed information on how toprepare jungle fighting positions, see FM 7-8.

E-4

FM 90-5 –

SHELTERS

Shelters are made when the tactical protection from the elements. However,situation permits. The poncho can be used as natural camouflage must still be applied toa roof for the shelter. It reduces the need for break up the outline of the poncho and reduceextensive concealing foliage and provides the glare of a wet poncho.

E-5

FM 90-5

APPENDIX F

NBC Warfare in Jungle Areas

Section I. GENERALJungle areas require exceptionally high and wind are reduced within thick jungles

standards of discipline and conditioning to due to the vegetation. These conditions affectmaintain an effective NBC defense readi- NBC operations because they reduce theness.The demand for these higher standards chances that NBC agents will disperse, thusresults from the jungle’s high temperature increasing their impact on operations in thatand humidity and heavy rainfall. Sunlight area.

Section II. CONDITIONS CREATED BY

not

NBC AGENTS

SPECIAL CONDITIONSNUCLEAR

The initial effects of nuclear blasts are concentrate them in low areas. These areassignificantly reduced by jungle foliage. are likely to become radiation “hotspots.”

The canopy may provide some protectionagainst thermal radiation. The blast wavewill blow down many trees and cause flyingdebris. These fallen trees may restrictmovement, but may also improveobservation and fields of fire of someweapons. Fallout may be temporarilyretained in the jungle canopy, reducing theimmediate hazard. Later rains, however, willwash these particles to the ground and

BIOLOGICAL

Jungle climates favor the use ofbiological agents. Biological agents thrive inheat, humidity, and shade. As with chemicalagents, downwind and spray hazards will bereduced by the lack of wind in the jungle.Strict supervision of field sanitation andadequate purified water supplies will providethe best defense against biological agents aswell as control natural diseases in the jungle.

CONTENTSSECTION PAGE

I. G e n e r a l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F-1II. Conditions Created by NBC Agents............................................................ F-1

Ill. Actions Taken to Protect Troops................................................................. F-2

F-1

–FM 90-5

CHEMICAL

If jungle enemies use chemical weapons,they can cause serious problems for UStroops. Persistent agents delivered by meansof artillery shells will remain effective forlong periods under the canopy. The jungleheat will vaporize chemical agents that aredelivered in liquid form. Because of low windspeeds, these vapors will hang in the air andremain hazardous for long periods. Thedownwind hazard, however, will be reduced.Likewise, the danger from sprayed agentswill be reduced. Protective masks andclothing will be uncomfortable in high heatand humidity. Commanders must plan for adecrease in performance by soldiers in thisenvironment. They should also plan for heatcasualties. Finally, NBC equipment must bemaintained so that it does not rot, mildew, orrust.

Section III. ACTIONS TAKEN TOPROTECT TROOPS

JUNGLE MISSION ORIENTEDPROTECTION POSTUREWhen temperatures rise to the 85 to 100

degree Fahrenheit range, troops can beexpected to continue moderate or heavyworkloads only if they are permitted toreduce their mission oriented protectionposture (MOPP) level. This increases the riskof chemical casualties if the unit comes underchemical attack. Vision, especiallydownward vision, is limited while wearingthe mask. While these factors tend todiscourage the wearing of protectiveequipment, leaders must balance the need toaccomplish their mission as opposed to theNBC threat.

As in any other environment, the com-mander must plan his MOPP level basedupon the mission and the estimate of thechemical threat. The level and the length ofexertion are important factors. Long-term

F-2

FM 90-5–

efforts, such as a road march, are moretaxing than short-term, high-energy tasks,such as an assault.

A commander considering protectivemeasures should keep two principles in mind.The first is that although troop safety is animportant consideration, the accomplish-ment of the mission is of greater importance.The second is that even though a higher levelof protection increases the risk of heatcasualties, these casualties are not ashazardous or as long lasting as are chemicalcasualties. Heatstroke, for example, is fatalabout 50 percent of the time, but makes up avery small percentage of all heat casualties.Physical conditioning and acclimatization ofsoldiers have an impact on how long they canoperate in protective equipment.

Assuming troops are acclimatized, workrates can be exceeded for short periods ifadequate rest and water are provided. In allcases leaders must balance the chances ofexposing their units to heat exhaustion orchemical agents to the need to accomplishthe mission. The ideal MOPP is the categorythat provides the highest degree of protectionfrom chemical effects and still permits themission to be accomplished.

F-3

—FM 90-5

The following measures can

Rotating heavy work among elementsor individuals

Authorizing longer and more frequentrest periods

improve unit efficiency at any MOPP level:

Providing adequate drinking water

Using truckpossible

or air transport when

NOTE: For further information, see FM 21-40.

F-4

FM 90-5–

Communicat ion

Section I. GENERAL

APPENDIX G

Techniques in a Jungle Environment

Rapid, reliable communications areessential in jungle operations. Command,control, fire support, resupply, andevacuation are all dependent on effectivecommunications. The importance ofestablishing and maintaining reliablecommunications cannot be overemphasized.For this reason, a commander must givecommunications high priority in hisplanning and supervision.

Jungle operations place additionaldemands on the resources of communica-

Section II. COMMUNICATINGIN THE JUNGLE

TACTICALCOMMUNICATIONS

MEANSWith the range of FM communications in

a jungle environment significantly reduceddue to the dense undergrowth, heavy rains,and hilly terrain, all means of com-

tions units and personnel. Tactical andsignal units may require augmentation ofsignal personnel and equipment to accom-plish the command and control functions.Besides providing normal tactical com-munications networks, signal units mayhave to operate long distance radio sets.Army aircraft will have to be used in manyinstances to provide a radio relay capabilityas well as to assist wire-laying operations.

complements one another. For all operations,backup means of communications mustbe planned. The common means of com-munication available are visual, sound,

munications should be used in a manner that messenger, wire, and radio.

CONTENTSSECTION PAGE

I. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .II. Communicating in the Jungle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Ill. Avoiding Enemy Interference . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

G-1

— FM 90-5

VISUAL COMMUNICATIONS

Such means as arm-and-hand signals,pyrotechnics, flashlights, headlights, smokegrenades, mirrors, and panels normallyallow quick transmission of messages andinstructions. However, visual means ofcommunication in the jungle are restricted bythe dense vegetation. Commanders willrarely have visual contact with all elementsor members of their unit.

Arm-and-hand signals are used in alltypes of operations. The effectiveness of arm-and-hand signals can be improved byinsuring that each soldier understands themeaning of the signal and passes it on toothers in his vicinity.

Pyrotechnics can be used in mostconditions of visibility. Certain standard

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FM 90-5—

colors of smoke or flare signals have limiteduse because they blend in with vegetation(green) or offer little contrast with fog or haze(white). Careful selection of colors (such asred or yellow) which contrast with thebackground color of the jungle increases theeffective range of pyrotechnic signals. Thejungle canopy can affect the use of starclusters and parachute flares in two ways.

Overhead clearance required for firingflares, is limited,

Once clear of the canopy, the flare or starcluster may be hard to see by other groundunits looking through the canopy. The dis-advantage of pyrotechnic signals is that theycan be easily seen and imitated by the enemy.

SOUND COMMUNICATIONS

These means include both voice anddevices such as whistles, horns, gongs, andexplosives. Sound signals are used to attractattention, transmit prearranged messages,or spread alarms. They are good only forshort distances. Range and reliability will bereduced by battle noise, weather, terrain, andvegetation. As they may also be heard by theenemy, they should be restricted for securityreasons. Sound signals must be simple toavoid misunderstandings. The means forsound signals are usually prescribed by theunit SOP and communications-electronicsoperation instructions (CEOI).

MESSENGER COMMUNICATIONS

These types are most secure and a goodway to send long messages and documents.However, the speed of surface messengers isseverely limited by jungle terrain andvegetation. The lack of roads restricts full useof motor vehicles. Foot messengers may havedifficulties with land navigation and naturalobstacles. The use of air messengers maybe abetter alternative, but one that is limited byavailability of aircraft, scarcity of goodlanding zones, weather conditions, and the

fact that air activitylocating friendly troopmessenger, messagesTheir text must becomplete.

aids the enemy inareas. When using ashould be written.clear, concise, and

WIRE COMMUNICATIONS

These methods are established wheneverfeasible. Wire is more secure than radio, hardto jam, and allows conversation with break-in capability.

The heavy rain and high humidity of thetropics reduce the range (about 20 percent)and reliability of wire communications. Wirelaying in the jungle requires more time andsuitable w-ire laying routes are limited. Theincreased cover and concealment make iteasier for the enemy to intercept or interruptwire communications and to ambushmaintenance crews. Wire laid by air on top ofthe jungle canopy is extremely difficult tomaintain and recover; however, it is lesslikely to be damaged by vehicles or weather.Splices should be carefully made to avoidsignal losses when wet.

RADIO COMMUNICATIONS

Radio communications are normally thefastest means available but the least secure.

Effective radio communications inthe jungle require emphasis on:

Use of antennas and field expedients

Use of retransmissions and radiorelays

Continuous preventive maintenance

Communications security (CO MS EC)

Trained operators

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FM 90-5

The usefulness of radio communicationsis reduced in jungle operations. VHF andUHF radios (FM radios included) areparticularly limited by the jungle growth andterrain that absorb and obstruct thetransmissions. It is not unusual for the rangeof a set operated in the jungle to be reduced by10 to 25 percent of the normal range.

ANTENNAS AND FIELD EXPEDIENTANTENNAS

In order to overcome environmentalconditions in the jungle, existing antennasmust be used properly and field expedientantennas produced to extend the capacity ofcurrent equipment.

To use existing antennas properly,the following items must be accom-plished:

Keep whip antenna vertical whentransmitting

Insure the antenna is not grounded bybeing in contact with foreign object

Position antennas to achieve the bestl i n e - o f - s i g h t p o s s i b l e b e t w e e nstations (such as on top of a hill)

The problems of line-of-sight antennalocations and operations security are bestsolved by remoting the transmitter from thecommand post.

The AN/GRA-39 radio set control groupallows the operator to remote the radio up to3.2 kilometers away from the observationpost. It should be noted that there is nopractical advantage to be gained byinstalling the radio and antenna away fromthe command post (remoting) unless thedistance is 1 kilometer or more. The errorinherent in radio direction finding

G-4

equipment does not provide for a consistentaccuracy less than 1 kilometer.

Field expedient antennas will enhancethe communications capacity of a unitoperating in the jungle if they are properlyconstructed. WD-1 or portions of the RC-292antenna can be used as the radiating element(antenna). Wood or plastic spoons can beused as insulators when insulators are notavailable. Resistors should be obtainedthrough communications maintenancechannels.

Useful field expedient antennas inthe jungle are:

Field expedient RC-292

Patrol antenna

The standard issue RC-292 is a highly-effective, omnidirectional antenna. It isusually more effective than a whip antenna,and is particularly effective in the VHFrange. With all its components, it weighs 48pounds and two soldiers can erect it in 15minutes.

FM 90-5 –

Leaders should consider using fieldexpedient versions of this antenna in thejungle for these reasons:

Excessive load for dismounted sol-diers

Awkward to assemble in restrictedterrain

Increased chance of losing parts

Portions of the RC-292 may be used toconstruct a field expedient antenna. Only thevertical sections, antenna base, ground planesections, and transmission line are needed.

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FM 90-5

Another field expedient antenna can beconstructed without using any of thestandard RC-292 components. This antennahas various names such as the fieldexpedient 292, the jungle antenna, and thefield expedient ground plane antenna.

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FM 90-5 —

A third type of expedient antenna used inthe jungle is the patrol antenna. It is the sameas the jungle antenna minus the groundplane element. Insure that the length isdetermined by using the 1/2 wavelengthinstead of the 1/4 wavelength column of thechart. The range of the set will be increased 2to 3 times its normal range. This antenna iseasier to handle and construct.

RETRANSMISSIONAND RADIO RELAY

With the decrease in range of most radiosused in jungle operations, retransmission

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FM 90-5

will be a good method to improvecommunications. Commanders shouldconsider establishing retransmission sitesand using additional signal personnel. Radiorelay sites, either airborne or on high terrain,will also improve radio communicationsbetween stations.

EQUIPMENT MAINTENANCEIN THE JUNGLE

Moisture commonly found in the jungleenvironment can result in numerous outagesof communications-electronic equipment.

The following measures, combinedwith normal maintenance, will helpcounteract the problems.

Seal the radios with silicone com-pound.

Pack radios in waterproof containerswhen not in use (remove batteries).

Protect handsets and microphoneswith plastic bags. (Batteries andrations are packed in plastic bags.)Check frequently for moisture build-up in the bags.

When radios are protected by plasticbags, make sure the battery vent is notobstructed. Radios protected in this mannermust be constantly checked to insuremoisture does not build up in the bag. Cleanradios as frequently as individual and crew-served weapons are cleaned.

Section III. AVOIDING ENEMYINTERFERENCE

COMMUNICATIONSSECURITY

In the past, jungle enemies have reliedheavily on friendly radio messages asprimary intelligence sources. Communica-tions security denies or delays unauthorized

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FM 90-5 –

persons from gaining information fromtelecommunications.

ANTIJAMMING

Radio operators should use the followingantijamming procedures to thwart enemyjamming efforts.

Recognition. The first thing an operatormust do when there is interference on hisradio is to try to find its cause. As symptomsof jamming are often similar to other types ofinterference, he should not assume that it isjamming. If the interference decreases when

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—FM 90-5

the receiver antenna is removed, theinterference is jamming; if it does not, theinterference is generated inside the receiver.

Continued Operation. Normal radiooperation is continued once jamming hasbeen identified so that the enemy cannotdetermine the effect of his jamming. The ruleis: during jamming, operators continueoperating unless ordered to shut down.

Reporting. All operators must reportjamming to their next higher headquarters,by another means of communications; forexample, wire or messenger. A typicaljamming report tells date and time ofjamming, frequencies affected, type andstrength of jamming signal, and designa tionof the unit making the report.

The exact format of the report is found inthe unit’s CEOI.

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FM 90-5–

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FM 90-5

APPENDIX H

The Individual Soldier’s Combat Load

Section I. GENERALAll equipment considered essential to SOP should dictate the items that are re-

mission completion should be carried by the moved from rucksacks and included in equip-individual at all times. Rucksacks should be ment carried by each soldier when on short-packed in such a way that they can be duration missions where rucksacks are leftdropped or hidden, for recovery later, to allow behind. Packing lists should also be designedtroops to move freely upon contact or on for squads and platoons with careful at-patrol. In an emergency, they may be tention given to balancing loads. (Fordiscarded completely. Those essential items example, machinegunners should not bethat must be placed in the rucksack, due to given extra equipment to pack until thethe extended nature of operations, should be fighting and existence loads of the otherremoved when the situation dictates. members of the platoon are equal to that ofCombat-essential items should not be left in the machinegunners.)rucksacks that are cached or dropped. Unit

Section II. PREPARING THE LOAD

WEIGHT CARRIED

The problem of excessive weight in exis-tence loads needs to be closely monitored bycommanders at all levels. Specific companyand platoon SOPs need to be reinforced withinspections prior to deployment, demandingstrict adherence to packing lists. Unusableequipment should not be carried.

WATER CARRIEDWater will constitute the second greatest

part of each soldier’s load. Jungle fightersmust be issued more canteens than normal,and they may have to carry 5 to 10 quarts ofwater attached to their rucksacks, especiallyin the dry season. Water purification tabletsshould be carried so that stream water maybe used.

AMMUNITION CARRIED

Units should be told how long they canexpect to operate without resupply. Thisfigure becomes the basis for planning theequipment, supplies, and ammunition to becarried. Ammunition will normally make upthe greatest part of each soldier’s load, andammunition supplies must be planned to lastuntil troops can be resupplied. Rifle andmachinegun ammunition and grenadesshould be loaded on pallets in a rear area sothat units can easily be resupplied byhelicopter, if required. Every soldier shouldcarry colored smoke grenades and flares forsignaling, and tripflares and Claymoremines for security. Special ammunition maybe carried, if required by the mission. Themost common types of special ammunition

SECTIONCONTENTS

PAGEI.. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............H-1

Il. Preparing the Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H-1

Ill. Carrying the Load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H-5

H-1

FM 90-5

and C4 explosives, concussion grenades, andCS munitions.

The following description of a soldier’scombat load should be used only as a guide indeveloping a unit SOP. Fighting andexistence loads will vary according to eachunit’s special needs and missions.

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FM 90-5

H-3

- FM 90-5

H-4

FM 90-5

Section III. CARRYING THE LOADUSE OF THE RUCKSACK

Platoon- and company-sized units operat i ona l a reas , and prec ludeconducting offensive operations in jungle compromising their location for frequentterrain must emphasize self-reliance. Units resupply operations.must carry rucksacks and be able to operatefor extended periods of time with routine To minimize the weight of rucksacks,resupply being accomplished every 5 to 7 commanders must carefully analyze theirdays. This will allow units to develop their missions, and allow nothing but mission-

H-5

FM 90-5

essential equipment to be carried. Detailedpacking lists and thorough inspection priorto a mission will insure nonessential itemsare not taken to the field.

When units must carry rucksacks, troopsshould not be expected to fight with thisburden. Unit SOPS must be developed andpracticed concerning the disposition ofrucksacks in various situations. Rucksacksshould contain nothing other than existenceitems, so the grounding or caching of themshould have no effect on the combateffectiveness of an element or unit.

A unit moves from point to point withrucksacks on. After the movement phase ofan operation is over, rucksacks should beremoved and secured.

DISPOSITION OFRUCKSACKS

Techniques of handling rucksacks willvary according to the situation.

SHORT-DURATION MISSIONS(48 HOURS OR LESS)

Rucksacks should not be carried. Rationscan be placed in a sock and securely tied tothe back straps on the load-bearing harness.This method will not restrict mobility andnoise will be reduced. The poncho, tied to theback of the pistol belt, will be the only otheritem needed from the existence load. Thebalance of the equipment to be carried, inexcess of a unit’s standard fighting load, willbe determined by the mission. Bulky itemscan be carried in rucksacks, but loads shouldbe rotated frequently.

CHANCE CONTACT

Rucksacks should be dropped im-mediately when contact is made, to allowrapid reaction and maneuverability. Themission to secure these rucksacks should begiven to the squad or fire team that isproviding rear security. The rucksacks need

H-6

not be gathered or centralized in thissituation, due to the usuall y short duration ofthis type of contact. If the unit must movebecause of enemy pressure, or in case of aneed for reinforcements, all rucksacks mustbe left behind. Upon returning to retrievedropped rucksacks, a unit must be alert forambushes and care taken to avoid casualtiesfrom enemy boobytraps placed in and aroundthe equipment.

PATROL BASE OPERATIONS

Elements or squads moving out of patrolbases to conduct short-duration missionsshould consolidate and conceal rucksacksprior to moving out. The only time rucksacksshould be carried is when the mission doesnot call for return to the patrol base. If thepatrol base is forced to withdraw from itslocation, all rucksacks will probably be leftbehind in order to break contact and to moverapidly for linkup with the balance of theunit. Reinforcements to assist a squad orelement in contact while away from theirpatrol base should not take rucksacks whenmoving to their assistance. If the situation isso critical that the entire unit must move tothe assistance of an element or squad,rucksacks should be quickly consolidated,concealed, and left behind.

CACHING RUCKSACKS

This technique is used as a last resort. Itis a difficult mission to successfullyaccomplish. If a situation arises where acommander decides to cache, care must betaken in selecting a cache site. An easilyidentified area should be used as a referencepoint. From there, azimuth and pace countshould be used to actual cache sites. Naturallines of drift should be avoided and careshould be taken not to leave trails into cachesites. Security must be established 360degrees around the proposed site, and mustbe far enough out to insure that enemy forcescannot observe the activity. Items that willbe needed in the event a unit is unable to

FM 90-5—

return to the cached items should be removedand included in the fighting load. (See short-duration missions.) Natural camouflage(deadfall, thickets, caves, etc.) should be usedto conceal rucksacks. Pits can be dug if thearea can be returned to its natural state whencaching is completed. When returning tocache sites to recover rucksacks, unit leadersmust consider the sites danger areas and actaccordingly. Each cache site should have theequipment arranged in such a manner that itis easy to determine if anyone has tampered

with the equipment. This helps in preventingcasualties from boobytraps and mines.Soldiers should not group around theequipment when it is recovered and securitymust be maintained at all times whileredistributing the rucksacks.

In all situations, the commander shouldremember that rucksacks are expendable.Leaders should tailor the fighting loads oftheir units to such a degree that the loss of allrucksacks would not hamper the unit’sability to continue the mission.

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FM 90-5

APPENDIX I

Adjustment of Indirect Fire by Sound

Section I. GENERAL

To effectively use indirect firepower, it issometimes necessary to adjust fire, and in ajungle environment this requires specialtechniques. In the limited visibility of thejungle, the only method available for adjust-ment may be by the sound of the explosion ofthe round. The techniques described areequally effective in the adjustment ofartillery or mortars.

The basic principle of adjustment bysound is that the direction and distance to thetarget are known, and the direction anddistance to the explosion of the round can becalculated fromThese data are

the sound ofcompared to

the explosion.determine the

appropriate correction in deviation and inrange. The problem encountered in thismethod is that the heavy foliage distortssound and makes it difficult to determinerange or lateral shift corrections. There is adistinct technique used to determine thecorrection in each of the two dimensions.

CONTENTSSECTION PAGE

I. General...................................................................I-1

II. Techniques Used to DetermineCorrections..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-2

III. Other Considerations....................................... I-3

I-1

—FM 90-5

Section II. TECHNIQUES USED TO DETERMINECORRECTIONS

CORRECTION IN DEVIATION

The direction from the observer to thetarget is measured from a map or by com-pass. The direction to the explosion ismeasured with a compass. These twoazimuths, expressed in roils, form an angle asillustrated.

CORRECTION IN RANGE

The distance from the observer to thetarget can be measured on a map or can beestimated. The distance to the explosion ofthe round is calculated by counting thenumber of seconds from the impact of the pro-jectile until the observer hears the explosion.Multiply the number of seconds by the speedof sound, 350 meters/second. Add or drop theresulting distance, as appropriate.

I-2

FM 90-5–

To tell the observer when the roundimpacts, the fire direction center (DFC)provides “splash and count.” In splash andcount, the FDC sends, “Splash - four, three,two, one-impact.” On the word “impact” theround lands, and the observer startscounting the seconds until he hears theexplosion.

Section III. OTHER CONSIDERATIONS

The FDC normally does not send “splashand count”; rather, it must be requested in thecall for fire by saying, “Cannot observe -splash and count.”

Many times in dense jungle terrain, around’s effect is lost in the trees. Delay fuzecan be used to penetrate the foilage and putthe desired effects on the ground. Acombination of fuze quick and fuze delay canbe effective.

I-3

FM 90-5

APPENDIX J

Defensive Formation

Section I. GENERALJungle defensive operations are based on Three defensive formations will be

the same fundamentals of the defense used in presented here: the perimeter, the triangle,other type operations. Some of the and the “Y.” Platoon-size elements will be thefundamentals may acquire a special signifi- primary consideration, although thecance in the jungle. The basic factors of techniques mentioned are adaptable to larger

observation and fields of fire, cover and units. It should be noted that all three de-fensive postures have definite advantages asconcealment, obstacles, key terrain, and well as inherent disadvantages. Units should

avenue of approach should always be con- vary their type of defensive posture in ordersidered carefully. to avoid establishing a pattern.

Section II. FORMATIONS

PERIMETER DEFENSE

The first of the defensive formations isthe perimeter. All elements are generally con-figured in a circular formation, and theterrain is used to the maximum advantage.

CONTENTS

SECTION PAGE

I . General.................................................................................J-1

II. Formations................................................................. J-1

J-1

—FM 90-5

Advantages are: I t i s m u t u a l l y s u p p o r t e d b yo b s e r v a t i o n / c o m m u n i c a t i o n , a n d

360-degree security.patrols are easily coordinated.

Disadvantages are:

Centralized control. Any pene t ra t ion c rea tesproblems of enfilade, masking, and/or

Quick emplacement, and it cancross fires.

be executed by any size unit. It is difficult to achieve finalprotective fires with the crew-served

The frontage of the perimeterweapons and, because of the circularconfiguration, the unit is vulnerable to

can be easily adjusted and internally re- the entire effects of the bursting radiusinforced. of an indirect fire weapon.

The basic technique used to establishthis defensive formation is the clock system.This involves the platoon using the directionof movement as 12 o’clock, with one squadoccupying from 8 to 12, one squad occupyingfrom 8 to 4, and the last squad occupyingfrom 4 to 12. The headquarters element wouldnormally be located in the center of theformation to facilitate control. It is generallysuggested that automatic weapons be placedto cover the most likely avenues of approach.At least one machinegun should be kept withthe headquarters, under the control of theunit leader, for deployment against a specificthreat.

TRIANGLE DEFENSEThe second of the defensive formations is

the triangle defense. This formation is amodification of the perimeter.

J-2

FM 90-5-

Advantages are: Disadvantages are:

360-degree security. One or more legs of the triangle

Quick emplacement, and it canmay be subjected to enfilade fire.

be executed by any size unit. Soldiers located at the corners

A t a r g e t a p p r o a c h i n gare bunched, thus increasing the dangerfrom indirect fire.

perpendicular to any side of the trianglebecomes vulnerable to at least one-third Penetration by the enemyof the fighting force and at least two creates problems of enfilade, masking,automatic weapons. and/or cross fire.

It is a dual purpose formation inthat it may be used as either a defensiveor offensive ambush formation.

This defensive formation is bestestablished by having the commander moveforward with one element and establish abase line. Again, 12 o’clock is used as thedirection of movement. The baseline could beestablished by the first squad, running from8 to 12. Once this base line is established andthe squad is prepared to provide support, thenext squad moves forward and occupies thestraight line position from 8 to 4; finally, thelast squad moves forward and occupies thestraight line position from 4 to 12. The head-quarters element will normally locate in thecenter of the formation. If three machinegunsare available, one will be placed at eachcomer in such a manner to allow flexibility inproviding final protective fires down either ofits two sides. If only two machineguns areavailable, one may be placed to cover the twosides deemed most vulnerable to attack. Thesecond machinegun should be kept with theheadquarters element under control of theunit leader. Firing positions should be prepared at all three comers.

“Y” DEFENSE

The third defensive formation is the “Y.”This formation, like the triangle, may beutilized as an offensive formation, usually inan ambush. Depending upon the situation, itcan be a very effective defensive formation.

J-3

–FM 90-5

The recommended technique foremplacement of this formation is for the unitleader to take one element and theheadquarters forward and establish thecenter of the sector. This establishes the 12o’clock position. The remaining elementsstay in security positions. Since all legs of the“ Y ” are mutually supporting, thecommander has the option of having allsoldiers on each leg face the same direction,or he may alternate fire teams. Once thedecision is made regarding which method isto be used, subsequent legs of the “Y” mustconform to the initial one. Once the leadsquad is emplaced, the next squad movesforward to the center point and is closelydirected into the 8 o’clock position. After thesecond element is in position, the thirdelement moves forward to the center pointand is closely directed into the 4 o’clockposition. If three machineguns are available,one is positioned at each leg, with possiblefinal protective fires across the fronts ofadjacent legs. If only two are available, theyare positioned at the center point to providefire down the legs. This positioning of two isnot preferred because it does not allow fordispersion; plus, the machineguns arebunched and extremely vulnerable toindirect fire.

J-4

FM 90-5

Glossary

ADAACPASPAVLBCBRC&CCEOICOMSECCPDZFACFDCFISTFOFPFFRAGOFSCOORDHEHEAT

HFICM

JOES

LAPES

LBELCMLZMETT

MOGASMOPPNBC

air defense artilleryarmored personnel carrierammunition supply pointarmored vehicle launched bridgechemical, biological, and radiologicalcommand and controlcommunications-electronics operation instructionscommunications securitycommand postdrop zoneforward air controllerfire direction centerfire support teamforward observerfinal protective firefragmentary orderfire support coordinatorhigh explosivehigh explosive antitankhigh frequencyimproved conventional munitions

jungle operations extraction system

low altitude parachute extraction systemload-bearing equipmentlanding craft, mechanizedlanding zonemission, enemy, terrain and weather, and troops and timeavailablemotor gasolinemission oriented protection posturenuclear, biological, chemical

GLOSSARY-1

—FM 90-5

OPOPORD

ORPPLPLLPOLPWPZRCLRSLAR

STANOTACAIRTOCTOWVTR

observation postoperation orderobjective rally pointphaselineprescribed load listpetroleum, oils, and lubricantsprisoner of warpickup zonerecoilless rifleside-looking airborne radar

surveillance, target acquisition, and night observationtactical aircrafttactical operations centertube-launched, optically-tracked, wire-guided missilevehicle track retriever

GLOSSARY-2

FM 90-5

By Order of the Secretary of the Army: 16 AUGUST 1982

E. C. MEYERGeneral, United States Army

Chief of Staff

Official:

ROBERT M. JOYCEMajor General, United States Army

The Adjutant General

DISTRIBUTION:

Active Army and USAR: To be distributed in accordance with DA Form 12-11B, Requirementsfor Jungle Operations (Qty rqr block no. 307), and Operations of Army Forces in the Field (Qty rqrblock no. 405).

ARNG: To be distributed in accordance with DA Form 12-11B, Requirements for JungleOperations (Qty rqr block no. 307).

Additional copies may be requisitioned from the US Army Adjutant General Publications Center,2800 Eastern Boulevard Baltimore, MD 21220.

U .S. GOVERNMENT PRINTING OFFICE : 1987 - 189-575 : QL 3

PIN: 051485-000