Notes on Ammunition 1918

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N O T E S O N

AMMUNITIONBULLETINS 216-R2 AND 287

Compiled by

Major Wm. C. Foote, C. A.

DOWNGRADED AT 3 YEflR INTERVALS;

DECLASSIFIED AFTER 12 YEARS.

DOD DIR 5200.10

COAST ARTILLERY SCHOOL

Fort Monroe, Va.



fBESS OF

BUEKE & GREGORY, INC.

NORFOLK, TA.



COAST ARTILLERY SCHOOLFORT MONROE, VIRGINIA

October 31, 1918.

The following "Notes on Am munition, "p repared under

the immediate supervision of the Commandant, is published

for use as a text book in the Coast Artillery School and in

thej[universities giving preliminary military training, and

supersedesâll bulletins heretofore published on this subject.

By order of Colonel Welshimer,

C. L. Kilburn,

Lt. Colonel, C. A.

Secretary.

V



NOTES ON AMMUNITION

T A B L E O F C O N T E N T S .

P A G E S

General Definition and Classification of Ammunition 5

Chapte r 1—Primers for Seacoast and Mobile Artillery 7

C hap ter I I— Prop el l ing Charges 20R eq uire m en ts of a Prop elling Ch arge 21D evelopm ent of the powder g ra in . . . . 22Sm okeless Pow der 24Nitrocellulose Pow der 24

Nitroglycerine Pow der 25M ak e up of the pow der charge 26Care an d storage of pow der 29

Ch apter I I I— Project i les 31C oas t A rtillery Pro jectiles 33M obile A rtillery Pro jectiles 41

Paint ings and Markings 37 and 44Care and Storage of Projectiles 39 an d4 8Cop per Fo uling of the Boro 49

Ch apter IV— Bu rst ing charges 51

C hap ter V— Fuzes 57Genera l classification of fuzes 57

D etailed desc ription and cu ts of fuzes 63

C ha pter VI— Effect of Fire 103

Appendix I— A m m unit ion Tables 124Ap pendix II— Bib liograp hy 130



NOTES ON AMMUNITION

G E N E R A L D E F I N I T I O N A N D C L A S S I F I C A T I O N

O F A M M U N I T I O N .

Ammunition, in gen eral, is the t er m app lied to all elem ents,including the projectile itself, used to send a projectilefrom the bore of a gun.

Round of Ammunition— those elem ents used in firing a gun

once. It is composed of:Primer— a device used to ignite the propelling charge.

Propelling charge—the explosive placed behind theprojectile in the bore of the gun and used toimpart motion to the projecti le.

Projectile—a missile thrown from a gun by the propelling charge to serve as a carrier for high explosive, gas, smoke, etc., which it is desired tocarry to and explode or scatter at a definitepoint .

Bursting Charge—-the explosive placed in the cavityof the projectile and designed to explode withsufficient v iolence to ru p tu re th e shell and hu rlthe fragments with destructive effect.

Fuze—a device attached to the projectile to causethe detonation of the shell at the time or underthe circumstances desired.

Kinds of Ammunition— the relatio n of the above elementsof a round of ammunition to each other determinesthe kind of am m un ition. Th is division is as follows:



Fixed Ammunition— In wh ich th e prim er, propellingcharge, and projectile are in a single metal contain er, as in th e Springfield rifle ca rtrid ge .Th is typ e of am m un ition is used in 3 " , 4.7 ",

and 75mm. guns .

Semi-Fixed Ammunition— in which the primer andpropelling charge are in a single metal container,and the projectile is loaded sep arate ly. Th istype is used in the 4.7" and 6" howitzers, and9.45" t rench mor tar .

Separate Loading Ammunition—in which primer,propelling charge, and projectile are each loadedas a sep arate un it . Th is typ e is used in gunsof 5" caliber and up, 155mm. gun, and howitzersof 8" caliber and up.



NOTES ON AMMUNITION

CHAPTER I

PRIMERS FOR SEACOAST AND MO BILE ARTILLERY

COAST ARTILLERY PRIMERS

Friction PercussionElectric DrillCo m bination Electric and Friction Ign it ing

1914 FR ICTIO N PR IM ER

The chief parts of the friction primer are as follows:To bin Bronze Bo dy Gas CheckB utto n and B utto n W ire Gas Check SeatSe rrated Cy linder Closing ScrewFriction Com position Black or Shrapnel Powd er

Closing Cup

This primer consists of a tobin bronze body resembling a small arm s c artrid ge case, drilled th roug h the baseto receive a wire to which is assembled the gas check anda button to engage in the firing leaf. A threaded housingcontains the friction composition and is covered by aclosing screw drilled with three holes to permit the accessof flame from the friction composition to the primer charge.

In assembling, the housing containing the friction pellet isscrewed home, the gas check is inserted and the wire passedth ru it. The closing screw is then screwed in and thebu tto n screwed on the wire and riveted. Th e three tubu larpellets of compressed powder are then inserted and thecen ter hole filled w ith grains of loose pow der. The endpellet is then inserted, the closing cup is pushed down on



top of it and the end of the primer crimped and shellaced.In action, the button which engages in the firing leaf

is pulled back. This pulls the wire back, forcing the serratedend of the wire through the friction pellet and seating the

gas check to prevent the escape of gas to the rear aroundthe wire. The tube of the primer expands under pressure,thus preventing the escape of gas around the exterior ofthe primer casing. The flame from the friction composition penetrates the holes in the closing screw, igniting the

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loose powder, which in turn ignites all the powder pellets,and forces out the closing cup allowing the flame to passthrough the vent in the breech block and ignite the propelling charge.

Used in Coast and Mobile Artillery for service andaction.

Friction composition: Sulphur, 9%Chlorate of potash, 52%Sulphate of antimony, 27%Glass, 12%

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E L E C T R I C P R I M E R .

The action of this primer is as follows: One end ofthe co nta ct wire is soldered to the c on tac t p lug, which isinsulated from the bod y and at tac he d to the b u t to n wirewhich is also insu lated from the bo dy . I t forms electrical contac t throu gh the bo tto m w ith the external circuit by m eansof clips att ac he d to th e firing m echan ism . T he oppositeend of the contact wire is soldered to the contact sleeve,which is in electrical co nta ct wi th the body . An electriccurrent of sufficient intensity to heat the contact wire ispassed through the primer and ignites the gun cotton.This ignites the primer charge of loose powder and pellets.The closing cap is blown out and name sent through thevent to the propell ing charge.

C O M B I N A T I O N E L E C T R I C - F R I C T I O N .

As the manufacture of this type has been discontinued no detailed description will be given here. Th is

prim er is designed to func tion as an electric prim er. Ifthis fails a lanyard may be attached and the primer firedby friction. Ho wever, the above ord er can no t be reversedas the contact wire would be broken.

P E R C U S S I O N P R I M E R .

There are two types of percussion primers in common

use in Seacoast Ammunition, the 110 grain and the 20grain. T he only difference betw een these two prim ersis in the amount of black powder contained in the body ofth e prim er. T hey are used in fixed an d semi-fixed am m unition . Th e essential elements of a simple percussion prim erare the primer cup, the anvil, and the percussion composition. All the m etal p ar ts are m ade of brass. A typical percussion com position standar d for the 110-grain percussion

primer is as follows:Lead Sulph-cyanate 2 5 %Ch lorate of Po tash 53 %Sulphide of Antimony 17%Trinitrotoluene 5%

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In the rea r of the prim er a recess or po cket is formedto con tain the percussion prim er prop er. T he cup , anvil,and percussion composition are assembled and inserted inthis recess. A hole, drilled thr ou gh the diap hra gm , allows

the flame to pass to th e prim er charg e. T he pow der ispressed into the body of the primer around a central wire,which, when removed, leaves a longitudinal hole throughthe full leng th of th e charge. E ig h t rad ial holes aredril led th rou gh the prim er b od y and the compressed charge.The compression of the powder and the drilling of the holesthrough it increase the time of burning of the charge andcause it to burn with a torch-like effect, making ignition

of the propelling charge more complete.In action, the firing pin strikes the cup, indents it , and

fires th e percussion pellet b y forcing it against the anvil.T he flame passes thro ug h the hole in the diap hrag m and setsoff the prim er charge . This blows ou t th e closing cap an dignites the propelling charge.

T he y are used in fixed and semi-fixed am m un ition only.

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DRILL PRIMER.

This primer is designed to replace the relatively expensive 1914 Friction and Electric primers for drill purposes

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an d sub-ca liber pr act ice. I t is a simplifiedffrictiorTprimerand its action is similar to that described above underfriction prime rs. It s adva nta ge s are th a t it is cheap andm ay be assem bled at the po st. To assemble the drillprimer: Clean the case in lye or sal-soda water, dry, andreload with the aid of the assembling tool as follows:a serrated wire is placed in the primer body, a button wirescrewed to its end , the friction com position inserted in itsliner., a cha rge of black p ow der p ou red in, and th e end of theprimer sealed with a moistened closing cup.

I G N I T I N G P R I M E R .

These primers are used in the base of sub-caliberammunition and require for their ignition a drill primerinse rted in the breech block. Th is prim er consists of acup provided with a central vent to allow the passage ofthe flame from the regular primer, this vent being closedbefore firing by a th in laye r of wax. This ignites the blackpowder in the body of the primer which forces a slidingvalve back against the vent in the cup, preventing the

escape of gas to the rear.CA KE AND STORAGE OF SEACOAST PR IM ER S.

Primers are issued in hermetically sealed tins insuitable wooden con tainers. T he y should be stored in adry, cool place apart from other kinds of ammunition andsecure from e ntran ce by un auth orized persons. Theseprim ers m us t no t be opened un til needed for use. Th ey

are inspected once a month by the responsible officer whosees that they are stored according to regulations and soreports to the fort commander.

M O B I LE A R T I L L E R Y P R I M E R S .

1914 F R I C T I O N P R I M E R . —

See Pag e 7 under Co ast Artillery Prim ers for thedetailed description and diagram of this primer.

21 G R A I N P E R C U SS IO N P R I M E R . —

This primer is so named because it contains 21 grainsof black pow der in the prim er charge. It s essential par tsare the primer cup, anvil, and percussion composition.It consists of a brass case resembling a small arms cartridge

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case. The head or rear of this case is counter sunk forminga cup shaped recess, in which the percussion primer properis inserted . T he percussion com position contains thefollowing ing redie nts: Fu lm ina te of M ercury 3 5 %

Ch lorate of Po tash 3 5 %Sulphide of An timony 30 %

In action the blow of the firing pin explodes the percussion element by forcing the primer cup against theanv il. The flame passes throu gh holes at the base of theanvil and ignites the prim er charge. Th is blows ou t theclosing cap and ignites the propelling charge.

This percussion p rim er is used in fixed and semi-fixed

mobile artillery ammunition, and in separate loadingam m un ition in certain instances such as the 155mm.Filloux gun, where the firing mechanism 1 is so arrangedthat it contains a firing pin.

" T " T U B E F R IC T IO N P R I M E R . —

This primer is designed for use in British howitzersand is fired by the pull of a lanyard from the side of the

piece instead of th e rea r as in the case of m ost friction pr im ers .I t consists of a head of gun m eta l brass, a body of solid drawnbrass, a soft copper ball, and a friction bar of round copperwire. The latter is twisted into a round bar with a lanyard-loop at one end, the body of the wire being roughened.A copper shearing wire holds the friction bar in placebefore firing. A hole in the side of th e he ad over th efriction bar is charged with 3 grains of friction composition

laid over the roughened portion of the friction bar, thehole being closed by a bra ss screw. The body is chargedwith 8 grains of black powder and sealed with a shellacedcork and pap er disc. T he upper pa rt of the bod y has acentral tube which is enlarged at its lower part into aconical recess into which the copper ball fits and is heldin place by a brass plug drilled with three holes to permitthe access of the flame to the black powder charge.

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T he action of th e " T " T ub e p rimer is as follows:W hen the lany ard is pulled t1 e friction bar is drawnth ro ugh the friction com position, igniting it . Th e flamepasses around the copper ball, through the fire holes inthe brass plug, and ignites the black powder in the

body of the tu be . The force i.>•;• he explosion dr ives th ecopper ball tightly into its co .^d recess, thus securingob tur atio n. Th e walls of the am er bod y expand und erpressure and pre ve nt th e escape of gas to the reararoun d the exterior of th e p rh ae r casing. T he force ofthe explosion of the primer charge forces out the closing•cork and ignites the propelling charge in the powder•chamber of the gun.

STORAGE AND CARE OF MOBILE ARTILLERY PRIMERS.

Pr im ers are issued in tin bo s sealed by a m etal stripsoldered to bo th box an d cover. Th is strip m ust no t beremoved until primers are required for use as dampnesswill cause misfires or hangfires. Prim er boxes shou ld bestored in dry dug outs, protected om w eather and enemyshell fire, and should be kept apart from all other kinds•of ammunition.

G E N E R A L P R E C A U T IO N S FO R T I E H A N D L I N G O F P R I M E R S .

Prim ers, if used in a dam ? a or d irt y condition, willnot seal the vent effectively, causing possible erosion ofthe vent and, in consequence, difficulties in the extractionof sub sequen t prim ers. Care sli uld be tak en th a t th e

primer bodies are not dented, disct

ted or touched with aiile, an d th a t the primer bodies nd vent are free from dirtwhen the primer is inserted in ih-i vent .

Pr im ers should be used 'in the order of their re ceip tat the battery to prevent then- deterioration from longstorage.

Any primer that has been tire, L and failed to functionshould have the button wire b • -t back through 180° to

prevent fur ther a t tempts a t nmi£.

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CHAPTER II

PROPELLING CHARGES.

Explosives in general— An explosive is a substan ce c apab leof being sud den ly transform ed in to ho t gases, wh ich at themoment of their formation tend to occupy a far greatervolume than the original substance from which they sprang,and in consequence exert great pressure on their immediatesurroun dings. Th e explosive reaction may be init iate dby hea t, friction, o r percussion . I n the case of high

explosives a detonating system is normally used, whichcorresponds to a very violent and sharp blow, accompaniedby he at an d flame. T he hea t given ou t by an explosionis due to the chemical action between the atoms makingup the su bstance, the a tom s rearranging themselves andjoining up with new partners to form more stable combinatio ns. In a prop ellant such as smokeless powd er th erate of explosion has to be controlled so as not to burst

the gun, but in a high explosive such as T. N. T. it is givenfree rein.

Ignition— the se tting on fire of a pow der grain or cha rge.Inflammation— the sp read of th e flame from g rain to

grain of the charge, or from point to point of the grain.Explosion— rapid conversion of a sub stance into a

large volume of hot gases and solids.

Progressive explosion— an explosion in which the conversion takes place comparatively slowly tending to produce a tearing or pushing effect.

Detonation—an explosion in which the conversiontakes place with extreme rapidity, producing a crushingor shattering effect.

P R O P E L L I N G C H A R G E S .

Powders which are used for propelling charges areprogressive explosives, which are comparatively slow burning, and must not be confused with the high explosivesused for shell fillers. W he n these pow ders are ign ited a tone point, the reaction proceeds progressively over thesurface of the grains, then at right angles into the grainun til th e whole m ass is consum ed. Explosions of this

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nature are not different in principle from the burning oflogs of wood in a stove . In b o th cases there is a pr ogressive change from particle to particle throughout thewhole m ass. T he ra te of bu rning depends no t only onthe substance burned, but on the size of the pieces, that is,

for the same substance, the rate of burning increases withthe surface exposed. A log of wood which would bu rnfor a long time if in one piece can be burned quickly ifcu t in to small M ndlings. T he principle difference is th a tpow der conta ins in itself all th e e lements necessary forits combustion, while wood will burn only if oxygen issupplied in sufficient quantity.

R E Q U I R E M E N T S O F A P R O P E L L I N G C H A R G E .

Safe to manufacture, and free from injurious effectsupon the operatives.

Incapable of being detonated.Should produce a minimum amount of erosion of the

bore and not overheat the gun.Grains should not be brittle or porous.

Must be stable in storage.Material should be available and cheap.Must produce the required muzzle velocity within

the limits of pressure allowed.

P O W D E R S U S E D A N D D I S C A R D E D .

Black powder in small grains was the first powder usedas a propelling charg e. I t is a m echan ical m ixtu re of

7 5 % saltpeter, .15 % charcoal, and 10% sulphur. Th esaltpeter furnishes the oxygen to burn the charcoal andsulphu r. Black powd er is extremely dangerous to m anu factu re and han dle . I t gives large volum es of smokewhen fired, fouls the bore, and burns too rapidly to giveproper distributio n of pressure. F or these reasons it isno longer used as a propelling charge, but is still used forsaluting purposes, primers, igniters, time trains in fuzes,

and bursting charges for shrapnel.About 1860 General Rodman discovered that bycompressing black powder into large grains a more progressive burning could be obtained.

After black powder brown prismatic powder was usedin our service. Th is was similar to black pow der, bu tthe charcoal was replaced by undercharred rye straw.

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Th is gave a slower bu rnin g pow der w ith less smoke. I tgave more uniform muzzle velocities than modern smokeless powder due mainly to uniformity in making up thepowder charge.

S I Z E AND S H A P E O F P O W D E R G R A I N .

The most desirable form of powder grain is one thatgives off gas slowly at first, starting the projectile beforethe high pressure is reached, then w ith increasing b urn ingsurfaces evolves gas more rapidly, maintaining the pressurebehind the projectile as it m oves down t he bore, and beingentirely consumed th e in sta nt th a t the projecti le leavesthe muzzle.

The form and size of the powder grain should be soregulated as to produce the required muzzle velocity withmaximum pressure not exceeding that allowed for the gun.

The rate of emission of gas from a burning grain isdependent upon the rate of burning and the area of thebu rnin g surface. Th e ra te of bu rnin g increases with the

pressure and also with the temperature of the burning gases.Carrying out this idea of a proper form of powder

grain, the cannon powder in our service is formed intocylindrical grains with seven longitudinal perforations.(See diagram on page 23 ). This form of gra in oftenleaves slivers of unburned powder after the projectileshav e left the b o r e of t h e gun. To overcome thisdefect, a grain having six cylindrical ribs on its circum

ference, the centers of the ribs being the six outside holesof the former sha ped grain. Th is grain is kno wn as thecorrugated multiperforated cylindrical grain, and is theform of grain now being m anufa ctu red in th e U . S. Thelength and diameter of the grain vary for different guns,the size increases with the caliber and length of gun,, andfor the same gun, decreases with increased muzzle velocity.Powder designed for one gun should never be used for anyother gun, except in cases of absolute necessity, and then apowder grain of larger dimension than the one usually usedshould be employed, as the use of a smaller grain will developpressures in excess of those for which the gun was designed,probably resulting in the destruction of the piece.

Critical dimension of a grain of powder is that dimension which when burned through the entire grain is con

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sum ed. I t is the thickn ess of the web betw een any twoholes or between an outside hole and the circumference.

In other services, cannon powders are made into grainsof various shapes. Cubes, solid and tubular rods of circularcross sections, flat strips, and rolled sheets are among other

practical forms.M A N U F A C T U R E O F S M O K E L E S S P O W D E R .

Modern propell ing charges are chemical compoundswhich bu rn pratically w itho ut smo ke. In our arm y andin the French the powder used is nearly all pure nitrocellulose, but the British use a mixture of nitrocellulose andnitroglycerine. Ex perim ents are being cond ucted in this

country which indicate that a flashless powder has beendeveloped, b u t no definite info rm ation is availab le. Thispowder is said to be satisfactory for howitzers but has notyet been developed to a point where it can be used in highvelocity guns.

N I T R O C E L L U L O S E P O W D E R .

Cotton linters, cheapest form of cotton, after bleachingand purifying, are run through a picker which opens upthe fibers and break s up th e lum ps. I t is the n thoroug hlydried and prepared for n itratio n. Th e m etho d of nitrationmost commonly employed is to put the cotton in a largevessel filled with a mixture of nitric and sulphuric acids.Sulphuric acid absorbs the water developed in the processof nitration, which would otherwise too greatly diluteth e nitric acid. After im m ersion for a definite length oftime the acid is drawn off and water run in, care beingtaken th at the cot ton is submerged during the change. W etnitra ted cotton is now rem oved from the n itra tor and repeatedly washed and boiled to remove all traces of thefree acid. As the keeping qualities of the nit ra te d co tton aredependent upon the thoroughness with which it is purified,specifications for powder in the United States Army and

Navy require that the nitrated cotton be given at leastfive boilings at this stage of manufacture, with a changeof water after each boiling, the total time being 40 hours.Following this preliminary purification, the cotton is runthro ug h a pu lping mach ine. Th is is necessary becauseof the difficulty experienced in removing the free acidunless the fibers are cu t up into short length s. After

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pulping , the c ot ton is given six m ore boilings, followed byten more cold w ater washings. Th e resulting m aterialis known as wet gun-cotton or pyrocellulose and is a highexplosive, very dangerous to handle when dry.

Colloidization. This process comprises a changing of

gun cotton, an explosive of the high order, to a low orderexplosive, by colloiding it in a mixture of two parts etherand one part alcohol by volume or 64% ether and 36%alcohol by w eigh t. I t is first pa rtial ly freed from w aterby a centrifugal wringer and by pressing the pyrocelluloseinto solid blocks and forcing alcohol through the mass,which forces ou t th e w ate r. T he blocks are tran sferredto a mixer and the proper am ou nt of ether add ed. T he

mixture of ether and alcohol dissolves the pyrocelluloseinto a soft paste-like mass in which all trace of the cellularstru ctu re of co tton has disapp eared. A stabilizing age nt,diphenylamine, is added during the mixing process.

As soon as the process of colloidization is complete,the mass is pressed into blocks, forced through a macaronipress to mix it , and the strands again pressed into blocks.These are transferred to a finishing press, where the material

is forced through dies and comes out in*the form of perforated rods, which are cu t up into sho rt leng ths. Th egrains are now thoroughly dried, and after drying thepowder is blended, and finally packed in air-tight cans orboxes.

N I T R O G L Y C E R I N E P O W D E R .

The British use a powder called "Cordite", the namebeing derived from th e cord-like form it assumes in m an ufacture. This pow der is a m ixture of 6 0 % gu n-cotton ,3 5 % nitroglycerine and 5% vaseline. This mixture producesan explosive of high order which is reduced to a powder oflow order by a process similar to the process of colloidization in nitrocellulose powder except that this is accomplished in the case of nitroglycerine powders by "Acetone'

1

in^the place of ether and alcohol.N itroglycerine pow ders are m ore powerful th an nitro

cellulose powder, permitting the use of smaller powderchambers, and hence of l ighter guns. Nitroglycerinepowders also give more regular ballistics, do not becomebrittle in storage, are cheaper, and more non-hygroscopicth a n nitrocellulose pow der. H ow ever, nitroglyce rine pow der

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has the disadvantage of producing greater temperatures-for a given pressu re, th us causing g reate r erosion of t hebore.

Ballistite is another nitroglycerine powder used inmobile art i llery. I t is used in tren ch m or tars .

M A K E U P OF P O W D E R C H A R G E .

Th e m aterial used for pow der bags is ra w silk, know nas cartridge cloth, wh ich b urn s w itho ut leaving a ny residue.Cotton cloth sometimes leaves burning fragments in thebore after firing. As th e p rodu cts of com bu stion of ni tro cellulose powder are explosive when mixed with air, a

spark left in the bore when the breech is opened, mayresult in an explosion, which is called "flareback."Pow der charges for guns in Co ast A rtillery are m ade

up of base charges, a different size charge being made upfor each caliber gun . Th ese base charges contain w ha t isknown as an "igniter" or igniting charge, to insurethe com plete ignition of the entire charg e. An ignitermay be either an end igniter, which is a small amount of

black powder quitted into the ends of the charge, or a coreigniter, which is a colum n of black pow der run nin g thro ug hthe center of the charge. These end and core ignitersare used so that the flame from the primer will instantlyignite the entire powder charge and thus insure uniformbu rnin g of the pow der. I n pow der charges for SeacoastMortars, where a system of zones is employed, requiring adifferent muzzle velocity for each zone, to obvia te the

necessity of issuing and ha nd ling ind ividua l charges for eachmuzzle veloc ity, sectionalized charges are used. Th is sectionalized charge consists of a base charge, with its end and coreigniters, and one or more increments, which are smallcharges in separate bags secured to the base charge bytyin g strips of cartrid ge cloth. These incre m ents do no tcontain igniters.

As all M obile A rtillery can no n now use two or m ore

muzzle velocities, sectionalized charges are used in allmobile artillery pow der charges. The re is a difference,however, between the sectionalized charges of mobileartillery and those used for the mortars in Coast Artillery,in that the increments in mobile artillery charges containcore igniters run nin g' longitud inally, w hereas tho se inseacoast mortars contain no igniters.

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In order th at the p owder charges m ay be hand ledeasily, it is nece ssary th a t they possess a ce rtain degree ofrigid ity. To secure this in sectionalized charges severalstrips or rods of nitrocellulose powder are inserted longitud ina lly along the ou ter surface of the charge. Th e

following diagram shows the construction of the powdercharge for an 8" Howitzer, Mark VI.

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CARE AND STORAGE OF POWDER.

In C oast A rtillery— pow der is issued in sealed m et alcontainers, which must not be opened unti l powder isneeded for use. I t should be stored in $ ry m agazines,where the temperature does not r ise above 95° F., andseparate from other Mnds of ammunition.

In Mobile Artillery—powder issued same as above.It should be stored apart from other ammunition in shellproof du go ut s if possible. If no du go uts are availab leit should be stored in dumps at least 20 yds. apart, andnot more than fif teen containers in each dump, protectedfrom the weather and enemy shell fire. It should be

carefully camouflaged, a nd ke pt at as uniform a tem pe rature as possible by protecting it from the direct rays ofthe sun.

D E T E R I O R A T I O N O F P O W D E R

Th e deterio ration of pow der m ay be detec ted by the characteristic odor of nitrous vapors upon opening a case ofpowder, by the fact that the powder bags are eaten away

or have turned yellow, brown, or black, or by the factth a t the pow der grains themselves become pa sty or containyellowish spots.

Deterioration may also be detected by a special test,kno w n as the m eth yl violet test. Th is consists in placinga number of grains in a bottle together with a piece of themethyl violet paper, upon which the date has been marked.Th is pa pe r is left in the bottl e for th irt y day s. If at th e

end of this time the paper has changed color, the powderhas deteriorated, and should be returned to the base forfurther examination.

G E N E R A L C O N S I D E R A T I O N O F P O W D E R .

The ballistic qualities of each lot of powder varyslightly. Therefore, it is im po rta n t th a t pow der charges

be grouped by lot nu m be r. Also for a given shoot, in orderto obtain as uniform a muzzle velocity as possible, it isessential to use powder of the same lot, using it in the orderof receipt at the battery.

Powder Blending is for the p urp ose of ob tainin gcharges wh ich give uniform muzzle velocities; this is accom plished by distributing among all the sections to be formed

29



an equal am ou nt from each of the original con taine rs used.Powder is blended in the shade so that the temperaturewill no t be un even ly effected by the ray s of th e sun ; also indry weather, as the presence of moisture in powder lowers

the muzzle velocity. Po w der is usu ally blen ded by theshovel or cycle method, in which a single pile of powder isshoveled from the bottom into five or more piles, and thenba ck again. Th is op eration, called a cycle, is performedfive times, and an equal amount of powder by weightplaced in each section. T he mixing is done on paulinsw ith wooden shovels to pr ev en t possible spa rks. Blendingis always done before firing of powder in any one lot in

Seacoast Artillery, never of powder of different lots withoutthe permission of the Ordnance Department.Iii the field blending is very obviously impracticable.

For this reason all powder in Mobile Artillery is blendedat the base, weighed out into the proper size charges,placed in bags, an d sealed in m etal con tainers. A b atte ryof mobile artillery receives its powder ready for use.

30



CHAPTER III

PROJECTILES.

G E N E R A L C O N S I D E R A T I O N S .

All modern projectiles have the same general shape,cylindrical w ith ogival hea d. Th e leng th is from 2\ to 5times the caliber of the gun. T he lon gitudinal sectionof the ogive is usually the arc of a circle, the radius of whichvaries from 2 calibers to 10.5 calibers. The ogive mayex tend to the po int, if a base fuze is used, or it m ay be t r u n ca ted to form th e fuze seat for a po int fuze. In rear of theogive is the maximum diameter of the shell itself, whichis know n as th e bourre let. T he body of the shell extendingfrom the rear of the bou rrelet to the rota tin g b an d is ofslightly smaller diam eter th an th e bourrelet. Th e copperrotating band has a greater diameter than the bore of thegun until the force of the explosion makes it conform to theshape -and size of th e lan ds and grooves. In rea r of therotating band is the base, which is cylindrical or conical,the lat ter shape being called "boat-tailed."

Diagram showing the general shape of a projectile andi ts impor tant par ts :

BOURFtELETr

Ogive— The head or ogive of a pro jectile is a c ircularcurve struck from a center on a line perpendicular to theaxis of the. projectile an d w ith a rad ius expressed in calibers.T he rad ius was form erly a bou t 2 calibers for all projectiles,b u t i t has been found in rece nt years th at a m arked reduction in air resistance and consequent increase in rangecould be ob taine d by increasing the radiu s of ogive. Th is

31



radius now runs as high as 10.5 calibers. Projectiles withthese sharp points, however, do not have the same capacityfor piercing armor as projectiles with blunter heads, eventhough the former are provided with armor piercing caps.

C. R. H.— This abbreviation means the " CaliberRadius of Head." (It is sometimes used in range tables,especially British.)

Bourrelet— The bourrelet has a carefully finishedsurface which is of but slightly less diameter than the diameter of the bore of the gun between lands. This difference in the diameter of bourrelet and that of the bore isknown as clearance and is only a few hundredths of an

inch. The purpose of the bourrelet is to provide a bearingsurface which centers the forward end of the projectile inthe bore, and so prevents any shock against the sides of thebore and consequent irregularity in departure from themuzzle. The body of the projectile is machined off to asmaller diameter than the bourrelet to prevent any contactwith the lands and thus reduce the friction. This also reducesthe cost of manufacture as the dimensions do not have to

be so exact nor the finish so smooth.Rotating Band—Between the body and the base an

undercut groove is made for the rotatin g band. Thebottom of the groove has waved ridges or knurling to prevent the turning of the band with respect to the projectile.A ring of copper, alloyed with 2\°/0 nickel, is heated andslipped over the base of the projectile, and pressed into theundercut groove while still hot. I t is machined into shapeafter it has cooled. The width of the band is from \to \ caliber, increasing with the caliber of the gun, andthe outside is usually cone shaped to fit the centering slope.The diameter of the band is somewhat greater than thediameter of the bore between grooves, so th at someof the copper must be scraped off as the projectile movesforward. To facilitate th is, one or more grooves, called"cannelures", are cut around the band. The purposes ofthe rotating band are to seat the projectile when rammed,and prevent the escape of gas forward, to center the rearof the projectile and to im part rotation to the projectile.

Base Cover—In base fuzed projectiles there is dangerof premature explosion in the bore of the gun due to leakageof the hot gases of the propelling charge through the baseplug and fuze threads. In point fuzed projectiles this

32



same danger appears, though to a less degree, due to thepores in th e m eta l of th e base of th e shell. Therefore t oprevent this leakage of the gases into the interior of theshell, base covers are attached to all heavy artillery projectiles after the y ha ve been fuzed. A circular un de rcu tgroove is made in the base of the projectile outside the baseplug. A lead disc is placed over th e base of th e projectilecovering the space w ithin th e circular groove. Over thisis placed a flanged copper disc, the flange entering theundercut groove, into which it is caulked with lead wire.

COVERS

COAST ARTILLERY PROJECTILES.

Projectiles used in Coast Artillery may be classifiedas follows:

Armor Piercing (A. P.) Shot—used against the sideof arm ored vessels at sho rt rang e to ob tainpenet ra t ion.

A. P. Shell—used against the side of armored vesselsat longer ranges to damage the armor withoutpenet ra t ion.

Deck Piercing (D. P.) Shell—used in high angle fireto penetrate the deck of vessels and explodeafter penetration.

Common Steel Shell—used in l ight armament againstunarmored ships .

Sub-Caliber—used in target practice.Target Practice—cast iron projectiles for use in

target pract ice .

COM PARISON OF SHOT AND SHE LL.

Shot and shell are of equal weight when used for thesame gun. Th e shot, how ever, is sho rter th an the shell,

33



has thicke r walls an d carries less high explosive. Due to thethicker walls of the shot it has a greater penetrative powerthan the shell. The diagram below shows this comparison.In the shell the bursting charge is 5 to 6% of the totalweight. In the shot it is 1.5 to 2% of the total weight of

the projectile./NCH <<7.P SHELL 1660 LBS.

•B to BOURffCLETC/7P,

// •//y/////y/

////^

r/////////////^7T7?^m.^^ \/////

t*..

\fVSE_£EAT

T

1_ _ _ _ — • — 'I

/NCH fJ.P SHOT I66O LBS.BfJND BOURRCLET

A C/TR

WINDSHIELD

Armor-piercing Cap—All armor-piercing projectilesare now fitted with soft steel caps which, under ordinary-

circumstances, increase the penet ra t ion of the projectilewhen attacking hard-faced armor.

As shown in the above diagram the A. P. cap is

34



fastened to the bo dy of the shell as follows: an annu largroove of semi-circular cross section is ground into the headof the shell an d a similar groove is cu t in th e cap . Thesegrooves coincide when the cap is placed in position. Tw opieces of wire are then driven into the grooves throughtangential holes drilled in the side of the cap, thus fastening

the cap to the head of the shell.If no A. P. cap were used on armor piercing projectiles,

upon impact of the point of the projectile with the specially hardened surface of modern armor the point wouldprobably be broken or crushed and the head of the projectile flattened. T he flattening of th e he ad causes loss ofpen etratio n. How ever, when using the A. P. cap, the capitself strains and bends the hard face of the armor plating.

The cap is soft and the hard point of the projectile is ableto pass through i t , and upon coming in contact with thearmor plate, already strained by the blow of the cap, it isable to pass more easily through it with no shattering ofthe point of the projectile.

Ballistic Cap (Windshield)— Until recen tly the cap in ou rservice was cylindrical in form with a blu n t nose. Th is formwas considered the best for the a tta c k of arm or. How ever,

a sharp-pointed cap is now being made because it was foundthat this form greatly improves the ballistic properties ofthe pro jectile. Th is new form of cap is being adde d to theprojectiles on hand as soon as the shot hoists of the emplacements have been modified to accommodate the increased leng th of shells. T he sho rt caps— arm or piercingcaps—have been threaded so that the new ball ist ic capsmay be added to the projectile by screwing them over theA. P . cap s. The effect of the se ballistic caps is a f latt ertrajectory, greater remaining volocity at a given range, increased range and greater perforating power.

35



12-Inch Shell w ith Old Cap 12-Inch Shell wi th New ModelLong Pointed Cap

S P E C IA L F E A T U R E S O F S EA C O A ST P R O J E C T I L E S .

Tracers—In order that the fire of the guns may bemore accurately controlled through ease of identificationof splashes and that the behavior of the projectile in itsflight may be more effectively studied, a device known as atrace r has been developed. There are two typ es of trace rs,a da y tracer and a nigh t trace r. The nigh t trace r consistsof a tracer and fuze, assembled in a short metal cylinder

which may be secured in a seat prepared in the base of theprojectile. There is a small air cha m ber at the m ou th ofthe tracer, covered by a metal disc, in which is cut a gasport, the size of which depends upon the caliber of the gunin wh ich the t racer is used. The cover is conn ected bya rod to th e friction elem ent. On explosion of the powder charge in the gun, the gas of the charge enters the air

36



cham be r of the tracer thr ou gh the gas po rt; and, while theprojectile remains in the bore, the gas in the air chamberis un de r high pres sure . After the projectile leaves the gun,th e pressure on the tracer po rt, being released, the cover

of the tracer is forced to the rear and thus draws the centralrod back and ignites the friction com pound, which in tur n ,ignites the com pressed, slow-burning com position. Th isbu rns w ith a bright w hite light for 15 to 20 seconds. D urin gth e da y the tracing feature is accomplished by placing in th ecavity of the projectile a mixture of lampblack and water.

On firing, the powder gases enter the shell throu gh asm all orifice a t one side of of th e base. After th e p rojectileleaves the muzzle the inte rnal pressu re forces the tra cerliquid into th e air. Ex pe rim en ts indic ate th at shell prov idedwith this day tracer can be observed for over 7,000 yards.

PAINTING AND MARKING OF SEACOAST PROJECTILES.

In general the painting of projectiles has two objects:to protect the metal from corrosion and to identify thetypes of projectiles and their contents.

The interior of all seacoast projectiles loaded withExplosive " D " are pain ted w ith a non-acid pain t knownas "r ubber in e" to pre ve nt the forming of sensitive compo un ds betw een the explosive and the steel casing of the shell.

The threads of base plugs, fuze plugs and fuzes shouldnot be painted with anything but cosmoline or vaseline.The use of any paint makes it impossible to remove theplugs when necessary.

The exterior of seacoast projectiles are painted variouscolors to indicate the material of which the projectile ismade, the explosive with which it is loaded, and whetheror not it is fuzed. All projec tiles are first pain ted b lackall over except the rotating band, which is never painted.Immediately before firing, however, the bourrelet may bepolished with emery cloth to reduce friction of the projectile and prevent paint from being deposited on the landsof the gun. To ind icate the cen ter of gr av ity, in orde r tofacilitate handling with the shot tongs, and to indicate thematerial of which the projectile is made a band is paintedaro un d the cen ter of gr av ity of the projectile. T he following colors are used :

Forged steel blue gray.Ca st steel w arm gray.

Cast iron olive green.37



DISTINCTIVE G0L0R5 FOR COASTARTILLERY PROJECTILESFORGED STEEL SHELL-UNFUZED

CAST STEEL SHEEL-FUZED

FORGED STEEL SHOT

CAST STEEL SHOT

TARGET PRACTICE PROJECTILES

BLUE GREY WARM GREY

\BLACK = OLIVE GRUN



The one exception to the general rule of using but oneband upon the center of gravity is upon the target practiceprojectile. This projectile is pain ted black all over, thecenter of gravity band of olive green is added, and anotherband of the same color is painted between the center of

gravi ty and the rotat ing band.To indicate whether a projectile is a shot or shell the

following paintings are used:

Sh ot— Th e entire ogive is pain ted the same color as th ecenter of gravity band.

Shell— Tw o-thirds of the ogive is pa inte d the same coloras the center of gravity band, or the ballistic cap aloneis painted that color, if it has one.

Loaded but not fuzed— Four black stripes, one in eachquad ra n t, are pain ted on the base of the projectile fromthe ro tatin g ba nd to the base cover groove. W henth e projectile is fuzed these stripes are pa in ted ou tw ith th e color of the balance of the ba se. T he basecover an d the ro tatin g ban d are never pa inted.

CARE AND STORAGE OF SEACOAST PROJECTILES.

Pile projectiles on their sideswith base towardaccessibleside of pile. Place skids betw een the m to pr ote ct th erotating band and pile each type of projectile separately,grouping them by lots.

Pro jectiles should be paint ed before storing and slushedwith oil if the magazines are damp.

G reat care should be exercised to avoid an y dam age tothe rota t ing band.

Before firing, the pai n t should be scraped from thebourrele t, th e projectiles tho rou gh ly cleaned and a fillisterof heavy grease placed immediately in front of the rotatingband .

Coast Artillery projectiles are usually shipped in crates;how ever, if no crates are available the ro tatin g ban ds shouldbe protected by rope grommets or other suitable material .

39



40



MOBILE ARTILLERY PROJECTILES.

Mobile Artillery projectiles may be classified as tothe material of which they are made, as to whether theyare base or point fuzed, and as to the use for which they

are designed. Pro jectiles are now m ade -of commonsteel, which may be cast or forged steel, and of semi-steel, which is obtained by purifying cast iron in aspecial furnace. Semi-steel con tains from 2 .7 5 % to 3. 25 % ofcarbon and is much more resistant than ordinary cast iron,althou gh less so th an steel. I t is used extensive ly becauseof its lower cost and ease of manufacture.

M obile A rtillery projectiles of less th an 10" caliber

hav e po int fuzes. Pro jectiles of 10" caliber an d over u sua llyhave base fuzes, although point fuzes are now coming intomore general use even on large caliber projectiles.

Mobile Artillery projectiles are classified as to theiruses as follows:

High explosive shells, shrapnel, chemical shells, including toxic, smoke, and incendiary shells, illuminating shells,and anti-aircraft projectiles.

H I G H E X P L O S I V E S H E L L .

H. E. shells may be common steel or semi-steel.They consist, as th e na m e imp lies, of a steel bo dy filledw ith a high explosive called the bu rsting ch arge. T he y areused in can no n of all calibers aga inst personnel and m ater iel.

The walls of the common steel mobile artillery shellare thinner than those of the armor piercing shell in Coast

Artillery, and thin ne r th an the semi-steel shell. Th e wallsof a howitzer shell are thinner than those of a gun shell asa general ru le for a given m ate rie l. B u t the use of all ofthem is practically the same.

S H R A P N E L .

Shrapnel may be defined as a projectile capable ofbursting in air under the action of a time fuze and throwing

out a number of lead balls with a velocity, which addedto the remaining velocity of the projectile can producekilling effects upon exposed troo ps . The case of a sh rap ne lwhen functioning as such should no t bu rst. Sh rapnelfuzes are also pro vided w ith a percussion elem ent w hichcauses a bu rst upo n imp act. Shrapnel is intend ed primarilyfor use against unprotected personnel.

41



Jfctse Cove??

i— -Base Cover Gfcvove and calking wire.

J r-Motaling Band. r Steel Shell.

( 3a-se Detonating J^h-ze, Medium Caliber

Capacity J312 oz\£^zplosive"D.

Co/nmon Sleel Shell.J Imbricating and Crimping Grooves.

rLoose Black Pois-der. rCentral Tuie,| &teelDiaphragm.

j i rS/ira/onel\0aits. Bourrelet. pSieelHead.\ i \

Common S/irapnel. ^•Cover Crimping Groove.j Groove. ~~~

J

j | — P e r c u s s i o n Cap.I \Com/onessedPoivderrr TinFoil.

\ cBody. fVents. /fs

fri/uen Cartridge Case.

Miah Explosive Shrapnel. P Vf

42



G A S S H E L L .

Gas shell are very similar to those used with highexplosives but are filled with non-explosive chemicals designed to kill or incapacitate troops by poisoning theminte rna lly or by direct action on the skin or eyes. W hilethe use of the term gas shell is general, it is a fact that noneof th e chem icals used are gases. M os t of them are liquidswhile a few are solids. The function of the shell is onlyto act as a container and carrier for the chemicals.

The p rinc ipa l difference betw een gas and high explosiveshell is that the nose of the gas shell is modified to receive

a different ty pe of bo os ter. (Boosters will be desc ribedlate r.) T he booster used w ith high explosive shells wouldnot be satisfactory in gas shell because in the latter typeenough high explosive must be contained in the booster torupture the shell walls and scatter the contents, whereasthe function of the high explosive shell booster is merelyto give an explosion of sufficient violence to detonate them ain charge of the shell. E ith er steel or semi-steel can

be used in th e m an uf ac tu re of gas shell. Because of th ehigh strength of steel, the shell walls may be made thinnerthan in the case of semi-steel and consequently a steel shellof a given weight can carry a considerable larger quantityof gas than can be put in a semi-steel shell of equal weight;on the other hand on account of the large amount ofexplosive required in the booster charge to open the wallsof the steel shell, there is a tendency for the chemical to

be dissipated to too great an exten t. T he present tend encyseems to be, therefore, towards the use of semi-steel forgas shell. Both steel and semi-steel shell are designated foruse in our service.

Because of the fact that some of the chemicals usedwould be attacked and rendered inert by the steel of theshell and booster, if it came in contact with them, it isnecessary th a t th e shell to be used- w ith th ese gases be

provided with a lining of some material on which thechemicals do no t act. A lead lining has been adop ted inour shells for this pu rpo se. E xp erim en ts are also beingmade on the use of enamel in the case of semi-steel shell.Enamelling of the steel shells is not feasible because thehigh tem pe rature s employed in enamelling interfere w iththe heat treatment previously given the shell .

43



S M O K E S H E L L .

Smoke shells are similar to high explosive and gasshells but filled with a chemical which is designed to

prod uce a he av y sm oke at th e po int of bu rst . Shellsof this type are used for two distinct purposes: for spottingth e po int of bu rs t of th e shell an d to produ ce a concentration of smoke in a given area (blinding observation posts,etc.) . W hite ph osp ho rou s is used as a filler for smokeshells up to 4 " . 7 caliber.

I N C E N D I A R Y S H E L L S .

Inc en dia ry shells are used to ignite an y com bustiblem ateriel in the vicinity of the bu rst. T he y are also usedvery effectively with time fuzes against balloons.

I L L U M I N A T I N G S H E L L S .

Illuminating shells are used chiefly in curved angle fireand con tain star s provide d w ith silk para ch ut es similar to

those used in fireworks. I t has a tim e fuze an d a small chargeof black powder whose function it is to throw the base tothe rear and ignite the stars . T he la tte r fall slowly andcast a bright light on the surrounding objects lasting about45 seconds. T he best height of bu rst is ab ou t 300 m eters.

A N T I A I R C R A F T P R O J E C T I L E S .

Formerly shrapnel were used in firing upon aircraft

but it has been proved that high explosive shells withclockw ork fuzes are m ore effective. T he func tion of an tiaircraft fire is to prevent observation by enemy observersby keeping them at such a height that observation is practically impossible.

P A I N T I N G A N D M A R K I N G M O B I L E A R T I L L E R Y P R O J E C T I L E S .

Mobile Artillery projectiles are painted for protectionof the metals and to serve as a means of identification.The ro ta tin g ban d , base cover a nd fuze cover of* all

projectiles will not be painted.The following colors are used to denote the various

types of shells:

44



DIS TIN CTIV E COLORS FOR PAINTING MOBILE AKTILLEKY PROJECTILES

COMMON STEEL HI6H EXPLOSIVE SHELL.

FIXED UNFIXED

DSEMI-3TEEL HIGH EXPLOSIVE SHELL

COMMON S HRAP NE L

ANTI-AIRCRAFT TRACER SHELL

DH.E. AMATOL 5HEU WITH 5H0KE MIXTURE

"TUBILLUMINATING SHELL

0

INCENDIARY SHELL

•TOXIC (GAS) SHELL

TARGET. PRACTICE S HEL L



Common steel high explosive shell.yellowfrom point tobase.Sem i-steel high explosive shell. . . yellow ogive, black bo dy .Com mon shrapnel red from point to base.A ntiaircra ft trac er shell blue from po int to base.Illum inatin g shell w hite from poin t to base .

Gas shell. . green from po int to ba se.Incend iary shell red ogive, olive green bo dy .Sm oke shell blac k from po int to base w ith an olive.

green band just above rotating bandAmatol shells contain

ing a smoke m ixt ur e, .olive green ban d jus t above th ebourrelet .

T arg et practice shells Black from po int to base.

Shells are stencilled indicating caliber and type ofcannon, character of shell filler, weight, lot number, purchase number, date of purchase, initial of manufacturer.Stencilling is done in black an yellow and white background, and in white on other colors.

45



WEIGHT ZONES NO. OF W£ICHTSHELL SQUARE STENCILINGTO A NOOVER hPUNCH (METRIC REMARKSMARK

INCLUDING MARKS EQUIVALENT)

91 LBS-3 OZ. 9ZLBSS0Z.ISS-G 9ZLBS -SOZ.93 LBS-6 OZ.

2

3

41 K 700 UNFUZED BUT4Z K. ZO O INCLUDING MARK1B

OR 13LBS-6OZ. 14-LB5-6OZ. 4 4Z K TO O BOOSTER 73-/-SSISS-H 94LBS-S0Z. 9SLB3 -I0O7-. S 43 K ZO O W/Tti 5PEC/AL

t 15LBS-10 OZ.16LB5-IZ0Z. 6 43 K 7O O AbAPTEP. 74-4-ZS

SHELLS NOTFOR SERVICE

WILL BE STENCILLED,RED PAINT WITHflAM/MG BOMB Z.INCHES HIGhAPPROXIMATELY ASSHOWN.

STENCIL WITHBLACK PAINT I.LETTERS .I2SSPACING LOTNUMBER OFlOAOLO SHELL.

STENCIL INBLACA'PAINTAS }*ER TA BLE TOINDICATE WEIG/YT ZONE..

MARK WITH PRICK PUNCH IN CENTEROF£ACH SQUARE.

PUNCH MARKS MUST HAVE SUFFICIENTSIZE NOT TO BE OBLITERATED BY PAINTING

PA INT WITH GREEN PAINT, BAND. 5 WIDE/•FROM FRONT OF BOURRELET ON ALLSHELLS CONTAINING SMOKE MIXTURE

STENCIL WITH BLACK PAINT .5 WIDEJLET/ER3, WEIGHT MARKINGS AS GIVEN ABOVE

LTENC/L WITH BLACK PAINT.I'LET

TERS..6 WIDE..ZL.INE,.IZSSPACING TYPEAND CALIBRE OFGUN OR HOWITZER.

/rPRO/EC T/LE A S ISSUED TO SER V/C£/S INTENDED TO BE USED INTEMCHANGE-ABLy INGUN AN HOWITZER, STENCILGH . AFTER SIZE

STENCIL WITHBLACK PAINT.3LETTERS./ LINES,./2SSPAC/NG SHELL FILLERMARK USING NOTATION IN TABLE BELOW

EXPLOSIVE SYMBOL

TN.T. CAST ACSO-SO AMATOL AMSO-SO

60-20 AMATOL AM8O-ZO

LVAGRAM FOR. PAINTING AND MARKING FILLED SHELLS• FOH PAINT SPECIFICATIONS SEE OKGNANC£ PA11PHL£T 1868A

46



SHELLS NOT FOR SERVICE WILL BESTENCILLED IN RED PAINT WITHFLAMING BOMB 2 INCHES HIGHAPPROXIMATELY AS SHOWN.

STENCIL WITH BLACK PAINTACTUAL WEIGHT OF SHELL WITHFUZE AND BASE COVER TOA/EARE-ST 5 POUNDS

GA.INT WITH GREEN PAINT BAND/. INCH W/DE ON ALLSHELLSCONTAINING SMOKE MIXTURE

STENCIL WITH BLACK PAINTI. INCH LETTERS,.8 WIDE,.2 LINE

.I25SPACIN6, LOT NUMBER OFLOADED SHELL.

STENCIL WITH BLACK PAINTI. LETTERS,.8 W/DE..BUNE,.IZSSPACINGTYPE AND CALIBER OF GUN.

STENCIL WITH BLACK PAINT.5 LETTER,.! LINESJ25-5PACIN6SHELL FILLER MARK, USIN6NOTATION IN TABLE BELOW.

EXPLOSIVE ^VMBOLT.N.TCAST /°.C.

SO-5OAMATOL AM SO-SOEXPLOSIVE 'D' D '.

STAMP WITH.125LETTERS ANDF/6URE5

TYPE OF FUZE, WHETHERDIAGRAM FOR PAINTING AND MARKING FILLED SHELL .08 DELAY, .04 DELAY, 0/9FOR PAINT SPECIFICATIONS SEE ORDNANCE PAMPHLET I86BA.NON-DELAY.

Stencilling indicating caliber and/type of cannon isT;infigures and letters 1" high on the body|of the projectile,viz: 6 G-6" Gun; 8 G-H—8" gun ror howitzer. 12 M— 12"Mortar; 3 AA—3" antiaircraft.The character of the shellfiller is indicated in \" letters just above the rotating band,viz: AC—T. N. T.; Am 50-50—Amatol 50-50; Expl D—Explosive "D". The weight of the projectile is stencilled

to the nearest five pounds on the ogive. Relative weightsare indicated by punch m arks above the bourrelet as follows:one—underweight; two—normal; three—above weight.The lot number, date of purchase, purchase number andmanufacturers initials are in 1-8" letters just above therotating band opposite the shell filler stencil.

47





C O P P E R F O U L I N G O F T H E B O R E .

Copper fouling of the bore due to the depositing ofcopper from the rotating band in the grooves increases theresistence in the bore and should be carefully guardedagain st. T he following m ethod of decoppering has beendeveloped and is now used i^n the French service.

This process consists of introducing into the chamber ofthe gun an alloy consist ing of 60% tin and 40% lead byweigh t wh ich bre aks up at the m om en t of firing in to tw ocomponents, the t in unit ing with the copper in the bore ofthe gu n to form a fusible bra ss alloy. The lead does no tunite with the copper but acts principally as a lubricant for

the succeeding rounds and tends to granulate the brassalloy and facilitate its removal.Exhaust ive tes ts made by the French have given

ra th er surprising resu lts. N ot only is the process ve ryeffective in rem ov ing th e copper, b u t it prolongs th e lifeof the gun and increases its range almost equal to that ofa new gun.

Th e alloy is used in two w ay s; in decoppering rounds,

to remove the existing copper fouling and in non-copperingrounds, to prevent the accumulation of such copper fromfurther firing. The alloy is issued in the form of thin bandsfolded flat and made up into 20 gram packages.

I t is inte nd ed th a t future pow der charges will containsufficient alloy to prevent further copper fouling but untilsuch a time as these non-cop pering rou nd s can be issuedcontinuously it will be necessary for batteries to make use

of the decoppering rounds at various intervals to keep theguns in good condition. T he cartridges and cartridge bagscontaining the alloy can be distinguished by the markA-n, A referring to the alloy a nd n to the nu m be r of gram sof alloy con tained in the charge. Unless t he charges arem arke d as con taining th e decoppering alloy it will beincum ben t on the ba t ter y personnel to introduce th ealloy into each charge before firing.

DIRECTIONS FOR INTRODUCING DECOPPERING ALLOY

IN C H A R G E S .

Remove from packet the proper amount of alloy asdesignated abo ve. (Tables showing am ou nt to be usedw ith all caliber guns will be issued as soon as pr ep are d. )

49



Crumple the band of alloy without crushing it so as to formit in proper size for in tro du ctio n in to cartrid ge bag . Un tiethe bag and place the alloy on top of smokeless chargeso that it will be close to the base of the shell and then retie

the bag.Before firing the round the gun to be decoppered shouldbe heated by firing a dozen or so rounds without alloyedcharges at a ra th er rap id ra te . C on tinue firing at thesame rate with the alloyed charges to prevent the gun fromcooling.

From 20 to 40 rounds are generally necessary to de-copper a gun of average wear and fouling.

When firing alloyed charges it is important that neitherthe bore, projecti les or rotating bands be lubricated.When the operation has been completed the gun must

be cleaned in the usu al w ay. N o notice need be takenof the yellowish or grayish color noticeable in the borein some cases.

50



CHAPTER IV

BURSTING CHARGES.

The criterion for a high explosive is the productionof a great volume of gas in so exceedingly short a periodas to be practically instantaneous; the shorter this periodis the "h igher" the explosive. To secure this great rapi di tyof chemical change, substances are selected that have theatoms necessary to form the heated gases, arranged in theclosest proximity to one another. In a chemical molecule,the atoms are so arranged (as distinct from mere mechanical

mixtures), and therefore chemical compounds are selectedfor bursting charges, since all bursting charges are explosives of high orde r. Such molecules conta in atom s capableof rea rra ng em en t. A molecule of T . N . T., for ins tance,contains atoms of carbon and oxygen not directly unitedbut straining at one another and only requiring a sufficientshock to break their bonds and rush together to form astable gas. T he disrup tion of the molecule of T . N . T.also libe rates oth er gases, chiefly n itroge n, tog ether withlarge qu an tities of w ater vap or, and some carbon rem ainsun bu rn t. T he presence of anoth er molecule, such asammonium nitrate, capable of breaking up by shock intogases conta inin g an excess of oxygen, aids the co m bustionof the products of detonation and forms more heated gases.

The velocity of detonation of T. N. T. is about 7,000

meters per second, whereas that of gun powder is only200 to 300 m eters per second. T he pressure reachedby some high explosives amounts to 300 tons per sq. inchas against ab ou t 50 tons for gun pow der. Th is accounts forthe great difference in the effects produced by explosives ofthe high order as compared with those produced by explosives of th e low order. M an y high explosives can onlybe ignited with difficulty, althou gh large qu an tities when

once inflamed, m ay even tually b ur n violently, bu t th eyare all readily caused to detonate by means of a sufficientlypowerful initia l im pu lse. The full pow er of a high explosiveis only ob tained when de ton atio n is com plete. High explosive shell sometimes only partially detonate or merelyexplode. (See ch ap te r on Pro pe lling Charges for the difference between detonate and explode).

51



R E Q U I R E M E N T S O F A G O O D S H E L L F I L L E R .

R eason ably safe to ma nu factu re and easy to load.Stand shock of discharge and of impact.Be detonated completely by a service fuze, and cause

sufficient fragmentation of the projectile.Be stable in storage and reasonably non-hyg roscopic.Not form sensit ive compounds with ordinary metals,

or if so, be able to be prevented by simple means.Supp ly am ple an d quickly ob tainab le at reasonable cost .

K I N D S O F E X P L O S I V E S U S E D A S B U R S T I N G C H A R G E S .

T. N. T.— Tri-nitro-toluol, com m on ly kno wn as T. N .

T., is known in other countries under such names as trotyl,tolite, etc. I t was ad op ted in this co un try some time beforethe war as a filler for high explosive shells, mines, bombs,etc., and is used alone or mixed with ammonium nitrate.I t is a cream colored crystalline sub stance when pu re, darkening on exposure to the light. I t m elts at 80° C to a brow n liquid.It s den sity wh en cast is ab o u t 1.55 to 1.60. Th e factthat T. N. T. melts at a temperature less than the boil ing

po int of w ater gives it a gre at ad van tag e over m ost otherhigh explosives, since it facilitates its manipulation for shellfilling. Other ad va nta ge s of T. N. T . are th a t it does no ttend to corrode and does not form sensitive compoundsw ith m etal s. A lkalis, how ever, ha ve a bad effect on itsstability, and it does not give proper density of loadingunless th e shells are ve ry carefully filled. T . N . T . m aybe used in shells of all caliber, but as a rule is used only in

point fuzed projectiles, as it has been found more advantageous to use Explosive D in base fuzed projectiles, in whichit is possible to load this explosive by means of tamping.

Amatol—a com binat ion of am m onium ni t ra te andT . N . T. Th e am m on ium n itr at e by itself is no t considered an explosive, but when mixed with T. N. T., formsa more powerful explosive than T. N. T. itself. I ts greatvalue is th a t it opens up a n eno rmo us supp ly, of cheap,

easily obtainab le m aterial . A m m onium ni trat e is a whitecrystalline substanc e, which w hen gro und up resemblescom m on table salt in appe aran ce. I t m elts at 170° Cwhen quite pure and dry, but when mixed with other saltssometimes found in am m on ium n itra te i t m ay melt attemperatures as low as 110°. Its chief disadvantage is thatit is ve ry hyg roscopic. Also due to th e oxidizing power

52



of ammonium nitrate very little smoke is given out at burstan d so ob serv ation is difficult. A m ato l is m ade up in twoways : one is a mixture of 50% T. N. T. with 50% ammonium nit rate , an d the other is a m ixture of 80 % am m onium ni tra te w ith 2 0 % of T. N . T. 50/50 am atol isfilled in to t he shell in a similar m an ner to th a t of fillingmolten T. N. T. 80/20 amatol, which is not fusible, maybe tam pe d in or loaded w ith an extrudin g m achine.

Smoke Mixture—All amatol filled shells contain someform of smo ke m ixtu re to aid in spo tting the bu rst. Inthe case of 50/50 amatol a mixture of 75% alumimumand 2 5 % 80/20 am atol is used. In the case of 80/20am atol a m ixture of am m onium chloride, am m oniumnitra te, and T . N . T . is used. This smoke m ixtureis compressed into 5 ounce cylinders and wrapped in waxedpap er to pr ote ct it from m oisture. One of these cylindersis dropped into the shell, a small amount of amatol ispoured in and allowed to cool so as to fasten the smokem ixtu re in th e bo tto m of the shell. T he n the filling isproceeded with as usual.

Amatol is used in point fuzed projectiles of all calibers.E X P L O S I V E " D . "

Explosive D has for many years been used in thisco un try as a high explosive shell filler, bu t is now usedin only certa in typ es of shells, T . N. T. and a m atol beingused to a far grea ter ex ten t. T he ad va nta ge s of explosiveD are its insensitiveness to shock, its stab ility in storage, and

the ava ilability of the m aterials used in its m anufa cture .However, its disadvantages are that it forms sensitivecom pound s w ith m etals and is no t fusible, thus requ iringtam pin g. Explosive D is an orange colored salt m eltingat a temperature very sl ightly below the ignit ion point(abo ut 302° C ). Th e pu re salt is very insensitive to shockand cannot be exploded by any of the ordinary shocksliable to be received during handling or loading.

Preparation of the empty shell—Shells to be filled withExplosive D should be thoroughly inspected to insurecom pleteness of coating of th e inte rio r of th e shell. G rea tcare should be taken that the cavity be free from all dirtan d chips of an y kind, a nd th a t there be no m etallic saltscontained in the paint or in any of the compositions usedto coat the interior of the shell, where it may come in con

53



tact with the shell filler. The paints generally used forthis interior pain ting are non-m etallic, chemical-resistantpa ints. No pa ints except those autho rized by the OrdnanceD ep artm en t should ever be used for this purp ose. Anothermeans of preventing any contact between the explosive andthe m etal is by use of a shell lining of T . N . T. Th is methodis briefly as follows: th e shell is cleaned and va rnish ed asfor cast T. N. T., then filled with molten T. N. T., allowedto sta nd for ab out a m inu te, and th e T. N . T. poured off,leaving a thin coating up on the walls of the cav ity. Theshell is filled withE xp losive D a nd a T .N .T . surrou nd formedaroun d the fuze. Th is su rrou nd un ites w ith the cavity

lining of T. N . T., and th us forms a to ta l surro un d of T. N. T.between the explosive and the metal wall of the shell.

S H E L L L O A D I N G .

T . N . T. and 50/50 am ato l are fusible and are loadedinto the shell in a molten state in the following manner:The explosive is melted in steam kettles or on steam-heatedpipes and poured into the shell at a temperature as near

the crystallizing poin t as possible. W hen it is pou red inho t, it crystallizes slowly, form ing large cry stals. Theresu lting charge is therefore less hom ogeneous and densethan in the case of explosive poured in at a temperaturea little above its se ttin g po in t. Hence the necessity ofpou ring at a low tem pera tu re . To prod uce a good solidfilling it is advantageous to have the shell at above 30° C,otherwise the cold metal will rapidly solidify the explosive

and the tra ppe d air would be retain ed . If proper careis not taken in loading the shell, voids may be formed inthe filler due to too rapid contraction of the explosive uponsolidification. This form ing of vo ids in the shell filler dueto improper loading is known as cavitation and is a seriousfault, for it is certain that this is one of the causes of failureof the shell to burs t. W here ca vi tat ion exists the headof the bursting charge sets back at the moment of discharge

leaving the deto na ting system . W hen this set back isappreciable the explosion of the detonating system isinsufficient to leap the gap with the necessary force, anda mild explosion or a blind results.

To prevent cavitation the liquid should be probedw ith wooden rods when nea ring the solidification pointso as to rem ov e all gases. Th is pro bing m us t be done

54



gently so as not to entangle air in the viscous mass, andmust not be continued after the first signs of solidification.In shells containing more than 5 pounds of explosive thefilling should be done in two or more stages, collected gasesbeing removed at each stage.

80120 Amatol— This form of am atol m ay be ta m pe dinto the shell in a heated condition by means of a speciallyadapted stemming rod, or may be loaded by means of anextrud ing m achine as follows: T he am ato l is carriedfrom a steam jacketed hopper and forced into the shellby means of a worm or screw feed device, which revolvesin a steel tube, the principle being similar to that of thefamilar meat grinder.

Explosive D— Since th is explosive is no t fusible, it isloaded through the base of the projectile in a powderedform and stemmed or tamped in with a suitable stemmingrod . Sm all po rtion s of the explosive are fed in to the shellat a time, each portion being carefully tamped before thenext is ad ded to ins ure efficient de ns ity of loading. SinceExplosive D is loaded in a powdered form it is impossibleto form a fuze seat in it that will stand up under transpor

tatio n. I t is necessary, therefore, to place an alum inumfuze seat liner in the fuze seat formed in the explosive or tocast th e fuze seat from T. N . T. I n the case of CoastArtillery projectiles, which are usually loaded at the pos.ts,the fuze seat is drilled with special tools and the fuze inserted directly.

Forming the Booster Cavity—The booster cavity is thecavity in the shell filler to admit the insertion of the booster

and the fuze.The method of forming the booster cavity in a shell

is either by drilling or forming. To drill th e cavity, theshell is filled completely and the cavity is drilled by meansof a special drill. Th is m eth od is dan gero us, how ever, andthe cav ity is usually formed instead . W hen the ca vityis to be formed, the shell is not completely filled, a holelarger th an th e boo ster being left. In to the end of th e

shell is fitted a form or mold. The up pe r end of this formis a cup in the bottom of which holes are drilled leadingin to the ca v ity of the shell. Th e lower end of the form

55



is a solid mold the size and shape of the booster. MoltenT. N. T. is poured into the cup of the form until the cavityof the shell and the cup are full. After the T. N . T. hassolidified, the form is twisted to break the T. N . T. in theholes of the cup, and the form is lifted out, leaving a cavitywhich exactly fits the booster and fuze.

56





in the projectile. A deto na tin g fuze consists of threeelements: 'primer, detonator and,booster. Either the pr imeror booster m ay be om itted . To secure th e m ost effectiveresults the booster charge should surround or be in intimatecon tact w ith the de ton ato r. If delay action is requiredone or more delay pellets are inserted between the primerand the detonator .

Fulminate of mercury is universally used for thepriming and deto natin g elements. I ts value as a deton atorlies in the suddenness of action and the enormous pressuresdeveloped, the volume of gases evolved being 1340 timesthe volume of the solid fulminate at ordinary temperaturesand pressures which is further increased by the heat resulting from th e explosion. I t may be developed by a blow,by the action of an electric spark, by friction, or by heatabove 195° C. W hen exploded in its own volum e, fulminateof mercury gives more than twice the pressure developedby nitroglycerine and nearly three times that of gun cotton.Repeated experiments with various compounds have proventhat fulminate of mercury is the only one which will always

insure detonation of the first order.Tetryl is used either alone or in combination with T. N.T. for the booster charge.

A percussion detonating fuze is said to be armed whenall the parts or particles of the fuze, which must move onim pac t in orde r to function , are free to do so. A fuze m ayarm by inertia or set-back, due to the abrupt forward motionof the projectile on discharge; by centrifugal force due to the

ro tatio n of the projectile; or by a combination of inertia andcentrifugal force.The action of the fuze arming by inertia is as follows:

this type of fuze consists of a primer-plunger, anvil or firingpin, arm ing sleeve, arm ing spring and creep spring. Th earming spring is fitted between the sleeve and the primer-plunger, and by keeping these two elements apart, preventsthe primer from coming into contact with the firing pin.

At the moment of departure the sleeve goes backwarddue to inertia, com pressing the arm ing spring. Clasp-hooks, which are fitted inside the sleeve, are then able toengage the no tches on the prim er-plunger. T he sleeve,plunger, and arming spring are thus linked togetherin one piece, which is held back only by the creep spring.The fuze is now armed, because the plunger is free to move

58



forward on impact, compressing the creep^spring, and firingth e prim er aga inst th e firing pin. Fuzes arm ing by inertiam ay be classified by th e sm allest coefficient of accelera tionwhich insures their working at the moment of discharge.

^^^^^^^^ss^^ô^^c^^sNôc\\\\

•S

I.S1

^^

The action of the fuze arming by centrifugal force is asfollows: fuzes of thi s typ e consist of the prim er-p lunger, firing pin, creep spring and locking bolts. Th e prime r-plungeris fixed in position awa y from the firing pin du ring tr an sp ortation an d load ing of the projectile by m eans of locking bolts ,wh ich are them selves held in place by small springs. Th ese

59



locking bolts are thrown out by centrifugal force due tothe rotation of the projectile, thus arming the fuze by-

freeing the primer-plunger and allowing it to move forwardon impact.

The fuze may arm when the shell is still in the boreof the gun or after it has left the muzzle. Even if arming

60



were to take place after the shell had left the bore of thegun, a premature functioning of the detonator while in thebore would result in detonation of the projectile, by exploding the booster which in turn would explode the shell.Therefore, a shell cannot be said to be "bore safe" unless

the detonator and booster are kept separate as long as theprojectile is in the bore of the gun, regardless of the timeof arm ing. M uc h time has been expended in perfectingan absolutely bore safe fuze, one that cannot function untilafter th e projectile has left the bore of the gun. Up to th epresent time all bore safe fuzes embody one of two designs.One of these is made with two relative positions of thedetonator and booster, and the other with a barrier between

these elem ents. In the first design, the de ton ato r is m ou nt ed within a saftey chamber, usually in the rear of the fuzestock. If the de ton ato r is exploded pre m atu rely , th eresulting gases will expand into this chamber and will notde ton ate the booster. E ithe r during flight or upo n im pa ctthe detonator slides into the booster and is then in thefiring position. I n the second design, the passage from th ede ton ato r to the booster is filled with compressed tet ry l

so that i t vir tually forms a combination with the formerelem ent. A barrier is placed in this passage which preve nts the de tona ting wave from firing the boo ster. To armthe fuze completely this barrier must be removed.

CARE AND HANDLING OF FUZES.

T he sensitiveness of fulm inate of m ercu ry a nd th eam ou n t of high explosive used in the boo ster charge rende rthe handling of fuzes, especially recovered detonatorssuch as may be found on the battle field, very dangerous.

A LL D E T O N A T I N G F U Z E S M U S T B E H A N D L E DW I T H C A R E .

They should only be disassembled by or under thedirection of a commissioned officer who thoroughly understan ds the ir con structio n and operation. Th e followingregulations must be enforced in the field:

1. I T I S A B S O L U T E L Y F O R B I D D E N T O D I S M A N T L E A N Y F U Z E .

61



2. ANY FUZE W HICH, IN SPITE OF TH IS PROHIBITION, HAS BEEN DISMANTLED, MUST BEDESTROYED. FIRING IT RISKS BURSTING THEGUN. HAN DLING IT IN VITE S SERIOUS ACC IDENTS.

& ANY FUZE THAT HAS BE EN F IR E D ANDFAILED TO FUNCTION IS DANGEROUS, BECAUSEIT IS ARMED AND LIABLE TO DETONATE AT THESLIGHTE ST JAR. IT IS ABSOLUTELY FO RB IDD ENTO TOUCH IT W H E T H E R IT IS SEPARATE ORATTACHED TO THE SHELL.

4. TO DESTROY A SHELL OR A FUZE PLACE

A CHARGE OF HIGH EXPLOSIVE IN CONTACTWITH IT, COVER OVER WITH EARTH AND SETOFF THE EXPLOSIVE WITH AN ELECTRICP RI M E R.

DETA ILED DESC RIPTION OF FUZES.

MARK I—CLASSIFICATION.

Country of Design— Russia Safety Devices—Method of Arm ing— Inertia safety chamberLocation in Projectile— Point arming sleeveTime of Action—Non-delay creep spring

Booster—self-contained

This is a modified Russian fuze and is used in steel

shells for 3" field guns.

62



iLJ

>

3DC

i

63

I



DESCRIPTION.

This fuze has what is known as the detonator safety

feature. Before arming, the detonator is surrounded byan air chamber in such a manner that if the detonator

should become ignited prematurely, either in storage orin the bore of the gun, the gases can expand into the safety

chamber and not cause the booster charge to explode andignite the bursting charge of the shell.

In action, the detonator is located in the safety

chamber until the striker rod moves forward on impact of

the projectile carrying the detonator opposite the booster

charge and impinging it on the firing pin. The striker

rod is held in the rearward position during transportationand storage by means of the arming sleeve and stirrups.

When the projectile is accelerated in the bore of the gun

the sleeve sets back over the stirrups, bringing them infront of the shoulder on the sleeve. The striker rod is

now held to the rear only by the restraining spring which

is compressed as the striker rod goes forward on impact.

This fuze differs from the types previously used in

that the firing pin explodes the detonator by direct impactwith it, rather than by means of a separate primer.

MARK II—CLASSIFICATION.

Country of Design—Russia Safety Devices—Method of Arming—Centri 3 centrifugal

fugal Force plungers, safe-

Location in Projectile—Point t y c h a m b e r

Time of Action—Delay or and firing pin

Non-delay bushing and re

straining spring.Booster—self-contained.

64



1=1

<

M3

I t - iio

65



D E S C R I P T I O N .

The Mark II fuze also embodies the detonator safetyfeature as described for the Mark I fuze.

In action, the detonator charge proper is located in the

safety cham be r unt il th e piece is fired. T he ro tat ion ofth e projectile th en causes th e centrifugal plungers to moveou tw ard aga inst their sp rings leav ing the plung er free tom ove forward in to th e ar m ed p osition where it is locked bythe expansion of th e sp lit ring ag ain st a shou lder in the fuzehe ad . On im pa ct, the firing pin is drive n in to the percussion prim er, wh ich ignites th e relay de ton atin g charge.The resulting flame ignites the detonator proper, exploding

the booster charg e, which ignites th e bu rsti ng charge ofthe shell.

M A R K I I I — C L A S S I F I C A T I O N .

C ou ntry of D esign— Fran ce Safety Devices—M eth od of Arm ing— Cen trifugal Spiral ribbon,

Force sa fe ty s p r i n gT im e of A c tio n — I n st an ta n eo u s ( c e n t r i f u g a lLocat ion—Point plunger)

Booster—Separate

There has been added to the original Mark III fuzean additional safety feature known as the centrifugalplunger, which breaks the passage between the upper andlower detonators until after the projectile has left the boreof the gun. Centrifuga l force causes it to m ove ou tw ard

aga inst its spring th u s allowing lower de ton ato r to beexploded.

66



I

67



MK.m FUZE WITH ADDEDSAFETY DEVICE

BRASSWE1PHTED END OF RIBBON

RIBBON

r-e-96S




The action of the fuze is as follows: The rotation ofthe projectile causes the spiral to unwind, due to centrifugalforce act ing on the weighted end. W hen the spiral flies

off the half rings acc om pa ny it. Th is arm s the fuze b ypermitt ing the backward thrust of the pin on impact tofall direc tly on the safety pin. W hen the safety pin is ben tthe firing pin impinges on the percussion prim er. T heexplosion of the primer in tur n explodes the uppe r de ton ato r.Th e explosive wave from the up per de tonator reaches the lowerdetonator through the central channel, exploding it andde ton ating the booster charge in the booster casing. These

explosions follow in such rapid succession as to m ake th ebursting of the shell practically simultaneous with thefirst impact of the firing pin head.

Regulations governing the transportation and handlingof the Mark III, instantaneous point detonating fuze.

This fuze is protected during transportation by havinga tarred tap e wound aro und the neck of the fuze and atinfoil cap fitted over the tap e. Th is pre vents inju ry t othe brass ribbon and thus insures proper functioning of thefuze. The following regulations must be enforced:

1. Do not remove the tarred tape and tinfoil capun til after the fuze has been screwed in to the projectile, whena pull on the loose end of the tape will quickly remove them.

2. Never screw a fuze of this type into a projectileif the tarred tape and tinfoil cap are not in their properplaces.

3. After the fuze is screwed into the projectile andthe tape removed from the neck of the fuze, examine thebrass ribbon and safety pin to see that they are properlyad justed . If the ribb on is broken , the fuze can no t function,for centrifugal force cannot act upon it unless the weightedend of the ribbo n is in place. If th e safety pin is no t inplace there is danger of a premature explosion of theprojectile.

69



M A RK IV. CLASSIFICATION.

Country of Design—FranceMethod of Arming—Inert iaLocat ion—Point

Time of Action—Delay orNon-delay

Safetycasin

Booste

Devices—safetyg, creep springr—separate


The firing pin is on a plug screwed in the head of thefuze. T he percussion p rim er is carried on a plun ger whichrests on the r et ar d carrier against wh ich it is held by the three

prongs of the safety casing. A n arm ing casing is placedinside of the safety casing and is pushed forward by thearm ing spring, wh ich rests on a shou lder of the plung er. Onfiring, the arming casing, by its inertia, compresses thearming spring, the lower edge pushing the prongs of thesafety casing off the plunger, and is itself caught by threeprongs which engage un de r an oth er shoulder on th e plunger,holding the arming spring compressed and making a rigid

un it of the arm ing casing, arm ing spring an d plung er. Th eplunger is prevented from drifting forward by a smallspiral spring which fits in female thr ea ds in bo th the plungeran d the re ta rd carrier. Th is spring is no t stron g enough topre ve nt the plunger from going forward on im pa ct. Onimpact the plunger drives forward in the safety casing andthe prim er strikes the firing pin an d de ton ates . T he flamefrom the primer either ignites the delay pellet or sets off

the detonator direct which detonates the booster charge.

70



DETONATING FUZE , MARK IV , FR.TYPE 24/31MODEL 1899-1915

DETONATOR

CREEP SPRING

RETARD CARRIER

PLUNGER

SAFETY CASING

PRh

ARMING^ SPRING

"ARMING CASING

FIRING

71



M A RK V. CLA SSIFICATION.

C ou n try of D esign— Fran ce Safety Devices-SafetyM etho d of A rm ing— Inertia casingLo cation— Poin t creep spring

Tim e of A ction— D elay or safety hea dNo n-delay safety supp ort

Booster—Separate

The Mark V fuze is designed and functions exactlyas the M ar k IV , except for the additio n of a hea d safety.The Mark IV fuze was designed for use in howitzers andm or tars w hich hav e relative ly low m uzzle velocities. I twas found, how ever, th a t this fuze, arm ed as it was byinertia, was too sensitive and armed too easily for use in gunsof high muzzle veloc ity. T he M ark V fuze was thereforedeveloped w ith an add ed safety feature which makes itm uch h ard er to ar m and ren ders it safe for use in h ig h ,power guns.


The action of the arming of the head safety is as follows:The safety support projects beyond the firing pin and prevents the firing pin from striking the primer even if theinterior arm ing device should function pre m atu rely . Thissafety support is held in place by a strong head safetyspring, one end of which rests on the shoulder of the safetysupport and the other on a shoulder of the head plunger.

When the gun is fired, the head plunger, due to inertia,compresses this spring and is caught and held to the headof the safety supp or t. This leaves the safety supp or t freeto drift forward, thus uncovering the firing pin.

However, i t has been found that the Mark V sometimesfails to function in high powered guns due to the crushingin of the forward cap on im pa ct, and th e conseq uent blocking of the movement of the safety support away from the

firing pin. Therefore, a M ar k IV fuze, known as the M arkIV* (star), with a specially strong retard spring, is used in155 mm. Filloux and other high velocity guns.

72



DETONATING FUZE, MAR K V,FR .TYP E 24/31

MODEL 1899-1908

CREEP SPRING

PLUN6ER

PRIMERAFETY CASING

FIRIN6 PINARMIN6

CA5INQ

ARMING 6PRIN6

W

SAFETY

SUPPORT

HEAD

SAFETYJPR/N6 HEAD PLUNGER

73



M A R K V II AND V I I - E .

CLASSIFICATION.

C ou nt ry of D esign— U . S. A. Safety Devices— Safety

an d F ran ce . screw or safety pin.M etho d of A rm ing— Inertia Creep spring.Locat ion—Point Booster—separateTime of Funct ion—Delay or

Non-delay


Since trench mortars have no rifling and thus no

rotation of the projectile, fuzes used in them must arm byiner tia. B u t th e low muzzle velocities developed in trenchm orta rs will no t arm the M ar k IV or M ar k V fuzes, andtherefore the Mark VII and VII-E were designed for usein this ty pe of ar m am en t alone. T he only differencebetween these two fuzes is that in the Mark VII there isa safety screw that has to be removed before firing, whilein the VII-E there is a safety pin.

The safety ring must be removed before the armingdevice in the fuze can func tion. Th is shou ld only be doneimmediately before the fuze is screwed into the projectile.Upon discharge, the set back, due to the abrupt forwardmovement of the shell, causes the percussion plunger toslide back into the bottom of the recess in the fuze body.As it does so, the rider pin slides along the cam-like sideof the firing pin and forces the point of the firing pin to acen tral position over the prim er. T he shear pin, now ben t,tends to hold the firing pin in this position. U pon im pac t,inertia drives the percussion plunger forward, overcomingthe restraining action of the creep spring, and the pointof th e firing pin strikes th e prim er. T he prim er is thusfired and th e flame is rap idly carried th roug h th e perforatedrelay pellet and explodes the detonator which in turnde ton ates the boo ster. In the delay ty pe the delay pelletdelays the action of the fuze for 1/5 of a second.

These fuzes are used in 6-inch trench mortar bombs;the delay type is also used in 240 mm. trench mortar bombs.

74



Mark VII

Filfminate

fkrcussionCap

Fbrcussion

Firing Pin

Creep Spring

P/Vot Pin

Closing Cap

Trench fioriar Fuze. Mark VII, Non'delay.

Mark VII—E

Fifing Ffn

Safety Pfo

fliif% tiechanism of Trench rtorfar Fuze,the* YM-€.

75



M A R K IX—CLASSIFICATION.

C ou ntry of Design— GreatBri ta in

Method of Arming—Combi

nation of inertia andcentrifugal force

Locat ion—PointTim e of Fu nction ing-D elay or

Non-de l ay

Safety Devices—safetyshut te rde tent

creep springBooster—Self-contained.


This fuze consists of a solid steel body, drilled toreceive a percussion plun ger, a d ete nt and spring, and a

76



centrifugal bo lt. T he percussion plung er is retain ed by asteel cap containing the firing pin and is held from creepingby a creep spring. T he de ten t and spring and centrifugalbolt are retain ed by screw plugs. T he percussion plung eris brass and is threaded inside to take the plug which retainsthe percussion prim er. T he de ten t is brass and consistsof a plunger and rod united by a ball and socket joint. Thecentrifugal bolt is brass and is held in place by the detentbefore the fuze arms.

In action the detent rod is withdrawn by set-back frombehind th e centrifugal bolt. Because of th e ball and socketjoint^the rod is thrown to the side of its recess by centrifugalforce" and catch es und er th e shou lder of th e recess, whileth e dete n t spring is overcom ing set bac k. T he centrifugalbolt being free to move towards the circumference of thefuze, after the detent is withdrawn, frees the percussionplun ger. A t the sam e tim e, due to centrifugal force, th eshutter is forced out against its spring, and the shutter roddrops down and catches on the corner of the shutter, holdingthe sh utte r open. In this w ay the passage between theprimer and the detonator is opened, allowing the primer tofire the de ton ato r. On im pa ct the percussion plungermoves forward impinging the percussion primer on thefiring pin. T he flame from th e prim er passes thro ug h thepercussion plunger plug and ignites the relay pellet whichin turn explodes the detonator which detonates the boostercharge.

M A R K X I I F U Z E .

CLASSIFICATION.C ou ntry of D esign— France. Safety devices— SafetyM eth od of A rm ing — Ine rtia. piece, sleeve, and creepLocation—Point. spring.Time of Fu nct io n— Instan Booster—S eparate ,

taneous.This fuze is under production in France, but as yet

only experimental lots have been produced in this country.

It is similar to the Mark III, instantaneous, fuze in itsuses. This fuze has been designed to be absolutely safeduring transportation and handling as well as very sensit iveat the moment of discharge and at the moment of impact.Furthermore its shape is very satisfactory from a ballisticpoint of view.

77



DESCRIPTION.

At the moment of discharge, the striker moves backwarddue to inertia pressing the long spring, but its point cannotreach the primer because the distance is too great. At the

same time the sleeve sets back compressing the arming springso th at the clasp hooks of the safety piece are no longer held inupper groove of the plunger. The safety piece is thereforefree to move backward due to inertia and the clasp hooksfit themselves into the lower groove of the plunger. Thestriker then moves forward due to the action of its spring.The sleeve goes forward also and the hooks of the safetypiece are held in position by the sleeve in the lower groove

of the plunger. Plunger, arm ing spring, sleeves and safetypiece are thus held together and slide forward due to theaction of the small spring behind. The primer is thenabout 1.5 mm from the firing pin. Upon impact, the strikeris suddenly stopped, while the other parts of the fuze continue forward. As a result the primer is forced against thestriker, causing the fuze to function. The action of thisfuze is instantaneous.

ADAPTERS AND BOOSTERS.

Due to the fact th at the opening in point fuzed projectiles must be large enough to permit the loading of the shellwith high explosive, there must be some way to reducethis opening to hold the fuze. This is accomplished bymeans of an adapter, which is a metal washer or bushing

used to reduce the opening in the point of a shell to thesize of the fuze or another adapter.A Booster, technically speaking, is a cylinder so inserted

in the shell as to enclose the fuze detonator, leaving a spacebetween the detonator and the outside casing sufficientto contain the Booster Charge. In ordinary usage the termbooster refers to the booster charge itself. The necessityof the booster in fuzes as an aid to the fuze detonator

has been explained at the beginning of the chapter.However, there is a distinction between the booster of aH. E. shell and that of a gas shell which must be clearlyunderstood. The function of a booster in a H. E. shell is toact as an auxiliary detonator and insure complete detonation of the bursting charge of the projectile. The boosterof a gas shell must be strong enough to completely rupture

78



MK.XII FUZE

STRIKER PLUG

STRIKER HEAD

•STRIKER ROD

SAFETY PIECE

HORNS OF

SAFETY PIECE

5 L E E V E

GROOVES 'OF

PRIMER PLUNGER

ARMING SPRING

F L A N G E

SPRING FIRING PIN

PERCUSSION CAP

PRIMER

DETONATOR

F-8-10

79



th e shell, as gas shells con tain no bu rstin g charge. I tm us t also be b orne in m ind th a t the liquids used in gas shellsare rendered iner t by action w ith ordinary m etals, and th attherefore, the. boo ster casings m us t be coated on the o utside with a lead coating when used in chemical shells.

M A R K I I I , S E M P L E T Y P E , B A S E D E T O N A T I N G F U Z E .

CLASSIFICATION.

C ou nt ry of D esign— U . S. A. Safety Devices—M eth od of Arm ing— Centrifugal R adial pins and

F orce S afety P l u n g e r

Location in Projectile— Base Creep SpringTime of Action—Delay orN o n - d e l a y B o o s t e r — S e l f

Contained


Before firing the plunger is held against the head of thefuze and away from the primer by means of the creep

spring, also th e S emple striker is held in such a position th a tit is no t opposite th e prim er. I t is locked in this positionby centrifugal locking bo lts. T he de tonato r is connectedto the booster by means of a passage filled with T. N. T.A section of this passag e lies in th e safety plu ng er. Before firing the passage is interrupted by the safety plungerbeing held by a safety spring in an offset position. Th isinsures the fuze being "bore safe" as there is no connection

between the detonator and the booster charge unti l afterthe shell has left the bore of the gun.Upon firing, the locking bolts fly out under centrifugal

force due to the ro ta tio n of th e pro jectile ; this frees th eSem ple strike r w hich also du e to centrifugal force ro tate saround its pivot pin, thus bringing the striker opposite theprim er. Th e plung er is held from drifting forward bym eans of the creep spring. A t the same tim e the safety

plunger, due to centrifugal force, moves outward- againstthe action of the safety spring until the passage throughit lies in line with the passage fron the detonator to thebooster, thus making a continuous train of T. N. T.betw een these tw o. On im pa ct the ine rtia of the strikingplung er causes it to mov e forward, overcoming th e resistanceof the creep spring, causing the striker to detonate the

80



BASE DETONATING FUSENARK III SE M PL E T Y PE

TFTRfL -A/7120GRAMSAPPROX

8/JFE7TYSPR/A/G

INT.-TOTAL WT /CRAMAPPPOX.

CRPFP SPPM

81



primer, which in turn either ignites the delay pellet orexplodes the d eton ator, which in tur n thro ug h the T . N . T .train detonates the booster charge.

Fuzes m ark ed " H " will be used in Ho witzers and willarm at 1500 R. P. M.

Fuzes marked "G" will be used in Guns and will armat 2000 R. P. M.

Fuzes m arke d " M " will be used in M or tar s and will armat 1300 R. P. M.

T I M E F U Z E S .P O W D E R T R A I N T I M E F U Z E S .

Fra nk ford Arsenal time fuzes ha ve a train of com pressedblack powder embedded in grooves (in the form of aboutf of a circle) in two m eta l rings. T he lower ring , whichis graduated on the outside in seconds of time, is movableand a change in position changes the length of the powder

train which must be burned through before the fuze acts.Moving the lower ring changes the relative position of theve nt which connects the two trains. Th e t ime train isignited at the moment of firing by the action of a ringresistance plung er striking a percussion cap . A safetypoint is provided where the vent is opposite the solidpo rtion of one of the rings, so th a t th e entire up pe r tra incan bu rn thro ug h w itho ut ignit ing the lower train . All

these fuzes have a percussion element as well as the timeelement.

At the t ime the United States entered the war wehad satisfactory powder train combination fuzes for timesof bu rning adju stable up to 21 and 31 seconds, respectively,in the two designs. These fuzes are sta nda rd and are nowbeing used in service. As it was desirable to ha ve tim efuzes available for longer periods a modification of the31 seconds fuze has been developed by the use of slowerburning powder. , This gives a maximum time of operationof 45 seconds.

82



C O M B I N A T I O N F U Z E S .

The 31-seeond Frankford Arsenal fuze is to be completely superseded by the 45-second fuze, which is identicalexcept in the speed of burning of the time train and the

gra du ation s of th e tim e-tra in ring. As ther e are aconsiderable nu m be r of 31-second fuzes used in theservice, only the description of that fuze will be given here,the 45-second fuze being too similar to require separateexplanation.

The principal parts of the time element of the 31second com bina tion fuze ar e: the tim e or concussion plunger,the concussion resistance ring, the firing pin, the vent

leading to the upper time train, the compressed powderpellet, the upper time train, the vent, the lower time train,and the compressed powder pellet in the vent leading to thepowder magazine.

The plunger is cylindrical and contains the primercom position in a recess in its ba se. T he concussion-resistance ring prevents contact of the primer and firingpin by supporting the weight of the plunger, which rests

on it . T he acceleration of the projectile at the m om en tof discharge causes the plunger, due to inertia, to spreadthe ring and bring the primer into contact with the firingpin. Th us begun, the functions of the im po rtan t pa rtsare best explained by the following description of the timeaction: Assuming first the "zero" setting as shown in theplate, the concussion plunger arms and fires its primerat the discharge of the gun . T he flame passes ou t throu gh

the ve nt , which is d rilled in th e walls of the plungerchamber and is exactly opposite the hole in the inner surface of the up per time trai n at its farth est end. A t thezero setting the vents are registered, the flame passingdirectly down vent to the lower end of the time train, thenthrough the vent to the magazine, from which the flameis tra ns m itte d to the bu rsting charge of the shell. A ssum ing any other setting, the rotation of the graduated ring

so that zero is the required number of divisions from theda tu m m ark, separates the v ents, thu s stopping the directaccess to the train and forcing the flame to travel counterclockwise un til it reaches the new position of the v en t,then pass dow n to the lower trai n and ba ck clockwise u ntilit reaches the new position of the lower vent, where it

83



ignites the powder pellet and explodes the powder m agazine.The lower powder train ring is graduated in a clockwisedirection on its outer edge fro m l to 31.6 seconds. For the31.6 setting the vent leading to the beginning of the lowertime train is opposite the end of the upper time train, andthe end of the lower time train is opposite the vent leadingto the magazine. I t will then be seen th a t the entirelength of both powder trains must be burned throughbefore the flame can reach the powder magazine and burstthe shell.

The safety setting is obtained by utilizing the solidsurfaces of the upper and lower time train rings left between

the ends of the annular grooves. This point is marked bya line on the outer edge of the movable time train and surmounted by an S and is located about halfway betweenthe zero mark and the 31.6 mark. When this point isbrought apposite the datum mark, the vent is rotated tobeneath the solid metal, separating the ends of the uppertime train in the upper ring; while the vent leading to thepowder magazine is covered by the solid metal separating

the ends of the lower time tra in in the lower ring. W iththe fuze set at safety, the upper time train may burn entirely out, if the plunger should be accidentally fired, withoutthe flame reaching the m agazine. The solid metal of thelower ring covering the vent gives additional safety in caseof gas or flame leakage.

Washers are glued to the upper surface of the graduatedtime train ring and to the upper face of the flange of the

fuze stock. Both surfaces are scored to make the washersadhere firmly. The washers act as a gas check and preventpremature action of the fuze.

The compressed pellet in the vent leading from theoutside to the beginning of the lower time train is to releasethe pressure of the gases of the burning train . The escapeof the gases from both time trains is through the annularspaces and out the vents in the closing cap.

The percussion element of the fuze consists of a centrifugal plunger and ordinary percussion plunger. Thecentrifugal plunger is provided with a slot to receive thefiring pin, which is mounted on a fulcrum and kept in theunarmed position by two pins which fit in recesses on opposite sides of the plunger by the tension of the springs.These springs are designed to suit the velocity of rotation

84





of the particular projectile in which the fuze is used.Centrifugal force due to the rotation of the projectile forcesthe pins outward against the tension of the springs, releasing the firing pin, which is also rotated into its armed position by centrifugal force. Tw o spring housings hold theentire plunger and i ts housing away from the primer duringhand ling, tran sp or tatio n and flight. Th e system of ven tsthr ou gh th e walls of th e fuze condu cts the flame from thepercussion primer to the magazine.

T he b o tto m closing screw closes th e percussion plungerrecess a nd keeps th e pow der in th e m agazine . An herm etically sealed water proof hood of thin brass is provided for

the fuze. T he hood should be stripp ed off before at te m p ting to set th e fuze. R em ove th e safety wire before settingthe fuze, and replace the wire if the round is not fired.If the safety wire cannot be replaced the round should notbe carried in the ammunition chest or roughly handled,and should be fired at the next firing.

C L O C K W O R K T I M E F U Z E S .

For certain classes of work, particularly in high anglefire as against aeroplane s an d balloons, an y pow der traintime fuze is not entirely satisfactory because the rate ofbu rning d epends on the atmo sphe ric pressure which becomesless at the higher alt itu des . A clockw ork fuze ha s beendeveloped which functions on elapsed time independent ofatmospheric conditions.

The Waltham Mechanical Time Fuze may be set for

any desired time of burst, and is similar in construction toa w atch . Th e shock of discharge sta rts the mechan ismwhich operates to release a trigger and firing pin after acer tain nu m ber of seconds ha ve elapsed, for wh ich the fuzeis set and which is indic ated by m arkings on a gra du ated rim .

The fuze consists of 65 parts and is driven by a steelwatch spring, which is wound by a special key through arecess in th e to p pla te cover. Th is spring is conn ected by

friction to a flat steel set plate on top of the fuze mechanism,by a flat steel spring washer, which is held against the plateby a knurled n u t. To set the fuze the cap, wh ich is atta ch edto a graduated ring, is turned until the desired setting oftim e in seconds on the scale is opp osite the ind icato r m arke don th e bo dy of the fuze. W hen this cap is tu rned , a steelhook, on the inside of the cap and attached to it , engages

86



87



in a small recess in the steel set plate, rotating this plateto the proper sett ing.

This set plate makes one revolution in approximately75 seconds in the case of the 75 second fuze, and thereforeis turned through an arc proportional to the desired t imeof bu rst as ind icated on th e gr ad ua ted ring. A steel pinwhich is engaged in a forked arm attached to the main shaftof th e m echan ism, serves to lock it . Th is pin ha s a smallshou lder on it , wh ich rests a ga inst a spring steel cup slottedin several places to m ake it m ore elastic. W he n th e gunis discharged the pin sets down into the cup, thereby releasing the forked arm, thus allowing the mechanism to

sta rt . T he pla te th en is revolved by the spring un ti l anotch in i ts periphery rotates to a posit ion opposite aprojection on the trigger releasing device, which then dropsin to place, releasing th e trigger and th e firing pin. Th etrigger releasing device is held in restraint by the hookprojection on one end, which is held at the periphery of theset plate unti l the notch rotates to a posit ion opposite thehoo k. Th e firing pin is forced in to th e prim er by a spring

wh ich is held in com pression by th e trigger. T he upperperpendicular arm is held in a safe position by the trigger,releasing arm, unless the fuze is rotating at a rate of over17-00 r. p . m . T he firing pin cann o t com e in co n tac t withthe primer, if it should be accidentally released, before theaction of a centrifugal safety device consisting of a smallsteel piece held between the firing pin and the primer bya spring, but moving out under centrifugal force.

A governor similar in con struction to the escapemen tin a w atch controls th e spring an d the tra in of gears. Th isescapement is placed on the center of rotation of the fuzeso that its function will not be appreciably affected by thecentrifugal force. Th is fuze ha s no percussion m echan ism.

S T O R A G E A N D C A R E O F F U Z E S .

Fuzes are packed in tin boxes sealed by means of a stripsoldered to box an d cover. These boxes should be storedin dry dug-outs or magazines, protected from weather andsplinters, and if possible, shell proof. Th ey should beke pt ap ar t from other kinds of am m un ition. Th ey shouldbe used in the order of their receipt at the battery to preventdeterio ration. As a general rule not m ore th an six pro

88



jectiles per gun shou ld be ke pt fuzed a t a tim e. If it isfound necessary to transport shells into which the fuzeshave already been fitted, the fuzes should be removed.

P A I N T I N G A N D M A K K I N G O F F U Z E S .

To indicate the time of functioning after impact, pointdetonating fuzes are painted in the following manner:

In sta nta ne ou s— the neck of th e fuze is blue an d thehead unpainted.

Non-delay—the head is painted white .Short delay—the head is painted black.Long delay—the head is painted violet .

All parts of base detonating fuzes that come in contactw ith the bu rsting charge are pain ted with a non-acid pa int .

ADDITIONAL NOTES ON FUZES.

The notat ion " 2 4 / 3 1 " on French fuzes refers to certaindim ensions: 24 being the diam eter of the gaine or stock inmill imeters and 31 the maximum diameter of the head.

This indicates the size shell or adapter into which the fuzecan be fitted.

All 24/31 fuzes fit U. S. boosters and adapters MarksI to VII inclusive for both H. E. and gas shell.

All semi-steel shell take the super-quick fuzes (P. D. F.Marks I I I , XII and XV—XII and XV are exper imenta l ) .

Base Detonating Fuzes. The base detonating fuzeMark III , Semple type, will replace all other types ofmedium and major caliber base detonating fuzes.

The medium and major caliber base detonating fuzes,model of 1906, arm by inertia and have self-containedboo sters. B oth are m ade up with Non-delay, .04 seconddelay and .08 delay primers, the type of primer being indicated by suitable m arkings on the base. Th e lot nu m beris also stamped on the base.

T he mino r caliber base de ton atin g fuze is a ring resistance fuze arm ed by the set back of t he plunger. I t ha sno bo os ter. I t is no t bore safe.

89



it

$ II

III!

i!

90





Fr ankfo rd Arsenal 21-sec- Fra nk ford Arsenal 3-in.ond com bina tion fuze for H . E . shra pn el. Bore3-in. H . E . shrap nel, m o- safety pellet,del of 1912.

K ru p p com bina tion fuze. 3-in. field shrap nel. About10,000 of these fuzes werepurch ased from the Krup pCompany; obsolete. Supply exhausted.

Detonating fuzes for use in steel projectiles containing a

bursting charge of high explosives.

Minor-caliber base detonat- For use in 6-pdr. and 2.38ing fuze. in. steel shell containing

a bursting charge of trini t rotoluol .

Point detonating fuze for For u se in steel shell for 3-in.mobile artillery . field gun tapped in the

point for this fuze. 8,000

have been manufacturedfor that number of steelshell now on ha nd . Nomore of these fuzes willbe manufac tured.

Medium caliber base deton- For use in all steel projecating fuze. tiles from 2.95 to 7-in. in

calibers inclusive. Superseding other fuzes for usein these projectiles whenthe present stock hasbeen exhausted and whenspecially ordered.

Siege base detonating fuze. For use in steel projectiles(Modified Pierce stock). of from 5-in. to 7-in. cali

ber adapted to this fuzeuntil the stock of fuzes onhand (about 9,500) hasb e e n exhausted. Nomore of these fuzes willbe manufactured.

92











I

I

£

97



I







£>£:r'OA/AT'//VG ruZTE MAGK

Scale-FullSizs101



Scale-Full Size.

Off

>STAMf* H, O orM

FOR BAS£

HAJORCALIBER BASE DET0NATIN6 FUZE

cAi.iBE.fz

102



CHAPTER VIEFFECT OF FIRE.

G E N E E A L C O N S I D E R A T I O N S .

In order to choose the proper cannon and ammunitionto be used in a given case, taking into account the purposeof the fire, one must know th e ac tion of the different typesof ammunition, which in turn requires a knowledge of thefactors affecting the pen etr atio n of the projectile. These

factors are the striking velocity, the shape and weight ofthe projectile, the type and position of the fuze, the angleof impact, and the nature of the object struck.

The importance of the value of the striking velocityin determ ining the pen etra tion is self-evident. Th is velocitytog ether w ith the mass (-f-) fixes the m om en tum whichm us t be overcome by the resisting force, th a t in turn ,being determined by the shape of the projectile and by the

nature of the object struck.The type of fuze (different time of functioning) determines the maximum possible penetration by l imitingthe time interval between impact and explosion, whilethe position at the point or in the base, determines theshape and strength.

The angle of impact (i.e., the angle between the tangentto the trajectory at the point of impact and the plane tan

gent to the surface struck at that point) is one of them ost vital factors in determ ining the pe ne tration . Up onit depends, in the first place, the question as to whetherany penetration will be obtained, or whether ricochet willre su lt. I t is influenced chiefly by the ang le of fall, afunction of the range and of the powder charge .used, andby the slope of the grou nd . I t will be som ew hat influencedby th e use of "nose disks ", which decrease the ballistic

coefficient, increase the angle of fall, and also tend to decrease the pe ne tratio n; as well as by the "p resen tation , " i .e . ,the angle between the tangent to the trajectory and thelarger axis of the projectile.

A hard even surface will tend to deflect a projectile atconsiderably greater angles of impact than will a soft orun even surface. Therefore, ricochet un de r conditions of

103



wet, muddy ground will be limited to much smaller anglesthan will be the case in dry weather or on hard ground.The slope of the ground at the exact point of impact is thefactor which, with the angle of fall, will determine the angleof impact, so that a slight gully or mound may completelychange the result to be expected from the general slope ofthe area.

It is impossible to alter many of the above factorsentering into the Ballistics of P en etra tion , and equallyimpossible to pred eterm ine some of the m . You willtherefore realize that there will be considerable uncertainty as to the action of a projectile fired under any given

conditions, and the best that can be done is to give tables,diagrams, etc., which show what may be considered astypica l cases. As such our jud gm en t m ay be guided bythem, but they are not to be taken in any sense as hard andfast rules.

A C T I O N O F H I G H - E X P L O S I V E S H E L L .

H . E . shell is used w ith a tim e fuze to give bu rst in air,or w ith fuzes of different degrees of de lay to give a burs tat different penetrations, or when ricochet is possible, togive with a delay fuze (about .05 sec.) a burst similar tothat obtained with the t ime fuze.

T he diagra m , pag e 105, shows the shape of the sheavesformed with an air burst, the dimensions given applyingto a 75 m m . shell. Shells of large r caliber will ha ve th e sam egeneral distribution but will cover a somewhat larger area.

Note that the main sheaf is perpendicular to the planeof fire; that the danger zone of a single shell is strictlylimited in extent, though large fragments may be dangerousat much greater distances than those given; and that thedanger zones for larger calibers increase in dimensions butnot proportionally to the change in size.

104



105



P E N E T R A T I O N O F P R O J E C T I L E S A TT H E P O I N T O F F A L L .

H . E . S H E L L .

When H. E. shell is used with other than a time fuze,the effects produced depend primarily upon the course itfollows after contact with the ground and upon the pointat wh ich th e bu rst take s place on this course. T he coursefollowed varies with several factors—the angle of impact,the residual velocity, the shape and weight of the shell,the presen tation, and the n atu re of the terrain. B ut ofall these factors the angle of impact is the most important.In accordance with the value of this angle the diagramsindicated below are obtained as the most probable courseof the projectile.

Angle of im pac t: e >0° b u t < 15°. (Fig. 2, page 107.)The shell ricochets after merely grazing the ground.

e > 15° bu t < 25°. (Figs. 3 an d 4). T he shell, in accord

ance with the terminal velocity and its more or less taperingform, ricochets after making a certain subterranean course,or else remains in the ground a short distance below thesurface.

e> 2 5 ° b u t< 4 0 ° . (Fig. 5). T he shell often assumesa winding course, usually with a tendency to return to thesurface.

e > 4 0 ° . (Fig. 6). T he shell gene rally assum es a r ectilinear course and is buried to a depth which depends uponthe terminal velocity, its weight, its shape, and the natureof the ground.

Fr om the preceding observ ations it is clear th a t deeppenetrations can be obtained only with the aid of projec

tiles of large caliber fired at very great angles.

The point of the burst and the form of crater produceddepe nds up on th e fuze used. Fo r bu rsts close to the grounduse insta ntan eo us or non -delay fuzes. In stan tan eo us fuzes(M ark I I I , Fren ch I . A. L.) when the y str ike at an anglegreate r th an 15° bu rst slightly abov e the ground an d forma very slight sphere of compression of a depth of only 10 to

106





15^ centimeters in the ground, whose crater indents thesurface only to a slight degree. (Fig. 7, pag e 109). W ithangles less th a n 15° it should no t be u sed, for ther e isdanger of the fuze failing to func tion.

The effect is similar to that of the burst in air, butsom ew hat redu ced . A vertica l sheaf of fragm ents is formedat the point of fall approximately perpendicular to theplane of fire. Th is ty pe gives a ra th er open smoke ballwhich does not rise to a great height.

A burst with slight penetration of the ground will begiven with an angle of impact of 15° to 25° using a non-delayfuze. A t a dep th of one or two length s of th e pro jectile,the shell excavates the terrain in the form of a hemisphericalshell crater, hurling fragments of earth and metal to a greatdistan ce. (Fig. 8). T he effect dep end s up on the n at u reof t he explosion, an d for th e same explosive, is p ropo rtional to the bu rstin g charg e. T he smoke ball w ith this fuzeis narrower and higher than with the instantaneous fuzesince the force of the explosion in a sidewise direction isl imited by the surrounding ear th.

A burst at a depth three or four times the length ofthe projectile will be given with an angle of impact from25° to 40° an d a delay fuze. T he vo lum e of th e e ar thexcavated increases, but a part of it falls back, forminga conical shell cra ter . (Fig. 9) .

A burst at a great depth will be obtained with an angle

of impact greater than 45° and delay fuze. The explosiveno longer has enough force to eject the earth above it .The sphere of compression forms an apparent dome at thesurface, sometimes surrounded by a circular excavation.This results in a camouflet or a mine producing no exteriorcra ter. (Fig . 10.)

The tables below indicate the approximate dimensions

of the excavations in a soil of average consistency, and arebased upon French shells.

108



109



TABLE I.

CLEAN=CUT CRATERS.

Elongated

shell Diameter Depth Volume

Millimeters Meters Meters Cubic Meters120 2 .5 0. 9 2. 6155 3.5 1.1 6.0220 4 .5 1.4 13.3

370 6.0 2 .2 36.0

Table I refers to clean-cut shell craters. It shows that even for

average calibers up to 220 mm inclusive, the shell need not penetrate

more than about 1 meter in order to throw out all excavated earth.

TABLE II. TABLE III.Earth Moved—Delayed Fuze, Angle Maximum depth.

of Impact from 25° to 45°.

Craters partially filled with loose earth Maximum depth

Elongated External High=cap Depth

shell Diameter Depth shell attained

Millimeters Meters Meters Millimeters Meters155 3.5 1.5 155 3.0220 5.5 2.3 220 4.5270 6.0 3.0 270 6.0370 10.0 6.0 370 10.0

If the depth of the burst increases, we obtain thefigures of Table II, corresponding to a larger volume ofearth removed, but with a shell crater partially filled up,the volume of earth ejected being less than in the caseindicated in Table I.

no



If the depth of the burst increases still more, we geta camoufl et (mine producing no exterior cra ter ), where allthe force of the explosion is expended under the form ofviolent pressure upon the neighbo ring soil. Th is pressureis disseminated in the underlying layers and enables us toat ta in d ep ths greater than 1 to 1.50 m eters in the finalpe ne tratio n of the projectile. Ta ble I I I indicates the max im um dep th which is thus ob tained. T he dullness of thedetonation varies directly with the depth of ground at thepoint of burst.

S H R A P N E L .

The effect of shrapnel fire is dependent upon the re

maining velocity at the point of burst and the additionalvelocity given by its explosive charge, which give theinitial velocity to the balls; the presentation and the rotational velocity at the moment of burst which determinethe direction; upon the ballistic coefficient of the balls whichw ith the other factors determines their rang e. I t is thereforeevident that larger sizes of shrapnel will give a larger effective pat te rn . I t is no t used, how ever, in calibers over 6".

The following information applies to the use of 155 mm.case bu rsting shrapn el. T he no rm al heigh t of bu rst is 4mils, but on account of the weight of the balls (25 gr.) andfragments, it is effective at higher bursts though the lengthof the effective pa tt er n is there by reduce d. Th is shrap nelis effective on a percussion bu rst at ranges u p to 2,000 m eters .

F igu re 11 , page 112, shows the cone of b ur st of 155m m . case-bursting shrapnel at 4000 m., 155 mm . L. gun,

full charge. H eight of burst 4 mils.

SPECIAL SHELLS.

Under special shells we shall include tracers, illuminating or star shells, smoke shells, gas shells, anti-balloon andanti-aircraft ammunition.

Tracers are used to visualize the trajectory in order to

more readily effect an adju stm en t upon a balloon. T hey arealso valuable for their incendiary effect.

Star shells are used to give illumination over certainareas which are to be watched or against which it is desiredto fire. The y ha ve an ince nd iary effect bu t little use canbe made of this property.

in





Chemical shells are of two ty pes : smoke and gas.W it h the first nam ed a white a nd opaque colum n ofsmoke is libe rated from each shell. These columns mergew ith each o ther and form a dense screen, thoug h w ith ahigh barometer and a low wind the smoke tends to riserat her rap idly . T he m ost favorable conditions for theemployment of these shell appear to be with a cross-wind

of ab ou t 6m. per second and a low baro m eter. In suchcases the shell should be concentrated on a point well towindward of the locality which it is desired to screen, sothat the smoke will be blown across it in a thick curtainperh aps 60m. high. T he phosph orus w ith which thesesmoke shells are filled is highly inflammable and has beenfound to have considerable incendiary effect.

Gas shells are filled with different chemical liquids

which are scattered over the ground as soon as the shellsbu rst and the n slowly vapo rize. Th e vap or of the lacrymatory shell produces intense irritation of the eyes andrespiratory organs. It is not poisonous, but those handlingthe shell, if there is a suspicion of leakage, should be provided with protective goggles, and should at all cost avoidrubbing the eyes with the hands.

Of the so called lethal gases, chlorine, phosgene, anda m ixture of the two are the most com mo n. These areextremely dangerous, very small amounts producing fatalresults .

The vapor of all these gases is heavier than air, and willtherefore remain close to the ground, filling trenches,dugouts, cellars, covered gun emplacements, woods andhollows. The rad ius of action of this type of shell dependsalmost en tirely on atm ospheric conditions, especially up onthe wind . T he effect never reaches m ore th an 10 to 20 km .behind the lines. Th e m ost favorable circum stances area clear day, when the vapors are nearly colorless, a totalabsence of wind , or only a ligh t breeze, (not over 3. 5m . persec.) blowing toward the enemy, and high humidity of theatm osp here . T he effect is pa rticula rly m arked in valleys,or small woods, and in forests the shells may be employedeven wh en a strong wind is blowing outside. In the open,on a damp and muggy day with little wind, the effect maylast for six hours or more, whereas on a dry, clear day, witha breeze, it will probably not persist for more than thirty

113



m inute s. In woods, buildings, or covered emplacem ents,the effect may be felt for as long as 24 hours.

Gas shells may be employed against a position whichit is desired to deny to the enemy for a certain length oft ime, or to create a barrage through which the enemy'stroops cannot pass .

Their chief value is, however, for counter-battery work.The gas sinks into the dugouts, it affects the whole of thepersonnel; and most of all it requires the wearing of protective masks which is certain to interfere with the serviceof the b att er y . M oreover, by takin g ad va nta ge of the wind,effect may be obtained, even if the position of the gunshas not been located with the accuracy that is requiredfor ob tainin g direct hit s on gun em place m ents. T he effect

will be most marked when the guns are concealed in woods,houses, etc., where they are least vulnerable to ordinarya t t ack .

The quantity of vapor necessary to obtain an effectivecloud can only be obtained by firing a large number of shell;with the 4.5 inch shell, at least one round for every twoyar ds of front. T he fire shou ld be rap id u nti l the necessarycloud has been produced, after which a slow rate will be

sufficient - to m ainta in i t . A djustm ent should be carriedout with the ordinary shell, so as to give the enemy nowarning of what is coming.

I t is cu sto m ary to fire 3 gas shells to one H . E . shell.Far from reducing the effect of the gas, shells bursting amongit may be expected to increase it by forming eddies whichwill allow th e gas to sink into the trenche s, du go uts, etc.Shrapnel fire may also be expected to be effective in combi

nation with smoke and gas, as these will probably causethe enemy to man his parapets, and in some cases to comeout into the open.

FIRE AGAINST BALLOONS AND AEROPLANES.

Owing to the height and distance behind the lines atwhich a balloon is stationed it requires a long range gun toreach i t . Since the damag e done by simply pu nctu ringthe envelope is only tem po rar y and easily repa ired it isdesirable to use a type of projectile which will completelydestroy it by a burst against it, or by an explosion of theballoon itself from ignition of the hydrogen.

The ordinary shrapnel is not available since the time

114



of burnin g of its fuze is too short for th e long ran ge (perhaps10,000 m.) which must be used, and its rate of burning isirregular, being affected by the hu m idity and den sity ofthe atm osp he re. A clock fuze has recen tly been developedwhich eliminates both of these sources of trouble, and which

is used with a shell with incendiary properties for balloonat tack.

Against aeroplanes, on account of their great speedand maneuvering ability and the long time of flight thepro ba bility of hit ting is very low. Shrapnel being limitedin its effect to one direction and also requiring a direct hiton the gasoline tan k or th e pilot, it is not ve ry effective.H. E. shell with its greater all-around danger zone and

with the very irregular fragments is more effective eitherby direct hit with a super-sensitive fuze or by explodingun de r the action of a clock fuze or an im proved pow der-traintime fuze, both of which have been developed for this use.Tw o m eth od s of at ta ck a re used. The first is by means of"zo ne fire", i. e., changing the range by definite steps inorder to sweep a larger area, or by firing rapidly at a determined point and then waiting until the plane has again

settled down and its new course determined, when theprocedure is repeated.

ROLE OF ARTILLERY

The role of artillery fire may be classified as follows:

1. Ag ainst un she ltered personnel or m ateriel. Th is

is principally the function of the machine guns and the 7$m m guns and will no t be em phasized here . The use ofheavily armed tanks may require the attention of theheavier artillery in the near future.

2. Barrage fire. Creeping barrage behind whichtroops ha ve to move forward. Stan ding barra ge on someportion of the enemy area to which it may or may not be

necessary for infa ntry to app roac h. F lan k ba rrage established to prev ent troop m ovem ents to the flank. M ostof this barrage work will be the task of the smaller gunsbut some so-called barrages on communications towardthe rear, and the reinforcement of the smaller calibers duringan em ergency, will be included in t he role of th e he av yartillery.

115



3. W ire cu tting . Th is is a tas k of th e he avy artilleryonly under exceptional circumstances.

4. D estru ction fire. Ex ecu ted by he av y artillery ontrenches ' s t rong points , canto nm ents , am m unit ion dum ps,railway junctions, etc., which owing to their protection orrange cannot be reached effectively by the light artillery.

5. Cou nter ba t tery work. Co unter ba t tery work iscarried on against two types of batteries; those well protected and dug-in, and those trusting merely to camouflageto conceal their positions. In counter-battery work, accurate,well ad juste d fire is necessa ry. The re are two typ es ofcou nter b a tte ry w ork : dem olition fire, for the com pletedestruction of the battery; and neutralization fire to denythe enem y effective use of their b at te ry . Th e at te m p t tosecure "neutralization" may be by the use of gas shells,or by means of very rapid, less accurate fire rather thanfire from exceedingly heavy guns.

6. Harassing fire. Mostly directed on importantcrossings and on points of traffic shown on photographs.It is executed at irregular intervals and should be intenseonly at probable hours of supply or if considerable enemymovement has been reported.

7. Balloon at tac ks to destro y or pre ve nt the use ofobservation balloons.

8. Anti-aircraft fire for protection against hostileplanes back of the front lines. Effective in keeping planesat such an alt i tude that accurate reconnaissance and photographic work are difficult.

FACTORS EN TE RIN G INT O CHO ICE OF G U N AND

AMMUNITION.

There are certain general considerations influencingthe choice of the proper combination of armament andam m un ition which should be kep t in m ind. Th e typ e ofprotection which the different targets have determinesw he the r direct fire or cu rved fire is to be used. If h eav yoverhead cover is provided gun fire with a comparativelyflat trajectory will not be effective, while howitzer or mortar

116



fire with a steep angle of fall will enable one to get penetration depending in amount on the weight of the projectile used. W ith a ta rg et of some he igh t the direc t fire of agun with a high remaining velocity and large danger spacewill give better results than the howitzer.

Different powder charges may be used with both guns,how itzers and m or tars . W henev er the proper choice isno t de term ined by the required angle of fall and strikingvelocity the lower charge should be used as it is m ore economical in cost and wear of the gun, unless this advantageis counterbalanced by the increased dispersion.

Targets protected by defilade which can be overcome

by no other means may be reached by the use of "nosedi sks" which increase the angle of fall. T he y are undesirable because they increase the dispersion. The re use isconfined to the light artillery.

The direction of the plane of fire with respect to thedimensions of the target is important in determining thetyp e and am ou nt of am m un ition necessary. Since the

longitudinal dispersion is much greater than the lateral,enfilade fire upo n a long narro w targ et, such as a trench ,will be m uch more economical of am m un ition . U ndersuch circum stances, how ever, one m us t consider w hethe rthe effective zone of burst of the projectile used is normalor parallel to the plane of fire.

If troops are to approach or follow an artillery barragethe safety zone required by the different shells must beconsidered. Tab le V gives approx im ate value s for different types and sizes of ammunition.

LONGITUDINAL LATERAL

Shrapnel \ zone of dispersion including fuze dispersion

75 mm shell ^ " " " " " " 50 m4 . 5 " " " 450—550m. 250m.

6" " 550—650 m. 300 m.

8" and 9" . 2 shell 700—900 m. 400 m.

117



T A B L E S F O R E F F E C T O F F I R E .

Since one cannot determine with accuracy all of thecauses entering into the results in artillery fire it must beborne in mind that the tables and figures given here areonly average values and in any instance may be deviatedfrom considerably.

When a mission can be accomplished in the timeallowed with small caliber guns or howitzers do not use theheavy art i l lery.

If the a rtillery a nd am m un ition given below as . bestsuited for different targets is not available it will be necessary to use a com bina tion app roac hing the desired one asclosely as possible. With these limitations understoodthe following tables may be used as a guide.

A T T A C K O N P E R S O N N E L .

Gun Projectile Fuze Rem arks

Unsheltered 75—155 mm" "

ShrapnelH .E . Shell

TimeDelay (.05s) angle of

fall < 15°

" " H. E. Shell Instantaneous angle offall > 15°

In trenches 75—155 mm Shrapnel Time with enfilade fire

" H .E . Shell Time angle offall < 15°

"

"

H .E . Shell

Gas shell

(Non-delay orinstantaneous)

angle offall > 15°

Gun Projectile Fuse Rem arks

Barrage 75—155 mm Shrapnel Time With enfilade fire,

best.Fronta l " H. E. shell Delay (.05) W ith frontal fire,co <15°

H. E. shell Instantaneous With frontal fire,co > 1 5°

Smoke For better screeningFlank " Shrapnel Time W ith frontal fire

H. E. shell Delay (.05s) or Large safety zone re-Instantaneous quired

118



If troops are not following, H. E. and Shrapnel may be used indiscriminately.Attack on Artillery Gu n Pro jectile Fuze RemarksNeutralization pro- All guns H. E. shell Fuze to depend on

tected or unprotected. 6" and up

Destruction Guns allUnprotected calibers

Protected

Howitzers

Destructive Fire on:

Wire entangle- Trench Morments

Trenches,

Mach. gun em

placementsObservation sta

tionsAmmuni t i o n

dumps, buildings, cantonments, etc.,

tars

Guns 75-155mm

Howitzers 8"

All light andmedium cali

berguns, howit

zersand trench

mortarsAll calibersguns andhowitzers

Incendiary

Railroads Above 105mm H. E. Shell

Concrete & steel Guns above H. E. Shellprotection 6" "vertical "

Horizontal pro- Howitzers H. E. Shelltection

Gas shell degree of protection. Instantaneous or non-delay.

H. E. shell Instantaneous co> 15°Non-delay u < 15°Non-delayTime or delay

(.05)Non-delay or

slight delay

H. E. Shell

Non-delay

Instantaneous

Delay

Instantaneous

Non-delay

Delay slight« (medium)

co > 15°co< 15°

Against

overheadcover

o>< 15C

co> 15°

For chevaux deFrise.For defil a d e dslope.

co< 15

co> 15°«> 25°

Non-delayDelay

Non-delayDelay

Base Delay

Non-delay

Non-Delay

Long delay

For cellars,or if someprot -e c tion

Use mixture ofthe two.

For penetration

if point fuzeused

To scattermateriel

For penetration.

119



EXPENDITURE OF AMMUNITION FOR

DIFFERENT MISSIONS

Table I.—.WIRE EN TA NG LE M EN T. Estimated expenditure ofammunition for a 25m breach in wire.

No. shellsestimatedAmmunitionrequire=Calibers Ground

ments for aRange conditions

wire enutn=mm at target.glement 30

Projectile Fuzes metersdeep

From 2500 75 Glacis or H. E. Shell Instantan- 600 at 2500to 4000 me- very slight eous or m; 700 at

meters coun t e r - Non-delay 3000m; 800slope; hard at 4000 m.ground or

muddy clayFrom 5000 75 Glacis or Instantan- 1000 at

to 7000 me- horizontal eous 5000 m;ters dry ground 1200 at

7000 m.From 2000 155 How- Steep coun- a a 200 at 2000to 4000 itzer ter-slope m; 270 at

meters 3000 m;330 at 4000m .

From 5000 155 gun or ounter-u a

330 at 5000to 7000 155 Schnei- slope m; 400 at

meters der Howit- 6000 m;480zer at 7000 m.

Table II.— CRUSHING FIR E AGAINST SH ELTER S.

From 2000 155 Howit- Medium * H. E. Shell Delay 80

to 4000 me zer otersMore than4000 meters

220 or 270155 gun

StrongMedium

««

u

a

a

150

1. Roof formed of alternate layers of logs and earth.

2. Roof of concrete or of rails and concrete.

120



Table III.—DESTRUCTION OF TRENCHES.

AmmunitionRange Calibers Estimated requirement

mm Projectile Fuze No. of rounds

From 3000 75 H. E. Shell Delay 10 per linear meterto 7000meters (1)

a « a per 100 importantpoint, viz: 4 roundsper linear meter (frontal fire); 1.5 rounds perlinear meter (enfilad

ing fire)From 2000 2 0 0 ( 2 ) . . . . u « 70-100 rounds per imto 5000 me- portant pointtersFrom 5000 155 gun or u a 5-6 per linear meter,to 7000 me- 155 Schnei- according to the rangeters der Howit- (frontal fire).

zer (3)

(1). Fire as far as possible exactly in enfilade.

(2). To reinforce the action of the 155 howitzer on the importantpoints.

(3). SAFETY ZONE:—Give the infantry a prohibited zone of 200meters during fire with the 155 howitzer. The troopsmust also be made to take shelter from the fragments,which may be projected several hundred meters to the

rear.

121



TABLE IV.—DESTRUCTION OF A FORT.

Good Ammunition.

Calibers Range

Targets mm. inKilo=

Shells Fuzes No. rounds.

meters

293 howitzer 8 100 for tar-

Rampart 320 gun 15 Long de- gets at ranges

Shelters 370 mortar370 howitzer

712

Semiarmorpiercing

lay basefuze

less than 9km. 150 for

400 howitzer 12 longer ran

ges.

Barracks, 293 howitzer 8 150—200 acinterme 320 gun 15 cording as

diatelarge she

370 mortar370 howitzer

712

a u the range isless or more

lters, Ger 400 howitzer 12 than 9 km.

man types

Armored 320 gun15turrets 370 howitzer 12 a u 150 per tar-

French 400 howitzer 12 gettype

Armored 320 gun 15batteries 370 howitzer 12 a u 400—500 perGerman 400 howitzer 12 target

type

Cementcorridors • (1) (1)

a « 100-150 per

(2)corridor.

Pits 155 gun 8240 gun 10320 gun 16 H. E. Shell Delay 150 per pit (2)

(1). All the above calibers and their corresponding ranges.

(2). Enfilade fire.

122



TABLE V. — DESTRU CTION OF TOWNS.

TABLE VI.—DESTRUCTION OF RAILWAYS.

Good

Targets Calibersmm.

ranges

inkilo=

Shells Fuzes

meters

Semiarmor270, 280 6 piercing Delaymortars action

293 8 a baseBridge

or viaduct

howitzers

320 gun 157

u

u

fuzesa

a

370, 400 12 a a

howitzers

155 8 H . E. Shell DelayFill gun

240 13 u a

1558 u a

Switches gun240 13 a u

100 12 Semiarmor u

rapid fire piercing140 13 ~or H. E. u

shell

These estimated expenditures apply to enfilade fire. For frontalfire, they should be quadrupled.

123

EstimatedRounds per 100sq. m. block of

houses.

4 of which1 will be

incendiary.

4

Estimated

requirement,No. of rounds

100 - 200rounds depending on thecaliber

*500

*400

400 rounds

200 rounds200 rounds

Kind of destruction

Destruction ofhouses

Crushing cellars

Calibersm m . .

155 howitzer;155 gun; 220;270

270, 280, 370mortars, 293,

370,400,howitzers.

Shells

H . E . Shell orincendiary

Semiarmor

piercing orH. E. Shell

Fuzes

Delayaction,combinationfuze.

Delayedactionbasefuze.



APPENDIX I

SEACOAST ARTILLERY AMMUNITION

CANNON

3" Gun

4" Gun

4.7" Gun

5" Gun

6" Gun

8" Gun

10" Gun

12" Gu n

12" MortarM 1890, '90M1

an d M 1908

TYPE

C. S. Shell

A. P. Shell

A. P. Shell

A. P. ShotA. P. Shell



A. P. Shot

A. P. Shot

A. P. ShellD . P. Shell

PROJECTILE

W E I G H T

lbs.

15

33

45

5858

106-108x

316-323x

604-617x

1046-1070x

700824

1046

B U R S T I N G C H G .

% tota l wt .

3

3

4

25

24

25

2

2

63

P R O P E L L I N GC H A R G E

lbs.

5

7 . 5

11

16.5 (M-'97)22.2 (M-1900)

29.7 (M-'97)32 (M-W-05)

83.5

182 (M-1900)162 (others )

334 (M-1900)

279 (others)655747

MUZZLE VELOCITY

2600 f.s.

2300 f.s.

2570 f.s.

2600 f.s.2600 f.s.

2600 f.s.2600 f.s.

2200 f.s.

2250 f.s.2250 f.s.

2250 f.s.

2250 f.s.1500 f.s. (maxim um)1300 f.s. (maxim um)1050 f.s. (maxim um)



12" Mortar D . P. Shel l 1046 3 78 lbs 1200 f.s.Model 1912 700 89 lbs . 1800 f.s.

14" Gun A. P. ShotA. P. Shell

1660x1660x

25

349 (M-'O7, '07M1430 (M-'IO, '10M1)

2150 f.s.2350 f.s.

16" Gun A. P. Shot 2400x 2 666.5 2250 f.s.A. P. Shell 2400x 5

The 3", 4" and 4.7" Gun use 110 grain percussion primer, all others use the 1914 Friction, Electric, or Combination

Electric-Friction primer.

The 3" and 4" amm unition is loaded fixed, the 4 .7" semi-fixed; all others sepa rate.

Reference x indicates shell with ballistic cap.

All seacoast projectiles from 3-in. to 6-in. inclusive have medium caliber base detonating fuze.

All seacoast projectiles from 8-in. to 16-in. inclusive have major caliber base detonating fuze.

Both medium and major caliber base detonating fuzes are to be replaced by base detonating fuze, mark III, Semple type.

The bursting charge for all seacoast projectiles is Explosive D.



HEAVY MOBILE ARTILLERY

CANNON

4.7" Howitzer

Pedestal andRailroad mt.

5" Siege Gun,Mod.

1890 & 1898

5" S. C. Gun,Wheel mount

6" S. C. Gun,Wheel mount

155mm Model1918

(Filloux)

7" Seige How.Mod. 1890 &

1898.

7" Navy GunR. R. Mount

P R O J E C T I L E

T Y P E

C. S. )(Shell)Mk. I. j

Mod. 1905.Shrapnel

C. S. ShellMk . I I

Shrapnel

C. S. ShellMk. II .

C. S. ShellMk. II.

C. S. Shell" Mk. I l l

ShrapnelMk. I.

ShellShrapnel

NavyShell

W E I G H T

lbs.60

45

45

45

52

90.5

95

95

105105

165

f\{

"

B UR STING- CHG.

%total wt.6%7%

1% (711balls)

4%

2%(280balls)

15%

15%

17%

1.5% (849balls)

• 7 %

2% (390

balls)

PR OPELLINGC HAR GE

110.5 oz.

17.5 oz.

28.9 oz.

3.5 lbs.

5.5 lbs.

16.5 lbs.

28 lbs.

/ 25 lbs.\ 28 lbs./ 25 lbs.\ 28 lbs.

[ 5 lbs.

J57.7

MUZZLEVELOC ITY

454 f.s.

620 f.s.

900 f.s.

1300 f.s.

1830 f.s.

/1950 f.s. \\ 2600 f.s. /

/1950 f.s. \\ 2600 f.s. /

596 m.s. \735 m.s. I596 m.s. \735 m.s. /

1100 f.s.

2700 f.s.

PR IMER

10 gr. Perc.

a

a

Obturating f

Friction [

1914 Fric .

1914 Fric.

21 gr. Pe rc.

«

Obturating 1Friction 1

CombinationElectric Percus

sion (Navy type)

FUZE

P . D. F., Mks. II ,I I I , IV & V.

Med. Cal. B. D.

31 " & 45" combina

tion.Med. Cal. Base Det.31 " & 45" combina

tion

P .D .F .Mks . I l l &V

P. D. F. Mks. I l l & V

P . D. F. Mks. I ll &IV & IV *

31" and 45" combination.

Med. Cal. Base Det.31 " and 45" combina

tion.

Tracer B. D. F.(Navy type)



8" How. Mod.1917 & 1918.

(Vickers, Mks.

v i & VII . )8" S. C. GunR. R. Mount

9.2" How.,Mk. I.

9.2" How.,Mk. II .

240 mm. How.

Model 1918.(Schneider)

10" S. C. Gun,R. R. Mount

12" S. C. Mortar R. R.Mount

12" S. C. Gun,R. R. MountC. S. Shell

12" Gun, M 1T8 (Bethlehem R. R.

Mount)14" S. C. Gun,

R. R. Mount

C. S. Shell,Mk. I.

C. S. Shelli Mk. I.

C. S. ShellMk. IX.

a

C. S. Shell

Mk. I

C. S.ShellMk. II .

H. E. ShellMk. VIII

C. S. ShellMk .XMk. VI

C. S. ShellMk. VI.

C. S. ShellMk. II .

20 0

20 0

290

a

35 6

51 0

700700

700 |

700

70 0

1200 lbs

1 5 %

15 %

12%

u

14 %

1 1 %

12%12%

14 %

1 3%

13%

/ 10.75 lb s.\ 17.5 lbs.

(Mk. VII)

/ 68 lbs.\ 56 lbs.

14 lbs.

24 lbs.

35 lbs.

160 lbs.

25-65 lbs. \25-65 lbs. /

250 lbs.

/ 240 lb s\ 337 lbs

450- lbs.

1300 f.s. \1500 f.s. /

(Mk. VII)

2600 f.s. \1950 f.s. J

1200 f.s. 1

1500 f.s. J

545 m.s.

(1700 f.s.)

2400 f.s.

1500 f.s.

2^50 f.s.

2400 f.s. \3200 f.s. J

2900 f.s.

21 gr. Perc. orT-tube fric.

1914 fric.

21 gr. P erc. orT-tube fric.

21 gr. Perc.

1914 Friction

1914 Friction

1941 Friction

1914 Friction

1914 Frict.

P. D. F. Marks II ,I I I , IV & IX

P. D. F. Mks. II; III,V & I X

P. D. F. Mks. II, III,IV & IX

P. D. F. Mks. II, III,

IV&IX

P . D. F. Mks. I l l, IV*,V, 75" Mech Time,M. C. B. D., Mk. Il l,

Semple Type.

Mk. Ill, IV.M. C. B. D. Mk. Il l,

Semple Type.

(Mks . Ill, IV*, V,75" Mech. Time,

M. C. B. D. Mk1 II I, Semple Type

M. C. B. D. Mk. I l l ,Semple Type

P . D. F. Mk. Il l, IV*,75" Mech. Time,

M. C. B. D. Mk. Il l,Semple Type.



PR OJEC TILECANNON PR IMER FUZER O P E L L I N G MUZZLE

T Y P E WEIGHT B UR STING C HAR GE VELOC ITY

14" Navy Gun, Shell 1400 lbs 2% 480 lbs 2800 f.s. Combination Tracer B. D. F.R. R. Mount electric-percus- (Navy Type).

sion (Navy Type )

16" Howitzer C. S. Shell 1660 lbs 14% 225 lb s 1900 f.s. 1914 Frict. Mks. Ill, IV; M. C.R. R. Mount Mk. IV. (Maximum) (Maxi um) B. D., Mk. Ill, Sem

ple Type.D. P. Shell M. 1917 u

C. S. Common Steel.

H. E. High Explosive.

D . P. Deck Piercing.

P. D. F. Point Detonating Fuze.

M. C. B. D. Major Caliber Base Deto natin g (fuze).

Bursting Charges: Cast T. N. T. and amatol, either 80-20 or 50-50, are used in projectiles under 10 inch in caliber.

Cast T. N. T., explosive D, and amatol are used in projectiles of 10-inch caliber and above.

All projectiles having base det onating or combination fuzes are issued fuzed; all others are issued unfuzed.



ANTI-AIRCRAFT AMMUNITION

CANNON T Y P E

P R O J E C T I L EW E I G H T

lbs.

B UR STING C HG.

% to tal wt.

P R O P E L L I N GC HAR GE

MUZZLEVELOCITY FUZE

75 mm Gun ShellShrapnel

14.315

10%270 ba lls 1.5 lbs.

1.5 lbs.1700 f.s.1700 f.s.

21 " Combination21'' Combination

3" Gun ShellShrapnel

1515

11% 6 lb s. 2600 f.s. ( 21" Spec. Time\ 21" Combination

4.7" Gun ShellShrapnel

4545

15% 11 lbs . 2600 f.s. /T imeDet . Mk . I I .\ 21 " Combination

49 Gr. Percussion primer used in 75 mm. Gun.

110 Gr. Percussion primer used in 3" and 4.7" Gun.

5" , 6" and 155 mm. G uns, using special'amm unition equipped with W altham Mechanical Time Fuze (Ohlson design),,

are used in anti-balloon firing.



APPENDIX II

BIBLIOGRAPHYCschappat, Lt. Col. Wm. Harvey... .Ordnance and Gunnery, 1917.Veaver, Gen. Erasmus MMarshalllines and WardBrunswig, Dr. Hlissak, Col. Ormand Mitchelllamilton, Douglas T

Encyclopedia Brittanica

/Var Department U. S. Army

Notes on Military Explosives, 1916.Explosives.Service of Coast Artillery.Explosives.Ordnance and. Gunnery, 1907.High Explosive Shell Manufacture, 1916.Shrapnel Shell Manufacture.Cartridge Manufacture.

Ammunition, Vol. 1, pp. 864-875.Explosives, Vol. X, pp. 81-84.Gunnery and Explosives for Field Ar til lery

Officers.

The following Ordnance Dep art men t (U. S. Army) Publications:

TITLE

Torm No. Specifications for:—

444 Phenol, picric acid, mono-nit ro-naphthalene, toluol, and tri-nitro-toluol

446 Cartr idge Cloth .450 Powder, smokeless, for cannon.451 Powder, smokeless, for small arm s.452A Armor piercing, deck piercing, and torpedo projecti les.452B Common steel shell and shrapnel .452C Cas t iron target -pra ctice projectiles.470 Army black powders.476 Fuzes.509 Ammonium picrate .

Documents

Notes on Ammunition 1918