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I U•CLAOSSI"iED

securitv Classification

DOCUMENT CONTROL DATA. R & Df,$ocudrly classificaetion of filtjv hlody of abstract and Indexini, annotation must be entered when the overatil rebarf is et-91am~ds

I ORIOIN&TING ACTIVITY (Corporate author) 2a0 REPORT SECURITY CLASSIFICATION

U. S. Aamu, litot c L ,boratoruesu UNCLASSIFIEDNatic, �.ssachusetts 01760.

5.REPORT TITt.LE

A HISTWY OF THE DEVELOPMENT OF Ali ARMOR ENSEMBLE FOR MINE CLEARANCE PERSOMNEL

4. OESCRIPTIVE NOTES (7Tpe ofreport and Inclueoje datee)

S. AUTHORIS) (Mitst name, middre initial. test naime)

Abraham L. Lastnik

[ REPORT DATE 7& TOTAL NO. OF PAGES i~b° NO. OF REPS

October 1970 31 7 42C S, CONTRACT OR GRANT NO. ee. ORIGINATOR'S REPORT NUMrSIrI•|

F IECT NO. 71-30-CE (c&LSEL-.8)

C. Sb. OTHER REPORT NOMS) (Any O•ler numbem Shat may be anslfaed

to0 DISTRIBUTION STATEMENT

Approved for public release and sale; Distribution unlimited.

it. SUPPLI[EENTARY NOTES 12. SPONSORING MILITARY ACTIVITY

U. S. Army Natick LaboratoriesSNatick, Massachusetts 01760

IS. ABSTRACT

- Mine clearance teams have always tried to adapt available armor clothing tothger operations with varying degrees of success. This report is concerned withthe history of the development of a full body coverage armor for mine clearancepersonnel to satisfy military requirements. Discussions are concerned with thehazards of mine clearance vulnerable body areas, operational concepts, design,protective characteristics and fabrication of the ensemble, and its evaluation.A sumary of recent armor material developments and typical applications isincluded. These materials may be applied to eny future concepts for full bodyarmor.

rem~ FORM says. I JAC 6.. WWCI IS063 Vo ARMY 3ecur.esflto

UCLA.SSIM]•y .yt rnrny| - Iio

LINK A LINK a .N4Key WORDII 1 LIROLEt. T _I MOL E: WY J4L

Develo#€entAClothing Sytems -9 • °

Protective Clothing 9Mine Clearance 4Military Personnel 4Fabrication 8Evaluation 8Design 8

II

S* I

_.,-

Set w~it7 Classification

II

UNCI••IFII

Approved for public release;distributlon unlimited.

AD

TECICAL REPOTI

71-30-CE

A HISTCY OF THE DEVELO4FAM OF AN ARMOR ENSEMBLE

FOR

MIN CLAF"!WCE PERSONNEL

by

Abraham L. Lastnik

October 1970

Series: C&Wi.IEL - 84

SClothing and Personal Life Support Equijpment LaboratoryU. S. ARW NATICK LABOATJTORBS

"Natick, MAssaciusetts

, IgI

44

MINE CLEARANCE SUITA. ARMOR (circa 1948) FOR MINES AND DEMOLITIONSB "ARMADILLO" SUIT ASSEMBLED BY TROOPS DURING

THE KOREAN WAR FROM SALVAGED !AMIN4ATED GLASS

RIECEPARTNC ARMOR ENSEMBLE DISCUSSED IN

THIS R PORT I

?I¢I

FOREWORD

During the late 1950's, these laboratories developed an armor ensembleto provide protection for mine clearance trcops against the effects of anti-personnel mines. The development was successfully completed in that it satis-

fied all requirements as known at that time. However, advances in CLAUi-personnelmines dictated the need for more sophisticated mine clearance techniques whichwould reduce the hazards to the mine clearance team, thereby negating the needfor total body coverage mine clearance armor.

Since the termination of the mine clearance armor program, these Labora-for total body coverage. These inquiries were from diverse sources for a

variety of uses. The proposed uses for full coverage body armor ranged fromwear by munitions handlers to tactical missions by the military, by lawenforcement agencies for bomb squad and riot control details, and forindustrial safety clothing.

Thib report reviews the development of the full coverage armor ensemblefor mine clearance personnel, highlighting the factors influencing the selec-tion of material, establishment of body area priorities and design. Thisinformation is presented so that succeeding developers and users of armorwill benefit from the engineering and design experience compiled by theU. S. Aray NatLck laboratories.

ZI

Iiii

TABLE OF cONTENTS

List of Figures and Tables v

Abstract

Historical Background 1

introduction 3

Hazards and Body Vulnerability 5

Operational Concepts 7

The Mine Clearance Ensemble 10

Compatibility 17

Test imi Evaluation 19

Fabrication 22

Recent Developments of Armor Materiel 23

References 25

Appendix 29

:3 iv

,9I

I

LIST OF 7GURES AND TABUES

F r Pae

I Armor Materiel Available to Mine Clearance Troops 2Circa 1956

2 Mine Clearance Sabot 4

3 Penetration of M16 Anti-Personnel Minae Fragments through 612 Ply Nylon Fabric Armor

4 Typical Fragment Grouping of an M16 Anti-Personnel Mine 8

5 Penetration of Mine Fraguents Through Ballistic Nylon 9Fabric Layers

S6 Armorr• ousers 127 Armored Sleeves

8 Mine Clearance Head and Face Armcr 13

9 Area of Available Vision to the Bare Headed 1Mn While 15Wearing the Combat Helmet and While Wearing the Helmetand Mine Clearance Visor

10 Transparent Armor Showing the Effect of I -2etrating 16Impacts of 17-grain 22 Caliber ?rojecti e

i Mine Clearance Armor Worn with Mine Clearance Gear 20

12 Mine Clearance Operations While Armor is Used 21

Table

I Armor Materials and Typical Applications 24

Apped4 X

Fig. A Penetration of Fuze Fragments through Ballistic Nylon 31Fabric

9Y

ABSTRACT

Mine clearance teams have always tried to adapt available armor clothingto their operations with varying degrees of success. This report is concernedwith the history of the development of a full body coverage armor for minefearance personnel to satisfy military requirements. Discussions are con-- -rn•d with the hazards of mine clearance vulnerable body areas, operational-- :erts, design, protective characteristics and fabrication of the ensemble,trd its evaluation. A summary of recent armor material developments and,Yýical applications is included. These materials may be applied to anyfuture concepts for full body armor.

i

I

4

vi

'g-=

fUDE~mMP!ME.Y20 F ATMOR" ~FOR

MIKE CLARANCE PERSONN•NL

Historical Background

Prior to World War II, armor for mine cisanr.nce peersonnel was not.opecificaZly identified under a particular designation. Armor was, however,ased by Engineer or Pioneer trcops who cleared or traversed mine fields. Bodyarmor of that era was too bulky, tco heavy and afforded inadequate protectionagainst mine fragments. Head protection was pr:vided by a helmet; face andeye protection was never satisfactorily obtained.

During World War I, armor was designed to prote,.t the neck and shoulders,and a visor fitted to the standard helmet t; protect tht eyes and face. Theseitems, used with bulky body armor, were too heavy and restrictive to perm.tý--general use. Also used during World War I was a slotted metal eye shieldsimilar to the Eskimo snow goggle. This shiecld was attached to the British-American combat helmet of 1918 by springs . Other eye protective deviceswere suggested during World War I, but all were variants of the slotted latai.goggles. A few suggested protective goggles were provided as a sort of trans-parent glass-celluloid laminated safety glass. --

The World War I armor would, no doubt, have prevented many casualtieshead it been used. Bashford Dean wrote that armor worn in the field duringWorld War' Iwas usually a commercial article purchased by the individual

i ~sdidr. •M_

With the advent of World War II, interest in personnel armor intensified.'(')It was soon apparent to the U.S. Army Infantry .Board that the World War I typehelmet, originally designed to prctect soldiers in trenches from air-burst frag-ments, was not adequate for a mobile war where missiles and fragments couldstrike from any direction. Thas, the M-! steel helmet and M-1 helmet linerwere developed (31 and made standard on 9 June 1941.,

Flak ar-mor, developed and usei by the Air Force in *Jorld War 7I, in com-binatiop with the -M-1 helmet assembly, was evaluated by the Corps of Engineersfor use by mine clearance personnel. The flak armor was reje,7ted because itsc oý=siess, bulkiness and exzýsssilve weight made it impossible for mine clearancetrzops to accomplish their mission.

In December 1944, the Ordnance Corps initiated a project to develop eyedefenses against anti-personanel mines. Because- ...f te urgent need for thisprctection, the Office cf the Surge-in G•-nera requested that eye d"fenses beprocured as soon as poszible with formal requlrementz to be established later.

N4

STEEL HELMET ANDLINER ASSEMBLY

STEEL EYE ARMOR

"FIG. I ARMOR MATERIELAVAILABLE TO MINECLEARANCE TROOPSCIRCA 1956.

* ARMORED VEST M 1952 MADE FROMPLIED NYLON FABRIC

S~2 •

I%

After many unsuccessful attempts, ,te T45E6 armored goggle was madestandard as the M-14 Eye Armor Goggle ( 4 j. This eye protective device is aHadfield steel shield which i'. pierced by a pattern of narrow horizontal slitsover each eye. This shield was contained by a rubber dust goggle frame.

With the end of World War II, the iuterest in armor decreased and itsdevelopment was virtually halted. In 1917, the respo 5ibility for the develop-ment of persnte armor was transferred from the Ordnanrte Corps to the Quarter-master Corps*.1emo a-sSrnfrrdfo

introduction

A requirement existed in Combat De-elopment- Objective Guide (6) to providearmor for the protection-of mine clearance personnel from fragments o? ekplodingmines.

The Military Characteristics developed oy the Continentdl Army Command V(CONORC) required that armor for mine clearance TLezsonnel provide, in addition

to all the characteristics attributed to the Armored Vest. the following:

1. Ma-ximum fragmentation protection Dossible to the body in its entirety.

2. Compatibility with F•%andard combat clothing.

'3. A weight of no more than 20 pounds.

4. A device £0r attachment to the feet so that personnel could operateoer mine fields without causing the detonation of mines by distributing pres-sure of body weight over a large area.

A review of Ketandard and experimental items (in 1956) uncovered thefol'lowing components (Figure 1):

1. Steel Helmet2. Helmet Liner

3. Armored Vest4. Eye Armor.

Records were also found of a device developed by the Corps of Engineersthat would permit troops to traverse mine fields. It consisted of a wide padsimil.ar to a bear-paw type snowshoe, worn attached to the combat boot. At with

-he bear-paw snowshoe, the anti-mine pads would distribute the body weight overa large area thereby pe-rmitting the user to traverse a mine field in relativesafety. Their bulk and large size: however, interfered with the utilizationof mine detectors. They also made it difficult to locate and to avoid tripwires. Assuming and arising from a kneei~ng and prone position were extremely

difficult, if not impossible, while wearing these devices.

[3

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44

CONARC would not accept the devices and subsequently withdrew the require-ment for foot protec n from -the military characteristics for armor for mineclearaace personnel M and later reinatitubd the requirement without furnish-ing details regarding expected performance. .g -

The U. S. Navy also developed an anti-mine foot protective device, Thi§footgear (Fig. 2) was extensively tested by the U.S. Marine Crps. tlOJ-V 1) 412)

MY3) These evaluations indicated that the device would protect the foot from

the Brissance effect (blast effect) from concussion type anti-personnel mines.Although the footgear was not intended to defeat fragments, it was conceivablethat it could be constructed of armor materials, thus incorporaiing a measureof fragmentation protection.

Personnel armor available in the supply system (Fig. l) for applicationto the protection of mine clearance personcel. would cover the following areas:

1. Helmet: protects the head exclusive of the neck, face and eyes.

2. M-14 Eye Armor: protects the eyes but restricts vision.

3- Armored 'lest: protects the upper torso and carotid arteries inthe neck.

4. Marine Corps anti-mine Sabot: protects the feet from the blasteffec-ts of concussion type. anti-personnel mines.

At tIs time the task of analyzing the mine clearance operation, the hazard,the protection required, and integration of standard items into a protective

ensemble, was initiated.

Hazards and Body Vulnerablita

Before starting the design and fabrication of armor o mine clearancepersonnel, conformi.ng with the military characteristics, information wasrequired regarding the nature of the fragmentation hazard and its dispersion.Also required was a priority listing of the vuJ nerable areas of the body.

Guidance from the Surgeon General's Office (14) confirmed informationderived fkom a study of wound ballistics data compiled in the Korean War.(15) (16) (17) The regional frequency of wounds indicated that the vulnerablebody areas require protection in the following order of importance regarding"vulnerability and lethality.

1. Torso2. Head and neck3. Abdomen and groin

k. F•xtemities.

re

~~uU 4741 4 041111111FROM

tf~srDETONATION100 CENTER

S80 n4nnm

46YDS

LL. 30

zI

ILIIw(--------------------------------1I6YDS

0 6

12 3 4 5 67T8 9 10 11 12jACCUMULATIVE PLYS OF NYLON FABRIC

FIG. 3 PENETRATION OF FRAGMENTS FROM A TYPICAL M16ANTI - PERSONNEL MINE THROUGH A TYPICAL 12-PLYNYLON ARMOR PANEL.

6

The Quartermaster Corps, with the cccperation of the Corpe of k ugineers,

conducted a series of tests to determine the nature of the hazard presentedby exploding anti-personnel mines (15) (19). These studies ectabliahed thefact that exploding mines would scatter a uniform distribution of frapexvitsover a 2 x 6 foot target. Figure 3 shows how m4y frPrae ts of the W-6 eati-personnel mine may be stopped by each layer of 12 ply nylon fabric armor.Figure 4 shows a typical grouping of a fragmented M16 aati-perswnel mrine;thus, it was ascetained that the head aad face Rrea mvald require as muchprotection as any other part of the body. Also established was the number oflayers of nylon armor fabric which would provide resistance to penetration offragents from exploding mines. Plgare 5 shows a reduction of data collectedby exploding a variety of anti-perso=nel mines. (18) (19) The plot is a meansof the data Which considers all mines exploded, including several Russianniaes, and all framents stopped by all layers of all rylon fabric targets whichwere spaced from 4 feet, to 32 feet from the exploding mine. The curve showsthe percentage of fragaents stopped by accumulative layers of ballistic nylonfabric. This percentage is based upon the assumption that the first layer ofylon fabric did not stop any fragments. Thus, if one layer did not stop any

fra4pents, two layers of fabric will then stop approximately 23 percent of allfragents penetrating the first layer, and the third ply of wylon fabric stoppedapproximately 10 percent of all fragments penetrating the first layer. Inreality, the protective characteristics of the armor are greater than indicatedby the chart because the first layer of fabric defeated an undetenalnablenumber of small fragments. This i'mormation, except for a concept of use,provided the tools required to prc•:esd with the development of armor for mineclearawne personnel.

Operational Concepts

The weight and bulk of available armor materials which will provide totalprotection from anti-personnel mine fragments is so great that it wouldimmobilize as individual, even if a flexible garment could be fabricated.Thus, the mine clearance armor ensemble was desiged to provide maximum frag-meatetion Protection possible in the most vital body areas without cmprcmisingthe operational functionability of mine clearance personnel.

It must be emphasized that "maxixim, ppote&tim7", as applied to the mineclearance ensemble, does not mean total protection. An individual wearing themine clearance ensemble and oparating within four yards of a detanated frag-mentation nine would prdaab3,v suffer fatal vouds. As the distance increasesfrcm the fatal four-yard radius, the probability of fatal wounding or the

penetration of the armor decreases.

Because armor specificaly intended for mine clearance personnel hadme-rar been a stLuard iteým ia the Aray sgpa system, doatriae or conceptsof use have not been developed. As a result of experience gaLned in thedavelopmeat and testing of mine alearaeca easemble, the follcwing recamaenda-timos are offered for consideration when formulating the logistical and use

coacept of the sasemble.

.7

AV 1IOTO 750 GRAINS

25 TO 50 GRAINS

~4 it4 NP 5

00 *t Is1Its~~ 0 Deof af tr t e

5TO 10 GRAINS

¶'6: po OVtse * a 0S *v 'toyt so.* a .*$

.. .~#6 . 1, * **d "'kpt . u . . .* %* ~ ~ ~ ~ ~ ~ ~ ~ ~ 14* 19 ft*- ** .... . * * % * ***.

#4444A It&a. I o

It ..........

0 'r 0 2 GRAINS -%gNE UP -0kA1TtJ'y .RS4A

IV9CI. P. T6 L!CA~D0 II Z8 PWOS OF CAST 7ThF-qcftrnto 14 SA'6tST %1CT6EE. 1951Nc 2

FIG. 4 TYPICAL FRAGMENT GROUPING OF AN M 16ANTIPERSONNEL MINE FRAGMENTED IN SAW-DUST BY PICATINNY ARSENAL..

I JMINES FIRED90 - -4, 8, 16, a 31 YDS,H FROM TARGETS

- M- 3cr M- 16

CL. z M2A3XC70 - - - M2A4

POMZ-2

S~509 60 - - _-

r"--140-

i~I r130

I w .10 4LZ__ji -I0 -- ,,

L - O - -

"0a 4w a. 10 28 0 12 14 16 18

LAYERS OF 14oz NYLON FABRIC(MIL -C- 12369)

FIG. 5 PENETRATION OF MINE FRAGMENTS THROUGHBALLISTIC NYLON FABRIC LAYERS (ACCUMULA-TIVELY). CHART ASSUMES THAT THE FIRSTLAYER HAD 100% FRAGMENT PENETRATION.

9

The prime consideration in the development of the mine clearance armorensemble was protection without compromising operational efficiency. Tailor-ing, appearance and drape were secondary considerations. Thfr ensemble wasdeveloped to be a spe -laized combat uniform, and it was recomended that itbe considered solely as a functional combat uniform.

Mine detection equipment. is provided to troops as a kit; it is therefore-recoxmended that the mine clearance armor ensemble be furnished as a component-of -he kilt. Because each soldier, in combat, is expected to have in hisPpossession a helmet and armored vest-, the kit would contain supplementary armorto prt•edt th'. face, neck, lower torso and groin, and extremities.

T- e entire ensemble, exclusive of the face and neck protection, should beworn by all members of the mine clearance team. The face and neck protectiondo not have to be worn- by -the security men, relief or reserve, and get-awaypersonnel.

Mi.ne 0learance Armor -Ensemble-

The mine clearance ensemble was developed,- giving consideration tc theareas of vulnerability and weight requirements, withcat compromising itsfunctionability and the protection it- would provide. In the development ofthe ensemble, prime cons deration was given to the use of standard armor andthe facile- provision for integration of future developments.

Armored Vest•Because the armoed- vest has proved itself in battle, it was considered

for use to .prptect the mest vulnerable area of the body - the torso. Thearmored vest- then served as the basis around which other components of the-ensemble would be developed. These other components would--not, however, havegreater protective characteristics than the vest affords to the upper torso,which requires the greatest protection. These guidelines served as a -controlfor the total weight of the ens ffIblai_

The armored vest is constructed of 12 plies of ballistic nylon fabric, (21)

spot laminated with a modified phenolic resin or button stitched. Figure 5indicates that 12 layers of nylon cloth, which constitutes the vest, will stop79 percent of all mine fragments penetrating the first layer. These data? •crrelate very closely with perfor-nje g : qristics of the armor asdeter_-4ned during the Korean War. it)5- -It is generally stated thatSthe armored vest stopped approximately 75 percent of all battlefield fragmentsduring the Korean War.

Helmet-

The helmet shell j2) and nylon liner (23 (24 assembly has slightlymcre resIstance to fragmentation penetration than the armored vest. Therefore,

10

Elit israsonable-to asinu: tht h-emt sebywl afford the isme level

* ~shell aad nylon-liner asommbly-should stop approxizaately 80 percent of themine frapwezts inpingibg upon it.

Armored 2rousere

The abdomen and coccyx,, as well as the loweer extremities., are protectedfom frapient penetration by trousers constructed iron ballistic mylon cloth.Bcause the- abdomen and coacyx -are considered to be more critical and vulner-

abeareas than the extremities., theyr are protected by 12 layers of azvorCloth$ ihe-'bil ah extremities- and--buttocks zara covered -with -4 -plleff -o 1W~hcloth. Figure5 Indicates that 12.lis of ballistic nylon cloth will stop

wILe te lwe exremtie -nd he utoý_ks re roectd fomapproximately

Significant rs ctoofwaist hr ip-mvmns

Armored Sleeves

To conplement the armored vest with protection for the uppe extrem ities,1Sleeves iere fabricated-of 4- ~lies of ballistic fabric. The Sleeves areattibchid to a noni-ballistic- jerkin vbic~h may be vorn- ove-i the armored vest.The artmoed. sleeves will stop aproximaite.y '50 pir-cent of all frngentspenetrating -the first la-ver of, nylon fabric. To permit the mine- clearancepersonneli -to bare their -arms -durin probing operation., the Sleeves er lt,allowing them'to'-b&: folded bAck, as shdow iný Fig. 7.

Armored Vi0or-

The -development-of -head ezd face, protection for mine clearance personnelVas accauqplihe as a project separate fraa the mine clearance sGit. Con- I-sideration2 vas given to hiIy speciaVI~ed physical, poychological,. andccnatibility problaus that aepresent when the head and face are. enclosed.Because,- this. develapment used -rigid -plastic laminated armor materials andtransparent armor materials, f~abrication and engineering tecbi~iqueo weredeveloped sliultansous2ir with the visor.

The helmiet and lin'er is a basic issue to every combat soldier. Sincethe steel helmet and -aylou liner assemblyr proivides slightl~y more ballisticprotection than is provideed by the armored vest,, it served z-s a base for thedevelopment for mine clearance face protection. A visor was developed to

E supplement -tht Lelmet and cover the face- and neck with armor.

SARMORED TROUSERS SHOWING THE FLAP I

'- CONFIGURATION WITH 12 PLIES OF BAL-' LISTIC ARMOR TO COVER- THE ABDOMEN

/-i AND GROIN AREA.

4s

FIG. 7 ARMORED SLEEVES ATTACHED TO NON-BALLISTICJERKIN WHICH IS WORN OVER A STANDARD AR-MORED VE3T.- SLEEVES ARE ROLLED BACK AS IFFOR A PROBING OPERATION.

I2

o COMBATHELME TASSEMBLY

SUPPORT""BAND

ARMOREDMASK

EYE ziARMOR-•••/. 4/ ARMORED

S• 0-- SHIELD -

1 -ARMORED _ -,

Big

FIG. 8 MINE CLEARANCE PROTECTIVEASSEMBLY FOR HEAD, FACE ANDNECK.

33

I

IIThe visor consists of five major components (Fig. 8).

1. Support Band: A plastic retaining device to hold the visor on thehelzet. It need not have ballistic resistant properties.

2. Mask: Rigid armor to cover the face. It is a six-ply, laminatednylon structueimlar to the structure of the Liner, Soldier's SteelHelme•. 2• •2 The protective chw acteristics of the mask are equivalentto that of eight plies of ballistic nylon fabric (Fig. 5). It is expected.to stop approximately 70 percent of all fragments penetrating the first layer.

_3. Dye Armor: Three replaceable transparent armor plastic laminates, acircular front piece flanked by o.vtl side pieces are set into the mask. Thisarrangement provides maxim= vision required for a mine clearence operation.Fi.gure 9 shows the area of vision available through the mine cleaiance visoras campared to the bare-headed mar. The transparent armor affords ballisticprotection equivalent of 17 layers of ballistic nylon as is shown in Figure 5.

The transparent armor id a cceposite system, nominaflly 7/16 inches thick,Icomposed of polymethyl methacrylate, polyvinyl butyral, and polyester filmbonded together in that order, with two transp•.rent adhesives. Each ccnponentof the composite axmor performs a rpecific task in the stopping of a ballistic i-.fraient. The hard, rigid polymethyl meý-hacrylate, the material facing theenvironment, absorbs much of the energy of the initial impact. Penetrationof the fragnent and cracking the outer surface dissipates more of the Impactenergy, thus slowing down the fralnent. The soft polyvinyl butyral interlayerthen stops the fra~ent. The polyester film serves to protect the soft inter-layar from the dust and dirt. The tough polyester backing of the armor filmprevents the spall, resulting from the impacted facing, from becomingsecondary hazards (pig. 10).

A contributing factor in the accomplishment of ballistic resistanpe cflaminated armor is "controlled delination" of the components, that is, thedissipation of impact energy as a result of the separation of the laminae.Thus, thý, adhesive strength of the bond between the polymethyl wthacryl&teaB the polyvinyl butyral must be controlled. T-Jo strong a bond wovIdreduce the ballistic limit of the nrmor.

4. Armored Bib-. Flexible armor fi. ed to the front of the aask to coverand protect the front of the neck. It is constructed from six plies of nylonfabric with en outer cover made of non-ballistic waterproof neoprene-coated,nylon fabric. It stops approtimately 65 percent of all mine frat ents pene-tratting the first layer of ballistic nylon fabric.

5. Akmored Shield: Flexibl- armor costructed similar•Jy ks the bib andoffers the same level of protection is attached to the rear of Om 0,pportbend vith quiu-.rlease fastening devices. The shield covtrrs and protectsthe back of the neck.

14I

0.0I*0

000

Oo Go__ _ 9'

w. 0 w.

IX 02 00 L

:1 0ODCI

4 4

t LL.

ljj.

15

! -

ACRYLIC PLATE

- - U• + ..

b COMPOSITE PLATE USING ACRYLIC, PVB and MYLAR

FIG. 10 TRANSPARENT ARMOR SHOWING THE EFFECT OF NON-PENE-TRATING IMPACTS OF ITGRAIN .22 CALIBER PROJECTILES.

aACRYLIC PLATE GENERATES SPALL WHEN IMPACTED AT ABOUT

b COMPOSITE PLATE MADE FROM ACRYLIC, POLYVINYL BUTYRALAND MYLAR PLASTICS GENERATED NO SPALL WHEN IMPACTEDAT ABOUT 1475 FEET PER SECOND.

16

The single size visor and its configuration is the result of a series ofcompromises in which weight distribution, area of vision, environmental condi-tions, and compatibility with mine clearance devices, armor materials andstandard clothing were considered.

Weight limitations and the vulnerable body areas dictated the variableprotective coverage provided by the mine clearance armor ensemble. The weightof the ensemble components is as follows:

Helmet and liner assembly 3.4 lbsVisor 3.0

Vest 8.5Sleeves 3-.4

STrousers '7. 4

25.7 lbs.

The total ensemble weighs approximately 25-1/2 pounds. Every combat soldieris expected to have a helmet and armored vest in a combat zone. Thus, about 32pounds of the mine clearance ensemble is standard issue to all combat soldie-.At the outset of a mine clearance operation, the mine clearance ueam would btýissued only about 13-1/2 pounds of additional armor.

Compatibility

An important and all-inclusive military requirement for all combat cloth-ing and headgear is that newly developed materiel must be compatible with allstandard clothing and equipment. To achieve this compatibility, informationwas required regarding the duties, tactics, and environments to which mineclearance personnel would be Subjected. This i a o~t~in~ d bystudying training manals •25j and training films (26J •27J M2 80) 29) andthrough interviews and demonstrations conducted with experienced combatengineer officers and enlisted men.

Assault breaching is considered the most demanding tactical mine clearanceoperation. Thus, armor designed to be worn in assault breaching should besuitable for rear area mine clearance operations and other specialized demoli-tion neutralization operations. So, the mine clearance ensemble was designedspecifically for the assault breaching.

An examination of available literature revealed no reference toenvironmental limitations for mine clearance operations. Therefore, it isexpected that mine clearance operations will be conducted in a variety ofclimatic environments ranging from extremely hot-wet to sub-freezing tempera-

turs.

To introduce a minimum of new items into the Army supply system, the mineclearance ensemble was designed to be worn as an outer garment over hot weather

17 '4

I~I.clothing or as a liner of the cold weather uniform. To conform with standard Icamouflage practices, the outer ply of the nylon dyed Olive Green 106. Thetrousers and sleeves, turned inside-out, could provide desert camouflage.

The mine clearance armor ensemble presented no sizing problems when itwas worn as an outer garment, even when it was worn inside-out. When wornas a liner with the cold-wet uniform, a sizing study indicated that threesizes; small, medium, and large, should fit 95 percent of the Army population.The addition of an extra-small and extra-large size would not be warrantedunless the ensemble was intended for general use throughout the Army. As aresult of the sizing study, a suggested sizing tariff for the mine clearanceensemble was recommended as followa: 30 percent small, 50 percent medium,and 20 percent large. This tariff would be applicable to both the upper andlower torso components.

The increased weight of the mine clearance ensemble worn in hot environ-ments would impose a heat stress upon the troops. Because the clearance of amine field is a slow and deliberate operation, it was anticipated that theadditional weight and accompanying therm tress would not significantlyeffect the efficiency of the operation.M60

The movement of rolling up the sleeve of the mine clearance ensemble,during a probing operation, can be easily accomplished under all circumstancesexcept when the armor is worn as a lining under cold weather gear. In thisinstance, the aperture of the standard field jacket sleeve would not accom-modate the bulk of the garments which it covers. It must be noted, however,that the aperture of the field Jacket sleeve could not be pulled over theunderwear and O.D. shirt of the cold-wet uniform to expose the forearm even !

when the mine clearance armor is not worn.

Donning and doffing the trousers over the leather combat boot can beaccomplished easily. But, because the insulated combat boot is considerablylarger than the leather boot, it must be removed prior to donning or doffingthe armored trousers. Consideration was given to slitting the trousers orenlarging them. This was rejected because the circumference of the trouseropening was approximately the same as the thigh circumference; thus, a slitwould be required for the full length of the trouser leg. Making the trouserleg larger would increase the weight and bulk of the trousers considerably.

The armored visor provides a universal fit. The single size visorrequires no head size adjustment because it snaps onto the brim of the standardst-el helmet. There is, however, a single adjustment to accommodate head length..A tape and buckle adjustment permits the mask to move vertically approximatelyone-half inch. A second snap was placed on the support band to permit the mask,o be moved to a forward position, to accommodate the M-17 Protective Mask.

The visor will fit the 95 percentile of the Army male population. The visor

18

is compatible with mine clearance equipment arA wili not te! fr& e w'.h t'revision (Fig. 8) or hearing required to accompl!1h a mine clearane-e cperatioin.

The fogging of transparent armor of the mine clearance visor Is a probleminherent in all face and eye protective devices which enclose the fa-e. ?Es:ausetne space ir the visor is small compared to the volume of breath exhaled, agreat quantity of saturated water vapor at body temperatare will contactv theinner surface of the armor lens. This condensate, in disVrete droplets, caues

a translucency which impedes vision. In cold environments. fr'szing of thedroplets forms minute ice crystals which scatter light and are harder to remove-than the water droplets. A continuous thin-water film of .uniform thicknesswould be fully transparent. However, any foreign matter on the lens surfacewould prevent the formation of a uniform, continuous iarer of water. Treatmentof the lens surface with a wetting agent would tend to pre.:.t droplet formation.The use of water soluble soaps and organic detergents h l imited e.ecita÷ -ness as anti-fogging agents.

Test and Evaluation

After the design had been conceived and prototypes made, the miLne clearanceensemble was tested, evaluated, modified and retested. Listed balow are severalcritical tests and evaluations:

1. An informal design evaluation was conducted at Fort Devens, Mass.,

in December 1957, with officers and enlisted men of the 232nd Engineers,4th Regimental Combat Team. The test was observed and evaluated by theparticipants, human factors engineers, and clothing design personnel. Thisevaluation showed that there was no difficulty in donning or doffing the armor,and that it was compatible with the standard cold-wet uniform. The ensemblewas found to be compatible with mine clearance equipment which consisted of aheadset, detector and power pack (Figure U). No excessive restrictions orencumberances were experienced in carrying out a mine clearance operation.In a withdrawal action under simulated attack, the visor was removed and arapid evacuation of the minefield was accomplished with no Pncmberances.The visor did restrict hearing and vision, but the concensus wac that it wouUinot reduce the efficiency of a breaching operation.

2. A field test of the mine clearance armor suit wag conduoted by theU.S. Army Quartermaster Field Evaluation Agency in 1958. %31) Th1is tetdetermined that a turtleneck armored collar was not satisfactcry. With theexception of the collar, the suit was compatible with the cold-wet uniform.There was no difficulty in donning and doffing the uniform except remova. ordoring trousers over the insulated boots.

3. An engineering test of the mine clearanca ensemble was conducted bythe U.S. Army QuamrerZpaster Fie.&d Baluatton Agency cnnci,'rently with asazrvie test in 1959 •32. This test showed that raIne clearar:-e operations -

19

FIG. I I MINE CLEARANCE ARMOR WORIN UNDER THECOLD-WET UNIFORM AND WITH TWO TYPESOF MINE DETECTORS. THE INSET SHOWS THEARMOR AND KIT BEING USED IN THE PRONEPOSITION.

20

M~il

I W

FIG. 12 MINE CLEARANCE OPERATIONS WHILE ARMOR IS USED.[ A. MINE CLEARANCE TEAM PREPARE TO ENTER FIELD

B3. PROBING FOR MINESC. USING MINE DETECTOR0. SENSING TRIP WIREE. EXPOSING MINE 21

can be performed satisfactorily wbile wearing the ensuerble (As. 12). minordifficulties experienced were attributed to weight, buLik and beat stress *

Imposed by the enseoble and interference with vision. The noted deficienciesScorrected wherever feasible to do so, e.g., non-elastic suspenders wQeA

provided to prevent sagging of trousers, seAs ware reinforced, and the visorcontour was modified.

4, An engineering test of the arine Corps mine clearan=3 footgoar w.evaluated by the U. S. Amy Queartermaster Feld lvaluati6n Agency in 1959.T33)This test shored that the footgear did not interfere vith the performance ofmine clearanne operations. It was remoamendel, however, that the footgear beworn only by those personnel using the mine detector equipment in the standingposition.

5. A wound ba~lis.ice stueq(3) was conducted by the Directorate ofMedical Research, USA Chemical Research and Development Laboratories in 1961

to debe if the mine clearanc: ensemble would provide protection from anexploding anti-personnel mine. The study showed that persons wearing thenine clearance ensemble with the MarIo. Corps sabot (footgear) will be protectedagainst frra~e from the an4 ;i-per,--nnal Amin, X-14I.

Fabrication

Fabrication of the flexible components of the mine clearance armorensemble may be easily accomplished by ordinary tailoring techniques.These cmponents are as follows:

1. Bib and shield of visor2. Armored vest3. SleevesI- Trousers

The visor (Fig. 8), however, presented fabrication t•echniques thatencompassed both desi- and eugineerir lprobleAs. 2he suprt band, a spring-1ike device, to hold the visor onto the h32net, is made by bonding coated orimpregnated fabric by means of high Vressure laminating. The rak was made byhigh pressure lusinating coated beallistic nylon fabric, with & three-pieceall-metal mold consisting of a split cavity and a force plug. 2he material inthe eye ports was comlessed, thus the ports were easily pushel out of themask and required very little trimming.

The optical system of the visor presented the greatest fabrication problemof the ensemble. Sye armor use for this ensemble consists of a three-co"ponentlaminate bonded with two different adhesives. Optical flaws resulting Ifominadequate fabrication techniques could make the laminate useless as eyepiecesfor mine clearance purposes. I

Optical aberration which must be avoided is as follows:

1. Deviation of the line of dight is a shift in direction of the line ofsight. This characteristic, when present in formed materials, is due tounequal stretching of the materials.

2. Displacement of the line of sight is a shift In position of the lineof sight. This optical aberration is a function of material thickness, indexof refraction, and angle of incidence.

3. Distortion is an aberration arising from variations in magnificalionwithin a small area as a result of varied thickness and/or irregularities inthe contour of optical surfaces.

With the available materials, in the thickness required. for effectiveprotection, it is impossible to make optically acceptable curved eye armor.Fabrication of curved eye armor ;ould result in stretching the outer surfaceand compressing the inner surface of a laminate and would probably introduceuneven surfaces and variations in thickness. The thickness required for thiscurved eye armor would make it virtually impossible to attain good binocularvision without grinding; and this material system used for this armor cannotbe ground. Thus, mandatory use of flat eye armor limited the configurationof the visor.

The transparent armor used for this development was a laminate nominally7/16-inches thick which was composed of polymethyl methacrylate, polyvinylbutyral and polyester film. The transparent armor is laminated by applyingheat and pressure to the laminae bonded with transparent adhesive. Thefollowing two techniques were successfully used to fabricate transparent armor:

1. Flat bed compression molding.

2. Autoclave under pressur- (method used for the manufacture of safety

Recent Developments of Armor Materiel

The mine clearance ensemble was developed for members of a team thatshould, dur.ng an operation, maintain a minimum distance of 15 yards from eachother. (25 New doctrine introduced in 1966 required that the mine clearanceteam members maintain distances greater than 15 yards between themselves. TheArr.ay testing of the 1yln fabric against the fragmentattion effects of anti-personnel mines (1d) W93 indicated that the ensemble would prcvide -- ificaint

protection at a distance of 4 yards from the blast center (Fig. 3). CGýrentdoctrine specifies zhat a minimum distarceof 25 meters (27.34 yards) betweenr&embers of a mine clearance operation. 35 Extrapolating from data in Figure 3,there would be a small probability of inflicting serious irju-7y to the unarmoredman 25 yards from the blast center of the M16 anti-perscnne:. L-tne.

I

r2

The mine clearance armor ensemble was only one of a series of armor clothing

and helmets being developed for the combat soldier. Continued research anddevelopment has providid new armor materials, design techniques and tools thatwill serv-i to provide suitable armor for future requirements. Table X liststqypical applications of common armor materials. their weight and level ofprotection,

T:.BLE I

ARMOR MATWRIA AIl TYPICAL APPLICATIONS(3 6 ) (37)Areal

Material Application Density/ft 2 ThreatNylon fabric Vest, Helmets 7.5 - 38.6 nz Fragments

Titanium Helmets, Vest 17.5 - 18.6 oz High VelocityFragments

Nylon felt Vests 0.04- 0.9 oz FragmentsS(38) hi ds8 o ruet

Polycarbonate Sy es hie1(- 8.4 oz yvagments

Ceramic/mRp*(39) VastE, Leg Armor 6.5 - 9.3 lbs Small Arms

Aluminum Honeycomb (40 Boots Variable BrissanceEffect

*Glass Reinforced Plastic

More efficient. armor can be designed through the use of rigid metallic 'or ceramic compt"net~ts. To provide adequate protect.!,,,-. to the body with rigid

armor and not resti.Sct the user's function, new concepts were required for thedlesign of systems that conform -with the changing shapes and dimensions of themoving body,,, Techniques were developed for measuring lynamic changes of body~dimensions. I Increased weight that, accompanies increased levels of protection•would have a greater tolerance 'Level if it was evenly distributed over the bodywithout areae" or points of concentrated pressure. A device was developed •,••plot pressiure areas that are imposed on the d~mamic: body by armor systems.M);

With the aid of this instrumnent and knowledge of body dimensioeaa changes, -armor can be designed so 'What maximum protection Ypav be provided with .",he]

acceptable parameters of fit, comfort, weight distributizn and the dynarc4response required for a designated mission.

24

1. Dean, Bashford, Helmets ad Body Armor in Modern Warfarp. New Haven:Yale University Press, 1920.

2. Development of Helpet6and Body Armor in World War II, R&D Service Office,OFD. Corps., Fept. 1945.3ý MIL-L-191OB., Military Specification., Liner, Soldier'.sSteal Helmet, M-I,

1957.4. MIL-A-3511, Mill tary Specification., Armor. EyeM., 1962.

5. War Department Memo No. 30-5-2, dated 25 Jmne 1947.

6. CDO Q11 1439a (18),1 1955.

7. Approved Military Characteristics for Protective & Mine ClearancePersonnel Armor, QWTC 1-51, Reconfii.i.ed Q=C 7-55 - (Coiitident.ial)

8. Ajti-Mlne Foot Pads, Report from , Sub-Committee, to QWMTC,29 April 1952.

9. Letter file CPM 7-80-05-001, Subject: Mine Clearance Foot A-mor, 2ndIndorsement, letter file AD3-3 476 dated 21 Msrch 1958.

10. The P ective. lties-of -the Thermal Boot Ahoinst Explosgve Ordnance -UKJune 1952.

11. Holland, Lawrence (UK). A -ethod for Obtainin the Force - Time Relation-sLATJ of Certain Egplosive Ordnnce April 1955.

12. Lewis, F. J. (M1C), USN, Device fcr Protectin the Lower Extremities from-the Blast Porces of Small, Anti-2eraonnel Min•so Jbrch 1956 (Confidenttal).

13. Stu&d of Armored Footwear TS-303M, arine Corps Development Center,

Quantico, Va., 30 June 1957 (Confidential).

14. Summary of ArM Personnel Armor Conference 8. 9. 10 Oct i958 at QXE&ROCommand, Natick, Mass. (Confidential).

15. ft~ughton., G. B. ( Col. ),, Wound Ballistics, Killed in Action. KbreE,20 iMarch Z952 - 23 Aprlj 1952. Rept. No. 316 Arqy Chemical Center,. &I.June 19;Q2 (Secret).

16. inAction.,_Korea,,_-__and Debiec, R.P., Wound Ballistics KilledinAction. Korea.15 November 1952 -, 1 March 195I, Volume III, Rept. No.

221, Army Chemical Center, Md., Octcber 1953 (Secret).

23

&

17. Briefing on Personnel Armor to Chief R&D/DA, 12 July 1957 (Secret).

18. Report of Test of Development of Body Armor fcr Protection Against A.P.Mine Phase I, FE 54093, QM&E Command, Natick, Mass., 23 March 1955.

19. Report of Test of Development of Body Armor for Protectio , Aiainst A.P.Mines. Phase II, FEA 55056, QMR&E Command, Natick, Mass., July 1956Tdnfidential).

20. MIL-A-12370B(QMI), Military Specification, I•rmor, BodQ. FragmentationProtective 4 M-1952-A, 1 Feb 1955.

21. MIL-C-12369B(QmE). Military Specification, Cloth, Nylon, Ballistic,for Armor 11 Sept, ber 1957.

22. MIL-H-1988A, Military Specification, Helmet, Soldier's Steel, M-1,22 July 1956.

23. MIL-L-4100, Military Specification, Liner, Ground Troop's Helmet.(Combat), 14 March 1.969.

24. Landsberg, M. I., and J. L. Lewis, Final Develpqment and EngineeringTest Report of Liner, Helmet, Soldieres Steel T54-1 and Liner, Helmet-Combat T53-2, Tech. Rpt. CP-2, QMR&E Command, Natick, Mass. November 1955.

25. F74 20-32, Employment of land Mines, July 1955.

26. TF 20-1979, Land Mine Warfare - Part I - Introduction (Training Film)1956.

27. TF-20-1987, Land Mine Warfare - Part IV- Assault Breeching (TrainingFilm) 1955.

28. TF-20-1988, Land Mine Warfare - Part X -Area Clearing (Training Film)1955.

29. TF-20-1989, land Mine Warfare - Part XI -,Behavior in a Minefield(Training Film) F1955.

30. Goddard, W. J., J. H. Vanderbie, and A. L. Lactnik, Hot Weather BodyArmor, An Analysis of Requirements and Feasib~lit., Clothizg BranchSeries Report 5, Textile, Clothing & Footwear Division, QW&E Command,Vatick, Mass., June 1958.

26

4-

31. Matthews, J. 14., A Field Test of Suit, Mine Clearance Armor, TechnicalReport T-79, 58001F, USAWM Field Evaluation Agency, Ft.. L-e, Va.,September 1958.

32. An Engineering Test of Mine Clearance Ensemble1 Techninal.Report T-3iB,735506-FI, W4WM Field Evaluation Agency, F%. L.e, Va.,June 1959.

33. ,An Engineering Test of Mine Clearance Ensemble T 8-1Sulplemental Reappt of Mine Clearance Footgear, Technical Report T-119,

58OlF, USAQM Field Evaluation Agency, Ft. Lee, Va., June 1959.

34. Stewart, G. Mj, E. E. Hawkins, R. L. Williams, and J. C. London Jr.,Evaluation of Mine Clearance Ensemble Against APERS Mine M-i4, CRDLTech em-o. 21-6,, 2 Nov 61

35. FM 20-12, Land Mine Warfare, August 1966, with Change Mc. 1, dated9 August 1W '

36. Barron, E. R., R. Smith, P. Durand, and A. Lastnik, T"e Appication ofLightweight Armor Materials to U.S. Combat Protective Clothing Scienceof Advanced Materials and Process Engineering, Vol. 12, October 1967.

37. Barron, BE. B. and A. Iastnik, Personnel Armor Systems, Minutes of theEleventh Explosive Safety Seminar, Vol. I, conducted by the ArmedServices Explosives Safety Board, Washington, D. C. September 1969.

38. Iaetnik, A. L., B. T. Cleavly and J. B. Brown, Development and Fabrica-tion of a Polycarbonate Eyeshield for the U.S. Army Flyerts Helmet,Technical Report 71-3-CE, U.S. Army Natick (Mass) Laboratories, June 1970.

39. Barron, BE. B., A. L. Alesi and A. F. Park, Body Armor for Aircrewman,Technical Report 69-43-CE, U.S. Army Natick (Mass) laboratories, January 1970.

40. Fujinaka, E. S. and J. L. Mac Donald, Research and DevelopRe;nt of BlastProtective Footgear. Tech. Rept., TS-131, U.S. Army Natick iJass)Laboratories, March 1965.

41. Weir, W. B., Design and Develop2ent of an Aritculated Armor attainet,Final Report, USA Quartermaster Research and Engineering Command,Contract DA19-129-44-1809, lIt Research Institute, Chicago, Illinois,August 1964.

42. Seribano, F., M. Burns and E. R. Barron, Design, Development andFabrication of a Personnel Armor Load Profile Analszer, Tech. Rpt.70-65-CE, US ArWy Natick (Mass) Laboratories, April 1970.

1' 27

r | i

APPE~D!x

The mine clearance ensemble has been considered and exarLi.•d fcr a numberof specific applications. Some agencies ionducted tests, others e-,allatedthe available data. The following is a aiscussibn of several propac-d• appli-cations.

a. Fuze Handler's Protective Garment

A protective garment was required t the Harry DiTP.ai OrInance F&zelaboratories (1960) for personnel who were to transfer sensit'-:e fuzzes froman environmental test chamber to an armored box for transportation to the nexttest station or to a neutralization area. Tests were conducted to iVterninethe effectiveness of the material system against tha hazard of exploiing fuzes.

Three test panels, each made of 12 plies of ballistic naylon, fabric,backed by a soft pine wood block, were exposed to the explosive effects offuzes. Panels number 1 and 2 were each tested with fizes T906 from a distanceof 28 and 60 inches, respectively. The first panel, 28 inches frcom the fuze,collected 648.6 milligrams of fragments; panel nurber 2, 60 inches from theblast, collected 384.5 milligrams of fragments. Panel member 3, 36 inches fromfuze T178, collected 776.2 milligrams of fragments. Seven fragments averagingthree grains each, three fragments averaging 2 grains each, and one fragment

of 1.7 grains passed through panels l, 2 and 3, respectively, and wereimbedded in the wooden backstop. Figure A. shows the percentage of fragmenrtst)-nt are stopped by the accumulative layers of nylon, assuming that the firstlayer had 100 percent fragment penetration. Panel number 3 apparently hadbeen exposed to the worse conditions; its penetration resistance charac-teristics, as shown on Figure A, are similar to that of fabrics exposed todetonations of anti-personnel mines shown in Figure 5- Thu,3, extrapolation t"b18 layers of nylon appear to be reasonable, thereby predicting the penetratlo.resistance capabilities of the transparent armor.

The Diamond Ordnance Fuze Laboratories required frontal protect-ior-only and suggested that the armor material be incorporated in different2ydesigned garments.

b. Fire Fighter's Suit

An inquiry was !IW oy the Safety Director Ordnance Weapons Cormmand(1959) regarding the suitability of the ensemble for protecting fireman whoenter into areas that may contain a potentially explosive elezent. Withoutspecific information regarding the nature of the explosive particles, fewcouclusions ca be drawn. The nylon fabric has a melting range Ln the vicinityof 375°F. The effectiveness as armor would be expected to be prolonged if itwere wcorn under a reflective garment. The mult!-layers of the ga-rment Voul'd

also act as an insulator against heat.

29

c. Demolitions Disposal

The U. S. Naval Weapons Laboratory tested the mine clearance ensembleand recommended it favorably to the U. S. Explosive Ordnance Disposal Facility(1965). The U. S. Army Natick Laboratories had suspended all future work withthe ensemble, but had provided procurement information and offered technicalassistance if the U.S. Navy wished to acquire additional items. Inquiriesregarding full body armor were also made by the U.S. Naval Ammunition DepotEarle (1969).

30

100 PANEL DISTANCE FUZE1 28" T 9601,90 • _._..__oo__ 36

S3 36!" T 1 78

80

60wW 50

I-. Ioz 40w

00 4 6 8 I0 12 i4 16 18

LAYERS OF 14oz NYLON FABRIC(MIL-C- 12369)

FIG. A PENETRATION OF FUZE FRAGMENTS THROUGHBALLISTIC NYLON FABRIC LAYERS (AC\PUMULA-TIVELY). CHART ASSUME THAT THE F'RSTLAYER HAD 100% FRAGMENT PENETRATION.

31