os 969 rockets and launchers-all types

8/14/2019 OS 969 Rockets and Launchers-All types

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DECLASSIFIEDC 3 6 OS 9-69

NANCEs c * \ O O I.ROCKETSAND

LAUNCHERSALL TYPES

FEBRUARY 1944

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DECLASSIFIEDTHE COMMAND AND STAFF COLLEGE

LIBRARY

Class Symbol M 6 1 4 ? " G 9 - BAccession Number A. X...Q..d.\)...lL.,

edient pending theK wwxl wi me imormation contained herein in anapproved War Department manual.

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r>DECLASSIFIEDORDNANCE SCHOOL TEXT OS 9-69N o. 9-69 THE ORDNANCE SCHOOLAberdeen Proving Ground, February 1944

DOWNGRADED-AT 3 YEHR INTERVALS-DECLSSSjnED AFTER 12DOD DIH 5200.10

ROCKETS AND LAUNCHERS,

ALL TYPES

Prepared under the direction ofthe Commandant, The Ordnance School

CONTENTSCHAPTER Paragraph1. General 12. 2.36" Rockets 103. 3.25" Target Rockets 614. 4.5" Rockets and Launchers 655. 7.2" Rockets and Launchers 946. 8" Rockets - 1137. 10" Rockets 114

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P R E L I M I N A R Y P R I N T I N Gfor limited distribution and subject tocor rec tion . Students a re urged to addm ater ial as it becomes available and makewhatever corrections a r e necessary.Blank pages for this purpose are available in sections concerned with new i tem s.

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DECLASSIFIEDROCKETS AND LAUNCHERS,

ALL TYPESCHAPTER 1-GENERAL

1 PURPOSE 4 HISTORY OF ROCKETSTh is text i s publish ed for us e in a. The rocket has from earlycourses at The Ordnance School . t imes at t racted at tent ion for mil i tarypu rpo ses , f i rs t in Asia and late r in2 SCOPE Europe and Am erica . No gre at pro -Chapter 1 covers mater i a l com- g re s s wa s made until the beginning ofmon to all ro ck et s, such as the the ory of expe rime nts by a Wil liam Congreve.flight, the history of rockets, and their Congreve extended the work of Generaladvantag es and disad van tages . Suc - Desaguliers, who was in charge of theceeding chapters are concerned with famous Woolwich lab ora tor y in England.the various standard and development Congreve set himself the task of p r o -ro ck ets , with a cha pter assigne d to each ducing a rocket capable of carrying ansize of rocket. incendiary or explosive charge andhaving a ran ge up to 2 m ile s. After3 REFERENCES some p rel im ina ry t r i al s he was givenpe rm iss ion to ut i l ize the Royal L ab -Inform ation included in this text or ato ry to con struc t ro ck et s of his ownha s bee n se cu red from the following design. The re su l ts obtained we re sopublicat ions: prom ising t h a t i n 1805 Sir Sydney

Smi th 's exped ition aga ins t B o u l o g n ea. Standard Nom enclature List included boa ts espe cial ly f i tted f o rS-9, R ocke ts, All Typ es, and Com po- salvo firing of rockets. Rough weathernents . preve nted the ir use on that occasion,but the following y ea r they w ere use db . Training Circular No. 104, ag ain st -the sa m e place and, althoughAntitank Ro cke t, 2.36", M6 and M7, and deflected by a stro ng wind from theLa unch er, dated 15 Dec em ber 1942. fort i ficat ions, which we re their o bject ive , they did, con side rab le damage inthe town itself.c. Tec hnical Manuals:TM 9-390, T arget Rocket Pro jecto r ,M l; TM 9 -3 93 , 4.5-In ch A r t i l l e r y b . In 1812 t h e Fie ld RocketRocket Launcher, T35, and 4.5-Inch Brigade was formed and was orderedH.E. Rocket , M8;TM 9-395,4.5" Rocket to join the Allies before Leipzig. Cap-Mater i e l . tain Bogue of the Horse A rti l le ry , theonly Eng lish officer p re se nt , was m adethe com m an der . The effect of the ro ck -d. M in ute s of th e O r d n a n c e et s on this oc casion the fir st t im eTechnical Commit tee . they had ever been used in European- 3 DECLASSIFIED


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ROCKETS DECLASSIFIEDGENERALland warfare was very marked. TheRocket Brigade also dis t inguished i tself3 y ea rs la te r a t Water loo.

c. During most of the 19thcentury, ro ckets car r ied an im portantshare of art i l lery functions, al thoughthey did not come within measurabledis tance of superseding ar t i l le ry , asCongreve in his enthusiasm had predicted . With the deve lopm ent of rifling ,breechloading, independent recoil , ands mo ke le ss po wder, th e a d v a n t a g e sclaimed for rockets were discounted,and they were declared obsolete by theend of the century.

d. One of the fi rs t Am erica nprop one nts of ro ck ets wa s Edwin Taylor,who, pr io r to and during the Spanish-American War, advocated the use ofrockets to propel shells f i l led with dynami te and n i t rog lycer ine . At t h at ime these cha rges were too sens i t iveto withstand the high acceleration produced by a gun.e. At the beginning of WorldWar II, littl e in te re st was shown inroc ke ts by the a rme d fo rce s of thiscou ntry . With the developm ent of asuccessful ant iairc raft roc ke t by theBri t ish , however , r es ea rc h was begunon a larg e sc ale . Work in the Ordnance

Depa rtment on rock ets as mil i ta ryproje c t i les using avai lable mod ern p ro pellan ts was begun on a smal l sca le atAberdeen Proving Ground, Maryland,by Col. L. A. Skinner in 1932. Much ofthe ba sic information which he sec ure dha s been of grea t as sis tan ce in thela rg e- sc ale development which com menced in October 1942.5 THEORY OF FLIGHTa. Method of propulsion. If, ina sys tem of fo rce s acting aga inst eachothe r, the forc es ar e unbalanced (i .e . ,one of the forces is greater than theother) , movement will proceed in thedire ction of the gr ea te r forc e. If gasis placed under pressure in a tubeclosed at one end, a system of unbal

anced forces is setup which can resultin movement of the tube. F i g u r e 1il l us tra te s such an arran gem ent in i tssim pl est asp ec t and ind icates how aro ck et s ec ur es pro pulsio n. It will benoted that the pressure is applied inall dire cti on s (at the mom ent of maximum pressure of the gas). The arrowsindicate the fo rce s exerc ised by thepressure, and the length of each arrow indi ca tes the magn itude of eachfo rc e. The fo rce s ne ar the open end ofthe tube a re sm aller , bec au se the gas hasless pressure at that point . The forcesactin g on the w alls of the tube cancel

*

A BO MOVEMENTt T *B t W t


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DECLASSIFIED ROCKETSforces acting against the semic losedend B of the rocket cancel the fo rc e sacting against an equal area of the fullyclosed end A. Since the tube is p a r t i a l l y c l o s e d , a g r e a t e r p r e s s u r e isachieved and the resul t ing force onthe effective area of end A is g r e a t e rthan h e r e t o f o r e . The force actingagains t the end A may be m e a s u re d int e r m s of the a r e a of the a pe r tu re inthe end B and the p r e s s u r e of the gas.The smal le r the a p e r t u r e , the gre a t e rt he p re s s u re of the ga s , but at the samet im e , the s m a l l e r the a pe r tu re , theg r e a t e r the force applied to the effect ive a rea of the end A. A great manycomplica t ions enter the theory of flightat this point, but, for the sake of a bas icexplanation, they will be ignored.

c. Introduction of the nozzle.(1) Forward half. By t ape r ing the end

B to the r e a r , the p r e s s u r e of the gasi s not changed, but a smooth, nonturbulent flow of escaping gas is c re a t e d .Th is t ape red sec t ion form s the fo rwardhalf of the nozz le .(2) Rear half. If an extensionwhich expands from the a pe r tu re isadded to the nozzle , a sys tem of fo rceswhich give a fo rward th rus t to the tubeis set up. F igu re 4 i l l u s t r a t e s howth i s is accomplished. There are p r a c -

T TIK B'LINE OF MOVEMENT

FIG. 4t i ca l l imi t s to the length of th i s expansion as well as to the angle at whichthe expansion develops. In ge ne ra l , itm ay be said that the expanding part

GENERALshould be as long as poss ible in orderto secure the maximum forward thrus tand should diverge as rapidly as poss ible , but not so rapidly as to allow theflow of gas to leave the surface of thewal l s .6 DESIGNa. Terminology. A rocket cons i s t s , in genera l , of severa l componen ts . (See fig. 6.) The explosive headis the fo rward pa r t of the completeround that contains the explosive c ha rg e.The motor is the tube that contains thepro pe llan t, which upon ignition produces the n e c e s s a r y g a s e s . The finsa re the at tachments tha t s tabi l ize therocke t in flight. The nozzle is the exitvent for the motor gases . The explosive head is usually placed at the frontend of the rock et . The motor is attachedto the ba s e of the head. The nozzle isat the r e a r end of the motor , and thefins are attached externally at the s a m eplac e . Th is te rminology is not used todes ignate the component par ts of anypar t icu la r s tandard rocke t but is r e se rved for discuss ions of roc ke t s inge ne ra l .

b_. Explosive head. Explosiveheads for the var ious s tandard rocke tsdiffer considerably in shape but alwayshave a s t reaml ined appearance .c. Motor. The motor for alls tandard rocke ts is a tube . The wallsof the tube have sufficient strength towithstand the an t ic ipa ted pres suresresul t ing from the burning of the propel lant . A balance must be s t ruck between the weight of the motor (the thickn e s s of its walls) and the pre s s u re t ha tis to be achiev ed. A m a xim um p re s s u re

i s des i ra b le , but excessive motor weightw i l l m a te r i a l l y r e duc e the effectiveflight of the roc ke t .d. Nozzle . The development ofthe most efficient nozzle is st i l l inp r o c e s s . At pre s e n t the nozzle is asmooth piece in the form of a ventur i .The forward curve is smooth and hasa long radia l d is tance . The r e a r por

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DECLASSIFIEDROCKETSGENERALtion of the venturi develops at an angleof approximately 20, the limit bestsuited to secure the maximum thrust.

e. Fins. The fins vary in shapewith the different rockets.f_ Propellant. The development of a suitable propellant for rocketshas been a difficult process. At presenta propellant powder in stick form isused. This powder, which is ballistite,burns slowly and evenly, providing themaximum allowable pressure. The rate

at which the powder burns (which is adetermining factor of pressure) is determined by many factors. One of theseis the diameter of the nozzle, whichregulates the rate of escape of the gas.If the gas fails to escape at the properrate, the pressure within the motorincreases. As this internal pressurebuilds up, the rate of burning of thepropellant will increase, further increasing the pressure until the wallstrength of th e motor is exceeded.The composition and the rate of burning of the propellant, then, affect notonly the design of the nozzle but alsothe thickness of the motor. It may beseen that the balance to be achieved between the various components is a delicate one.7 ADVANTAGES AND LIMITATIONS

a. A p p l i c a t i o n s of r o c k e t s .(1) Rockets are of grea t impor t ancebecause they produce no r e c o i l . Thelack of r eco i l permi t s t he i r use ona i rp l anes and smal l boats and on lightt anks , car s , moto rcyc les a n d o thervehic les incapable of withstanding largereco i l fo rces . It also permi ts t h efiring if gre nad es and explosive cha rgesfrom a tube held in the hands .

(2) Another feature of rocke t sthat gives them mil i tary importance isthe rela t ive l ightnes s of the proje ctor incomparison with a gun f i r ing ammunition of equal weight . This permits f i reto be deliv ered from a re a s to which gunsand howitzers cannot be t r an sp o r t ed .

(3) Lack of recoi l is an impor tant considerat ion , for it gives widelatitude in the select ion of mounts andm i s s i l e s . The mount may be of moredel icate construct ion than is possiblewith a gun of equal cal iber; missi lesthat cannot withstand gun accelerationcan be projected rocket fashion. Absence of r eco i l has also permitted thedevelopment of sensi t ive and efficientfuzes .

(4) Of t remendous importancein conside ring the advantages of rocketsa r e the ease and cheapness of manufac tu re of the l auncher in comparisonwith the complexity and high cost of agun. The rocket launcher is simply aguide and consis t s e i ther of a tube orp a r a l l e l t r ack s .

b . Advantages of rockets.Theadvantages of rockets , then , may besu mmar i zed as follows:(1) Absence of r eco i l .(2) Accelerations that are notexcessive and that are easily controlled.(3) Need for only a l ight,-inexpen sive, eas i ly ma ss-manufacturedguide launcher.c. Limitat ions of rockets. Thefollowing disa dva ntag es l im it the applicat ion of r o ck e t s .(1) The da ng ers resu lting fromthe blast of the gases escaping throughthe nozzle .(2) D ec re as ed acc ura cy in comparison with a gun.

8 USESAt the present time there arefive kinds of rockets. They are classified for use as follows:

a Antitank.-The antitank rocket is fired from the shoulder for effective action against armored vehiclesand hard-surfaced materials.

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DECLASSIFIEDROCKETSGENERAL

b . Antiaircraft t a r g e t rocket.This rocket is fired from a speciallauncher to simulate the flight of lowflyirig aircraft in order to provide antiaircraft gun crews with a more accur a t e one epti on of combat firing.

c. Artillery and aircraft ar til lery. This rocket is used in much thesame manner as artillery in generaland with the same mission. As air craft artil lery , it is fired from planesagainst other planes and from planesagainst ground targets.

d. Practice. These rocketsare fired to simulate the firing of high-explosive rockets, to which they correspond, without the danger or expenseof firing the latter.__. Chemical. These rocketsproject smoke and other chemical

agents.9 ROCKETS

a. Listing .The following rockets a re issued to the service:*

(1) Rocket, H.E., AT, 2.36",M6A1.(2) R o c k e t practice, 2.36",

M7A1.(3) Rocket, targe t, A.A., 3.25",M 2 .(4 ) R o c k e t , H.E ., 4.5", M 8

w/Fuze, P.D., M4.(5) Rocket, practice, 4.5", M9

w/dummy fuze.

b . Characteristics. A l l t h eabove r o c k e t s a re projected fromlaunchers with either rails or a tubeto serve as a guide. As the function ofrockets vary, their design varies a c cordingly, but all have the m o t o rnozzle, and fins at the rea r .

c. Painting. The rockets having a high-explosive content a re paintedolive drab;those having inert heads a repainted blue . Painting will be discussedin more detail in the section devotedto each particular rocket.

d. Packing. Packing will bediscussed in the sections devoted toeach partic ular rocket.

e. General safety precautions.(1) A distinctive feature of rockets i sthe blas t at the base of the launcher whenthe rocket is being projected. Pe rs on nel are warned to stay clear of the blastarea, for this blast is highly destructive.

(2) All ro cke ts should be storedat a temperature that does not exceedthe temperature range specified for therocket. No rounds should be left exposed to the direct rays of the sun forany length of time in order to avoidheating the powder to a temperatureabove that at which th e rocket i s de signed to operate . Local conditionswill govern the type of storage placethat i s supplied. The several t e m perature limits have been carefullydetermined for these rounds , and theselimits should not be exceeded.

*The nomenclature of the rockets listed is correct and complete. However,in the interest of brevity it will be shortened throughout the following discussions. Modifications are occurring rapidly, and therefore the above listis subject to change.- 7 - DECLASSIFIED


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DECLASSIFIED M6A1ROCKETCHAPTER 2 - 2 . 3 6 " ROCKETS

SECTION I

ROCKET, H.E., AT, 2.36", M6A110 GENERAL attack, r o c k e t e e r s m us t man euver

a. Description. The antitank themselves in the most favorable porocket, 2.36", M6A1, is both an off ens ive sit ion to direct their fire against theand defensive weapon. In both types of nearest hostile vehicle. The antitankaction, it is used primarily to fire upon rocke t is valuable in the following de-host ile ar mo re d vehicles which come fensive situations: the close-in defensewithin effective range. It is essen- of c rew-served weapons;the protect iontially a weapon of opportunity. It is of motorized columns on the march and21.6" long and weighs 3.5 lb . It has a at temp orary hal ts; the protection ofrelatively low ra te of fire and a d i s - min efie lds , wire entanglements , obs ertinctive flash d isc harg e. Its muzzle vation and command posts; and the de-velocity is approximately 265 ft./sec. fense of all rear-area installations ofThe maximum range is 700 yd. , but all arms and services within the rangethe rocket is comparative ly inacc urate of hostile mechanized for ces .at ranges over 300 yd. In the hands of (3) Miscellaneous. In additiontrained personnel, it is a powerful sup- to the above uses as an antitank p ro -porting weapon at short ranges with jectile, this rocket can also be used inlimited fields of f ire. It is highly ef

a statio nary emplacement for demolifective against all known types of me tion or as an antitank mine or a boobydium tanks. trap.b . Tactical use. (1) Offensive c. Eff ec t. - (1) The rocket willaction. Being both highly mobile and penetra te 3" of hom ogeneous-steel a r effective against pill-box and mecha mo r plate at all ranges and at anglesnized defenses, t h e antitank rocket, of impact as low as 30. The force of2.36", M6A1, is a valuable weapon to the detonation is so grea t that the metalbe carried by landing fo rce s, raiding of the ar mor plate is ra ised to a stategroup s, tank-hunting par ti es , and mo of incandescence and heated pa rt ic le storized reconnaissance units. It is of the me tal fly from the back of thecapable of delivering harassing fire plate in a cone-shaped spray. Tins'against an ar ea targe t from rang es as spray has antipersonnel effect as fargreat as 600 yd. and so is extremely as 30 yd. and usually causes any am -valuable in attacks on vehicular biv munition which it st rikes to detonate.ouacs and halted or disabled armoredvehicles and for use in ambushes. (2) Against masonry and st ruc

(2) Defensive action. Thefore- tur al ste el , the rocket has a powerfulmost use of this weapon is that of a de- bla st a n d shattering effect. It willfensive weapon against the attack of penetra te up to 9" of pine timbe r, butmechanized forces. It should always it s continuing spray is not as effectivebe conserved for this emergency pur- as in the penetration of armor plate.pose. Whenever time pe rmi ts , rocke t Ground impact will n o t ordinarilyteams will be assigned a definite place cause detonation at high angles of imin t h e antimechanized defense of a pact. At low angles of impac t, theweapon, unit, or installation; and if blas t effect is similar to that of thenatural cover is not available, two- 75-mm high-explosive shell. Impactman-typefox holes will be dug for each against water will never cause detorocket team. In the event of a surpr ise nation.

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ROCKETDECLASSIFIED M6A111 ROCKET LAUNCHER, M1A1a. General.The 2.36" antitankrocket launcher, M1A1, is an electrically operated weapon of the open-tubetype. It is fired from the shoulder inthe standing, kneeling, sitting, or pronepositions. The tube has a smooth boreand is approximately 54.5" long. It is2.37" in internal diameter and weighs13.26 lb.

b. Description. (1) Attachedto the left side of the barrel are thefront and rear sights. The rear sightis a peep sight;the front sight consistsof three studs for ranges of 100, 200,and 300 yd. Intermediate or greaterranges, lead, and windage must be es ti mated by the firer.

(2) Ahead of the front sight andsecured to the tube by a screw and nutis a flash deflector of conical wirescreen with a mounting clamp whichoverlaps the muzzle end of the launcher.The flash deflector deflects particlesof unburned powder which might flyback in the face of the firer.

(3) The hand grip consists ofthe left and right trigger grips attachedto the trigger support. The triggersupport a c c o m m o d a t e s the triggerguard, t rigger, and the lower and upper trigger-switch contacts. The trigger is pinned at its upper end to thetrigger support and is free to pivot.

(4) The stock h a s a narrowvertical slot by means of which it slipsover the stock support, to which it isattached by screws. In the bottom ofthe stock there are two vertica l cylindrical compartments for accommodating four batteries. The two bat ter iesin the re ar compartment are in actualuse; the two batteries in the front compartment are spares. Eveready 791-Abatteries are issued initially. Whenreplacement is necessary, two separatecells of the battery BA-42 type can beused if the Eveready batteries are notavailable. The batteries are kept in position by a hasp assembly which fits onthe bottom of the stock and is kept closedby a spring-actuated hasp catch whichengages the stock pin.(5) On the left side of the stock

is a small electric lamp for testing theelectric circuit and battery. The lampis connected parallel with the firingmechanism, and it lights when the tr ig ger is squeezed, regardless of whetherthe rocket is in the launcher or not. Aspare lamp is car ried in a circularcompartment on the right side of thestock, under the circuit indicator cover.

(6) The face guard, pressed onthe ba rrel above the stock and held inposition by its own tension, protectsthe firer's face from the heat in thetube.

BAR CONTACTLOWER TRIGGER

BATTERY SPRING SWITCH CONTACTFIGURE 7. - ROCKET LAUNCHER, M1A1

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ROCKETM6 A 1 DECLASSIFIED(7) At the r e a r of the b a rr e l isa sp r ing-ac tua ted t a i l - la t ch assem bly .Th e function of the la tch is to engag enotc hes on the tail of the ro ck et andhold it in position for firin g. T h e

br ee ch guard at the bre ec h end of thebarrel faci l i tates loading of the rocket ,pro te cts the ta i l - la tch asse m bly , pr events distortion of the end of the barr e l , and prevents entry of dirt andforeign m at er ia l when the end of thelauncher r e s ts on the ground.. E le ctr ica l functioning (seef i g . 7)."^- (1) W hen th e t r i g g e r i s

squeezed , i t pr e ss e s the ba r contactagains t the lower t r igg er- sw t ich contact to complete the electr ic circui t .(2) The b atte ry sp rin g in thebas e of the stock con tacts the b at te r ie sand is connected by wir e to the stocksupport to complete the electr ic circui t .F ro m the re a r of the s tock to the insulated contact spr ings , the barrel i s

wound with bra cin g w ire . Th e two co ntact springs, one on each side of thetube , se rv e as conn ecting points for thecontact wire leading from the roc ke t .In this m an ne r, the circ ui t is com pleted.The ele ct r ic c urre nt pa ss es throughthe ro ck et and se ts off an e le c tri c ign i te r w hich ig n ite s th e p r o p e l l i n gcharge .(3) When the p re ss u re on thet r igger i s re le ase d , the t r ig ge r spr ingforces the t r igger to the forward posit ion and the electr ic circui t is broken.

12 ROCKET COMPONENTSThe M6A1 ro ck et is 21.62" longand consists of a body and ogive assem bly, com plete with explosive com ponents, and a sta bi l iz er and fuze a s sembly, complete with explosive andp ro pe lla nt c o m p o n e n t s . T he to ta lweight of the rocket is divided betweenthese two component as se m bl ie s , thefo rm er weighing 1.57 l b. , the latt er ,1.82 lb . In the following pa ra gr ap hseach component will be de sc ribe d. Theexplosive components will be disc uss edsepara t e ly .

13 BODY AND OGIVE ASSEMBLYT hi s as sem bly (see fig. 6) comp ri s e s the head of the roc ke t. Takenby itself, i t has the general appearanceof a boa ttailed ar ti l le ry p rojec tile. Itc o n si st s of a body, o give, and body union.

a. Body.- This (see fig. 8) isa steel cup, 4.11" long, with a diameterof 2.23 " at it s fo rw ar d open end and

nJJFIG. 8 -BODY

with w all s 0.087" thick . The re a r halfof the body is slightly tapered, andin the r e a r face is punched a hexagonal hole , 1.06" a c r o s s the flat s. Intoth is h ole is fitted the body union. Anexternal longitudinal groove, 0.175"wide and 0.037" de ep, is p re ss ed 0.385"to the r e a r of the forw ard end of thebody.

b . Ogive. T he ogive (see fig.9) i s a co ne , 4 -1 /2 " in height and2.245" in di am et er . The walls of thecone are 0.031" thick and are bulgedout t o form a flange approximately1/2" wide at the b a se . T his flange fitsover the open end of the body and actsa s the forw ard be arin g surface of thero ck et in i ts trav el through the launcher.The flange is clinched sec urely into

FIG. -OGIVE

the groove in the forward outer su rface of the body. Fo ur dep ress ions

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DECLASSIFIEDM6 A1ROCKET

by the f i r ing-pin spr ing . A c i r cu m fer en tial gro ov e, 0.045" dee p, midway-down the length of the firing pin, r e ceives the safety pin when the latter isin pl ac e. The safety pin, when in th isgroo ve, holds the fir ing pin secu rel y ina re ar w ar d posit ion. When the safetypin is rem ov ed , the firing pin is free tomove forwa rd, res t ra i ne d only by theaction of the fir ing-p in sp rin g. D rop ping the rocket as l i t t le as 4 ' wil l provide sufficient im pac t for th e firin g pinto ove rcom e the tension of the springand caus e the ro cke t to be detonated .Th ere fo re, when the safety pin is r e moved, i t i s necessary to take everyprecaution not to drop the rocket.

2 Below and in lin e with thefiring pin and s prin g is the M18 de ton ator a ssem bly and the explosive cha rge .The detonator assembly consis ts of analuminum detona tor cup, 0.342" deep ,0.190" in dia m ete r, and cr im ped at bothends. I t is housed in a b ra s s deton atorholder that sc re w s into the inte rna llyth re ad ed opening of the fuze body . Ab ra ss b oo s t er cup, 0 .480"deep, 0 .530" india m ete r , and external ly thread ed on therim, is screwed into place in the fuzebody after the d etonato r hold er is f i t ted.The bo oste r cup and the deton atorholder are separated by an onionskindisk and a detonator-holder re ta iningdisk. The second disk is ma de of aluminum and seals , in turn, the detonatorhold er in place in the fuze body. Th elow er or unth reade d ex ter na l half of thebooster cup extends beyond the fuzebody, and, when the s t ab il ize r ass em blyis screw ed into the roc ke t body, theboo ster cup fi ts into a r e c e s s in theexplos ive charge .

(2) Fin assembly. The fin assembly, which guides the rocket inflight, (see fig. 12) consists of six steelfins and the n ozz le. Each fin is attach edto the noz zle by two spot welds on thelower flange.(a) The fins ar e m ade of shee ts tee l 0.041" thick and 5-1/2" long. Thefins a re flanged at top and bottom in the

sha pe show n in fig ure 12. In the upperedge of each fin is cut a notch 1-2/3"

/- '.V.'.JECTION AA

F I C 12 -FIN ASSEMBLYfrom the leading edge . Th is notch iskep t fr e e of pa int and is tinned withso ld er . On the side surfac e of eachfin, an area 1/8" in diameter is treatedsim ila rly . All extern al surface s of thefin assembly except the tinned surfaces of the fins, which are keptfree asel ec tr ic co ntac ts , ar e coated with olive-drab lacquer enamel .

(b) The nozzle is a steel cupinternally threaded at the forward end.The r e a r face of the cup nar row s andcont inues to the rear , forming thenozzle proper. The internal surface ofthe rear half of the nozzle is curvedsm oo thly , as illu str ate d in figure 13,and is given a fine finish. The forward

half of the noz zle i s 1.49" in dia m ete r;the rear half is 0.687"in diameter. Inte rn al sur fa ce s of the nozzle a re coatedwith a light coat of priming paint.(3) Electric wiring and attachmen ts. T hi s com ponent ignites thepropellant and is an electric squib withtwo insulated lead wires of unequal

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DECLASSIFIED M6 A1length. The squib is t h ru s t up into thes tabi l izer tube so that i ts forward endis approx imately 5-1 /2" forward of there a r end of the noz zle. Both lead w ire s ,one 18 -3 /4 " long, the other 6-3/4 "long ,extend rea rw ar d out of the noz zle. Theshort length is stripped sufficiently atits free end to allow it to be soldere d toa tinned spot on one of the fins . Thelonger length of wire is wrapped twiceabout the under p roj ect ion of one of thef ins. The l a s t 6 -1 /2" of the wire arela id bare , and a 1/2" length is foldedback twice upon itself. Over this nodeof wire is wrapped a 6" length of 1/2"b l a c k tape. This taping facil i tatesgrasping the end of the wire. The wireis then sp ira led to take up its slack , andthe free end is r e v e r s e d and tapedlightly (with cellulose tape) to t he r e a rend of a fin (see fig. 6). When therocke t is loaded into the launcher, thewire is tor n from the tape and i ts baredlength engaged in the launcher c l ips .

(4) Trap assembly. The trapassembly, which holds the propel lantin the be st burning posit ion, co nsis ts ofa s teel trap body and a t rap r ing ,shaped as i l lus t ra ted in figure 14, thet rap ring being s taked to the t r ap body.The as sembly is either cadmium orzinc plated.(a) The t rap body is made ofsteel and has eight equally spaced ri b s .(b) The t rap r ing is made of

s tee l .

TRAP BODY

TRAP RING

F I G . 14 TRAP ASSEMBLY

ROCKETc. Assembly. The fuze body isinserted" in the forward end of thestabil izer tube and is held in place bythe tight fit requ i red . A s i l ve r - s o lde r

r ing is slipped down the tube and, uponheating, melts and sea l s the in ternaljoint between fuze body and tube. Following this, a dome-shaped disk i sslipped down the tube , convex side up,and pr es se d flat again st the fuze body.The disk is a safety factor; it r e m ove sthe possibil i ty of propellant f lames orgases working through or around thefuze body to cause pre m atu re funct ioning of the rock et. The firing pin is inse r ted and the safety pin run throughthe t ran sv ers e ho le and the f i r ing-pingroove. The detonator holder, withdetonator , i s screwed into the fuzebody , followed by disks and the boostercup. The propel lant is inse r ted in thetube. The t rap as sembly is screwedinto the large opening of the nozzle ,where it r e s t s on the rim just belowthe interna l th re ad s. Then the fin assembly is screw ed onto the re a r thr ead sof the s tabi l izer tube . Pet tman cementis applied to the th reads of the nozzleto waterproof the th read mesh . Ther e a r end of the nozzle is closed with achipboard disk, which is notched toprovide for the passage of the leadwi re s .15 EXPLOSIVE COMPONENTSa. Propellant . The propellantcons i s t s of five sticks of ba l l i s t i t e ,each 0.36" in d ia m e te r and 4.15" long.The -rocket is not loaded by weight butby length of powder stick the purposebeing to keep the p r es s ure for variousrounds at a relat ively constant value.On the av era ge , however, the prop ellantweighs approximate ly 61-1 /2 g ra m s.The propel lant and it s components areloaded as follows: A space r tube , madeof kra ft pa pe r, 1" in diamete r and 3/4"long, is slipped into the s tabi l izer tube ,coming to res t aga ins t the flatteneddisk. The five propellant s t icks areslipped into the tube, coming to r e s tupon the r im of the sp ac er. When the

DEGUVSSIFIED15


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M6 A1 DECLASSIFIEDROCKET

nozzle is screwed onto the stabilizertube, the propellant sticks re st on therim of the trap ring and are held securely in place.b . Ot he r ex p l o s i v e components. The body contains the explosivecharge, and in the fuze body are theM18 detonator and the booster. Thedetonator consists of an upper detonator charge of 0.98 grains of lead azideand a detonator pellet of 1.26 grains oftetryl. The booster charge is a pelletof tetryl weighing 1.86 grains.

16 PAINTING AND MARKINGa. Painting. All external surfaces of the complete rocket are coatedwith o l i v e - d r a b ammunition paint.Those surfaces previously mentioned asbeing unpainted remain so.b. Marking. Just below thejoint of ogive and body, the name ofthe round, the lot number, the manu

facturer 's initials, and the month andyear of loading are marked circumferentially with yellow marking ink.All the letters and figures are 3/8"high. Sample marking:ROCKET, H.E., A.T., M6A1

Lot 1234-56, P.A. 9-4317 PACKING

The M6A1 rocket i s packedone per individual fiber container, M87(see fig. 15). Twenty such loaded containers are packed in a wooden packingbox. The box, complete with contents,weighs approximately 136 lb. and isequipped with two rope handles to facilitate its handling.a. Container, M87. This container follows the standard design forfiber containers, consisting of a cylindrical tube and cover of laminatedasphalt-filled c h i p b o a r d . The container is 22-1/2" long and 2-3/4" indiameter. The tube and cover are eachclosed at one end with a terneplate endplate. A plywood support ring rests ona chipboard spacer at the lower end ofthe tube. It prevents the nose of the

rocket from touching the end plate.

After the round is inserted in the container, the cover is sealed in place bymeans of a strip of 2" adhesive tape20-1/2" long. This strip is olive drabin color and has the designation of therocket (Rocket, H.E., A.T., 2.36", M6A1)marked on it in yellow figures andletters.

b . Packing box (1) The packingbox (see fig. 15) is 18-2/3" x 13-1/2" x24-1/2" and is sturdily constructed of3/4" lumber reinforced by end and topcleats . Two 16" lengths of manila ropeare securely attached to opposite sidesof the box and serve as carrying handles.The box is stained a light brown, and allthe exposed metal parts are paintedwith light-brown lusterless enamel.The box has identifying marking (seefig. 15) in black paint.(2) The 20 loaded containersare i n s e r t e d in the compartments(formed in the box by fiberboard di

viders) so that adjacent containers aretail end up and nose end up, respectively.18 SAFETY PRECAUTIONSa. The safety pin should be removed only after the nose of the rocketis placed in the launcher.

b . The rocket is sensitive andwill function if dropped on its nose upona hard surface from a height of 4'. Donot remove the safety pin except as explained above. Even when still in thepacking containers the rockets must notbe subjected to rough handling.c. Rockets which have been unpacked but not fired should be returnedto their original packing containers.The safety pin and the nozzle disk mustbe in place. The fiber container shouldbe resealed with the adhesive tape.d. Rockets should be stored ina dry, cool place. They should not bestored where temperatures exceed 120F . , and they should not be exposed tothe direct rays of the sun.e. Face guard and gloves must

be worn when the rocket is fired.- 1 6 DECLASSIFIED


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ROCKETDECLASSIFIED M6 A1

YJ '[3.Q.

O-jU l1g W

r 0 5

^ ^

L k

RC23

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M7A1 DECLASSIFIEDOCKET

SECTION II

ROCKET, PRACTICE, 2.36", M7A1

19 GENERALT he M7A1 rocket (see'fig. 15) iss im ilar in design and con struc tion to theM6A1 rocket, lacking only an explosivecharg e . I t has the same d ime nsion s ,weight, and t ra je c to ry a s t h e H .E.roc ket. It is f ired in the sam e ran ge sas the M 6A1 without the co st or dan gerincidental to fir ing the H.E. round.

a. Weight rod. A s te el rod ,5 .33" l o n g , 0 .75" in d iam ete r , a n dthr ea de d at one end, is fitted into thefuze bo dy. Th is rod m ak es up for theweight of the exp losive ch arg e and fuzepre sen t in the M6A1 ro ck et. All othercomponents of the M7A1 pract ice roundare s imilar to the components of theM6A1 rocket.

b . Use. After i th as be en fi re d,the pract ice rocket , M7A1, may be usedagain as a dummy round in teachingmethods of loading and handling.c. Painting and marking.(1) Painting. All external surfaces ofthe M7A1 pr ac tic e roc ket , a re coatedwith blue lacquer enam el . F in su rfaces serving as contact points for theigniter system are left unpainted andare t inned with solder.

(2) Marking. In the sam e po sition as on the M6A1 H.E. rocket, theno m en cla tur e of the roun d, the lot number, and month and year of manufactureappear in white marking ink.

d. Packing. (1) Th e pra cticero ck et i s packed in the sam e mannerand in the same container as the M6A1rocket (see par. 17). The sealing s tripfor the con tain er is light b lue, and theapp rop ria te nom encla ture is s tenci ledin white.(2) Tw enty c o n t a i n e r s a r epack ed into the wooden packing box inthe sam e ma nner a s the H.E. M 6A1rou nd . Th e packing box is identical butis mar ke d to corr esp ond with the cont e n t s . In add ition, a 3" blue band encircles the box when the contents arepr ac tic e r oc ke ts . Blue paint is alsoapplied to the vertical cleats at each

end of the box.e . P rec a ut ions. T h e s a m epreca ut ion s desc r ibed in paragraph 18m ust be ex erc ised in the s torag e andhandling of the p ra ct ice ro ck et. Howev er, s ince th er e is no burstin g chargeor fir ing m ech anism , the remo val ofthe safety pin d oes not ar m the M7A1roc ke t .

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ROCKETDECLASSIFIED M7A1

DECLASSIFIED-19


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M6A3 DECLASSIFIEDROCKETSECTION III

ROCKET, H.E. , AT, 2.36", M6A3

2 0 REASO NS FOR CHANGE a. Change in ogiv e. The designof the co nica l ogive of the M 6A1 roc ke tproved to be unde sirab le for se ve ra lre as on s. F ir st , the ogive tended totelescope on imp act . This re sul te d inpoor t ra ns m iss ion of the imp act forceto the fuze, allowing a va ria tio n in thet ime interv al between imp act of thero ck et and functioning of the fuze insuccess ively f i red roc ke ts . Secondly ,on im pac t at ang les of 20 or m or e theconical ogive tended to shear off at thejoint of ogive and body. Th is sh ea rin ghad a s er io us effect on pe ne tratio n ofthe ta rg et . The m ajor difficulty withthe co nic al ogive w as th at it faile d toprovide f o r a uni form, sat i s factorypene trat ion of the tar ge t by al l ro ck et s.

b . Change in ta il a s s e m b l yWith the contemplated addition of ahemispher ical ogive i t was real izedthat the cen ter of p re ss u re of the rocke twould be moved forward and that therocket would have a definite wobblethrough i t s t ra jectory unless the ta i lassem bly we re improved . Fo r th isreason i t was decided to redesign theta i l assem bly . A c i rcu la r assemblywas the design finally accepted.c. Redesignat ionof model number. The North African the ater hasrenovated the M6A1 and M7A1 rocketsand assign ed the mode l num ber M6A2

to the renov ated ro un ds . Although theOrdnance Department did not officiallyrecog nize this de signat ion, i t wa s feltthat the M6A2 designation should not beapplied to any new am m unition be ca useof possible confusion and misunders tanding. For th is reason the des ignation M6A3 and M7A3 (se e sec tion IV)have been appl ied.

- 2 0DECLASSIFIED

21 HEMISPHERICAL OGIVEa . D escr ip ti on . T h e o g i v e ,made of sheet steel, has the shape illu st ra te d in figure 1 7. It is 4-9/16"long and 2.245" in di am ete r at the flange.The hem isph ere is curved on a 1" radius.b . Ef f ec t i v en es s . - W i t h t h ehe m isp he ric al ogive, the fuze of thero ck e t ha s be en found to function in anave rage of 875 m icrose con ds comparedto an average of 1250 microseconds inthe M6A1 with a con ical ogive. Pe ne

trat ion has been uniformly improved.The im pr ov em en ts in functioning andpenetrat ion are due to the even t ransm iss ion of im pac t force through thestraig ht side s of t h e hem isphericalogive. On angle im pa cts , the M6A3 hasresisted shearing and has maintaineda fast fuze action and uniformly highpenet ra t ion .22 TAIL ASSEMBLYa. D esc ri pt io n of fin. The newtype of fin used on the M6A3 rocket hasthe shap e il l us tra te d in figure 18. Eachof the four fins re qu ire d in the completeas se m bly is m ade of .025" shee t stee l.The broad blade of the fin is 2-5/16"long and curved over an arc of 90.

b . A s s e m b l y - Each fin is jo inedto the other by welding with an overlap

-


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M6A3ROCKETDECLASSIFIEDof approximately 1/2". lne oases 01the fins are spot welded to the nozzle.rough the upright section of one of

Jfour fins is a small hole. This hole(for insertion of one qf the ignition| e s . In the blade of each fin is alsverse groove which is continuousthe grooves in the other three finsle complete assembly. This grooveis tinned and serves as a contact pointwith the electrical s y s t e m of th elauncher.

TAIL ASSEMBLY

ffectlveness. The M6A3c. Efirocket with the circular fin has slightlybetter ballistic qualities than the M6A1rocket had with the old-style tall assembly. Considering that the center ofpressure has been moved forward, thisis a marked improvement.2 3 OTHER CHANGESThere are no other changes inthe M6A3 rocket. In all other respectsit is similar to the M6A1 rocket.

11

SLOT

FIG.-18 TAIL ASS EM BLYSECTION IV

ROCKET, PRACTICE, 2.36, M7A3

2 4 CHANGES rocket. It is the practice counterpartThe M7A3 rocket has all the of the M6A3 and has the same ballisticchanges mentioned above in the M6A3 qualities.-21 DECLASSIFIED


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DECLASSIFIED

DECLASSIFIED


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M6 A 3 DECLASSIFIEDOCKET

1

DEAILOFMARKING

1

ROCKEHATM6A a. x tnui z Cs in the settin g pin, andthrough the body flash hole, where itini t iates the M17 detonator in the s l id er -detonator re c es s . This t ra ve l of theflame is , to al l intents and pu rpo ses,ins tantaneous . While th is pro cess oc curs , the delay element has been functioning, and in the event that a malfunction occurs in the instantaneouselem ent, the Ml 7 deton ator will function0.1 sec . la ter .(b) If the fuze has bee n se t fordelay action, both p ri m e rs function asin (a) above, but, since the setting pinhas been ro tate d 180, th er e is no wayto tra ns m it the re lay flame through thesett ing pin. The flame from the p rim erin the delay elem ent pa ss es throughthe com pre ssio n ch am ber and the delay element plug, causing the delay chargeto begin to burn . This charg e burnsfor 0.1 sec . and then ignites the d ela y c ha rge , w h i c h de tona te s . T h edetonating wave and the flame from

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M 8 DECLASSIFIEDROCKETthis explosion pa ss through the hole inthe setting pin and init iate the Ml 7detonator.

(8) Initiation of the M17 detonator causes detonation of the booster closing-cup charge.

(9) The d e t o n a t i o n of th ebooster-closing-cup charge detonatesthe booster charge, and the function ofthe fuze is completed.

o. Safety m eas ure . A nacceleration of 100 grav it ies (1 gravity inte rm s of acce leration is 32 ft./sec./sec.;100 grav ities = 3,200 ft ./ se c. /s ec .) ofshort duration must be attained in theflight of the rocket to initiate armingof the fuze. Forward accele ration ofthe rocket has ceased at a point approximately 85'from the launcher, andat this point the fuze is armed and therocket is ready to detonate upon impact.68 SHELL ASSEMBLY

a. Component parts. The shellassembly (see fig. 45) cons ists of theshell, burster tube, shell adapter, setscrew, fuze well cup, and shell plug.In the following subparagraphs thesecomponents will be described.

(1) She l l. - The shell is eitherforged or made from tubing in the shapeof a fla t-based cup, curved in slightly

at the top and centrally drilled andcountersunk in the bas e. It is 7.5" highand 4.5" in diameter a t the base and hasa wall thickness of 0.2". The forwardopening is 3.375" in diameter . At apoint 4.75" from the base , the wal lscurve inward toward the forward open

ing on an 8" radiu s. The base is 0.52"thick, and a centra l hole 1.5" in diameter is drilled and countersunk to adiameter of 1.74". The walls thickenat an angle of 15 from the base to apoint 1.250" above. This makes the interior surface of the shell entirelysmooth and adds support to the base ofthe shell casing. The lower 0.81" ofthe outer walls is threaded to fit therocke t body. Above the threads is anunthreaded portion, 0.15" wide. In theface of the base is an annular groovewhose diameter is 3.00". The grooveis approximately 0.20" in width anddepth.

(2) Burster tube. The burstertube is steel tubing, 15-1/2" long and1-3/4" in external diam eter, with a wallthickness of 0.120". The bottom of thetube is smoothly rounded. The burstertube fits snugly and is brazed in placein the countersunk lower centra l shellhole.

(3) Shell adapter.The adapteris a malleable- iron r ing of a size to fithalfway into the shel l nose . The upperouter surface1 of the adapter is curvedto follow the contour of the shell body.The inner surface of the adapter isthreaded to seat the fuze. In the wallof the adapter is a threaded hole, 0.25"

in diameter, that seats the setscrew.The adapter is fitted into the nose open-in of the shell and welded into place.

(4) Setscrew. This is a simplecommercial set screw, slotted at oneend, that locks the fuze when the latteris inserted in the adapter.

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M 8DECLASSIFIED ROCKET

PECLASSIFIED6 5


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DECLASSIFIED8ROCKET(5) Fuze well cup. This cup ismade of thin steel (0.012" thick) in theshape of a cylinder. It is 2.83" in di ameter, 4.67" deep, and is rimmed witha single thread at the open end. The

single thread screws into the threadingof the adapter and holds the cup in place.(6) Shell p lug.- This plug ismade of cast iron, plastic, or sheetmetal. It is rimmed, slotted on the upper face, and threaded beneath the rim

to fit into the adapter. After the fuzewell cup is inserted, and prior to shipment, the shell plug is inserted; it isremoved only to insert the fuze.

b. P a i n t i n g a nd m a r k i n g .(1) Painting. After the explosive isloaded into the shell, all external su rfaces of the assembly, except the lowershell threads, are coated with lusterless olive-drab paint.

(2) Markin g. Circumferentially about the shell and 5" below theshell plug, the lot number of the shell,the loader's initials or symbol, and themonth and year of loading are stenciledin yellow 1/4" letters and figures.

69 BODY ASSEMBLYa. The body is a tube 23.29"long and 4.5" in diameter through approximately four-fifths of its length.The body is open at its forward end andis formed into a nozzle in the last one-fifth of its length. The central sectionof the body has no design peculiarities,but both ends deserve description.DECLASSIFIED

b. The forward end is as follows: At a point, 0.187" from the inneredge of the rim, is a series of internalthreads that fit the body to the shell assembly. In the rear of the threads isan external groove and an internal bulge,the groove being approximately 1/2"deep. The internal bulge acts as a res tto hold the trap assembly in place. Twoinches to the rear of the external grooveis a second external groove, approximately 0.06" deep. This second grooveis a safety device, for the body willshear at this point if excessive propellant pressures develop.

c. The rear end of the body, orthe nozzle, is as follows: The nozzlebegins at a point 5.721" from the rearface of the body. It is formed by aninitial inward curve on a radius of 3/4",followed by an outward curve on a radius of 1-3/4". The two curves forma venturi. The outer end of the secondcurve flattens out at an angle of 15from the longitudinal axis of the body.The throat of the venturi is 1.828" indiameter, and the rea r face is 2.62"in diameter. The last internal 3-7/8"of the nozzle are given a machine finish

of the finest quality. The outer edge ofthe nozzle seats the fin assembly.Extreme care is taken to keep thenozzle concentric with the central section of the body, for a lack of concentricity will cause a thrust of escapinggas that is not along the longitudinalaxis of the body. Such a thrust wouldresult in inaccuracy in the flight of therocket.66


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DECLASSIFIED70 TRAP ASSEMBLYa . Genera l . T h e t r a p a s s e m b l yis a w ire cage housed in the rock et bodyand providing a f r a m e w o r k to hold theprope l lan t in the prope r pos i t ion .b . Components . The t r a p a s sembly cons is ts of a t r a p r i n g , 10 t r a pw i r e s , and a t r ap p la te .

(1) T ra p ring. The t r ap r inghas the shape i l lu s t ra ted in f igure 48.It is made of s tee l , i s r i m m e d , and hasa 3 .47" d iam eter ac ro ss the r i m and a

cen t ra l d iame te r of 2.47". The t r a pw i r e s are run th rough the 10 equallyspaced 0 .16"-d iam eter ho les .(2) Tr ap w ire s. Ea ch of the 10t rap wi re s is i d e n t i c a l . E a c h i s a b r i g h tbas ic -s tee l w ire , 0 .162" in d i a m e t e r ,with a smal l head on each end. Eachhead is 0.19" long. The wire f rom thebas e of one hea d to the ba se of the o the r

is 16.88" lon g. One he ad i s f o r m e d p r i o rto insert ion of the w i r e in the t r ap r in g .The second is fo rm ed after ins ert ion inthe r ing.(3) T ra p pla te . Th is co m po nent (see fig. 49) is 4.24" in d i a m e t e r

M8ROCKETand 0.20" thi ck , with a cen tra l hole 2-1/8"in di am et er . Radial ly about the platea r e 10 equally spaced s lo ts , each0.164"wide and app rox im atel y 0.62" deep . Intothese s lots the trap wires are f i t ted, r e maining th er e by rea son of thei r tensio n.

c . A ssem bly . Before the she l la s s e m b l y is sc rewed in to the body thet r a p a s s e m b l y is s l ipped , t r ap - r in g endf i rs t , in to the thr ead ed end of the roc ke tbody until the t r ap p la te comes to r e s ton the in te rn al bulge of the body. Screw ing the she l l assembly in to the bodyf o r c e s the t rap pla te against the bulgeand holds the t r ap a s sembly in place .The tr ap w ire he ads extending above thesurface of the trap pla te fit into the annula r g roove in the bas e of the she l l .71 FIN ASSEMBLYa. General. The fin assemblyfor the M8 rocket is a unique arrangement that opens and guides the rocketin flight only after the rocket has clearedthe launcher. The fins of the assemblyare held in place by a component that isexpelled by the blast of the escaping gas.The fins continue to be held in place bythe walls of the launcher, and, afterclearing the bore, snap to their outstretched position.

b. Components. - The fin assembly consists of a fin collar, six fins,a fin retaining ring, and a fin retainer.

(1) Fin collar. This collar,0.094" thick and made of cadmium- orzinc-plated steel, fits into the notched

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M8ROCKETouter edge of the nozzle. The sectionof the collar that fits over the nozzlenotch is 2.630' in diameter and 0.706"deep. The collar then widens abruptlyto a diameter of 3.500". Above the ledgethus formed ar e co llar walls 0.562" high.A rim , 4.25" in diam eter, extends outward from the top of these wal ls. Sixequally spaced slo ts, 0.085" wide, ar ecut from the ledge and wall in the uppersection of the co lla r. Into these sixslots the holed ends of the six fins arefitted. When the fins ar e in their r e tained position, they rest against theexternal portion of the collar wall thatfits over the nozzle notch. In their flightposition, they are forced back againstthe rim of the collar.

(2) Fins. There are six fins inthe fin assembly, all identical, all madeof zinc- or cadmium-plated steel, andall having the shape illu stra ted in figure51. The fin is 4-1 /8" long and 0.078"

thick and has a maximum width of 13/16".When the fin is in the retained position,the sloped end A rests against the outerwall of the nozzle, the flat surface Drests on the lower outer wall of the fincollar, and the fin retaining ring passesthrough the hole B . In the flight posi tion, the fin has rotated 90 and thenotch C fits against the upper rim ofthe col lar . The end E of each fin isfitted through a slot in the fin collarand is held in place by the fin retainingring.

(3) Fin retaining ring. The finretaining ring is a length of 0.135" steelwire bent into a circ le 3-1/2" in diam ete r. The ring is not completelyclosed, a 1/2" ar c remaining open. Thering is run through the hole in each fin- 6 8

after the fins have been fitted into thefin collar s lo ts. The ring is then weldedin six places to the internal ridge of thefin collar.(4) Fin retainer. This component is a thin cadmium- or zinc-platedsteel washer having a m aximum radiusof 1-11/16". The central hole of thewasher is 2-1/4" in diam eter. The finretainer has the shape illustrated infigure 52. There a re six points A on

the perimeter of the retainer. Betweeneach two points is a cam surface B.The fin retainer is inserted in the rearend of the fin collar, with the fins intheir retained position. The points areplaced next to the edges of the fins, andthe retainer is rotated by engaging thenotch C. This rotation cam s the upperends of the fins outward, locking theminto position. They rem ain in this po sition until the retainer is expelled bythe b las t of the propellant gase s and therocket cl ea rs the bore of the proje ctor.72 IGNITER ASSEM BLYa. General. The igniter a s sembly~consists of an open fiber tubefitted into a pla stic b as e. The basehouses a primer for percussion ignition of the igniter and a ring that pro vides electrical contact for electricalignition of the ign ite r. Eith er methodof ignition can be used. The igniterfits into the open end of the nozzle,where it is secure d with cement. Whenthe igniter is initiated, it ignites thepropellant, the gase s of the latter blowing the igniter from the nozzle.-


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M 8DECLASSIFIED ROCKETb . Components. T h e igniter

assembly consists of the tube, closingcup, squib assembly, primer, primer holder assembly, c u p , contact-ringassembly, and igniter charge.

(1) Tube. The tube is a cartridge-paper cylinder, 3.54" long and1.25" in diam eter . Stenciled lengthwise in black letters and figures on thetube (keeping 7/8" at one end unlettered)are the name and use of .the assembly.

(2) Closing cup. This component is a glazed paperboard cup 9/16"deep and approximately 1.16" in diameter. The diameter i s controlled bythe necessity for a snug fit between theclosing cup and tube.

(3) Squib assembly. The squibis an elect rical ar rangem ent for ignitingthe charge and has two terminals a t tached to the lead wires.

(4) Primer. The primer is aNo. 28 cal..5O p rimer (see vol . 1).(5) P r im e r- ho ld e r assembly .

The primer holder is a steel cup witha wide rim. It is 0.24" deep and 0.3" indiameter. The rim is 0.8"in diameter.Equally spaced about th e undersurfaceof the rim are welded three studs,normal to the rim. The studs are each0.19" long and 0.09" thick.

(6) Cup. The plastic cup seatsall the other components of the igniterassembly, and the r im of the cup is c e mented to the nozzle. The cup is shapedas illustra ted in figure 53. The centralhole sea ts the primer holder assembly;the shallow annular groove sea ts thecontact ring. The sleeve is slotted atone point to permit the terminal of onelead wire to be engaged in one of thecontact-ring studs. The rim of the cupis chamfered to allow a close fit in thenozzle. In the base of the cup are sixholes, each 0.006" in diameter a n dspaced as shown in figure 53. The studsfit through these holes.

(7) Contact-ring a s s e m b l y . The contact ring is made of steel and is2.128" in diameter with a central hole1.3" in diameter. To one face of thering are welded three studs similarto those welded to the undersurface ofthe pr imer holder. These studs areplaced so that they will fit into the outerset of holes in the cup .

(8) Igniter charge. The ignitercharge consists of 648 grains of gradeA-l black powder.

c. Assembly. The p r i m e r -holder assembly is fitted into the centralcup hole so that the studs slip throughthe inner set of holes in the cup. The

FIG. S 3 IGNITER ASSEMBLYcontact-ring assembly is fitted into theannular groove of the cup so that thestuds slip through the outer set of holesin the cup. One terminal is engaged onone of the contact-ring studs; the secondterminal of the squib assembly is engaged on one of the prim er -holder s tuds.All studs are then riveted so that allpart s a re up tight. The squib is heldupright by the stiffness of the leadwires . The tube is slipped into thesleeve of the cup and secured with cement. The opening between cup andtube, where the term inal and lead wiresexit, is securely sealed with cement.The igniter charge is poured into thetube, and the closing cup, its outer wallcoated with cement, is pressed intoplace against the charge. The No. 28primer is seated, and the annular

-69 DECLASSIFIED


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DECLASSIFIED8ROCKETgroove between primer and primerholder is sealed with red N.R.C. compound.73 PROPELLANT

a. The propellant for the M8rocket consists of 30 sticks of ballistitew h ic h i s a double -base propellantpowder. Each stick is 5" long and 7/8"in diameter and has an axial hole 1/4"in diameter. Three sticks are on eachtrap wire, and there is sufficient clearance between stick and wire to allowthe burning of the inner stick wallsimultaneously with the burning of theouter wall. The three sticks which runonto each trap wire do not occupy allthe length of the wire. Motion is prevented by an adhesive strip, the propelling-charge holder, 1" x 30", that isbound about the wires of the trap a s sembly with one edge against the sticks .

b . Two igniter-bag assembliesare bound on two opposite columns ofpropellant. The bags assist the ignitionof the propellant by catching the flameof the igniter and igniting themselves.This ignites the upper propellant stickswhich otherwise might fail to ignite immediately. The igniter-bag assemblyconsists of an igniter-bag charge of333 grains of grade A-l black powderinclosed in a cotton bag sewn togetherfrom a 7-1/2" x 1-1/8"cloth. The endsof the bag are closed by 10" lengths oftying cord. This cord is also used totie the bags to the propellant.

c. When the rocket is fired ina temperature range of 20 to 90 F., afull propellant charge is used. When therocket is fired in a temperature rangeof 50 to 130F., three sticks of propellant must be removed to avoid a danger ously excessive propellant pressure.This temperature overlap makes possible firings at the same range witheither a full or a reduced charge. Thisis advantageous in instances whenrockets are prepared for firing then aresubjected to a change in temperature

DECLASSIFIED - 7 0

before being fired. To remove the r e quired amount of propellant, the shellassembly is unscrewed from the body.The body is then set upright on a sturdy,level, surface. Because of the presenceof the black-powder igniter bags, the re moval of the trap assembly must beundertaken with care . When the trapassembly has b e e n removed, threeequidistant trap wires are unsprungfrom the trap plate after the propelling-charge holder has been unwound. (Donot remove sticks from those wires thathold the igniter-bag assemblies.) Replace trap wires and reassemble theround.74 EXPLOSIVE CHARGE

a. The bursting charge for theM8 rocket is approximately 4.3 lb. ofcast TNT. The charge is poured intothe shell assembly, completely fillingthe burster tube. In the casting operation a fuze well is formed in the shellcharge. This well is 2.88" in diameterand 4.38" deep.b . To protect the b u r s t i n gcharge in the burster tube from the hightemperatures generated by the propellant gases, an insulator tube is insertedand fire clay poured into the burstertube. The insulator tube, made of chipboard, is 15-3/16" long and 1.49" in di

ameter . The wall thickness is 0.08".After the inner and outer surfaces havebeen coated with acidproof black paint,the insulator tube is slipped into theburster tube, where it seats on theburster-tube bottom. The end of theinsulator tube, extending above t h eburster tube, is pressed flat against theshell body. The fire clay is pressed intothe burster-tube bottom to a depth of1.28"under a pressure of 2501b./sq.in.75 PAINTING AND MARKINGa. Following the loading of theexplosive into the shell assembly, thelot number, loader 's initials or symbol,and the year and month of loading of theshell assembly are stenciled in 1/4"letters and figures on the shell. This-


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DECLASSIFIED M8ROCKETl e t t e r i n g a p p e a r s c i rcumferent ia l ly ,5" below the nose of the shell.

b . Following assembly of shelland body, the no m en cla tur e of the roundand the lot number of the shell and bodya r | s tenciled on the body. They ar estenciled in 1/2" letters and f igures,anfi the le tt e rs and fig ur es of the twolot nu m be rs, etc. , a re 1/4" high. Allof t h i s s tenc il ing a ppea r s c i r c um f erentially on the m otor in such a po si t ion that the lower l ine of charactersis 12" from the nos e of the sh el l. Thenomenclature reads as follows:"ROCKET, H.E.,

4.5-INCH, M8"c. All le t te rs and f igures a restenciled with yellow pa int on the olive drab lacquer enam el that co ve rs a l l ex ternal surfaces of the rocket.

76 PACKINGa. G eneral. T h e c o m p l e t eround (except fuze), with nose plug, ispacked in an individual fiber container.Three f iber containers ( three rounds)ar e bolted tog eth er into a bund le. It i sthis bundle that personnel will see inthe field, and they should be fam ilia rwith i ts ap ea ran ce , w eight, and d imensions .b . Container , f iber , 4 .5", M97.This is the individual fiber conta ine r inwhich the roc ke t is pac ked. It followsthe gene ral design for f iber co nt ai ne rs.It has an inner and outer tube and acover tub e. It is painte d black and isreinforced at the ends with steel endplate s. However, i t ha s no nose su pport , s ince the rockets contained are

unfuzed. The con taine r is 32-1/1 6" longand 5-5/16" in diam ete r and weighs39.5 lb. when loade d. The end pla te shave a cen ter bulge and a re em bos sedsemicircular ly with the nomenclatureof the container in 1/4" letters and figu r e s . After the rocket is packed in thecontainer , the loader 's init ials and thelot numb er a re ste nc iled on the endplate with white marking ink.

c. Sea ling strip. A 2" x 38"st ri p of yellow adhesive tape i s wrappe dabout the joint between cover and tube,sealing the joint and identifying the contents of the container as high explosive.d. Bundle. Th ree con taine rsa r e place d, cover end up, in the lowerclover-leaf end plate, and the bolt isrun through the end plate and engagedin the uppe r end pla te, wh ere it is s e cured , assem bling the bundle. T h ecom plete bund le is 33" long, 10" high,and 135 lb.in weight. The shipping andidentification plates have stamped ont h e m the information i l lustrated infigure 54.

e. Box. For oversea shipmenttwo roc ke ts in M97 con tainers a r epac ked in a wooden pack ing box. Thebox is 36" x 13-5/8" x 13-5/8" andwe ighs, com plete with con ten ts, 90 lb.77 SAFETY PRECAUTIONS

Due ca re m ust be exe rcise d inhandl ing t h e s e rock e ts , because oftheir high-explosive content. I t isimportant that the rocket be protectedaga inst th e dir ec t r a y s of the sun andthat i t never be s tored at tem per atu resabove the maximum at which it can befired . When the roc ke t is fuzed, furthe rca re mu st be taken with i ts handling;with the safety pin removed, the fuzemust be handled as though armed.78 BALLISTICSa. Range . - The maxim um rangeof the M8 rocket assembled with theM4 fuze is 4,500 yd.

b . M uzzle velocity. 90 0f t/s ec .c . Dispers ion . Fifty percen t ofa given number of round s f ired at m ax i

mum range will fall within a rectanglewhose dimensions are 65 yd. x 130 yd.d. P ressu re . The moto r p re s s u r e , a f 9 0 u F., is 3000 lb. /sq. in. withthe bas ic charge .e. M iscellaneous. To the M8rock et body may be asse m bled a va riet yof hea ds, containing va riou s che m icalagen ts .

- 7 1 PECLASSIFIED


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DECLASSIFIEDM8ROCKET

COO

DGOSNSRP

RC

HE

-72 DECLASSIFIED

O&

45NM

CWTHOFU

R

P

C

45NM

LGBU

WTH

FU

5O


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M 9DECLASSIFIED ROCKET

SECTION IIROCKET, PRACTICE, 4.5", M9

79 GENERALa. Use. The rocke t , p rac t ice ,4.5", M9, is a companion round to theM8 high-explosive roc ke t. It has thesame weight as the M8, is assembledwith similar components, has the s a m ebal l is t ics , and lacks only the explosivecharge and live fuze to be ident ical .Since it is s imi l a r in weight and has thesame t ra jecto ry as t h e M 8 , it is used togive rocket cre w s trainin g in handlingand firing without the danger or expenseincidental to the use of the M8 H.E.round. In addition, at shor t r anges , ifthe M9 is fired with the M4 fuze, thefunctioning of the fuze provides a su i t able smoke puff for r ang ing purposes .At ex treme ranges , the a u x i l i a r ybooster may be assembled with the M4fuze to provide a visible smoke puff.As an alt ern ati ve , a bag of black powderplaced below the M4 fuze will also produce a sat is factory smoke puff. T h e M 9rocket, then, is valuable both for dr i l lpurposes and for s imulat ing f i re .

b. The launch er . The M9 prac tice rocket is fired from the s ametypes afol#8fe&BA


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M 9 DECLASSIFIEDROCKETNOSE PLUG SETSCREWSHELL ADAPTER

INERT FILLERSHELL

PROPELLING-CHARGEHOLDERROCKET,LOTaunil [Hj[;-nt! S HE L L T UB E

PROPELLANT

IGNITER BAG

TRAP ASSEMBLYNOZZLE

FIN IGNITER CHARGE - -SQUIBFIN RETAINER

FIGURE 55. - ROCKET, PRACTICE, 4.5", M9

Below the nom enc la tu re i s t h e l o t 1/4" let ters , is s tenciled the lot numbernum ber of the round. All let te ring is of the shell.in wh ite , the no m enc lature in 1/2" l et 82 PACKINGt e r s an d f ig u r e s, th e l ot n u m b e r , E x ce p t fo r t h e s ea lin g s t r i ploa d e r ' s i n i t ia l s o r s ymbol , a nd t he (which is light blue instead of yellow)month and year of loading in 1/4" let- and the approp ria te change in nom enclate r s and f igure s . On the shel l , 5" b e tur e , the M8 and M9 ro ck ets a re packedlow the fuze opening, is sten cile d in identically. As with the M8 rocket , the1/2" w hite le t t er s , the word "INERT," M9 is shippe d unfuzed and with a noseand imm edia te ly below th i s word , in plug inser ted.DECLASSIFIED


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DECLASSIFIED 4.5"ROCKETSECTION III

4.5" ROCKET DEVELOPMENT

83 GENERAL d. Tests on the M8A1 indicatedAlthough the principles of oper- that the base of the head was weak and,ation of the various component parts of because of the large deflection underthe 4.5" rockets have been retained pressure, would not allow full advantagethroughout the course of their develop- to be taken of the strength of the newmerit, minor changes in the design of motor. A new head was designed tosome of the components have been overcome this difficulty. The roundmade from time to time with a view to composed of this new head and theimproving their functioning and the motor from the M8A1 was designated asfunctioning of the complete assembly. the M8A2. The M8A1 round is now inA brief history of the development of production but will be superseded bythese rockets is given below: the M8A2 as soon as the new head isin quantity production. The total pro-si. Production was b e g u n in curement of the M8, M8A1, and M8A2February 1943 on the design of shell will be covered by the authorization(head) and body (motor) designated as mentioned in b.the M8 and M9. During the course ofmanufacture and the ballistic accep- e. The round composed of thetance tests of the metal parts, several M8A2head and a high-strength motor isweaknesses in design and materia ls designated as the T22 rocket;the samewere revealed. Many metal par ts from head and motor with the head inert-different manufacturers failed in the loaded for the practice round is desigballist-ic tes&wbfn all other specifica- nated as the T46 rocket. This roundtions had been met. It was decided in is capable of withstanding workingthe latter part of June 1943 to discon- pressu res considerably in excess oftinue mass production and to place the the working pressures of the pre-item in the development stage. viously mentioned rounds, and it pro

,, n , vides for an increased powder chargeb. All p r o d u c 11 o n contracts a n d ^ i n c r e a s e d f a c t o r o f s a e t T h ewere canceled, and a contract for hm- c h a r a c t e r i s t i c s o f t h e r o u n d a r e a sited procurement was placed with the , n J T ^ ^ J - I J . f o l l o w s :Revere Copper and Brass Co. for a lotof 390,000, which would complete thelimited procurement of 550,000 origi- Designation:nally authorized. ' H.E. T22Practice T46

c. The design of the body(motor) was changed in July 1943 toprovide for an increase in strength, Length, w/M4A2 fuze orparticularly at the threaded end. An dummy fuze 32"effort was made to use the existing Weight, each type 38-3/4 lb.shell (head), which had been manu- High-explosive charge,factured for the M8 and M9, by ma- w/M4A2 fuze - - 4.3 1b.chining new base threads. The round Propellant 4.75 lb.composed of the strengthened motor and Velocity ^ 865 ft./sec.the modified head was designated as Temperature range 20 to 125 F.the M8A1. Maximum range (approx.) 4,200 yd.DE LA IFIED


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4.5" DECLASSIFIEDROCKETRange,

yd.

5007501,0001,2001,4001,6001,8002,0002,2002,4002,6002,8003,0003,2003,4003,6003,8004,000

Standard charge (4.6 lb.) forn o r ma l t emp er a tu r eAt 70 F .

Elevation,m i l s39588098116

136157180204228256286318356365

550

A r ea of impac t ,yd.

210 x 450

250 x 400

Low charge (4.2 lb.) forh igh tempera tu reAt 100 F.

Elevat ion ,m i l s466994116140

167193222253287325369

A r ea of impact ,yd.

125 x 200

FIGURE 56. - FIRING TABLE FOR THE M8 AND M9 R O C K E T S84 FIRING TABLEThe f ir ing table shown in f igure56 is derived from data computed byf ir ing the roc ke ts from a f ixed proving ground launcher . For th i s r eason thetab le may not be comple te ly accura tefor rockets f i red f rom mobile mounts(see section V). In any event, the datacompiled in the f ir ing table is r e a s o n ab ly accura te and wil l serve its purpose unt il supe rsed ed. Fir ing tab lesfor all launchers wil l be made ava i l able when the l au n ch e r s are i s sued .85 TEMPERATURE RANGESThe 4.5" r o c k e t s , M8 and M9,m ay be f i r ed wi th in tempera tu re r angesof 20to 120 F. The fu l l charge maybefired within a t emp er a tu r e r an g e of20 to 90 F . , and the r educed chargem ay be f ired in a t emp er a tu r e r an g e of50 to 120 F. F ig u r e 57 shows the re

lat ion between the full and r educedc h a r g e s for the low and h ig h t emp er a t u r e r a n g e s . A t e m p e r a t u r e of 20 F .for the full charge gives a p r e s s u r ePRESSURE L '7=-.

PBESS

0 5O 80 120

which corresponds to that obtained bythe reduced charge at 50 F . This is agood minimum operat ing pressure . Inaddition to a min imum opera t ing p res su re , there is a safe ma ximu m. Th ism a x i m u m p r e s s u r e is produced by thereduced charge at 120 F. Th u s , thereduced charge is necessary be tween

DECLASSIFIED - 7 6


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4.5"DECLASSIFIED ROCKETthe tem peratures of 90 and 120 F . inorder to remain within the safe operating pres su re . Below 50 F. the r e duced charge will give p re ssu re s belowthe minimum operating value. Between50 and 90 F., either charge will worksatisfactorily. However, the full charge

will give a greater range than the reduced charge as indicated by the firingtable given in figure 56. The overlapin tem perature range gives a versatilityin charges that is valuable tacticallyand provides a wide marg in of safetyin relation to operating pressured.

SECTION IVROCKET, FRAGMENTATION, 4.5", T29

86 GENERALThe T29 rocket (see fig. 58)consists of a 20-lb. fragmentation bomb,M40, assembled to the M8 4.5" rocketmotor. The assembly is made possibleby a special adapter. The M111A2bomb fuze is used with the T29 at thepresent time.

FIGURE 58. - ROCKET, FRAGMENTATION, 4 .5" , T29

DECLASSIFIED77


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NOTES

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NOTES

-7 9


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DECLASSIFIEDM4 A 1FUZESECTION V

4.5" ROCKET FUZE DEVELOPMENT

87 GENERALThe M4 P.D. rocket fuze a s sembled with the M8 rocke t has under gone change since its s tandardizat ion .Two success ive major changes resul tedin the M4A1 and the M4A2 fuzes . Thesechan ges and the modified fuzes are dis cussed in the fo l lowing paragraphs .88 FUZE, P.D., M4A1a. The pr incipal changes in the.M4 fuze (see fig. 37) to produce theM4A1 fuze are as follows:

(1) A different delay t ime hasbeen provided. App roxima tely 40 per cent of the present product ion of M4A1fuzes re tain the .1-sec. delay found inthe M4 fuze. Such fuzes a re for grounduse only. The remaining product ionquanti t ies of the M4A1 fuze have a.015 -sec . delay . Th is delay was requested by the A r my Air F o r c e s , andfuzes having this delay are for air useonly. The shor t -de lay charge cons i s t sof approximately .136 gra in of A r m yblack powder, grad e A-5, co mp r es sedat a p r e s s u r e of 60,000 lb . / sq . in . The. 1 - s e c . delay charge consis t s of 1.23g r a i n s of a s imi l a r powder p ressedunder a s i m i l a r p r e s s u r e . The d i men s ions of the delay-element housing depend on the type of delay charge used .When th e delay cha rge is inse rted in thesmal l cent ral cavi ty , the long narrowhole below the co m pre ssio n cham ber is1.520" long; when the shor t-d ela y cha rgeis inser ted , the hole is .355" long. Thedifference in length of this hole is obtained by increas ing the length of theco mp r es s i o n ch amb er . The differentdelay t imes wil l be included as p a r t ofthe nomenclature of the fuze and willappear s tamped on the fuze. Requestsfor the fuze should specify the delayt ime requ i red .

(2) The walls of the fuze havebeen made thinner so as to reduce thetotal weight of the fuze.(3) With the use of the two-zonepropel lant in the modified M8 rocket ,it was found necessary to r educe the

spring tension so that a lower accel eration would arm the fuze. The M4fuze required 160 G. to arm (in l a t e rproduct ion models th is requi rementwas reduced to 100 G.); the M4A1 r e q u i r e s 100 G. to arm.b . Upon co mp letion of th e p r e s ent product ion program for the M4A1fuze, it is contemplated that the fuze

w i l l b e declared l imi ted s tandard .Product ion of the M4A2 wi l l beginon a l a rge sca l e , and i s su es of theM4A1 will be made unt i l s tocks areexhausted .89 FUZE, P.D., M4 A 2The M4A2 rocket fuze (see fig.60) differs from the M4 and M4A1 inthe following respects:

a. The body has been redesignedto seat a new type of setting pin. In theM4 and M4A1 fuzes when the setting pinwas not rotated completely through 180,the flash holes in the setting pin werenot alined with the body flash hole andthe delay and instantaneous flash holes;the setting pin presented a solid metalsurface to the flame from either thesuper quick or delay elements, and thefuze would not function completely.When this condition existed, the rocketbecame a dud. To obviate this difficulty, the arrangement illustrated infigure 60 was devised. An obliquehole, 5/32" in diameter, is drilled fromthe upper rim of the delay-arming-pinhole to the body flash hole. Into this

- 8 0


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&SCUSSIFIED M4A2hole, at a 25 angle, is fitted the delayelement. The flash from th e delayelement is thus c ert ain to pa ss unobstructed through the body flash holeand set off the slid er deto nat or n omatter whether the setting pin is setcorrectly or not.

b. The new setting pin is 1.33"long and ha s a sing le diago nal flashhole passing through the unslotted end.This flash hole is .218" in dia m ete rand is set at angle of 28.

FIG 59 SETTING PIN

FUZEc. The sl ider for the M4A2fuze is m ad e of alu m inu m , affecting acon side rab le reduc tion in weight. Atthe same t ime, the lockingpinhas been

strengthened (see fig. 60). The combination of these two changes has donemu ch to pr eve nt m alfunctions of thefuze during ric oc he t. In the M4 andM4A1 fuzes , the heavy slid er occa sionally sh eare d the weaker locking pinand slid back into the unarm ed position.Such a malfunction is unlikely to occurnow.d. An other change i s the us e ofa l ea d- br as s forged body as a thirdalt ern ati ve . Th is is in addition to them al leable - i ron and gra y- i ro n cas tingspreviously specified.

DECLASSIFIED8 1


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M4A2FUZE

DECLASSIFIED8 2


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DECLASSIFIED 4.5*LAUNCHERS

SECTION VI4.5" ROCKET LAUNCHERS

90 GENERALa. Launchers for roc ket s, 4.5"

and larger , are of thr ee general cl a ssifications.

(1) Air-to-ground or ai r- to -a irlaunchers ar e mounted on ai rc ra ft andare used to launch rockets at groundtargets or at other air cra ft.

(2) Ground-to-ground launchersare mounted on vehic les or emplaced onthe ground and ar e used to launch ro ck ets at ground targets.

(3) Antiaircraft launchers aremounted on vehic les or emplaced onthe ground and a r e used to launchrockets at ai rc ra ft . They ar e not usedby the United States Army.

b. There are three types ofground-to-ground launchers.91 LAUNCHER, ROCKET, MULTIPLE

ARTILLERY, 4.5% T27 AND T27E1a. D e s c r i p t i o n . The T27launcher (see figs. 61 and 62), designedto provide a light and highly mobileweapon of great fire power for groundto-ground use, is an eight-tube launcher.It maybe mounted on a 1-1/2-ton truckor assembled for ground fire at a selected position. This weapon is in thedevelopment stage. A second pilot,which will be designated T27E1, is beingdesigned for breakdown into two-manloads not exceeding 120 lb . each.

b. Principal characteristics.No. of tubes 8Elevation -5 to +45Traverse Provided by turningtruck, or by shifting

trai l in ground fire.

Firing mechanism-Electric, p e r m i t ting single-round orripple fire.Blast protection for crew NoneSighting equipment For indirectf i r e on ly .Weight

c_. Ripple fire. Ripple fire re fers to the setting of the firing mechanism that permits the rockets to belaunched one after another at shortintervals.92 LAUNCHER, ROCKET, MULTIPLE

ARTILLERY, 4.5", T34a. Description. This groundto-ground launcher (see fig. 63), nowunder development, will be mounted onthe turret of an M4 medium tank. It isof the expendable type, composed of 60opaque plastic tubes which may bejettisoned at will. The rockets arefired electrically, either singly or inripple fire . Elevation is from -5 to+30 by means of the elevating mechanism of the gun in the turre t. Traverseis accomplished by movement of thet u r r e t . All 4.5" ground-to-groundrockets may be used in this launcher.T h e launcher weighs approximately1,800 lb.

b. Principal characteristics.No. of tubes - 60Elevation -5 to +30

Provided by rotat-Traverse ing turret.Firing mechanism- Electric, p e r m i t ting single-round orripple fire.

-83 DECLASSIFIED


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T36 DECkASSIBEDLAUNCHERBfafcft Tank itself.Sighting eq u ip m en t Ta nk equ ipment.Weight (approx.) 1,800 lb.93 LAUNCHER, ROCKET, MULTIPLEARTILLERY, 4.5", T36

a. D e s c r i p t i o n . Th is is aground-to-ground launcher with eightl ight steel tubes. It can be fired fromthe ground or instal led on a 1/4-ton4 x 4 t ruck . Fi r ing is e l ec t r i ca l , ins ingle rounds or in r ipp le f i r e . E levation is from -5 to +35. When mountedin the 1/4-ton t ruck , the l auncher ist r a v e r s e d by movement of the veh ic l e .When the l auncher is used as a groundweapon, it can be t ra ve rs e d through 20.This launcher is under development .

b. Pr i n c i p a l ch a r ac t e r i s t i c s .No. of tubes 8Elevat ion -5 to +45T r a v e r s e :

Truck-mounted Provided by turning t ruck.Ground-emplaced 20F ir in g m e c h a n i sm - E l e c tr ic , p e r m i t t ing single-roun d orr ipple f i re .Blas t pro tect ionSighting equipmentWeight

DECLASSIFIED - 8 4


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DECLASSIFIED T2 7LAUNCHER

DECLASSIFIED85


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T 3 4DECLASSIFIED LAUNCHER

FIGURE 63 . - T34 LAUNCH ER ON MEDIUM TANK, M 4-TYPE

os 969 rockets and launchers-all types

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