Japan Navy Underwater Ordnance 1945 [Op 1507]

8/13/2019 Japan Navy Underwater Ordnance 1945 [Op 1507]

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RESTRICTED ORDNANCE P MPHLET 15 7

J P NESE UNDERW TER ORDN NCE

A BURE U OF ORDNANCE PUBLICATION 2 PRIL 1945


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RESTRI TtED ORDNANCE PAMPHLET 15 7

J P NESE UNDERW TER ORDN NCE

2 APRIL 1945

This publication is RESTRICTED and shall be safeguarded in accordance with thesecurity provisions of U. S Navy Regulations 192 Article 76 .


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RESTR ICTED

N VY DEP RTMENTBURE U OF ORDN NCE

SHINGTON 25. D. C.

ORDNANCE PAMPHLET 1507JAPANESE UNDERWATER ORD AN CE

20 April 1945

1 Ordnance Pamphlet 1507 contains a summary of the more import.ant items of Jllpane e underwater ordnance. t is designed to aid inidentifying the items. to give their tactical characteristics and to outlineprecautions to be taken as required.

2 This publication is not intended to give instruction regarding thedisposal of such ordnance. These operations remain the duty of speciallytrained personnel.3 This pamphlet does not supersede any existing pUblication. Theinformation contained herein was gathered with the assistance of the

U S Navy Mine Disposal School.4 This publication is RESTR ICTED and shall be afeguarded inaccordance with the security provision of the U . Navy Regulations1920 Article 76.

G F. H USSEY JRRear Ad11tiral U S avyhief of the ure u of Ordnance


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CONTENTS

Chapter 1. Minescction I- Genera l . . . . . . . . . . . . . . . . .. . . . .

Section - T.' pe J A . . . . . . . . . . . . . . . . . . . :ection 'I'ype JB . . . . . . . . . . . . . . . . . . 5ectionection

SectionSectionSection

ection

4 I YI c JC5 I ypc JD6 J ypc JE7 Type

JG9- I ype .J11

SeeLion 100Typ J Iect ion - I yp e JJcction 12-- Ill ccovered mines ( Apricot

gl apefl llit, vocado, Banana,P UI , Plum POUl gr8nate.Quince) . . . . . . . . . . . . . . . . . . . . . .

Chapter 2. Depth Chargesection I- Gencl'Ill

Section 2 - J ype 2

91113l :i171921

clion : - 'I'."lle 29

-it cl ion -l- Expcdlllentni 120 Kg .. . . . . . . . . . 31t i o n 5 (' nrceo"cred Depth Charges

(Type 0 [odif. 2; TypeType 9 l ; Type 93 j 96:Yoko) . . . . . . . . . . . . . . . . . . . . . . . 32

Scetion. cctionSection. cc tionScct ion

ce lionSect ion

ceLionSect ion

Chapter 3. TorpedoesI-G e neral . .. . . . . . . . . . . . . . . . . . . .2 I ype 4-1 . . .361 t Year [OOcl4--S11t Yel'" )[01cl5 "I"."pe6- 1')' po 917 I ype 91, Modi . 2 . . . . . . . . . . .8 Type 91. Modif. 3 . . . . . . . . . .9- 1'ype 93

'-ee tion lO- Type 97:section l1 - 1. )' pc 2 ( pee ial ) . . . . . . . . . . . . .

CClion 1 l:nrecovercd r orpedocs (Type90; Type 92 ; 'l'ype 91; '['ype

3839olO11- 2.J4-1546

l.j: New KllT C; [i sce lluucous) 47

RESTRICTED v


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vi

TYPE.IA1B.I B.IH--

rB 1,1C.I D

.JD

.lE

JAPDESIGNATIOType , O ( l i f . I'I') ' l'e 93. ;\ Iode l I'1'.'"1)(' 9:3 . )lodd .'1' ,"1'1' n:L n c l l ;jT."IW I:l. )I OOci :J." lei if. IT. I " 9:1. )[ode l 1

.j. Modi . 1) l lI rk 2, Esplo, i ,'e 110 k. Modi ".I) l ll r k 2,'Ii ,'c L1 00k::;maU Type MineModell

.1: . m n l l ')1ypc )1 in~ , oo)I o


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Chapter IJAPANESE MINESSection I - GENERAL

DesignationThe . :s. NH\Y mAkes lwo classifications of Jap .l I l l ' R ( ' mines:, Th e fil') t con:'rs tho e that have b en

"CcO \ 'C I' d ,,"el ollici" lI." idenlifi ed , 'I'he second in.cludes ~ ( I Hwt hu\'c not.

An id entified mine cn lTi S A two-letter desigualion , I\A \ ' ORD 0 1,:\121-14 dUIed epl emb rl J4 ,I "tnlr, tl rr'I tho fi,' Ictte,'S shllil in all ease.'be J to indirfl tc lh (" Ilatio nulity and lh (' sCl'ond le t ICr ii sha ll incliclite the mine. 1' he.--c )C ttCI' drsif, IH1 -

t i ( ) n ~ are U,.. i ~ l l t ' d by UI(' BUl'eau of Ordnan(' only ,A mine wllit h has not been thus i n v ( ' s t i ~ l I t willhe identified hy 11 short fruit IlHmc. Th e ci rcu larI ltCI'. ment io n d 11' i o u ~ pro\-ides that fi IdIInits mu., th e nnillC if des ired. Ir th e Bu I'cnll of Ordnllll c(' l >I t;lblishes thn t fhe fruitIUlmer1 minI" is nr w type, it will nn npproprilllr Iwo- Ietl r l' i ~ l l f l t i n n to ~ ( ' e Ih ,' t(, llIpO I'llr,V lIppclllllion ,

' I hp i n s l t ' n t i o n f11rther authot'iz(' the m ; s i ~ nIIl('nt of fruit nnmes to thosc minc which have nothC'r n rrc'o"r l'rd hnt 1I'C' known to exisl onl ." tht'ougl1rvic1en('(' s11c'h (IS ('nrtut'cd doellmrnt 'l :u1(1 Pl'i l;;oncrof-' Vnr t ( ' S t i t l 1 0 1 l ~Explosive Charge

~ x r l o s h .. ~ { " ( 1 in ,JII)l I l I l f':-.e minr .. I'f" 'O\ 'I'f' d 01'I'('pol't ed 10 (Inf l ' hnye been one of th (l followin:.t :

H h i n l o ~ ; : ( R, fl . Rnd 1 'r r mpOl'ary , nml T."pe 111'(' toxic Hml IIlllst IW"('I' Ill'

IlHntllcd lI,v III f' hHI'CGcn el'HI C' lulI'IlC'If'l'i st ics flf the xplosi,'f'''' 11 1f' flS

fo llows :Shimos Compnsl'd oj' nlmost PilI'{' piel'il' 1I ('id ,It is nsed in fI enst f01'1ll in mnin chll l'g'c,1;t nnd lin ., nIf'mon ycllow ro lorinf , Tt llUl." hr l1 :o;rri 11ho{)st(,I' ('h lt l'ft in It J 1'l'IIlUhll' 01' JlI'{'s:-.ed t'ol'm ,Sh imosC' Itw lls nt a Icmpr l'lIt ll l'c of ~ ~ O to 1? 3 CB(,CH lI SC of 1 l 1 r l l l ' i t i ( ' ~ wh ich form picl'lltc CO Il1 -pounds, . hiJllOS(, may dctollllt r on I'api 1 hen t n ~ ,II is s l g-h mOr e powcl'fu I Ihn n TN"r,

Ty pe 88-CQ IllPO'N nf nmmoniuHl pl ' l'rhlol'n t

7,"Vf.. f elTo,si licon 16% , powcl ' l'('(1 wood G'j{ Itn(TCI'Ul f' oi l 3%, I t is uscd in n u l a l ' form inmain Chli l'J C S, and has adm'" g'I'I',v ('o rorin): , 'I'll( 'composition Ot th e ) , : p ~ h c n1ft" VH l' y hy 10 ""''' y pe 88 decomposes rap idly fit h i ~ 1 I tcmp Crtltlll'CS,Rnd is " cl'y scnsi t i ,'c to fl'iction , ~ L O I ' JJllwcrfulIlinn ' l ' ~ ' I it compal'es [avol'abl," \\' ilh o . ~ i v ~,'ontllining- alumi num ,

Ty pe 9S-- omposed of l icxa nill'odi phcn."IHllline 1111(1 1' l'illitl'otl niRolc 607(' , 11 lI secl in [I cast

fOJ'1ll in Iwtin ehal'ges, and has a clul'k ye llow ('0101'ing-. T ," pc 9 " power i approximHt('l." Ihnt of",),,,,),, I t melts at 6 to 70,

Type 1, Tem pora r y- Composed 01' AnrmoniumPiel'u te HI ' ; , Alllminuml 6% , :Powdf' I'('d \V ond 2 n ~lind (, J'lIll e oil 1' : , Tt is lIs('(l in a g'I'anlllnl' powd(' r1'01'111 in IllHin Ch IU'J?


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over

Horns 4)

Switch

Mnnrj .n ulley

Come -along- :n

Arming Switch Detail

.l w J

L ----::--III ChargeCohtaine

____ 7 - Booster

t : = : : ; ; ~ ~ 1 ~ . . . . . D e o n o o , Carrie,Mounting

MINE TYPE JA

L Mooring Bol/

TakingHydrastat

Carrier

MO- 70Figurr l-Cross-sectioual drllwi,'g of . ,i' e T y pe IA.

2 RESTRI TED


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j

Section 2-MINE TYPE JAT h i ~ ndlll' ilPIHll't'lItl.'" is o b ~ o l c t e onl.'" a rcw

'I pt'c imen)) I U l n l ' \"( ' r be(,n ell co untel'ed, t is sub -11181'i llC luid , mool'ed and fired by contact, Th e,Japanese designate it as Type , l' lod ifi ca tion 1.

The mine 111


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Sedion 3 MINE TYPE JBThis is a moored, contact mille with several varia-

tions, but lhe Japanese designations for all modelsis i l'ype 93 . p to the present time 'rype 93,Modell ; 'l ype O;J, .\ lodel 2 ; Type 93, Model 3;Type V3 Model 3, o d i f i n t i o l l 1 ; aod Type 93,Model 4 are kn owo to have been used.

These mines aI lui I by surface craft us offensiveor defcnsive w 'upons Hgainst submarines or surfacecraft. rrhe Ulu.ximulIl depth of water in which theycan be plllnled i. 3;;2 [ect; the minimuDl depth is25 fee l (appl'ox.). 'I'hc m'Lumum dcpth of themine ca.')c wh II Illoo vd is 246 feet.

With the eX','plion of the Type 93. 3,:Modificatio ll 1. whi II is described in d tail on page7, lhe physical clllu'uctcristics of the mines nre asfo llows :CaseShape-Spherical, 34 in diamete,'.

Color-B laek.Material lce l.Charge- rype 93, Mod el l -

and 220 lbs. 'l'ype1 Y I>e 93, Mod el 2-- xplosive.'l'ype 93 , Model 3 nknown .Type 9;1, Mod el 4- 220 lbs. Type I ,

Tcmpornry explosive.Total Weight l I lh ,.

Figure 4--Tlu spluricai J

External FiHing5Horns- Type 93, Model I- F'ou r, eleetroe hemi

( a I, 90 apUl' nTl nd the upper hemisphere, pacedal tcrnat ely 16': 2 and 11 ':6 from thc top ccnter oflbe case.

Type 93 , 2-- 'a me as Model 1 with anaddit.ional 3 l:ipaced c


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Keep CiOVIIT late4)

Contact rm ~ t l l i ~ ~ ~ i i a : i ~ ~ ~ = = = ~ ~ ~ ~ B I C ? a l ; t e r Release

Mooring S i n d l e ~ : = ~ ~ ~ ~ i ~ ~ooring Spindle Base P / c t e ~Soluble Plug M e l ~ a n t s ( n

Mooring Shackle .L t I

MINE TYPE JB

O e t o n a t a r Housing

?r---- Detonotor CorrierC ' e t a ' n a t o r Nut

R u b b < ~ r SleeveM OOIlt1o Shackle Cap

~ n ' O C K Absorber

MD 176 Fig re 6 A cross sect ion of the JB 'mille.Mooring Spindle and Shackle- Type 93, ) 10 ' Operation

I- PI ooouding from the { nlel o the base plnte - ; i J O I arter Ihe min II . scmbly ~ l r i k c ~ the wnter(Othcr modeL. belie cd to bc the Ille.) 111 011 IH)' illl ". a Ul e lal llImm I dr p, .W8Y f rOIll

6

Ancbor- lO 9 Ibs . x 33 x 3; :5Cable- 155 m of J3ml11 (.5 1 ) or

260m nf IOmm C3 n ) or: nO IlI Ill' (iItH ( :t l': )

till H chOl rc ling out II plummet cab le ns it sinks.WI lt' 1l th e plll111111 i reaches dep th pre, t 0 the(,l1hl( dl 11m . th e dl'um locks and Ihe an ( hor cpn-'HIt..: rl 'O II Ilip minC ( , 1 l ~ ( ' IIllif i n k ~ . l'celinj out

RESTRICTf )


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I

Section 4-MINE TYPE JCA moored, contllct mine laid by surface cmft as

a defens ive weapon against either subm arine orsurIace craft, and designated by tbe Japanese asMark 5, Modificat ion 1. The maximum depthin wllich it can be planted is 689 .feetj minimumdepth is aPP oxirnatcly 55 feet. The maximumdepth of 1 110 III ine case wben moo red is 64 feet.The JC , round in the Central Pacific, has hadlimited usc.

A description of the case and external fittingsfollows:Case

Shap- pher ical, 32': 7 in diam tel'.Color- Black.Material-Slee l.Charg-l 2 Ib . block-fitted himose .Total Weight-456 Ib .

External FiHingsHorns- Foul', clcctt'och cmienl, 90 apart aroundthe upper hemi phcre.Cover Plat 15 ill diameter, in the center of

the upper berni.phere, secured by I bo lts.Lifting Lugs- Th ree, eq ually spaced around theupper hemisphere nea , the edge of the coverplate.Base Plat 10':5 diameter in the center of the

lower hemisphere.Support Legs- Four. equally spac d around the

lowe r hernisphc e ne,,, the base-plate pocket.Anchor No t recove,ed.Mooring Cabl-525' of 0 ~ 3 5 diameter cable.

OperationDetails of neither the anchol nor the d plhtaking mechanism nl e known. Shortly after the

mine is launched , hOWC CI' , two switches c lose toarm it. First tension on the mooring spi ndl e closesthe moo ring safety switch j sccond) dissolutjoll of asoluble plu g a ll ows a pring- loaded arming switchin t.he co vel plat.o to close. The mine is then armed.

The mine fi res when one of the hOI'ns is bent sufficicnlly to break g lass vinl) a llowing an electrolyte to run into a bHttcl Y cup and form H smull cell.The reslIlhllll eutTent fires Ih e delonntol'.SaFety Precautions

Th e mooring safety switch i designed to openflud distll l11 th e mine when tension is released fromIhe moo l'jng sp indl e. This feature, however, is 110tdependable.

Fig re 9-Mi e typ e.

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FillingTowing r G r c k ~ ~ t

Detona tor CarrierKeep

Filling Hale

10

rro , , Swive I

. r rJJnn Arms (4)

,nnrnl l Container

,

o I owing Swivelw w

MINE TYPE J MD 174i ure 10 Mine t y pe JD.

RESTRI TED


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Section 5- MIN TYPE JD

1''''0 types or this mine are known to exist , hothdesigna ted by the Japanesc as Mark 2 EXI)losi,'cHook. Onl y the Mark 2 Explo ive Hook, Mod ification 1 has been recovered. The u :Mark 2Explos ive Hook has bccn reported fr om intelligence sources.

The intended use of the JD is an cxplosivcgrapnel for minesweeping. t bas been used , however, 8S a controlled beach mine. Then used as aI rapnel it is towed behind a ship. and whcn it . ~a mine mooring cable, the Explosh'c IIook is firedclcetrically from the ship. When used as a controlled mine it is planted on beaches and approa ehes to beaehes and is fir d elect ri cally from anobscI'vation post.

General chara cteristics of the mine are as fol lows:Cose

Shape- Cy lindrical , 8 in diameter, with ,"nunded ends. Fitted with 4 projecting grapnel armswi th a maximum span of ] ] ~ and towinl 'braek t on each end.

Length- Body 10 ; Overall 25 .Color G ray .Material- Steel.Charge to 19 Ibs. east Sbimose, or granular

Type 8 explosive.Total Weight 28 to 39 Ibs.

External FiHingsDetonator Carrier-l'.'5 in diameter in the mid

dle of the body.Filling Hoi One on each end, 2 . 5 in diameter.Pad Ey One, on the top ce nter line next to

the letona tor -carrier keep ring.Towing Swil Ols- Two, one attached to aeh towing braeket.

OperationThis mine is armed during assembly. When

used as 8 grapnel, a sweep wire serves as a towingcab le and proper depth s maintained by suspending the mine from a minesweeping Boat on a Boatpendant. The mine is electrically con necled to the

lowing ship by u I'ubber covered cab le stopped offon Ihe towing cubic. 'Yhen an object is snared, anohsen 'c l on lh lowi ng boat fir s the charge elecIIi ClllI.v. The ollly difference belween the 'Mark 2,Moclifi IIlion 1 and Mad, 2 is that the latter firesboth elcc trically and automatically when an addi tiol1l1l tcn, ion of 55 Ibs. is pnt on the mine.Safety Precautions

:\l ililt. I' I."pc ha s any disarming [ c R l l I I

Fig e II - Vi w0/ Tpe ID tr lhe xplosive hook. .

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12

Horn HornSafety Fork

Filling Hole . . ,, : .

MIN TYPE JEFig ure 12 A cross section of m T y pe IE .

Mainharge

MD 93

Figure 1 he J is oft e Pla ced as a land mine, as tJell as lor betlch defenses.RESTRI TED


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Section 6- MINE TYPE JEA manually laid henli:.;phct"icai , contact mine

used both 011 benches and nn lan(1. and dcs ignlltedby th J H J 1 l 1 n ( , ~ L ' : ; 01 Smtlll Type )linc. )I odcl I. T wo elcc ll'ochcmiclll horn..; protl'ud e from th e min'C8lS(;; : :nn g li n ',' lind trip w i l n H I ~ he nttnched toIh horns.

Extens ive lUI S been mad e of the i l lshallow-wllter apPl'Oflches to beaches and on reefs ion beach s nbo\'c th e high -wllter mm'k: nnel nlon1I'oads and landin g s trips of nit-

Th e h n l ' l I t c l ' i s t i of th e mine I I I as [ollows:Case

Shap m i ~ p h i r ; l W :;, in tliR1l1 cl(,1 lind10'.''; high.Color- Black.Material tec l.Charge---44 lb. of cast expl osiw.Total Weight- 110 Ib s.

External FittingsHo rns- 'rwo. c1e('1 ochcm iell l. 1 0 npn I' t nnd

from 1he top center of the cnse.Cover Plat 5':2 in diamctcr. in the top center

of thc cascoArming Plunge r- O':45 in diameter, Apl' ing-

loadcd . in the ccnte , of the co,er plate. '['heplnn cr is grool'ed and i. bcld lip by a sa fcty fork.

Carrying Handles- Tw o. 1 O apart, fromt he horns nnd 7 ,'5 [rom t he ce nt I of the case.

Filling Hol e Cover-3 .'.l in dhtOlcter. in th eter of Ule base.Operation

The detonato ' is housed in the boostC r wlw l1 themine is aSf;cmb lccl. The mine, however. notarmed until th e sarc f;. fOl'k is ,'cmoved f ,'olll Ihe

arming plunger whieJl moves down under springp J ' e . . ~ I 1 l


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MAIN

RCINFORCING

INE TRUCK

4

igure S Mil l ype IEKEEP RING COVeR PLATe

P O r

DETON TOR

BOOSTER

BOOSTeR ell

igu re 16--C oss secl ioll of ,,,i,,e Type .RESTRI TED


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Section 7- MIN TYPE JFA conll'olic . ground mine designated by the

Japanese as ' ' 'J'yl'c ~ 4 , 2, lL is u ed defeusivel y and la id [rolll 'urface cra ft in harborsor har cOl n l l a n c ~ s and controlled from observntion posts on the shore. t was used, however, onAdltk, AlasL;a , as a eonll'oll ed land mine, t mayaL a b, used as a controlled mine planted in shall ow\1 111 ,. pproachcs to beaches,

Gt n\" jo d Hl raetcristics of the mine arc as. follows .

oseShap Hemispherical , 2 ':4 in diameter, 25':6

high, with a steel skirt 9 high and 24 in diameter, welded around the top. The mine is boltedto a four-wh ee led cast-iron anchor tl'llek.

Color- Black.Ma terial- Steel.Charge- 190 Ibs. (approximatcly) ranula,'

Type 88 explosive.Tota l Weight- 580 Ibs, (approximately).

External FittingsBo oster Cover Plate-4 in diameter, on sid e of

ense, 3':5 below edge of skirt, secured by six bolts.

The tirillcr cable e ll tel'S lhrough a stuffing box inthe ee ntcr of this 1}late.External FittingsLifting Holes- i'ou l , l : ~ in diameter, on theski 't , 90 Mpa 't anti 1" below tILe top.

Cov er Plate ,.,t in Ui .lIl1cll 'l' in th e top c( nlerof the case.

Pad Eye- One, ou the case, 13 below lJe uppe r edge of the skirt.Cable Cl am Shackled to the pad eye, Thispre,'eots stra in on the cable fro m being t ransmitted to the detona tor.

Mine Anchor Truc.k- Reetangula r, cast iron, fit d with foul wh eels.Operation

The detonator is housed in the booster duringassembly, aDd , wh en laid, a rubber-co vered firingcable COlU}eets the mine with an observation poston tile shore, The m inc is fired electricaIly by anobserve .Safety Precautions

Th e mi_oc contains no self-dis8l"1ning features.When used as a land mine, it is likely to be buriedwiill other explosives.

.

RESTRI TED 15


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I i Mrn Horn Add Type j.

Ksep RingCase

n i n Charge

o 0I w W

MINE TYPE JG.

VARIOUS SH P MINE CASES FOR MINE TYPE JGo 0t w w

Figure 17 Cross sec fion of nIh l t y pe IG. Note tbe 'va r iO lS shapes o he mine cases.MD-I72,

16 RESTRI TED


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Section 8-MINE TYPE JGJ contact ben h mine des ignated by the Jap

anese as .. Small Ty pe Aline, Model 2." A singleeleetTochemical horn protrudes from the top of themine cnse, and snug lin and trip wires JUay beattached to Ule horn. Th is mine has genelally r . plllcc d the JE li S n bri lf h II uri la nd min e. 11 willbe found in shallo\\'WIl LCl ' appl'oach s to beachesaud on ree fs j on beaches above the Iligh wat rmurk j a nd along IQllCi s and landing strips of airfi elds.

A general clcSC l'ipt ion or th e mine is as follows:Case

Shape T I l1llca lcd cone 14':.: ) in diameter I1tand 7 in dinmetCl' at top.

Height-Cas ' only. ]0'.'25: en e with horn , 14'.'6.Charge 22 Ibs. (approx.) en t T?pe 9 explosive.

Weight-52.5 to 62.5 Ibs.

External FittingsHorn- One, electrochemi ca l, on the cove l' pla te,

i g h t l y of center .Cover P la te 5 ,2 in diameter in the top cC' ute ror th e case.

Filling Hol e Cover- 3'.'25 in diameter , in thehas .

Arming Plunger- O'.;') in dinmclcl', 011 th e coverphlle bes ide the horn . .It cO llll1 ins two O'.'t dia meter su rety -pin holes.

Ca rry ing Handles- 'l'wo .1 0 apart a n I 4helow 1he top of tb e case.

OperationTh e detonator is housed in the booster wh en lhemine is assembled. When plunted, a safety pinis mnnually withdrawn fl'om the arming plu.oger,and t he plunger mo\'cs down under sp ring pres o UJ'C and bJ'idges tbe 31'ming sw itch contacts in thefil'in g ei l'cuil. This arm8 Ul e mi ne.

Th e mine fires when the horu is ben t suffi cientlyto b, uk it. glass vial allowing electrolyte to runinlo a balte",\" cup and g ~ n e r t e suffi cient current10 fl,c Ihe detonator .Safety PrEl cautions

'fh e JO contltins no self dismming features.W hen "" ,1 as a land min e it has been founel buriedwith ol hel' xp los ives.

Fig ' 18- MI . type IG g ll re 19- T y pe IG I,. th e water

RESTRICTED 17


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8

RingArming SpringLifting

Arming ~ f J ~ ~ ~ ~ ~echanism ~ ~ ~ ~ j ~ ~ Plate/ C etonat,,, Contact/ Bo,oster

l y c e r i n e ~ ~ = l t ~ ~ ~ ~ ~ ~ iash - PotMooringSpring~ o o r i n a Safety

Note :Chain from mooring spindlenot shown .

Support Legs 4)

Fig , 2 C ,'oss se ti-oil. 0 ';1U t y pe ..L.JMIN TYPE JRESTRI TED

MD-17I


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,Section 9-MINE TYPE JH

A mOOl'eli, co ntact mine laid by su rface craft.Two type ) of this mine al'e known to cllit andbot.h are de ' ignatcd by t.he Japan Mal'k 6.Oll ly the Mal'k ti Model j " h becn l'ecovel'ed.Th e Mark 6 )10dcl 2 h becn l'epol'ted f"omiuteUigl'IIl' . :'OUI'CC:S. The depth of water in whichthe mine Ill;].'" he laid DOL known, although a casedcpth o ' ' Iud a lIlool'ing c u ~ l e leugt.h of3360' h. b.c ll l'epol,ted [01' lhe Mul'k 6 ModeJ2. H I I H ~ oec n limited, although l:tpecimcuswere c o n ~ I on' wnjalein anel UUUItl.

The c l H l r m t c i l : i l i c ~ or th mine lll'C u.s follows:Case

Shape-:Sphcl'icai, 41','- - in diameter.Color- B lack.Material- :steel.Charge- Mal'k 6 Model 1---- 7 Ibs. block-fitted

himose.Mark 6, )[odel 2--HO Ills. ('I'ype ) explosive.Total Weight- Mark 6 )lodel 1-1000Ibs.

Mark 6, Model 2- 903 Ibs.External Fittings

Horns- ltOll l', clcct l'ochcmical, 90 0 npul'l aroundthe upper hemisphel'e.

Figllre 21 Mine type JH.

Cov r Plate l : - l in diameter in the top centerof tilc ca.c, . ured 1G bolts,

Arming Switch c h a n i s m in diameter, inLite cente r of the CO,fe l' plate.

Lifting Lug Tbl' 'e l arouud lippe" hemisphere,l'tUO UpUl'l .

Mooring Bridl:-, j ... t lng or H\'c LoIII" ' IlI11h'I CO to thIlIOUI'IlIg' )p i l ldle.

On th e lower h e l l l i ~ p h COlllength ') ur chain, four of whicbsup pOl'\. leb'S, and oue to the

Moor,ng Spindle Hous:og- : '.'6 iu dinmcler, in1he iJolloIII cente l' of Ihe ca c.

Support Legs- Polil', 1lI'UUII(] lhe lowel" hcrni: \ ph , 'c. th) apal'l,

Mooring Cabl e-6-101l1111 (0':U-O':39) diameter.Operation

llio detAils or thc allchol' nor thc dC lnh -takingIll ctllll nbmi arc known. 'hortly ufter the mine isIUlUlChed tell -ion all the mooring elwin closes the11100rilll: safety .w i th Di;,,;olution or solubleplug allows the s p l i n ~ l u l i d e d al lllillg .... wilclt toc lo.' ;c, arming the minc.

'rh e min e fires when one of lhe hOl'ns is bentsufficiently to break its glass vial, allowing elecIl'olyte to run into the battel'Y CLIp ,, d generateli uffi icli l currcnt to fire the detonator,Safety Precautions

The mooriuO' safety switch is designed to openand disarUl the mine when tension is "elllo" d {rom1hc moor in g spi ndle, 'rhis feature, howc,'er, is notdependable

figure 22 Type Jff floating RESTRICTED 19


25/54

Fig re 2 J M i . type J a,sembl.d.

Fig re 24--Type JI j/O /U g, f1lll y armed. Tbeb,Joyant tail piece lppo rts t e mineapproximately 4 feet belo ,,, rface.

2 RESTRI TED

Figure 5-Type J j/oating armed.


26/54

Section 10- MINE TYPE JIAn aircralt laid, contact, drifting mine usedas au offenshoc weapon ngainst surface craIt and

designated by the Japanese as K-2. The minedrifts approximately 6' under .he surface of .hewater, supported from its buoyant tail section bya bort length of cab le. Tbe tail has the appearnoce of nn oi l drum loating \ rtically on lhe sur-face when the mjn e is armed. After an unknownleng .h of time the JI scuttles itselI.The physical characteristics of the mine are asfollows:Case

Shape-Cylindrical, 14 in diameter.Color B lack.Material-Steel.Length (including tail)-6 '1 .Length (without tail )--4'l .Charge-123 lhs. east Type 98 exploshe.Total Weight 3 00 lbs.

External FittingsHorns rhrce, switch, equally spaced aJ ound

top of mine.Suspension Lug- One. on the top cen ter I ne of

the mine.Detonator Pocket-4'.'25 in diameter, 1 0around the ca'e hom the booster pocket.

Fill ing Plug 3 ':75 in diameter, in the nose ofUle min e.

Soluble Plugs- 'l'wo; one on the lOp cenler line4 (rom the after cnd of the mine and the apex ofthe toil.

Tail Release Mec hanism- On the top center lineof the mine, 2 from the after end.

Operationfu; the mine is launched from .he aircraft arm

ing lanyards withdraw salety forks from the tailrelease and booster release mechanisms. 'rhebooster is reiclu;cd under spring pl'es5LUoC aDd ispCl mru1cntJy housed over the detonator while themillc is sti L in thc nil'. On its initia l plunge intothe wuter, the hydrostatic switch operates, closingand locking the cU'cuit hom the battery to thehoms. Positive buoyallcy of the tail brings .heUille back to the sW'face and it floats Dose down-ward with the tail fillS parUy out of the water.Disso lution of a sol ubi plug releases thc minefrom the tail, and the ease sinks to the end of themooring cable. The weigbt of the case on the cableinverts the tail and it floats base upward on the SDrface. The strain of the case on .he cable also releases the horDS, which snap outward i.n the armedposition; and closes a horn safety switch, armingIhe minc,

'rhe mine fires when onc of the horns is bent suffi-cienU y to make a co ntuet anel close the circuit be-twe II lhe battery aDd detonatol'.

Arte,' an UllknowD period of time the solubleplug in the tail di olves, [Iooding U,e float andallowing the. mine assembly to sink.Safety Precautions

ince the horus require onl y n fOl ce of npptOX-imately five pounds to bend Ihem, it is I . sible thatIhe mine may fire on striking the bottom, ThereHI e DO disarming features if the mine hould driltasho e; and movement of thc JI on Ihe be.1eh mayhend a hom and detonate thc mine.

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Section I I MINE TYPE JJfhis ail craft laid, moored, contact mine bears a

rese mblance to thc U. S. Mine Mark 10, Mod. 1.'l'he mine case is a cy linder that f1.ats ve rtically inUle water when mDDred. I t has fDur electrochemical h. rns equipped with brackets that are extended utward ab.ve the t.l-- Df case by spring pressure.'I h e physical characteristics . f Ule mine are asf Il ws:

aseSha p Cylindrical, 24 in diameter and 52':5

IngMaterial- Steel.T tal Weight- GOO Ibs.Charg 240 Ibs. Type 98 eXp losive.

External Fittings . w , elcctrochemi a l. equall)' paced

ar und the t p . f the case. Each h rn is equippedwith a spring-I ad ed steel extensi.n.

Det nat r H using- On the side . f the case nearthe b tt m .

BDoster Release Mechanism- In an pening onthe easc 1 O from the det nator housing.

Base Plate On th e bDllDm f the ease, equippedwith mD. riug lever c.ntrDlIed by a soluble-plugmec hanism ; and a hydrDStat assembly.Operation

'I'he anchDr fo r this mine has n t been rec.vered,therefore ts operation is not known. l he mineis laid with a parachute frDm aircraft; s me timeafter laying the spring extensiDns Dn the h rns arereleased and snap Dutward. Hydrostatic pressurereleases the bDoster, which is driven ac ross thebooster tube under spring pressure, housing it overthe det nat r. DissDlution Df the sD luble plug inthe base plate all ws mDDring tensi n to. pera te themooring lever, arming the mine.

The mine fires wh en ne . f its h rn s is bent suffi-ciently to break a glass vial all.wing electrDlyte to.run into. a battel'Y, generating suffici ent current tonre the det na t rSafety Precautions

safety switch is des igned to di arm the minewhen the mooring cable breaks Dr is cut, but thisrea ture is nDt reliable. Theref re i f f und adrift,.1 Dn the beach, it sh. uld be c n idered danger us

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Section 12-UNRECOVERED MINES11.1 nddition to the forcgoi.ug mines, specimens of

which have been recovered, there a.re the followingtypes about which tl.cre s intelligence informationonly.

MINES TYPE "APRICOT" AND" GRAPEFRUIT"rrh ese represent two types of antisubmarinc,

contact net mines des ignated by the Japanese asI"l'ype 96" and u'l'ype 96, J)'fodication 1." 'fhemaximum depth of waler in which the nels are la idis 700" 1 lind the depth of the mine case may va ryfrom S' to 300' . Drug lines tram the head rope ofUl e net 1.0 the firing mechanism fire lhe mines whensubjected to 'uitable tension.

'rh e physical characte ristics of the mines are asfo llows :Case

Sha peCylindrica l with rOllnded ends. 20'.' j indiameter and 27 '.'2 long.

Mate ria l- Steel.Cha rge--Apricot-121 lbs. granular Type 88

explosive.Gra pef ru.i t- 132 lbs. gr anul ar 'fype 88 explosive.Total Weight -A pr icot 3 Ibs.

Gra pef rui t-249 Ibs.Firing Mechanism

Modified type nJ depth charge pislol.Operation

As the net is low ered into the wnter, a hydrostnticn lly-opc l llt d detent on the mines restrainslhe drAg lines f l O ~ l tT'nn:o:mitting- tension to th efiring mechani sm until n minimum depth of i ~ h tfeet i. enched. 1 'he GRAPEFRUl 'I' ha theadditionnl ~ l l r ( l t . v fnctor of a shear pin in th e firingmechanism to (ll'cvcnt firing on n s lif ht tension.Therea fter . the mines will fire wh en a minimumtension of 300 Ills. is npp lied to the firing meehanisms through th e drug lin s.Safety Precautions

There nre 11 0 known sell.disnrming features.MINE TYPE "AVOCADO"

This is a moored , co ntact mine laid by su rfacecraft. The Japanese designation for this min e isnot known. Un like the majority of Japanese eon-

tact min cs, the AVOCADO 'S firing mechanism isan impact-inertia pendulum dev'ice rather thanelectrochemica l horns.

The characteristics of the mine arc as follows:Case

Sha pe-Spherical, 32':5 in diameter.Material- Steel.Charge--17U lbs. 1'ype 8 explosive.Tota l Weight-- l50 Ib .

Operationhortly.it r the mine ass tubly st ,ike. the water

upon laying, a metal plummet drops .away f.romanchor, reeling out a plummet cable as it sinksWh en the plummet reaches a depth preset on thecabl e drulD, the drum i locked ""d lhe anchorSC P111'HtCS fl'OIll the mille elise und sinks, reeling outmool'jug cable from a drum , \V eight of the plummet holds a sp l'ing-Ioa'ded pawl from cngaging aratchet on the mooring cable drum. When theplummet touches the bottom, release or tension onthe plummet cord allows the pawl to engafre tile

e t , locking the dnn . 'l'he mine is then pulleddownWlll'd ulld will moor at a dcpth below the u -face equlll to th e length of the plumm t cord, Nofurther detai ls of tht aJ'miufr pro ed ul'e nl'c known.Wh en the mine is sll'uck or tilted sttlIicienUy torause a ll ine l'tia pendu lum to make onc of three(Iectl'i eal cont act.. , the ci rcuit th" ough th e batteryHnd clctonlltoi:' is closed and th e min e f i r e ~

MINE TYPE 'BANANA"A mo ored, cODtact mine laid by su rrace OJaii:.

Th e .Tllpallcse clesignfltiOI1 is unkno\nl. trhc baseplate of tbe "BANAN'A " is simil"r 1.0 U,e DutchYiekc l's fwd th Briti . h T-)fT{ 3 min es, and mayhllve been cop ied from them. Th general charaeIO'ist ies of tho min e arc IlSCase

Shape-Tw o hemi sphcl' s. 33','5 in diameter ,joined by a cy lindrica l mid -section (width unImown ) .

Material-Steel.Charge--275 Ibs. Type exp losive.

External FiHingsHorns--FOllr, elect rochemical. q l l I I ~ spaced

i1lO l t the upper hemisphere.24 RESTRICTED


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Base Plate--In ccnt., of lower hemi phere, containing a straight-shank moo ri,n' spindle.

Cover Plate--ln the ee nte of the upper homi sphere.Operation

hortly a rt e,' the min assembl y st rikes the walerupon laying, a meta l plummet dl'op ' away fromancbol', reeling out a plummet ca ble us it s inks.When the p l u l l l m reaches a dcpth I 'e-set 0 11 thecahle drum, the d UlIl is locked and the anchor separates from th e mine case and sink s, l'ccliug outmooring ca bl e from a ( um. Weight of the plummet holds a spring-loaded pawl from ara tchet on Ule mooring cable drull). When theplummet touches the bottom, release of tension onthe 1>lmmnet co rd aUows the pawl to engage theratchet, locking thc drum . 'I'hc minc is tben pulleddownward and will moor at a dcpth below tbe surface cqual to the Icngth of the plummet co rd . Disso lution of a so lublc washcr permits mooring tenSjOD to withdraw th e mooring sp indle in the minebase plate, ~ r m i n the mine.The mine fires wb en one of the horns is bent suffi

ciently to break its vial allowing electrolyte to runinto a battcry cup, generating sufficient eurrcnt tofir e the detonator.Safety Precautions

A mooring saIety switch s des igncd to openand disarm th e mine wh en tcn ion is removed fromthe mooring spindle. This featu re, howeve r, is otdependable.

MINE TYPE PEARA moored, co ntact mine laid by submarines as an

offensive wcapon and designated by the Japaneseas Urr ype 3, 1\Ial'k 6. t 'llbe mine can be plantedin woter having a maximulIl depth or1220'. 'rhecase can be moored at a maximum depth of 66'.'rho minimum dopth of the min e case be low thesur'ince is [lot known. 'rhe chal'8ctel'istics givenbel w arc s imilar to th e mine JA, and it is iblethat th PEAR is 3n improved design of thatmine.Case

Shap 'fwo hemisphere 35'.'5 in diam eter,joined hy n lO cylindrical mid-section.

MINES - UNRECOVEREDColor G ree n over red .Material- Stee l.Charge- lAO Ib. himose.Total Weight 900 Ib .

External FittingsHorn Fonl , electrochemical , OIl upper hemi-spbere.perationNotlli ng is known of the anchor, arming devices

Ot depth-taking me chanism. 'l'he mine fir es wh enone of the horns is bent sufficiently to break itsgin ' \'ial, aUowing electrolyte to run into a batte,'Y ge nerating ufficient eUlTent to Ii e the detonato .

MINE TYPE PLUM'I'his mine was reported n CINCPAC-CINCPOA

Item #9330 as the Japanese Type 3, Mark 1Aerial Uine Mod el 1, Temporarily Designated'K. ' t No other information is known about thePLill l. The mine JI , recently recovered in thePhilippines, is an aircraft laid, drifting mine andis labele I by the Japanese as 'i'emporarily Designa ted K-2. The similarity of des ignation mayindicate that lhe K-2 is a modification of thep rJ UM:.

-MINE TYPE POMEGRANATE

1.\ moored, contact mine lHid by surface eraftither as an offens ive or defens ive wen pOll . TheJapanese designation is not known. The P MEGRANATE is similar to the British Vickers andis equil>ped with an upper and/ or lower co pperantenna to increase its operating areo. 'j1be characte ristics of th e mine are as follows:CaseSha pe- ph e ;ca l, 41 in dillmel .Material- teel.External FittingsHorns ix , elect-roehemi ca l, tonr equally paced

on upper hemi sphere, two 1 00 apllrt on lower hem.isphcl'c.Antenna U I>per nnd/ or lowc r, copper cable.

RESTRICTED 25


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JAPANESE UNDERWATER ORDNANCEOperation

, 0 information is available on the anchor ofdepth taking mechanism. The mine fires when thesteel bull of a sltip contacts the copper antenna,or wb en one of the horns is bent sufficiently tobreak its glass via l allowing electrolyte to run intothe battery, generating sufficient current to fire thedetoIHunr

MINE TYPE QUINCEA moored, controlled mine laid by sudace craft

as a barbor defense weapou and designated by theJapanese as I rype 92. " ''his mine uses an acous-tic monitori ng system to indicate the presence ofshipping. I t is fired elec trically from a controlpost on the beach. The maximum depth of waterin which the QUINCE is laid is 393' , and thenormal depth is 98'-131'. QUINCE mines are1aid in two rows, with mines paced 426 apart,

OP 15 7and rows 524' apart. Tbe maximum distance of afie ld of such mines f rom the cont rol n t i 1miles. The phy ical characteristics of tbe mine areas follows:Case

Shape- Unknown,4 ':9 in height.Cha rge-lIO Olbs. Type 8 l ,,;vpTota l Weight-1650 Ih.

OperationUpon laying, the mine assembly sinks to the bot

tom and the ease remain attached to tbe anchorfo r approximately one hour. At tbe end of thattime the ca e rises and assumcs its correct depth.Repor ts indicate tha t tll ese mines are laid in groupsof six. Hyd rophoncs in the mine field transmitsound of ap lll'oaching ship to tbe control post, andat the discretion of the observer, the mines are firedelect cally ei thcl' ingly or in r o n n ~

-

26 RESTRI TED


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ChapterJAPANESE EPTH CHARGES

Section l - GENERALrrhe U. S. Navy makes no separate designation

of Japanese depth charges but uses instead, thetranslated Japanll 'e names. Thus, one cannot te ll ,by looking at lhe name, whether the type has beenrecovered or not.

Three typc of Japane 'e depth charges havebeen recovered and additional types have heen reported from inlelligence sources. rrhe pi tols of allcharges, both recove"ed and reported, with the exception of .. Experimental Manufactu re U e 120KGDepth Charge " opera te on seepage-hole principle.Water gradually eeps_ nto a cy linder and huildsup sufficienl pressure to lire lhe depth charge.

Operation of pistols using this principle is dependent upon the rate of flow of water through anor ifice rather than on hydro tatic pressure alone.

The explosives used n J apane e depth chargesarc the 'ame a lho 'e u ed ill min ,with the ex-ce ption of Type 97. The general characteristics ofth is explosive re as oUO\ :

Type 97- Composed of Hexanitrodiphenylamine(HND ) 40 % "nd Trinih'otoluene (TNT) 60%.This explosive is used in a cast form and ha s asom ewhat clarker eo lor than Shimose. t has amelling point of 70 -S0o C. and is slightly lesspowedul than I T. The ex plosive is ve ry toxicnnd mu st not be handled by the bare hands.

JAPANESE DEPTH CHARGESTYPE DIAMETERI LENGTH I CHARGE IDEPTH SETTING DESCRIBEDON PAGE

88 17' 8 29':7 326# 80 ' or 150' 3291 \fodell , 17',' 29'.'7 220# 0' or 165' 32Modi . 193 n- 36 Un- 100' 32known known95 17','75 30'.'5 220# 100' ,200' 2995 Modi . 1 30 ': 5 325# 100', 200' , 300' 29390',490'95 Modif. 2 17':75 30':5 242# Unknown 2996 , Model l Un- Un- 242# 100', 200', 300' 32known known2 Modif.l 17':56 30'.'5 357# 100',200',300' 28390',490'2 Modi .ll 17'.'56 30':5 220# Unknown 32Exp . Use Un- Un- Un - Delay igniter 31120KG known known known nsedYOKO Un- Un- 55 # 130', 165' 33known known

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Section 2-DEPTH CHARGE TYPE 2An antisubmarine weapon launched from sur

fa ce craft and designated by the Japanese as. l'ype 2, ~ l o d i f i c a t i o u 1. u

Th e general cllal'uctc l'is tics of the depth chat'geare as follows:Case

Shap Cy lindrical, l i ,'oG in d iameter and 30' 5lourr

Color- B lack,t e r i a l

Charge--3fi7 Ibs. 'l'y pc 9 explos ive.Total Weight--lO I Ibs,

External FittingsPistol- ill end of c ntl'al tube, locked by a bay

onet joi nt. li'i ve depth se l.tinb S , 30, 60, 90, 120,lind 150 (100' , 2UU', 3UO' , 390' , '190' ) meters areinscr ibed a ll fa ce.

Filling Hoi Two, 180 apa,'t, on th e oppositeend of the case fr om the pistol. A b,'oken whi te

l

s tripe, 1 wide, is painted around the end of thecase co ntaining the lilting holes .

Pad Eyes- Two Oll caeh end,Booster- l n the oppos ite end oC the l u l tubetrom UC pislol.

Ope rationPr ior to laullchin g, Lhe dc pth-:setting uial is

tUl'lJ cd to nll y onc of {h'c ~ c t l open ing a p Hg e hole in th e va lve pint . 1 is not kn ownwheth cl' ti l(: detonatol' il hou::tcd in th e booste r U ua ll y or hydrosta t icall y . \\Thcn Ihe c i tU N is sub merged wa te r cnic l"S t il pistol t hr ough t he holesin th e dept h se llin g di nl :m d I h l ' the hole inthe valvo p la te. \VIl n suflicil' ll t p rcs.'i llrc has beenbuil t up in th e pi tol. Ihe firing rin is rclcasedundor slwing pressul'e and dri ve n on lO th e de tonato r, firing th e hul'g .

\ Vh cn th e depth- ctt ing diul is sct on U urc,th e depth-sctting valve pos it ions the va h'c SlO min s llch a manner tha t lhe pistol callnot opernt e.

Filfure 27 Two v iews of the type 2 depth ch4rlfe

28 RESTRICTED


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Section 3- DEPTH CHARGE TYPE 9SAn antisubmal'ine weapon launched fr om sur

face 'aft. Thr e types of tltis depth eha rge havebeen , eco e,'ed to da te and ae designa ted by theJapanese us Type 95 j Type 9,j, )[odification1n and .. Type 95, Modilicution 2. The onlypistol rcco \ rcd bas been with the Type 95 charffc.Data on the operation und character istics of pistolsfor Modifieations t and 2 have 'ome f, oll1 intelli,gence SO Ul' CCS.

'l'he physical churacte ri stics or thelic charges arcas follows:CaseShap

1011 0 .'y liudl'icnl, J7',';,j in ditllllClCr alld 30'.'5

Co lor- Crey,Material- Sleel.

Cha rge--Type 9;;-220 Ius, TYI,e 8 explosivewith himo:sc booster.

Type 9;; , Modification 1-325 Ibs , fyoe9 exp losive,

Type 9.j, ) Lodification 2-2-1-2 Ibs. TypeJ J T empol'a l'Y explosive.Total Weight- Type ~ ; ; : J ; ; 2 Ius,

Ty ) fj,j , ) lodHication 1 1 . j j Ibs.'J'. p 95, )[odifiention 2-371 Ius,

External FittingsEnd Plate-l6 . 2.j in dimllctl'I . fOJ'ming one end

of he ease,Pistol Cover ',' l in


35/54

J P NESE UNDERW TER ORDNANCE

Depth Control Valve-Screwed into the opposite end of lhe central tube from pistol cover.Type 95 has depth settings of 30 and 60 meters(100' and 200' ) and 30 meters with parachute.'l'ype 95 Modification 1, has been reported withsettings of 30 60 90 120 and 150 meters (100',200', 300', 390', 490').

Pad Eyes-Two on each end of lhe cascoOperationPrior to launching lhe charge the depth-setting

dial on the deplh eo nt rol valve is turned from" Safe to the desired setting, unlocking thehooster can and aligning ODe of three seepage holesunder the depth conlrol valve ~ l h the water inlet

OP 15 7

hol e. Thc safety fork is also removed from thepistol covel' at this time. 'l'he charge is thenlauDched and, as it siDks, increasing hydrostaticpl'cssure forces the pislol and booster toward oneanother. The size of the seepage hole determinesthe flow water inlo the space behind the pistol andbooster, and the peed with which these two partscome together. When the two meet, the detoDatorhou es in the boo leI' and the spring-loaded firingpin sleeve is uDlocked. Further pressure releasesthe firing piD which theD strik s the detonator andexplodes the charge.

WheD the charge is set on Safe lhc boosteris locked to the depth-coDtrol va ve. the pistol ssecured to the pistol cover nd Tiline the water.cntry holes is nncovered .

3 RESTRICTED


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Section 4- DEPTH CHARGE EXPERIMENTAL MANUFACTURE USE 12 KG ..An otTensive weapon used against surlace ship

ping and carried abOlll'd suicide moto ' boats.Th i charge, designated by the Jalaoesc as Experimenta Manufacture Use 120 Kg. DepthCharge, was recovered by Mobile Explosives Investigation Unit :,umber 1 in the Philippine area.Two ot these weapons are carried aboard light,high-speed, plywood-constructed motor boats. Tbestandard depth charge pistol is replaced by a delayed-action pull igniter. Thc charges are eitherdropped close aboard or are released when thesuicide boat crashes into the ta rget ship. The

igniter fires the depth charge shortly after it is released from the motor boat.1 he physical characteristics of the charge areas follows:Case

Shap Cylindrical (similar to Type 95, Modification 1 which is 17':7 in diameter and 30':5 long).

Ma terial-Steel.Charg Cast explosive (type and weight unknown ).Total Weight- 264 lbs.

External FittingsI gniter- In tube 1 s" in diamcter centrally lo

cated in end of charge.Filling Hoi_One, centrally located in opposite

end from igniter.Pad Eyes-Two on each end.

OperationTwo depth charges are placed in racks, one on

each side of the boat, and the pull cords from theigniters are attached to the rack. The suicideboat then beads for the nearest target and eithermanually releases its charges alongside or crashesinto the target, whereby the charges are aulematically released through a lever system on the boat.As the charges drop away from the boat the pullcords fire tbe igniters, which explode the chargesafter a short dclay.Safety Precautions

There are no known safety precautions on thischarge, and it must be considered dangerous ifOllod on a beach.

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Section S-UNRECOVERED DEPTH CHARGES::ie\eI'NI additional JlIl'lInc.e depth charges, be

lieved to be in use, are deseribed on th e followingpages. 'inee this inforlllution has been derivedfrom inlelligen c SOUI 'c:s it must be eva luated accordingly.

DEPTH CHARGE TYPE 2, MODIFICATION 2An unti -submul'inc wcapon launched from sur

fa ce crULl. in ee lhjs chu l'ge has the 'umc typenumber as Ule ""n e 1\Lodification I , it mny be

moli ifie/l t ion or that ehmge.Gencru) Chartlctcl'istics of the charge ur c as fol

lows:Case

Shape and Size- Cylindrical, in diamete r,3 0 ~ 5 long.

Material- t eJCharg 220 Ibs. 'l'yp 88 expl os ive.Tota l Weight 352 Ibs.

External FillingsF illing Holes- Two. 1\ 00 apa l'l, Oil opposit end

of the Cse ft om the pistol.Pad Eyes- Two on e/leh encl .

OperationNo flU'Ute l' inLol'malion is livailablc regarding its

usc as II depth ehll'go . lI ow \e r . it has h n adopt-p iI for 11 e as a land mine on Iwo Jim8 .

DEPTH CHARGE TYPE 88An anti-submlll'il1c w l Ipon IUli nchcd from SUl'fa ce era rt.fhe physicn l l ~ t of the charRC nre as

follows :Case

Sha p C.dilldr-iclIl. 17': in diam ter and 29':7long.

Charg 326 Ib, . block-fitted 'himose explosive.To ta l Weight 523 Ibs. ( Ie s ace"," ories).

OperationNothing is known about. we operation of tlus

depth charge except tbat it sinks at tbe rale of11.5 feet per eeond Ilnd it enll be set to fire atei ther 25 or J5 meters or 150' ) depth.

DEPTH CHARGE TYPE 91An lI_uti -submnljn wClpon, laun ched from SUI

face C'urt , des ignatcd b,\' the Japanese as TypeVI, lUodel J, }'lm..lifjC:llion 1. 11

Thc ph ys icul clulI'u ctcl'ist ics of the churge al'c asfollowCase

Sha p t:,r linol'icill, lj':ti in d i i . l l l l e t ~ I ilud 29':7

Charge- iiO uf Type titi xplosi \'e with~ h i l l l o booster,

Total Weight- 3;;2 Ibs.Operation

NoLl,i, " i kllown bout the ol''' l Ill io ll o[ thish l l q cxe pt th at it at th c I'al c of ti.6 feet

pC I' ~ c c o n d unci it nn be tieL to fire III eit her 25 or;;U mete's (SO' or t65' ) dep th .

DEPTH CHARGE TYPE 93An nnl i-subuuu'i II wenpon launched horn SUI'

crait.Th r ph. sicili chu l'llct('I'i d ics HI C us follows:

CaseShapc-Cy lindricnl. 36" long.To ta l Weight 44 l lbs.

OperationTh e only depth setting given i, 30 met ,., (100' ) .

A rlHl'H chutc is 1 1 ed wh en launched fl 'om slowc ,aft.

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DEPTH CHARGE TYPE 9An antisubmnri ne weapon laullched from sur-

face craft. Only one type of this charge has beenreported and this is de ignated by the Japanese as

Type 96, ModelL J rrhis charge has characteristics sim ilar to the Type 95, Modification 2. JJ

The physical characteristics r the cba rge nre asfollows:Case

Sha pe and Siz l1nklloll l1.Charg 2


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J P NESE TORPEDOES

TYPE I USED I ENGTH I IAMETER CHARGE I TOTAL SOURCE OF IDESCRIBEDON WF. IGHT W EIGHT INFORMATION ON PAGE44 44, Model PT , 18' 11 17 7 460# 1830# Reco"e"ed 362, Modi . 1 PicketBoat6lh Year Model S 22'5" 45 1# 3200# Rero errd 37CL, DD8lh Year Model CL,DD 1 27 '6 24" 0# 1 5 00# Rerovered 38( less w. head)89 89, Modif. 2 SS I 3'8 -H 60# I 660# In tell. Rel)L . I 3989, Modif. 1 SS 23'6" 2 ] 600# I 3660# Recovered 3990 O , CA, 27'] 0" 24 " , 0# 3.;20# ln le ll. Rept- . 47CL91, Modif.1 AlC. PT 17'3 17' 7 338# 1730# Recovered 4091, Modif. 2 A/ C, PT 18' 420# I 00# Reco"e,OO 4191, Modif. 3 A/ C, PT 17'4 J7'.'7 522# 1800# Heco"e,:ed 4291, Modif. 3 A/C T 18'9 17'.'7 12# 2 100# Hecovered 42with Mod if 6warhead91, Modi . 3 AlC 1 ' ] 7. 7 4.93# I 00# Reeo"ered 42with Type 3warhead92 SS 23'8" 21 660# ,3369# Inlell . Repts. i 4793 , Modell DD , CA, 29 '6" 24" 10 0# 6000- Recovered 44Modi . 2 CL 6500#94 , Modi . I AlC 22' ] 7':7 867# I 245# ln t ell . Hep s. 4794, JI'lodif. 2 I C 17'4" 17'.'7 462# 1823 # Intell . Rept .. 4795 SS 23'8" 2] " 880# 3520# Intell. Hepls. 48New Kure A/C Un 17'.'7 660# 1870# In le ll . Her ls. 48

nown

2 (SI)ecial ) AlC , PT 18'3': 2 17','7 6,,0# 1800# Recovered 4.697 ?fidgetISubmarines 18'5" 17','7 790# 22U5# R overed 45

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Chapter 3J P NESE TORPEDOES

Section l GENER LSeveral types of Japanese torpedoes bavc been

recovered and possible their character-istics bave been determined by running tbem ontb torpedo testing range at 'ewport, R 1. Perfonnance bas been c timated on tbe torpedoeswbich cou ld uot be ranged because of poor condi-tion. In aeldition to the torpedoes recovered, sev-eral other types have been reported from intelli-gence sources.

Japane e torpedoes are designated by the yearin which U e torpedo was fir t run on a testingrange. Tbe type designation of a torpedo is notchanged because of subsequent modifications aslong a the main engine and diameter of the tor-pedo remain UlO same. s the Japanese use sev-eral different systems for designating the year, thefollowing list i only approximate:

DESIGNATION OF TORPEDO'fype 446th Year Modelth Year Model

Type 89Type 90'fype 91Type 93Type 97Type 2

FIRSTTRlAL19111917191919291930193119331937194.2

Explosive cbarges u ed with Japanese torpedoes,with the exception of Type 94, are the same an nmines and depth charges described on the pre-ceding pages. The characteristics of this explosiveare an follows:

Ty pe 94-00mposed of Oyclonite 40 , and Tri-nitroanisole 60 . This explosive is used in a cantform and is rated as slightly more powerful thanTNT.

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Section 2 TORPEDO TYPE 44An aircraft torpedo powered by a fourcylinder

rcci pl'ocatiJlg sleam engine. and si milar in designto early American an Europell ll models. fwotypes of this torpedo have been reported. butonly onc, designated by the Japanese, Type 44,Mod cl 2 Modification I , bas bec n Iccovered. Information on the other, d ignatcd 'l'ype 44, basbcen dcri"ed from intclli enc sources. Allhoughbclieved to be obsolete, this torp celo may st ill beu cd on P'l' or pickct boats. H leaves n visiblewak e.

The physical characteristics of the torpedoes areas follows,Description

Length Overall-18 ' l1 .Length of I ' ILength of Airflask- 10'.Length of Afterbody l 10".(Inc luding Tail )Diameter- 17'.'7.Total Weight- IS30 Ibs.

~ 1 6 0 Ibs. 'I.vpe 97 or 9 explos ive.Tail Fins 4 .

Range/ Speed-, l300 yards at 36 knots.700 yards at 26 knot.

Exp loder- Typc 91 , Mod el 3, nos , impact.Operation

After the tOIpedo has travelled through thewal l a certain dislnllce, an impeller, 0 the noseof the exploder bein"' rolated by water pressure,111'1118 the exp lode r. Impact WiUl the target shears1wo pins in the nose of the exp lodc l and drives thefiring pin onlo the detonato ') fil'ing the cha.rge.Threc bentle,ers arc attached to the exp loder toinsure its operat ion in case the torpedo shouldst rike the tnrget at an oblique angle, I'athol thanI hcad.on.Safety Precautions

Should this tOI'pcdo be found on the beach or inl l o w wntcl' , it must be considered dangerons.

Movement of one of the bent.le'ers, or the impellermight initinte detonation. Likewi e, movement ofthc torpedo might cause the engine to turn over afew revolutions. driving it fOl'wnrd on the beach.hnnld the hent levers or impeller stTike anything,

Ihe tm'pedo would probably detonate.

Gyro ngle Sefflng Device

igure 9 T y pe 44 torpedo w ith w arh d removed

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Section 3- TORPEDO 6th YEAR MODELA 21 torpedo powered by a four-cylinder recip

rocating steam engi ne, this weapon was designedto be lau nched from emisers, de troycrs and subma l ines. Jt leaves a visible wake and is believedto be ob ' oletc.

The genera l c h ~ r c t e r i s t i c s of the torpedo are asfoUows :Description

Length Overall-2 2 'S .Length of Warhead-3 ' ] .Length of Airtlask-12'9 .Length of Afterbody-6 ' r .(Including Tail )Diameter 1 .Total Weight-3200 lbs.Cha rge-451 lbs. himose.Tail Fins-4 .Range/ Speed- 7650 yard at 37 knots.

10900 yard at 32 knots.]6100 ya rds 25 knots.

Depth Setting : 6 to 52: .Exploder- Type 91. Model 2. nose. impael.

Operations the torpedo tra els through the wate,', an im

peller on the nose of the exploder otates, armingthe exp loder. I mpact witll the In ''get shears twopins in the exp loder and dr ives lbe fi r ing pill ontothe detonator, firing Ule chulge. '1 h1 cObent leversare attached to the nose of the exploder to insureits operation in ea e lhe torpedo should strikethe target at al oblique angle, rather than " headon.

Safety Precautions'hould th is lO pedo be found on Lbe beach or in

shallow watel', it must be co osid rcd dangerous.MOement of one of th e bent..l ve,S 0 lhe illlpellermi ght initiate detonation . Lik ewise, movement ofthe torpedo might ca use the corrine to turf over afew revo lutions, dl i\-ing it [orwul d on the belich_

0uld lbe bill-levers 0 imp lie,' , l .il,e anything,lhe to,'P do would p obnbl) detonnte.

Starting LeverRecess for Plate to Connect Flask and fterbody yro nDIe Setting DeviceGuide S uide Stud

Figu.re 3 Ty pe th year torpedo 1vith -warhead re,,ove d .

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Section 4 TORPEDO 8th YEAR MODELA 24 torpedo powered by a fooreywlder recip.

roea ting steam engine and fired from either eruisers or des troyers. On e of the first Japanese longrange torpedoes, it leaves a visible wake and it isbelieved to be obsolete.

The physical characteristies of the torpedo areas follows :Descrit ion

Length Overall- nknow n (27' 6 reported fomintelligence sources) .

Length o Warhead- Unk nown (3 '9 reportedfrom inte ll igence sources) .

Length of Airftask- I 6'9 .Length of Afterbody- 6' U 'h .(Including Tail)Diameter 4 .Total Weight- 5S00 Ibs.Cba'rgo nknown S 0 lb. 'l'ype 97 explosive

reported from intelligcnce OUlCes) .Tail Fi0s-4 .Range/ Speed- I0950 yards at 41 knots.

16400 yard at 32 knots.21900 yards at 26 knots.

Depth Setting- 6 : 6 to 52: S.Exploder- Believed to be Type 91, 1I1odel 1,nose, impact.

erationAs the tor pedo travels th rough lbe wate r, an impeller on tbe nose of the exploder rolate , arming

the exploder. Im pact wi lh tbe tr get sbears twopin s in the exploder and drives U,e firing pin ontolhe detonator, firing lbe charge. Three bent-leversare attached to the exploder to in ore its operationin ease lhe torpedo houId st r ike the target at anoblique angle, rather than h d OD. Safety Precautions

Should this torpedo be found on the beach or inhallow water , it must be considered dangerous.Movement of one of the bent-levers, or U,e impelier

might initiate detonation. Likewise, movement ofthe torpedo might cau e the engine to turn over afew revolutions, dri ving it forward on the beach.Shou ld the bent-levers or impeller strike anything,the torpedo would probably detona te.

Gyro ng ng Device uide Sfuduide f V r,i,rYJl Fin

Figure I The 24-iltch tYi Bth year lo g r rege torpedo w llh wa rhe d re ,oved.

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Section 5-TORPEDO TYPE 89L 21 torpedo powered by n two-cylinder double

ncting reciprocating steam engine and fi red fromsubmarines. The engine design hears a markedsimi lari ty to t be British Whi tehead to '-pedoeswhich were old to J apa n in 19 23_ 'rb,-ee rno lifications of this torpedo orc believed to exist; howeve I , only Oll e, de. ignl.ltcd by the Japanese Tn1C9, l\'i:oci ifieatio ll I , bas bee n T'ecovered. ' rh e Dth el'two, 'r y pe V, and 'rypc 9, ~ I o d i f i c a t i o n 2. lIa\'I'heen I epol't ed .from in te lligence l 1 l c e s . Th is 101'-p do IClwes a vis ible wake when fired .

The phy ical charnet 'istics of the topedo arcIlS f oll ows :Description

Length Overall fype 9-23'8 _Type 89, Mod ifieation 1- 23'G " _

Length of Warhead-3'S _Length of Airflask l'ype 9-10'5 _Type 0, '-'[od ifica ti on 1-

13 '5",Length of Afterbody- TYllC , 9- J'4".( Illcluling Ta il )

6'4 ,Diameter 21 .

'fypc 9, ?t[odi fication 1-

Total Weig ht- 3GGO Il>s.Charge-GOO lbs. T.'pe 9 1. 9) 0 1 "hililose explo

o ive.Ta il Fins-- l.Range/ Speed- 6000 ya rds at 45 knots.

6550 at -13 knot".10900 Y8l' 8 at 35 knots.

Depth Setting 6 6 to 52 .Warhead- T. o R9, Modifieation 1- 1 ,,-pe

Mod el 2.Typ e RH . nd ' l ' ~ fI,

'- l ' nknown.Exploder- 'l'YI)e '9 and Type 9, Mod ifi 'alion

'- Bclltlc\'cr, nose impact .Type 89, Modi fication l - T.vpe 90. bail. impaet

~ e l ' t i a , fitted on top centerline of warhead.Operation

.As th e 9, Modifi clllion 1, tOJ'pedo travelsth rough the water, pre 'urc depl'csse t he bail ontli exp loder. free ing an wCI'tin l ' i ~ g e r and rotating a n impell el', tPbe rotation of the impeller ar msIh ex plode", and impact of lhe torpedo with thl a r ~ disp ln ces th e inertia t r i g ~ e t)'his f rees afil' ing' pin , whi ch is d r iven dowll\nll'r IIndel' s p ringprc:-;s lIJ'c onto th e detonator , firjng th e chal'g'C.

'I' he opet'ation or the rr ypc and 'r .vpe 9,.\(odifi cnt ion 2 c . ~ is s imihll' to th e 6th Year

o r l r l . As t he torpedo travel s ,"hrollg-h tht: water,ill1 impc ll f 1 on th c nose of the exploder I ota tcs,l r n i n ~ the' ex ploder . Im pAct with th (' lnrr;ret

:-:hei-ll's two pin.' in the exp lode l' ilnd dl'iv s thef i r i l l ~ pin ont o Ihe detonntol' , fit 'int th' ch


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Section 6-TORPEDO TYPE 91A 17':7 torlledo pow ered by an eight eylinder

radial . team c u rrill O fiDd designed for use by aircraft Ilod PT boals, Owing to its length, theType 91 most be dropped fl'om relatively lowbeigbts; otberwise the head or tail would probablybl'eak oiL Th,"'c di1rereut types of the torpecl o andsevel'a l types 01' warheads have be"'n recovered .Becaose Uley V Iy widely in design and operationea 11 type will be discussed sepal'ately on the fol lowing page..., .

" TYPE 91, ) ODIF'I A'l'10. I "Earliest of the Type 9 ) torpedoes recove l'ed. th is

model cun be I'ecognized by I'ivet.,; on warhead .aft rbody and lail. t is a s ingle sp('ed lOl'ped onnd leaves l pal,tly visible wake.

The physical chlll'netel'i tics of the to rpedo areas follows:Description

Length Overall- 17'3" ,Length of Warhead- 3 l ,Length of AiIflas k '11':5,Length of Af terbody- 5'2':5,( Includi ng tl'o i l )Diameter- 17':7.Total Weight- 1730 lbs.

Charg :J:3 lb. , him08e, Type 94 0" 97 e"plo.o i lC.

Tall Fins- i , long hOl'izonlnl , h o r t ... crticlli.Range/ Speed-3300 yard at 42 knots.Depth e t t i n g 6 ~ 6 to ; ; 2 ~ .Warhead l'ype 91, Modificatiou 1.Exploder- Type 90, Model 2, bail. impact-in.

,' 'Iin in pocket on top e nl .-line of wa 'head.Operation

As the to rp edo truvcJ '\ thl'ough the wntCl', pressUl'e depresse the bail on Ule exploder. This unlocks an ill C 'lin t rigger and fr es the impeller. Rotation of the impell er 81'mS the c (p ioder, and imra ct with the target displaces the inertia trigger.This release ' th e firing pin which. driven downwitI'd un de t' spring l I l s ll'ikes the detonator,fir-inl the r lHl l'ge .Safety Precautions

This to rpedo must he co nsid er'cd dnngcl'ol1s ifround in h n l l wntcl' 01' on the bench. l\Iovem ntof the bllil ma y aetoat the exploder and fire the,hlllI C. l id mo,'em Ilt or Ih e torpedo itself may\'uu:-;c the engi ne to LUi'll O\'er Il few I'evolutions.d l i v i n ~ l h ~ lOt'pedo [OI 'W[ l I ' ] on the bench. This,Ino, Inn,\ a('tllatc ih ex ploder. fhin lhf ('Ila r-gp .

Access Hole to Wafer TankWarhead Converted TO xe rcise Head Starting Gear RackAngling Device

Access Hole for Bayonet Joinf Locking RingFig " J J- The h n, 1 aud PT bo 1/ lau nched T y pe 9 J IOJ p e /o.

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Section 7-TYPE 91 MODIFICATION 2This model torpedo has eight tail fius rathel"

tlllln (Olll', and is ct.luipped with anti l'oll flipperson ei ther side of tho alc I'lJody. Th e wal heud uudIlftcl'hody arc or weld ed instead or riveted con

~ t n l ( : t i o n t has u Single Speed Hnd It. un s a v i : ~ i b l ewake.

Th e physicfl i eh'II'll cler ist ics or tile LOl fwdu a rc asfo llows:Description

Length Overall- IS'.Length of Warhead I O" .Length of Airflask- '11':;,.Length of Afterbody ' 2':" ,(Including 'I'ail )DiameteT- ] ' . ~ rTotal Weight- I. 40 Ihs.

Charge-- ' 0 Ibs. himose, 'rype 94 or 97 explosive.

Tail FinsRAnge/ Speed-3300 yards at 42 knots.Depth Settiug6:6 to 52: " .Warhead- Ty pe 91. Mndifi eaLio l1 2.Exploder l'ype 90. :Modcl 2. hail J impnct. in .

t'l'ti :l , in pocket 011 top ccnl eT lin e of wHI 'head.Operation

'l'hi, tn rp ('do O p C H t c ~ in the SHill manner as' I,v l' l' I. Modificntion I described nil the precedingpag'rs. II has been replaced in );v the Typenl , ~ [ d i f i t i o n 3, and Type 2.Safety PrecautionsSHIlIC as Type 91 }.IodifientioD I .

Guide S Gro ngling Deviceccess Hole for Wafer Tank F Botfle Filling Hole~

ccess Hole for Balance Chamberof Anti-roll Flipper

ccess Hole for Bayonet Joint Locking RingFigure J4 Type 91 Mod/fiea No 2 torpedo witb wnrbead rentoved. Note Ibe 8 t if fim nlld tb. pivotpoint fO I tbe altti-roll flipper-. Tbis flipper has been removell frotlt the torpedo.

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Section 8- TYPE 91 , MODIFICATION 3This Hlodel IOI'PCliu ha:. bCl'n rec{w l'reti with tlu'ee

e1i/ren_nl l.."pcs or w H l h c a d ~ . Two of the wal'hruds.de,


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Th e Typo 00 , Model 2 exploder arms and firesin th e sum e manner as described for the Type 91,,\[odifiention 1 tOl pedo,

Th e hycilop lane explode l allows tbe torpedo tobe se t lit depths that will in nre detonation nndel1he talge1. rnther tban on the ide, t sbould fireHt fh p (' nd 01 it " 1"1111 due to the c ~ t : : i e of tensionon III< hv l ophl i t lowi ng cahl

TORPEDOES TYPE 91

afety Precautions''his torpedo must be ~ i d c to be dan crous

if fOlln d in shallow Welter or on a bench. [ovc-ment of th e hydroplane towing cable may explodethe chAl ge. Safety precautions descl'ibed underTOlpedo T pe DI. ,[odifieation 1. should be ob,

e d

-.

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Sedion 9- TORPEDO TYPE 93A t I" LUl'pcdll powel'ed by H t wo cylindcr d o u b l e ~

Heling I'(:c ipl'ocatin s tea m ng-ine and launchedfl'om destroye l'S and cl'ui ers. 1.'he w,e of oxygenin plnec of compressed ail' e liminates PL"lClicaUy 011gas bubbles, l e l l \ i l l g olll y a slightly visible wuke.I ts usc nkio gives this lOr)) do a high speed undlong runge. Only one type of Ul is torpedo. d c s i ~naled by the .Ja pune e us Type 93 , Model l . Modifiealion 2. hn. be n "('eO\'el ed 10 dale.

'fh l p h , \ s i c h , l I U C H r i N t i ~ or Ih ' tOl'P 'do ill'Cfollows:

DescriptionLength Overall- 29'6".Length of Warhead--4'7".Length of Airtiask- 1S'1 " .Length of Afterbody- G'lO".I ln ellldin T"il )

Diameter-2 4 ".Total Weigbt-600U-u;'OO Ius.

b a r g e l O ~ O lb. Type :/; explLTail Fins - .Operation

1\ :, t i l ( ' torpedo trave l os tlJt'ough tbe water, pres"'III" Ul'PI 'CSSCS th e uail 011 the xploc1cl', unlockingUti in I,till i g ~ e nd otates the impeller. Thi1I1' Ill S tht' ('xp lodcl', Impnct with lhe target dispilll ('s til(' in ertia tl'it g'Cl' Hnd I'rec.'i the firing pinwi1i(h. Lid"en downward nnder sp ring pressu re.Nll ikl' Ihe uelolHllor. firing tilt. l 'IIIII'ge.Safety Precautions

Shollid th is torpedo he fou nd in sha llow waterOJ' un I h b neh. it must be considcl'ed dangerous.) l o\'('men1 of tit torpedo might sctnute the expln(lel', fi "ing the clHlrge.

Figu re J This 24it,ch dest ro yer or cr-,, ;ser {aw"ch ed torpedo is one 0/ tbe largest 1u,derwa ter ord a ceUNtlS used by the Japall t se . Its use of oxyge . instea d of co.",pre$lt d air allolUs t to travelwi th prac tically 110 v isib le w ake,

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Section l l - TORPEDO TYPE 2 (SPECIAL )Powered by an eight-cylinder rad ial steam co-

gine, th is 17':7 a ircraft torpedo is belie ed to bavereplaced the Type 91 torpedoes.

The physical cha l actc ristics of the torpedo nre asfollows:

DescriptionLength Overa ll - l '3 .Length of Warhead-G .Length of Airflask-7'O':b.Length of (Including Tail )Diameter- 17.'7.Tota l Weight- l SOO Ib8.Charge-G50 lbs. 'fype 97 explo h e .Ta il Fins-- l .Range/ Spee d- 3000 yards at 42 knots.(Estimated)Depth Set ting- S :a to ;;9:4.E xploder- Type 2, 0 1 'f ype ~ O . bail impact in ,

erti a, in pock l on top ccntcl'line of wa l h ead.

ccess Hole

Ope ra t ionV-h en Ute torpedo is laullched, a s


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Section 12 UNRECOVERED TORPEDOESSeveral additional types of Japanese torpedoes

are be lieved to be in ervice. The data on cbaracteristics and description of these torpedoes, takenfrom intelligence "eports, are given on tbe following pages.

TORPEDO TYPE 9A 24" torpedo powered by a two-cylinder double

acting reciprocating stcam engine and des igned foruse by destroyers and' cruiscrs. Tbis torpedo haslargely been replaced by the Type 93 .

General characteristics of the torpedo are asfo llows:Description

Length Overall- 27'10"_Length of Warhead-3'10 _Length of Airfiask-13'1 .Length of Afterbody-10' l l .(IlJeluding Tail )Diameter- 24"Total Weight- 3520 Ibs .Range/ Spee 8752 yards at 45 knots.

10940 yards at 42 knots.16410 yards at 32 knots.

Charge-8S0 Ibs. Type 94 or himose explosive.Depth Setting- 7' to 59'.Exploder- Type 90, bllil , impact-inertia in

pocket on top centerline of warhead.Operation

s tbe torpedo travels tbrougb tbe water, pressure depresses tbe bail, unlocking the inertia-trigger , and rotates the impeller. Tb.is arms tb.e exploder, and impact with the target displaces theinertia trigger and releases the firing pin. Underspring pressure, the firi ng pin is driven downwardonto the detonator, firing tbe charge.Safety Precautions

Tbis torpedo mu st be considered dangerons ifound on the beach. Neitber tbe exploder, nor thetorpedo itself should be moved, as movement mayinitiate detonation.

TORPEDO TYPE 92A 21" torpedo powered by an electric motor and

dcsigned for lise by submarines_ This torpedo isreported as trackless, firing on either impact or

magn etic actuation. It is believed to be patternedartc,' n GertOnn electric torpedo.The physical chllracteristics of ti,e torpedo are asrollows :Description

Length Overall- 23 'S" .Diameter 1 .To tal Weight- 33 69 Ibs.Charge-G60 Ibs. Typ 97 explosive.Range/ Speed yards at 30 knots.( Wh en baUCI'ies lI 'e p 'e- warmed )

3300 YII"d at knots.( Wh cn baue 'ies 1I,'e not prewarmed )Ex ploder- I IIIpa ct or magnet ie

OperationNothing is kn o\\'n about the operation of this torpedo. It is 'epo,ted as producing a distinctly

whining noise at short distaDces.Safety Precautions

This IO"pedo mu st he p 'es umed dange rons i1foun d in shallow wuter or on the beach.

TORPEDO TYPE 94'1'\\'0 lIlod els of this 17'7 aircraft torpedo, desig

nated by the Japanese as Type 94 , Modification 1a nd Type 94 , Modification 2, bave been reported_Ge neral characteris tics of the torpedoes are as

foll ows:Description

Length Ov era ll- Type 94, Modification 1-22'.Type 94, Modification 2--17'4 .

Length of War head- Type 94, Modification 2--5' .

Diameter- 17' 7.Tota l Weight- 'I'YI)C 94, Modification 1-3245Ibs .

Type 94 , Modification 2--1S23Ibs.Charge- 'Iype 94, Modification 1-867 Ibs. Shi

lUose O' Type 97 explosive.Type 94, Modification 2--462 Ibs. ex

plos ive.Range/ Speed- 1'ype 94, Modification 1-4923yards at 45 Imots.

Type 94, Modification 2--3300y ll rds t 42 knots.

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JAPANESE UNDERWATER ORDNANCEOperation

Nothing is knowlJ ubout th e op erat io n of th estorpedoes. Ty pe 91, d i f i J , is repor l 'd toha ve un nil' spcc tl I ) m.e of J. I .j kn o t.s ut nn altitudeof 5 feel.

TORPEDO TYPE 95A 2J tOI') cdo powe l'ed b.l' u two-cylinder double

Heling rec ipl'ocnting s team eng ine und fi red fr omsubmarines. Th e use of oxygen in place of c mpl 'cssed ai l' ' e i j only 1.1 s lightly isiblc wuke.

PhYl) icul huructeris ties of the torpedo UI' " 3.-;follow8 :Description

Length Diameter 1 .To ta l Weight- 35tu II .Charg 0 Ibs. of Ty pe 97 explos ive.Range/ Spee d4 00 ," lrds 8t 3 knots .

7100.1'111'(1 " l i t 36 knots.

OP 1507Operation

Not hi ng known Ilbout UIC operation o[ Uti '[OIlledo.

TORPEDO TYPE NEW KURE"Vc l'Y litt le is known nbout th is air C l'u(L to r

p do. J i.s repolted us weighing 1 70 Ibs . andcurrying I I chlll'ge of 6UO lUi;. of Ty pe 97 explosi '\ .Th e I'lln ge is 160U YUl'd s l i t kn ots, and the airxpct d rclca."ic is IVO kn ots a l an I.Iltitude of 160 ree l.

MISCelLANEOUSInl'Ol'lllul ion hlts bee n received on t wo ad litiollul

lU,opcti oC- I from in l -lligcncc sour ces whi ch it is helic"ctL wOl'lhwh il lo pl jnt he,e. 'I'lie 6rsl or the."ICix fil'cd fr om P'I hOllls which has (I gyro-controlCHPll blc or s ln : ing the 10"1)(' 0 on a zi g-.lug courseIII 1 1 I 1 or I,j .

Th e ~ e e o l l d torpedo fh ell 1'1'0111 IUlld I IIS('. IIlIhc: ; I:IIH.I III:u; /I ..Ill ig or 72 00 y nl'ds at GO knot. S.' i'her ai" Iwo t,"pes or tllifo; toq wdo, one l a' longand Ihe oth C' J' 11'4 101lff', The diumeter for both

"c pol'ted as 14"-15" .

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54/54

DISTRIBUTIONI{ equests [0 uddiliolU,l copies of 01 130; shou ld b submitted Ol NAV nD

0 101 I, OHDNANC I: PI BLI( JI I'WNS AND ( ) H ~ Q O N Inthe nN lI'cst Ordnunce Pllblication l ) Dislrihlliion Cent er : Ynrci , \V as ll. 25,D. C.j Adnk. ~ J \ . I 8 s k n : 1inl'c hdand . (,ulif.; :hUllll Island. Marianas Pear l Jlnl - r , T. II . ; ~ l n n l l Admil lllty Islnnds. Di stribution Ce nt er tllHiling IHI (( I'esses shou ld be obtu inrd f,'om Li st 1 nn or the . tllndHl'd ~ 8 \ y Distributiolll,isl , or from th e re,'en' side or NA VOIlD 1.DI TI l IBI T lON :

;:;'lIndR,'d Nav.\' Disl r ih tinn I,isl Tn. 28 ( ' ) li nd 31 (R ); l'lI l i('s \lnl ( s. ) ntliCl'wis' noted.

I . i t .n,c,f, h,j ,l.n,q,I',t,lI ,W a.b.-c ( 1 ,e, l m 1 .1 ,11 . h,m II .nn ,qq ,IIt1 ,vv ( I ), vv (4 ) iH o. n ( I'E(,IAI, 1.1;:; 1 0 . 1') ; 1().(2 i\ ,opi,s) . o ; I 1 11 ( B Ships, NO ) ;14 .3 II ppliellble Add e ce;;.

II Ma y 20M J1) U. S GOVERNMENT RINTING OFfiCE: 1904$-6109.0- 138

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Japan Navy Underwater Ordnance 1945 [Op 1507]