Anti-armor weapons of the japanese infantry.

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#1

Kawamura Type 97 cal. 20 mm



The desing of this heavy antitank rifle belong to the ing. Masawa Kawamura who start the development in 1935.

For 1937 the desing was completed and the weapon was officially adopted for the army in 1937 ( some were bought for the Navy also). The working mechanism of this rifle is semiautomatic with an roting bolt wich is gas operated. The loading is made from the top (bren like) and in accept an 7 shot magazine.

The weight is about 55 kg , in order to carry it quickly 2 handlebars resembleming a bike could be atached in the front and the rear pad. For aditional protection in the shooting and 4 mm steel shield can be added, in this case the weight climbs to 66 kg.

The weapon is very powerful, it shoots a 20mm ( 20 mm round x125mm case) specially designed cartrigde, the muzzle velocity is about 815 m/s and is stated that it could penetrated the light M-3 stuart from 150 meters away.

#2

Hi.

Some additions:

The typ 97 20 mm automatic gun (original designation) was a side development of the type 98 20 mm aa-gun using the same muzzle break and other design parts. The total weight was 55 kg, 72,5 kg with handles. The shield wasn´t used often to increase mobility.

In 1943 the rifle was reworked to spare raw materials lowering the weight with handles to 59 kg.

The crew of one rifle was 4 men, gunner, loader, 2 ammunition carrier. A sqad consisted of two rifle teams, 1 squad leader (NCO) and 1 runner.

During transport the rifle was disassembled in two parts and carried by three horses with 150 shots. With cavalry units the rifle was loaded on 2 horses with 105 shots to increase mobility.

The type 97 ap-round wit a muzzle velocity of 865 m/sec could penetrate 30 mm/90° on 350 m and 20 mm/90° on 700 m. Additionally the type 98 20X141 mm he-round could be fired against soft targets like field fortifications etc. The main charge was HMX and Nitropenta. Maximum range with the type 98 round was 4000 m.

Yours

tom! :wink:

#3

Great info here. I’m wondering about the production totals and of how common these weapons were. My guess is that they were fairly rare.

#4

Hi.

Type 94 37 mm rapid fire infantry gun:

This gun was planned from 1933 on as replacement for the type Taisho 11 37 mm infantry gun. It should be used as infantry gun and anti-tank gun. Other specifications were low weight for easy handling, an armour shield and transport with a light towing vehicle or 4 horses.

The first prototypes were built in 1934 with rubber tires for high transport speed. During tests the tires were found very vulnerable for small arms fire so they were replaced by wodden or metal wheels with rubber band.

The gun worked semi-automatic making a maximum rof of 20 rpm possible, 15 rpm cyclic. The total weight was 327 kg. This was found acceptable. The 4 mm thick shield was often removed to spare the weight making the gun more mobile. Two hande bars could be attached on the lafette for man transport.

In 1936 the gun was first used in China. The 0,49 kg type 95 he-round was found useful against soft targets on ranges up to 5000 m. Due to the lack of armoured vehicles in the chinese forces the ap-abilities were not necessaryly needed.

Shooting range tests showed a problem with the early ap-round lowering the penetration ability to 20 mm/90° 350 m. In the mid-thirties additional research was made on this problem leading to a new projectile introduced around 1937 giving the gun a penetration ability of 40mm/90° on 300 mm and 25 mm/90° on 900 m.

The type 94 gun was also used in a modified version as type 95 37 mm tank gun on the type 95 light tank Ha-Go and the type 94 tk special tractors and the early type 97 tankettes Te-Ke.

The Nomonham Incident showed the inefficiency against modern medium tanks as used by the Soviets. The high rof made the gun very useful against light ands medium field fortifications but due to the small caliber almost useless against heavyly fortified or concrete targets.

As the road transport speed was limited due to the wheels used a special transport carrier was developed in the late 1930´s. The gun was fixed on this carriage and then a road speed of up to 52 kph instead of 25 kph was possible.

A gun section with the type 94 rapid-fire infantry gun consisted of 11 men, leader, gunner 1 (giving direction), gunner 2 (directing gun), 2 loaders, 6 ammunition soldiers, also for close defence, and 1 driver. A gun platoon was two gun sections, section commander, 2 runners.

A Battalion anti-tank/infanry gun company consisted of two gun sections, company headquater ( Commander, 7 runners and orderlies, 1 NCO personnel administration, 1 NCO supply, 1 NCO arms and equipment, 2 medics), Ammunition platoon (commander, 20 NCO´s and men) and observation section (1 NCO, 6 men).

Yours

tom!

#5

Hi.

Some 400 were made. The japanese army realised early that the rifle wasn´t very efective compared to the relatively high weight. Nevertheless the production was never cancelled totally.

Yours

tom! :wink:

#6

Very good info and pictures Tom, only a thing…

The type 97 ap-round wit a muzzle velocity of 865 m/sec could penetrate 30 mm/90° on 350 m and 20 mm/90° on 700 m. Additionally the type 98 20X141 mm he-round could be fired against soft targets like field fortifications etc
.

The cartrigde used by the Type 97 wasnt 20x141 mm but 20x125 mm.

Ap shot.

The larger 20x141 round belong to the Army AA cannon type 98.

And this is a Type 97 captured by the russians, it had the handlebars but no shield.

#7

Hi.

The 20X141 mm was the type 98 he-round… hm.

Maybe the author meant the projectile of the type 98 he-round of the aa-gun, used with a 125mm cartridge. That would make more sense to me.

Yours

tom! :wink:

#8

Is probably that, because the cartrigde cases were NOT interchangeable.

[LEFT]Lunge Hollow Charge:

This was a semi-suicide weapon ( not intended as it but the close blast and fragmentation effect made it in that way)
A hollow charge mine was attached at the edge of the pole. Gripping the pole, stab it against tank and the mine is exploded.


[/LEFT]

#9

Hi.

From the US TM 9-1985-4:

I renamed it with german designations.

from top:

  • wooden handle
  • safety pin
  • shear wire
  • connection cylinder
  • striker
  • threaded connecting ring
  • detonator
  • steel case
  • explosive filling
  • steel cone
  • bottom plate
  • legs

pull out safety pin, struck it against target, shear wire breaks, detonation

penetration: 130 mm

A similar construction with more chances to survive the explosion but only for lightly armoured vehicles and soft targets:

Suction-cup mine:

same source

from top:

  • pull igniters
  • safety fuze
  • blasting cap
  • connecting sleeve
  • primacord
  • handle
  • charge container
  • cast explosive
  • blasting cap
  • suction cup

total length: 1800 mm
charge container: 135 mm X diameter 112,5 mm
charge weight: 2010 g
charge type: 53 % RDX, 47 % TNT

Two delay elements/primacords are used parallel to make sure the explosion happens.

suck mine against target, pull friction igniters, safety fuze delay time 10-15 sec, upper blasting caps detonate igniting primacord, lower blasting caps ignite explosive

edit:
Some of these devices were used during the December 1944 airbourne operations against US airstrips on Leyte and the Philippines

Yours

tom! :wink:

#10

Intreresting this last one, I dont have any knowlegde of it, seems to be a “blast effect only” weapon, rather similar to the german Geballte ladung or the russian RPG-40. ¿ wich was their japanese designation?

More info I ve found in www.lonesentry.com.

LUNGE MINE

Perhaps the oddest of these antitank charges is the so-called “Lunge Mine” encountered on Leyte Island. This weapon—an armor-piercing charge on the end of a pole—derives its name from the way in which it must be thrust against the side of a tank in order to detonate.
The mine is an explosive-filled, sheet-steel cone, about 12 inches long and 8 inches in diameter at the base. As in all hollow charges, the cavity in the bottom of the cone tends to guide the force of the explosion out from the bottom of the cone and against the armor plate of the target. A metal sleeve extends from the top, or point end, of the cone and houses the simple firing device—a nail on the end of the broomstick-like handle which fits into the sleeve. The detonator is little more than an ordinary blasting cap set into the top of the cone, where the nail will strike the cap if the handle is jammed down in the sleeve. During transport, however, the handle is held immobile in the sleeve by a simple safety pin inserted through the sleeve and handle. A further safety feature is a thin holding pin, or shear wire, similarly installed through sleeve and handle. Three legs, 5 1/4 inches long, are attached to the bottom of the cone; the Japanese claim that these legs increase the penetrating power of the weapon. The penetrating effect of the charge is greater when the explosion occurs a few inches away from the armor.
The Japanese suicide soldier will use the Lunge Mine as he would a rifle and bayonet, thrusting the three legs of the mine base against the side of the tank. The mine explodes on contact.

The Japanese suicide soldier has been taught to wield this weapon as he would a rifle and bayonet. The prescribed method of operation is for the soldier to remove the safety pin as he approaches the tank to be attacked, and to grasp the center of the handle with his left hand, and the butt end with his right. Then, holding the stick level, with the mine to the front, he lunges forward as in a bayonet attack, thrusting the three legs on the mine base against the side of the tank. The shock of contact will break the shear wire and the striker nail will be shoved into the detonator cap, thus exploding the mine as it is held against the armor. At this point the Jap soldier’s mission ends for all time.
From experiments conducted in Manila, the Japanese claim that the 6 1/2 pounds of explosive in the mine is capable of penetrating 6 inches of armor, provided that the mine contacts the plate squarely. However, if contact is made at an angle of 60 degrees, the mine is reputed to penetrate 4 inches of armor. To date all attempts by the enemy to use the Lunge Mine against our tanks have met with failure.

#11

I seem to recall the japs using this weapon in MOH Rising Sun.

#12

Type 99 AT Mine

This AT mine was thrown to the tank, or attached by its magnets. Four black boxes around the mine are magnets. One Type 99 AT Mine could destroy a 20 mm thick armor and two piled mines could destroy a 30 mm thick armor. Similar in use as the german hafthohlladung but without the benefit of the shaped charge.

Size : 120 mm (diameter) x 38 mm (thickness) Weight : 1.25 kg Explosive : TNT 680 g

#13

Hi.

from top left:

  • safety pin
  • compression spring
  • percussion cap
  • Locking balls
  • delay pellet
  • striker
  • detonator
  • explosive
  • canvas cover
  • magnets

Description:

The mine resembles a canvas cloth bag, disk shaped, with a snap-fastened flap on the outer edge for inserting the eight blocks of explosive (cast mixture of 50-50 RDX-TNT). Opposite the filling flap on the outer edge of the mine is a metal adaper which is externally threaded to receive the fuze. Four equally spaced permanent magnets are attached by khaki webbing to the outer edge of the mine body.

The mine is packed two to a wooden box complete with wooden shipping plugs in in the fuze adapters. The fuzes are enclosed in tubular metal cases sealed with a paper band and tear string. For carrying on the field, the mines are packed individually ina khaki-colored cloth pouch.

The fuze contains two springs, a compresion spring and a firing pin spring, the latter of which is contained in a firing pin sleve. Four steel retaining balls fit into holes in the firing pin sleve and notches in the firing pin, retaining the position of the firing pin.
A fuze cap provides a base for the first spring and is grooved on the inside about one-third of the way up from its base.
There is a safety pin which passes through the fuze body just below the base of the safety cap and between the striker and the percussion cap.
The powder relay train threads into the base of the fuze body, and the detonator tube threads over the base of the delay train container.

Operation:
The fuze is carried separately and is secured to the mine by a locking ring. In use the safety pin is pulled, the fuze cap given a sharp rap, and the mine either placed on or tossed on armour plate within a range of ten feet.
When the fuze cap is forced downward against the compression spring, its groove aligns with the retaining balls. The tension of the firing pin spring forces the retaining balls into this groove and also forces the striker down onto the percussion cap.

Test detonations of this mine indicate a distinct “Munroe-Effect” at the junction of the inner edges of the explosive blocks.

There were some tests with a similar mine type with ring-mounted explosive filing leaving a central hole increasing the Munroe-Effect. The magnets were placed on the canvas cover not on the edges of the mine. Development was ceased in 1941 as the penetration was only 35 mm.

Yours

tom! :wink:

#14

Very nice, you always seems to have very good pictures of this devices, thanks. :rolleyes:

#15

Hi.

I´m studying the japanese military of ww2 for 4 years now and I digged out some very interesting facts and especially pics.

Type Ra 37 mm at-gun:

From 1936 on the japanese army captured a number of german 3,7 cm Pak Rheinmetall (official designation, 35 or 35/36 is a post-war addition) in China and in various border incidents between Manshuria and Mongolia/Soviet Union. As this gun was far superiour to the japanese guns and with a relatively low weight the gun was introduced officially.

The guns were equipped with japanese optics. To increase mobility a small guidance wheel could be attached to the trails. Additionally the gun shield (120 kg) was often removed by the troops to lower the weight.

The ammunition was copied from the rounds captured and had a similar effect.

The gun was used in China and also on Guadalcanal and replaced the type 94 rapid-fire infantry gun in regimental at-companies.

type 1 37 mm at-gun:

After capturing the type Ra at-guns the type 94 rapid-fire infantry gun was reworked using design elements of the captured guns. In a first step the chamber volume was increased to increase the propellant weight and thus to increase the muzzle velocity. The tests showed an increase in penetration but the total penetration ability was still unsatisfactorily and due to the heavier recoil an enlarged recoil mechanism was necessary increasing the weight of the gun unacceptable.

Nevertheless the army decided to mount the improved barrel on the mounting of the type 95 37 mm tank gun and introduced it as type 98 37 mm tank gun with a penetration ability of 25 mm/90° on 500 m. This gun was used on type 95 light tank Ha-Go, type 94 tk special tractor, type 97 tankette Te-Ke, type 98 light tank Ke-Ni and type 97 command tank Shi-Ki (mounted in the bow).

In a side development for the tank troops the chamber walls were strengthened to allow the use of a propellant with higher energy. This gun was named type 100 37 mm tank gun. As the penetration was only increased slightly to 26 mm/90° on 500m only few guns were produced and used on the type 95 light tank Ha-Go and the early type 2 amphibious tank Ka-Mi.

As the Nomonhan-Incident in 1939 showed the at-abilities of the japanese forces were weak the decision was made to increase the maximum allowed weight for a light at-gun. So the type 100 gun was reworked. The breech was remodelled and the barrel length was extended from L/36,7 to L/45,9 (some sources mentions L/50). This lead to a significant increase of the armour penetration to 44 mm/90° on 500m. On the other hand the weight increase could be limited to 27 kg compared to the type 94 37 mm infantry gun using lighter materials.

The gun was introduced as type 1 37 mm at-gun in 1941. The total production numer is unknown. It replaced the type 94 37 mm rapid-fire infantry gun in the regimental at-companies.


type 1 37 mm tank gun and coaxial type 97 7,7 mm tank machine gun in the gun mount used with the type 98 and type 2 light tanks (mounted on a carriage for tests)

The same barrel was introduced on a slightly reworked mount of the type 100 tank gun as type 1 37 mm tank gun, too, replacing its predecessors. The type 1 37 mm tank gun was used on the type 95 light tank Ha-Go, the type 97 tankette Te-Ke, the type 98 light tank Ke-Ni, the type 2 light tank Ke-To, the type 2 amphibious tank Ka-Mi and on the type 5 tank prototype Chi-Ri (bow-mount).

Yours

tom!

#16

Hi.

Type 1 47 mm at-gun:

In 1938 the japanese Kwantung Army captured some soviet 45 mm at-guns. The Army Technical Bureau started some intense testing. The gun was found superiour to all own models and as it was based on the already introduced type Ra 37 mm gun (it was in fact an upgunned version of the 3,7 cm Pak Rheinmetall) the decision was made to start the development of a similar weapon with a caliber of 47 mm.

There were two large handicaps slowing down the development:

  1. The Army High Command saw no use for such a gun
    Therefore the development was seen as “basic research” and not supported properly
  2. The main requirement for all infantry support weapons was a weight limit to allow easy transport of the weapon by the crew.
    Even the type Ra at-gun reached the limit and so an equilibrium had to be found between weight and effectiveness lowering the ap-abilities of the first test guns noticeably.

With the devastating results of the Nomonhan-Incident in 1939 showing a lack of Antitank defense ability of the infantry the weight limit was dropped and the development of the 47 mm at-gun was fastened . In September 1939 the production and testing of the final construction started.

The gun was in general an enlarged version of the type 94 rapid-fire infantry gun using the same breech type and firing mechanism. Two tires allowed a maximum transport speed of 50 kph. The shield was mounted angled. With a total weight of 750 kg the gun was too heavy for crew transport and the penetration of 50 mm/90° on 500 m was compareable to at-guns of other countries of that time.

Production started in Spring 1941 at the Osaka Army Arsenal which tested all guns and supervised allmost all artillery and at-gun production for the japanese Army.

The guns were used in the regimental at-companies.

During 1942 the few guns produced were found useful against the lightly armoured allied vehicles and light tanks but useless against the Mathilda II. After the US Medium M4 reached the battlefields the guns became almost totally useless.

Additional ammunition research lead to an increased penetration of 45 mm/90° on 700 m but the frontral armour of the Sherman still could only be penetrated below 50 m and the side armour below 250 m.

Some 2300 guns were produced and used until the end.

The gun was also mounted on an enlarged gun mount of the type 98 37 mm tank gun and introduced as type 1 47 mm tank gun. This gun was used with the type 97 medium tank Shinhoto Chi-Ha, type 98 experimental medium tank Chi-Ho, type 1 medium tank Chi-He, type 3 amphibious tank Ka-Chi, and type 5 experimental amphibious tank Ka-To in bow-mount.

Yours

tom!

#17

This 47 mm weapon was the most close that the japanese have to a decent Antitank weapon, still weak.

Very good Information as usual Tom. :cool:

Type 2 AT Rifle Grenade

In 1942, a new AT grenade was bought by a disguised merchant vessel to Japan from Germany. It was a hollow charge grenade and a gift to Hirohito from Hitler.
In AT grenade, there were two kinds of caliber, 40 mm and 30mm. The inner barrel of the grenade launcher was rifled and that rifling was reproduced in the rear of the grenades to give the spin stabilization.

Though it was officially anounced that it can destoy a 40 mm thick armor, actually it was almost useless againt Allied medium tanks.

#18

Hi.

40 mm hollow-charge rifle grenade:



impact fuze

from top:

  • booster
  • detonator
  • creep spring
  • clock spring
  • striker
  • arming sleeve
  • striker carrier
  • arming spring

data:
over-all length: 202,7 mm
maximum diameter: 40,2 mm
total weight: 353 g
filling: 50/50 RDX/TNT
weight of filling: 108 g

description:
This grenade is a copy of the german “große Gewehrpanzergranate” and is fired from a cup launcher attached to the standard 6,5 mm rifle.
The body is cylindrical with a semiconical shaped head. It is made in two parts threaded together and fitted with a ballistic cap and cone to give the kollow-charge effect. The forward part contains the explosive charge cast around the cone. The after part which is made of aluminium had a rifled collar near the base and contains the fuze ans explosive train.
The fuze is held in by a base plate with a protruding spigot which is screwed into the base of the grenade. The fuze is held in position by the spigot. The needle firing pin is secured in a housing that has four stirrup-like springs protruding from the side. Around the housing is a setback spring held in by an arming sleeve which has two sets of grooves notched on the inner side. Holding the firing pin stationary is a coil clock spring which is held in by the arming sleeve. There is also a creep spring between the firing pin and the detonator.
The propellimg charge consists of a special cartridge with a wooden bullet.

operation:
On firing, the setback causes the arming sleeve to move down and it is held down by the stirrup springs which engage in the groove in the arming sleeve. Centrifugal force then causes the clock spring to expand and the fuze is armed. On impact the firing pin housing overcomes the creep spring and moves onto the flash cap setting off the detonator and booster

The 40 mm rifle grenade was also used in CBUs as type 2 1/2 kg hollow-charge bomblett with a diferent fuze and an attached fin.

30 mm hollow-charge rifle grenade:

data:
overall length: 158,6 mm
maximum diameter: 29,97 mm
total weight: 233,89 g
filling: 50/50 RDX/TNT
weight of filling: 49,6 g

description:
The explosive head of the 30 mm grenade is of the same type construction as that of the 40 mm grenade, but on a smaller scale. The spigots of both grenade types are identical with the exeption of the threads on their forward ends. Both grenades use the same fuze

operation:
The operation of the 30 mm grenade is identical to that of the 40 nn grenade.

Both rifle grenades were fired by the type 2 cup-type rifle grenade launcher, see next post (due to limitation of pictures per post).

By the way, the pic panzerknacker posted in his last post shows two versions of an experimental 45 mm hollow-charge rifle grenade and on the right the final version of this grenade for the type 2 launcher

Yours

tom!

#19

Hi.

Type 2 rifle grenade launcher:

The type 2 grenade launcher is a copy of the german “Schiessbecher”. Examples of the German Schiessbecher and its antitank (hollow-charge) grenades were delivered to Japan by blockade breaker. Two blockade breakers with identical cargos were sent to Japan to improve the odds of the mission’s success. The blockade breaker Tannenfels arrived in Japan first, on 12 May 1942. By August of 1942, the Type 2 and its hollow-charge grenades were being produced, and some examples had reached Guadalcanal by October of 1942. Production of the Type 2 grenade launcher was halted in 1943. Approximately 49,000 Type 2 grenade launchers were produced from 1942 to 1943. This figure is very small when compared to the more than 1.4 million Schiessbecher that were delivered to German troops from 1942 to 1944.

All known examples of the Type 2 grenade launcher were made by the Chigusa factory of the Nagoya Army Arsenal. The Type 2 was used with the Type 38 6,5 mm or Type 99 7,7 mm rifle.
The physical characteristics of this launcher remained stable throughout its short production period; however, variations in the launcher’s markings have been identified. Early launchers were dated using the Showa era, and later launchers were dated using a secret code.

Two hollow-charge grenades were used with the Type 2 grenade launcher–a 30 mm version and a 40 mm version. Two types of launching cartridges were used; one had a wooden bullet, and the other had a crimped case mouth. The Type 2 grenade launcher was issued with a canvas carrying pouch, barrel wrench, and canvas pouch for carrying 10 rifle grenades.

Yours

tom!

#20

Hi.

experimental 57 mm at-gun:

Realising that the type 1 47 mm at-gun will not be capable of destroying the newer allied tank designs the japanese Army started the development of a 57 mm version in April 1941. The gun should also be used as main armament of the succesor of the type 1 medium tank Chi-He.

The type 1 at gun was enlarged to cope with the higher recoil forces of the 57 mm gun. This increased the weight to 1600 kg which was indicutably high. All tries to lower the weight meant to lower the penetration ability. The last design could only penetrate 60 mm/90° on 1000m at a weight of 1540 kg.

The japanese Army had to realize that a good at-gun-design would be too heavy to be used with the actual infantry doctrine. The development was stopped in 1943 and the capacities were used to design a mobile, self-propelled at-weapon.

experimental 37 mm at-gun Raku:

In early 1942 the japanese Army started this project based on the type 1 37 mm at-gun for the planned airbourne regiments. The main task was to develop a lighter and smaller gun with the same penetration ability as the type 1 at-gun. The gun should be disassembleable to be packed into two containers which should be dropped from transport aircraft.

The wheels were redesigned with stabilising metal circles. Using a small box carriage and a smaller shield the total weight could be lowered to 243 kg. The efficiency was compareable to the type 1 at-gun but this weapon was found too weak to get used in further battles.

The design was cancelled in 1943.

Yours

tom!