Section I. INTRODUCTION
1. In general, the development of Japanese weapons may be divided into periods, each of which follows a war.
2. The progenitors of current Japanese weapons, as well as some of the weapons still in use, were designed between 1905 and 1912. A few models were modified in 1914-1915. Developments of the First World War were noticeable in a group of weapons developed in 1921 and 1922. Then in 1925 began a great program of redesign which finally included all Japanese weapons of every description.
3. All categories of artillery were redesigned between 1925 and 1936. Infantry mortars were redesigned between 1929 and 1939, and automatic weapons, with many new weapons added, between 1932 and 1939.
4. Although no weapon designed in 1940 is known, a modern, efficient 47-mm gun was produced in 1941, and it is possible that the design of this weapon was influenced by the Nomonhan Incident when Japanese and Russian border forces fought for 24 days in 1939. It is believed that other new designs, especially anti-aircraft artillery, have made their appearance, but up to this writing these have not been encountered.
5. As a result of early Japanese successes in the present war, various United States, Dutch, and British weapons are found in use by the Japanese. In one or two cases the Japanese have copied captured weapons exactly. In others, they have manufactured ammunition to use in the captured artillery.
1. PISTOLS, REVOLVERS, AND RIFLES. a. General. (1) All known Japanese rifles and carbines are of Arisaka design. immediately after the Russo-Japanese War, Model 38 (1905) 6.5-mm Rifle was introduced and all subsequent rifles and carbines have adhered to this design. later models have a folding monopod attached to the lower band. The design closely follows the Mauser and is simple and sturdy. The safety mechanism is an unusual feature.
Section II. INFANTRY WEAPONS
(2) The only known Japanese military revolver is a very clumsy copy of a Smith and Wesson top-break revolver. This weapon was introduced in 1893.
(3) The first Japanese military magazine pistol was designed by General Nambu. Despite its superficial resemblance to the German Luger, the action of the Nambu pistol is unique. The original design was improved in the Model 14 (1925) pistol.
(4) The Model 94 (1934) pistol is a crude attempt to make a small pistol along general Browning lines.
b. Nambu 8-mm pistol.
Figure 167. Nambu 8-mm pistol.
(1) General description. This is a semiautomatic, recoil-operated, magazine-fed hand weapon (fig. 167). It is equipped with a grip safety below the trigger guard. The markings on the right side of the receiver read "Nambu model." In addition to the markings, the weapons is easily identified by the recoil-spring housing (a bulge on the left side of the receiver and the adjustable rear sight. This is a leaf with an open V notch sliding on a ramp and is graduated from 100 to 500 meters. The weapon may be equipped with a wooden holster, also designed to be used as a should stock when attached to the heel of the butt.
Caliber 8-mm (.315 inch). Capacity of magazine 8 rounds. Weight (empty) 31 ounces. Muzzle velocity 950 feet per second.
(3) Ammunition. Rimless ball cartridges are provided and are interchangeable in the model 14 and the model 94 pistols described on the following pages.
c. Model 14 (1925) 8-mm pistol. (1) General description. The model 14 (1925) 8-mm pistol is a semiautomatic, recoil-operated, magazine-fed hand weapon (fig. 168). It is a development of the Nambu 8-mm pistol. Markings on the left side of the receiver read "14th year model". The front sight is a blade type sight and the rear
Figure 168. Model 14 (1925) 8-mm pistol.
sight is a non-adjustable open V notch. The safety lever is moved to the forward position for "fire" and rearward for "safe." An unusually large trigger guard permits firing with a gloved hand.
Caliber 8-mm (.315 inch). Capacity of magazine 8 rounds. Weight (empty) 2 pounds. Muzzle velocity 950 feet per second.
(3) Ammunition. Rimless ball cartridges are provided and are interchangeable in the Nambu and the model 94 pistols.
d. Model 94 (1934) 8-mm pistol. (1) General description. The model 94 (1934) 8-mm pistol is the latest design of semiautomatic pistol manufactured by the Japanese. It is believed to be inferior to the Nambu and the model 14 pistols because of poor design and manufacture. It is a semiautomatic, recoil-operated, magazine-fed hand weapon (fig. 169). Markings on the left side of the receiver read "Model 94". The front sight is a blade type sight and the rear sight is a non-adjustable open V notch type. The safety catch on the left rear of the receiver is moved upwards for "safe" and downwards for "fire."
Caliber 8-mm (.315 inch). Capacity of magazine 6 rounds. Weight (empty) 1 pound 11 ounces. Muzzle velocity 900 feet per second.
(3) Ammunition. Rimless ball cartridges are provided and are interchangeable in the Nambu and the model 14 pistols.
e. Model 26 (1893) 9-mm pistol. (1) General description. This revolver is solely a double action weapons with a cylinder having six chambers (fig. 170). It is a copy of the old Smith and Wesson top-break type. The weapon is equipped with blade type front sight and notch type rear sight. There is no positive safety device and owing to the extremely heavy trigger pull it has a comparatively
Figure 169. Model 94 (1934) 8-mm pistol, showing holster and magazine.
low rate of fire. Moreover crude construction prohibits positive alignment of barrel and cylinder making its accuracy questionable. The markings on the right side of the frame read "26th year model."
Caliber 9-mm (.354 inch). Capacity 6 rounds. Weight (empty) 2 1/4 pounds. Over-all length 8.5 inches.
(3) Ammunition. The weapon fires 9-mm rimmed ball ammunition.
f. Model 38 (1905) 6.5-mm rifle. (1) General description. This rifle is a manually operated, clip loaded, magazine-fed weapon, with the Mauser type bolt action which is found in most military rifles. It is commonly referred to as the Arisaka rifle. The rifle in manufactured in 3 standard lengths as shown in figure 171; the longest of which is the standard infantry weapon. The shorter rifles are issued to other arms. The "safety" is locked by pressing the knob at the end of the bolt and turning it to the right. It has a blade type front sight and a leaf rear sight graduated from 100 to 2,400 meters. There is no windage or drift adjustment. The small caliber, long barrel, and medium muzzle velocity of this piece results in relatively no recoil and comparatively little muzzle flash. The markings on top of the receiver read "Model 38."
Caliber 6.5-mm (0.256 inch). Muzzle velocity 2,400 feet per second. Magazine capacity 5 rounds.
(3) Ammunition. The cartridges are semi-rimmed. Ball ammunition and tracer ammunition have been recovered.
g. Model 44 (1911) cavalry carbine. (1) General description. This carbine (fig. 172) is substantially the same as the model 38 (1905) short rifle. The action, operations, and sights are similar on all Arisaka rifles. This model, however, has a permanently attached spike type bayonet, that folds under and rests in a slot in the stock while being carried. This rifle has a blade front sight and a leaf rear sight graduated from 300 to 2000 meters. There is no windage or drift adjustment.
Caliber 6.5-mm (0.256 inch). Length over-all (bayonet folded) 38 1/4 inches. Weight (empty) 8.75 pounds. Muzzle velocity 2,400 feet per second. Magazine capacity 5 rounds.
(3) Ammunition. The weapon uses the same ammunition as the model 38 rifle, and the cartridges are semirimmed. Both ball and tracer ammunition have been recovered.
Figure 171. Model 38 (1905) 6.5-mm rifle.
Figure 172. Model 44 (1911) cavalry carbine (showing bayonet folded and open).
h. Model 99 (1939) 7.7-mm rifle. (1) General description. The Japanese are replacing their 6.5-mm weapons with this shorter, heavier caliber weapon (fig. 173). This rifle is an improved version of model 38 (1905) Arisaka rifle. The rifle has a blade front sight and a leaf rear sight graduated from 500 to 1500 meters. Modifications, other than the larger caliber which also help to identify this piece, are as follows: Monopod under fore end; anti-aircraft sight arms attached to rear sight leaf; magazine floor plate hinged to forward part of trigger guard; sling swivels attached to side instead of under part of rifle. The markings on the top of the receiver read "Model 99." Reports have been received that a short model (38 inches overall) is being issued to service troops.
Caliber 7.7-mm (0.303 inch). Length over-all (without bayonet) 44 inches. Muzzle velocity 2,300 feet per second. Weight 8.8 pounds.
(3) Ammunition. This is supplied in 5 round clips, 3 clips to a package. It is a rimless type
Figure 173. Model 99 (1939) 7.7-mm rifle and bayonet.
supplied in ball, tracer, and armor piercing varieties, and has standard markings. This ammunition can be used in the 7.7-mm model 92 (1932) machine gun, but the model 92 ammunition is semirimmed and cannot be used in the rifle.
i. Sniper's rifle. (1) General description. This particular piece of equipment is found in two models, model 97 (1937) 6.5-mm and model 99 (1939) 7.7-mm (fig. 174). The two rifles are the same length as the long model 38 (1905) 6.5-mm and can be identified by the fact that, in addition to standard sights, the sniper's model has a telescope mounted on the left of the receiver, a turned down bolt handle, and a monopod under fore end. It is believed that these rifles are manufactured more carefully than the standard rifles.
Model 97 caliber 6.5-mm (.256 inch). Model 99 caliber 7.7-mm (.303 inch). Weight (with scope) 9 3/4 pounds. Length over-all 50 1/4 inches. Sights: ---Front Blade type. ---Rear Sliding leaf, graduated from 300 to 1,500 meters. Telescope sight: ---Type Fixed focus. ---Magnification 2.5x. ---Field of vision 10°. ---Weight 17 ounces.
(3) Ammunition. The model 97 (1937) 6.5-mm fires standard 6.5-mm semirimmed ammunition. Model 99 (1939) 7.7-mm fires standard 7.7-mm rimless ammunition.
j. Rifle grenade launchers (dischargers). (1) Spigot type launcher. This attachment (fig. 175) is placed over the rifle muzzle and locked into place, behind the front sight. Two types of grenades are known to be fired from this launcher. Both types are projected by a special cartridge (fitted with a wooden bullet) which is normally packed in the grenade fin assembly.
(a)Fragmentation grenade Model 91 (1931). This grenade has been adopted for use as a rifle grenade by replacing the propellant charge normally found screwed into the base of this grenade, with a fin assembly. Prior to firing, the safety pin must be removed from the fuze. When projected, the fuze action will be started by the shock of the explosion upon the base of the grenade. Grenade will detonate in 7-8 seconds (approx.) after firing.
Figure 174. Model 97 (1937) 6.5-mm Sniper's Rifle (with telescope and carrying case).
Figure 175. Spigot type grenade launcher and ammunition (at the top is shown the fragmentation grenade in position for firing, at bottom, the smoke grenade and launcher).
(b)Rifle smoke grenade. The rifle smoke grenade weighs 1.3 pounds and is painted silver. It contains approximately 0.6 pounds of an HC white smoke mixture. no fuze is used, the action being started by the flash of the propelling charge.
Figure 176. Rifled-type grenade launcher with armor piercing (hollow charge) rifle grenade.
(2) Rifled type launcher. This launcher (fig. 176) is designed for projecting the hollow charge high explosive AP grenade. When fired the action of the discharger cup rifling on the lugs (prerifled rotating band) of the grenade forces the projectile to rotate, giving stability in flight. It is reported that this grenade is projected by a special cartridge fitted with a wooden bullet.
Figure 177. Cup type launcher Model 100 fitted on muzzle of rifle.
(3) Cup type launcher Model 100. This launcher is used for projecting the Model 99 (1939) fragmentation grenade. The launcher is attached to the muzzle of the rifle, and the grenade, with safety pin removed, placed inside the cup. Standard ball ammunition is used for projecting the grenade, which has a range of approximately 100 yards when using any standard Japanese rifle. The grenade time fuze is started when the weapon is fired, detonating in approximately 4-5 seconds.
2. MACHINE GUNS. a. General. (1) The basic machine guns is the "Nambu," Model 11 (1922) 6.5-mm light
machine gun, which is a modification of the French Hotchkiss. Other types that have been directly copied are the Lewis, the Vickers, and in one instance the Oerlikon. These weapons will be found listed in the following pages. A matter of note is that Japanese machine guns generally do not employ slow initial extraction and therefore stoppages are frequent. The Japanese, on order to overcome this, have employed various methods of oiling ammunition either by automatic or gravity oilers, built directly on to the weapon, or oiling ammunition before loading into box magazines. To complicate the ammunition picture even further, they have indicated that their 6.5-mm machine guns normally used a reduced charge, possibly to overcome stoppage and to avoid pre-oiling. Also their 7.7-mm light and heavy machine guns are built to use either a rimmed, semirimmed or rimless ammunition, which, with one exception noted in the following pages, is not interchangeable.
(2) Submachine guns. No submachine gun of Japanese manufacture, comparable to the Thompson, M3 or Reising has been found, although several German Solothurn 7.63-mm (.30 cal.) and 9-mm (.35 cal.) SMGs and Schmeisser MP 28II, SMGs have been recovered.
b. Model 11 (1922) 6.5-mm light machine gun.
Figure 178. Model 11 (1922) 6.5-mm light machine gun.
(1) General description. This is a gas operated, air-cooled, machine gun with hopper feed which holds 6-5 round clips of ammunition (fig. 178). Positive identification can be made from the following markings which appear on the top of the receiver and read "11th year model." It is equipped with a blade front-sight and a V notched rear leaf-sight sliding on a ramp. There is no windage or drift adjustment. The safety lever (see fig. 178) is turned down to a vertical position to make the weapon safe.
Caliber 6.5-mm (0.256 inch). Hopper capacity 6-5 round clips. Weight 22 1/2 pounds. Muzzle velocity 2,440 feet per second. Sight graduations 300 to 1,500 meters. Cyclic rate of fire 500 rounds per minute.
(3) Ammunition. Clips of 5 rounds standard or reduced charge 6.5-mm ball rifle ammunition are used.
c. Model 96 (1936) 6.5-mm light machine gun.
Figure 179. Model 96 (1936) 6.5-mm light machine gun (showing magazine, magazine filler and telescopic sight).
(1) General description. This is a gas-operated, magazine-fed, air-cooled, full automatic light machine gun (fig. 179). Its appearance is somewhat similar to that of the British Bren. The markings read "Model 96" are are stamped on the top of the receiver. This weapon has a blade front sight and a leaf rear sight controlled by a "click" drum. The graduations are from 200 to 1,500 meters and there is a windage adjustment. There is also a telescopic sight with a 10° field of view and a 2 1/2 magnification. A safety lever is located on the left side of the trigger housing and is set at horizontal to "fire," and vertical for "safe."
Caliber 6.5-mm (0.256 inch). Weight (without bayonet or magazine) 20 pounds. Magazine capacity 30 rounds Muzzle velocity 2,410 feet per second. Cyclic rate of fire 550 rounds per minute.
(3) Ammunition. 6.5-mm semirimmed cartridges in boxes marked (G) are provided for this weapon. These have the same dimensions as the
standard 6.5-mm cartridge although the Japanese have indicated that these have a reduced propelling charge. The regular rifle ammunition may cause stoppages, but can safely be used.
d. Model 99 (1939) 7.7-mm light machine gun.
Figure 180. Model 99 (1939) 7.7-mm light machine gun.
(1) General description. This is a gas-operated, magazine-fed, air-cooled, ight machine gun (fig. 180). Its appearance is almost identical to model 96 with two exceptions, that it has an adjustable rear monopod and a barrel locking nut instead of a barrel catch. It can further be identified by the markings on the top of the receiver meaning "99 Model." It has a blade front sight and a rear peep sight controlled by a "click" drum graduated from 200 to 1,500 meters. There is a windage adjustment. A telescopic sight 10° field of view and 2 1/2 X magnification is also provided. The safety lever on the right side of the trigger housing is set at horizontal to fire", and vertical for "safe".
Caliber 7.7-mm (0.303 inch). Length over-all 42 inches. Weight (without magazine or bayonet) 20 pounds. Magazine capacity 30 rounds. Muzzle velocity 2,300 feet per second. Cyclic rate of fire 800 rounds per minute.
(3) Ammunition. The weapon uses 7.7-mm rimless ammunition only. This ammunition can be used in model 92 heavy machine gun, but the semirimmed ammunition for model 92 cannot be used in this gun.
e. Model 92 (1932) 7.7-mm Lewis type MG.
Figure 181. Model 92 (1932) 7.7-mm Lewis type machine gun.
(1) General description. This weapon is an air-cooled, gas operated, drum-fed, full automatic gun. (See fig. 181.) With the exception that the cocking handle is on the left and that there is no provision allowing it to be changed to the right side of
the gun, if so desired, this weapon is a duplicate of the British Lewis. It can easily be recognized by its similarity to the latter weapon. The markings meaning "92 Model" are stamped on the receiver. Without removing the gun from its mount, the main portion of the tripod head can be moved from a horizontal to a vertical position, making a satisfactory AA mount. The can be done in approximately 15 second.
Caliber 7.7-mm (0.303 inch). Length over-all 56 inches. Weight (without tripod) 26 pounds. Traverse 360°. Elevation (with mount in AA position) 85°. Magazine capacity 47 rounds.
(Magazines having 97 round capacity also have been found)
Muzzle velocity 2,400 feet per second (approximately). Cyclic rate of fire 600 rounds per minute. Sight: ---Front Blade type. ---Rear Folding leaf peep-sight graduated from 0 to 1,700 meters
(3) Ammunition. 7.7-mm rimmed ammunition, Japanese copy of British 0.303, and British MK VII .303 in. ball ammunition.
f. Model 92 (1932) 7.7-mm heavy machine gun.
Figure 182. Model 92 (1932) 7.7-mm heavy machine gun.
(1) General description. This is the standard Japanese heavy machine gun. It is a gas-operated, strip-fed, full automatic, air-cooled, modified Hotchkiss-type weapon
Its forerunner, which may still be used, was the Model 3 (1914) which fired 6.5-mm ammunition. Markings which appear on the receiver read "92 Model." The standard sights consist of a blade front sight and a rear peep sight mounted on a post adjustable for windage and range (300 to 2,700 meters). Special antiaircraft front and rear sights are provided, and there are 3 variations of optical rear sights which are often used. The weapon is set on safety by turning the trigger thumb piece.
Caliber 7.7-mm (0.303 inch). Weight (including tripod) 122 pounds. Strip capacity 30 round clips. Cyclic rate of fire 450 rounds per minute. Muzzle velocity 2,400 feet per second.
(3) Ammunition. This gun uses 7.7-mm semirimmed ammunition (Ball, tracer, AP and incendiary). It can also use the 7.7-rimless ammunition if loaded on strips.
g. Model 93 (1933) 13-mm machine gun.
Figure 183. Model 93 (1933) 13-mm machine gun.
(1) General description. This is a gas-operated, air-cooled, magazine-fed, full automatic, Hotchkiss type weapon (fig. 183). While it is primarily an antiaircraft gun, it can be used for ground purposes. This weapon has been found in single and twin mounts (see sec. III, par. 3). The markings meaning "93 Model" appear on the receiver. The antiaircraft sights on dual mounts are of the calculating type graduated for ranges from 200 to 3,000 meters, with provision for corrections based on plane speeds varying up to 500 kilometers per hour. For ground use there is a blade front sight and a leaf rear sight graduated from 200 to 3,600 meters.
Caliber 13.2-mm (0.52 inch). Length over-all (including flash hider) 89 inches. Weight (without mount or magazine) 87 pounds. Magazine capacity 30 rounds. Muzzle velocity 2,250 feet per second. Elevation 0° to +85°. Traverse 360°. Sights: ---A/A--(dual mount only) Calculating type graduated from 200 to 3,000 meters range
and an estimated speed of from 0 to 500 kilometers per hour.
Folding leaf graduated from 300 to 3,600 meters.
Cyclic rate of fire 500 rounds per minute.
(3) Ammunition. Ball, armor piercing, and tracer cartridges are provided.
3. MORTARS AND GRENADE DISCHARGERS. a. General. Although all known types of both mortars and grenade dischargers are dealt with here, there are indications that the Japanese Army has mortars heavier than 90-mm and at least up to 150-mm.
b. Model 10 (1921) 50-mm grenade discharger.
Figure 184. Model 10 (1921) 50-mm grenade discharger (at bottom is the discharger prepared for carrying).
(1) General description. This is a smooth-bore, muzzle-loaded weapon (fig. 184). It has the special feature of a range control device in the form of a graduated thimble by which a gas port at the base of the tube can be varied in size. For shorter ranges, part of the propellant gases escape to the side. It is believed that this weapon is used primarily for discharging flares and that the heavier model 89 grenade discharger is used for firing high explosive and other projectiles.
Caliber 50-mm (1.97 inch). Length of barrel 9 1/2 inches. Over-all length 20 inches. Weight 5 1/2 pounds. Range for M91 (grenade) 65-175 yards.
(3) Operation. There is no safety device on this weapon. To operate, first remove the safety pin from projectile. The grenade or signal projectile is placed in the barrel. The weapon is fired by a trigger attached to the pedestal.
(4) Ammunition. This weapon fires Model 91 grenade, Model 11 smoke shell, Model 10 flare shell, Model 10 signal shell, Model 91 pyrotechnic grenade and Model 10 blank.
c. Model 89 (1929) 50-mm grenade discharger.
Figure 185. Model 89 (1929) 50-mm grenade discharger with various types of ammunition and equipment.
(1) General description. This is a muzzle-fed, rifled weapon which is widely used in the Japanese Army (fig. 185). The standard projectile
[Photos only -- have been integrated with object descriptions]
is a high explosive shell which contains the propellant charge in its base. Ranges are controlled by rotation of the knurled range knob. Rotation of the projectile is obtained because the rotating band is expanded against the rifling when the weapon is fired. The weapon is trigger fired. A recent modification of the discharger is fitted with a device to indicate the correct firing angle (45°). There are two range scales. One gives the ranges (120 to 670 meters) governing the use of the Model 89 HE shell and the other (50 to 170 meters) is used for firing Model 91 grenades.
Caliber 50-mm (1.97 inch). Weight 10 1/4 pounds. Range (Model 89 shells) 120 meters (131 yards) to 670 meters (737 yards).
Figure 186. 50-mm grenade discharger shell, incendiary.
(3) Ammunition. The following types of ammunition are known to be provided: Model 89 High explosive shell, model 91 grenade, smoke shell, model 94 practice shell, pyrotechnic signals (described in chapter 10), and incendiary (fig. 186). The incendiary shell has a light metal body and weighs approximately 1.25 pounds. It contains about 0.7 pounds of incendiary mixture. The smoke shell weighs approximately 2 pounds, contains about 4 ounces of HC type smoke mixture. The body has the same shape as the high explosive shell, but may be distinguished by having two white bands on the body.
d. Model 98 (1938) 50-mm mortar.
Figure 187. Model 98 (1938) 50-mm mortar with projectile.
(1) General description. This is a smooth-bore muzzle loaded weapon with fixed elevation of approximately 40° and limited traverse (fig. 187). It is fired by a lanyard attached to a friction primer affixed to the base of the tube. A special feature is a range slide which may be clamped to the muzzle. This regulates the length of the stick (spigot) extending into the barrel. The greater the distance the stick extends into the barrel, the greater the range.
Length of barrel 25 inches. Total weight (complete with base) 48 pounds. Elevation 40°. Traverse 7°. Weight of ammunition 10 pounds. Fuse Time (activated by friction igniter).
(3) Ammunition. The weapon fires a stick bomb weighing approximately 10 pounds and containing 7 pounds of picric acid in blocks. A smaller bomb containing 5 pounds of picric is also used. A finned bangalore torpedo may also be fired. No other ammunition has been recovered to date.
e. Model 11 (1922) 70-mm mortar.
Figure 188. Model 11 (1922) 70-mm mortar.
(1) General description. This is an obsolescent muzzle-loaded, rifle-bore weapon (fig. 188). The barrel is supported by a single elevating screw. The markings on the breech end of the barrel read "11th year model high angle infantry gun." The latch pin on the breech end of the barrel must be set in to release the safety device. The weapon is fired by means of a lanyard attached to the striker arm.
Caliber 70-mm (2.76 inch). Total weight (including base-plate) 133.75 pounds. Elevation 37° to 77°. Traverse 23°.
(3) Ammunition. The high explosive shell has the propellant powder in its base and operates in the same manner as the model 89 grenade discharger shell previously described.
f. 70-mm barrage mortar.
Figure 189. 70-mm barrage mortar showing spike and block used as base.
Figure 190. Shell used in 70-mm barrage mortar and its method of functioning.
(1) General description. This is a smooth-bore, muzzle-loaded weapon of very simple construction (fig. 189). It fires a shell probably designed for used against low flying aircraft (fig. 190), or firing over the heads of ground troops. When fired, the projectile reaches a ranges of 3000 to 4000 feet when it expels parachute-supported high explosive charges 11/16 in diameter and 3 inches long which in turn explode in the air. If an unexploded shell be found on the ground, it should be marked "Dangerous" and left for disposal by trained personnel.
g. Model 97 (1937) 81-mm mortar.
Figure 191. Model 97 (1937) 81-mm mortar.
(1) General description. This weapon is very similar to United States 81-mm mortar M1. It is a smooth-bore, muzzle-loading, high-angle fire weapon, (fig. 191) which breaks down into 3 sections for transport. The markings which appear on the base of the barrel read "97 model small trench mortar." The mortar is provided with a collimator sight which is heavier and more complex than the U.S. M1 sight.
Caliber 81-mm (3.19 inch). Maximum range (light shell) 3,100 yards (approximately). Length of barrel 49 1/2 inches. Total weight 145 pounds. Weight of shell 6.93 pounds (1 pound of TNT).
(3) Ammunition. This weapon fires high explosive shells which are interchangeable with the United States M43 81-mm light shell. Heavier shells have been reported but no specimens have been recovered. The fuzes can be adjusted to give instantaneous or delay action detonations.
h. Model 99 (1939) 81-mm mortar.
Figure 192. Model 99 (1939) 81-mm mortar and standard projectile..
(1) General description. Model 99 is similar to model 97 except that it has a much shorter barrel and is equipped for trigger firing with a mechanism at base of the barrel (fig. 192).
The weapon is fired by hitting the protruding end of the firing pin cam shaft with a wooden mallet.
[Photos only -- have been integrated with object descriptions]
[Photos only -- have been integrated with object descriptions]
[Photos only -- have been integrated with object descriptions]
For transport, this mortar breaks down into three sections, each weighing approximately 17 pounds. It may be fired with United States M43 81-mm mortar shells, in which case a maximum range of 2,500 yards may be obtained.
Caliber 81-mm (3.19 inch). Maximum range 2,200 yards. Length of barrel 25 1/4 inches. Total weight 52 pounds.
(3) Ammunition. HE and smoke or chemical shells have been recovered. The fuse may be adjusted for instantaneous or delay detonations.
i. Model 94 (1934) 90-mm mortar.
Figure 193. Model 94 (1934) 90-mm mortar.
(1) General description. This is a smooth-bore, muzzle-loading weapon with a fixed firing pin (fig. 193). A special feature is the recoil system, consisting of two recoil cylinders on a one piece U-shaped frame with cylinders located on each side of the barrel. The Japanese markings on the base of the barrel read "94 model light trench mortar."
Caliber 90-mm (3.54 inch). Maximum range 4,150 yards. Length of barrel 52 inches (approximately). Total weight 340 pounds. Sight Panoramic telescope sight.
(3) Ammunition. Model 94 mortar fires HE and incendiary ammunition. The incendiary shell is 16 inches long, weighs 11.5 pounds. The mixture is white phosphorus, carbon disulphide and 40 impregnated rubber pellets. This shell can be identified by a red band below the fuse, a blue band between the fuze and bourrelet, a yellow band between the bourrelet and fin, and a white band at the function of the shell body and the fin. The fuze may be
adjusted to give either instantaneous or delayed detonation.
j. Model 93 (1933) 150-mm mortar.
Figure 194. A portable model 93 (1933) 150-mm mortar in action.
(1) General description. The photograph (fib. 194) shown is believed to be that of the model 93 (1933) 150-mm mortar, a smooth-bore, muzzle-loaded, lanyard fired weapon.
Caliber 150-mm (5.9 inch). Maximum range 2,100 meters (2,300 yards). Length of tube 59 inches (approximately). Weight of tube 220 pounds (approximately). Elevation 43° to 80°. Traverse 7°. Sights Telescopic.
(3) Ammunition. Projectile reported as weighing (total) 56 pounds and containing approximately 14 pounds of explosive.
4. GRENADES, LAND MINES, AND BOOBY TRAPS. a. General. The following pages give a general picture of Japanese grenades and land mines. Certain of these can be and have been used as booby traps.
b. Booby traps.
Figure 195. Illustration of method used by the Japanese to construct a booby trap
using model 91 (1931) hand grenade.
Although the Japanese use of booby traps has been limited as compared to the German, it is to be expected that these traps will be more and more frequently encountered as Allied Forces push the Japanese from prepared positions. As many types of Japanese ammunition are suitable for employment as booby traps only the most common are listed. The model 23 pull type fragmentation grenade is particularly suitable for this purpose when attached to doors, window frames, and general items of abandoned equipment. In addition numerous reports have been received of captured allied grenades (i.e., British No. 36 and United States MK 2) being similarly employed. Although there is no evidence to date that the stick grenade, the bangalore torpedo, or the explosive cannister from the barrage mortar shell have been used as booby traps, the fact that all have pull igniters and accidents have occurred to troops handling them, prove that they are most suitable as such. The 3 types of fragmentation grenade models 91, 97, and 99 ("Kiskda") grenade are equipped with percussion ignited fuses. They have been used with a suspension wire device which can be tripped. The grenade is placed bottom-up inside an improvised tube thus ensuring that the grenade will fall head first so as to detonate the fuse, when a wire is tripped (see fig. 195) A piece of bamboo or empty cartridge case is sometimes issued in lieu of a tube.
[Photos only -- have been integrated with object descriptions]
Another and less elaborate variation is found in the use of the above listed grenades under a foot board. The delay powder train may be first removed. The weight of the foot fires the detonator instantaneously. Many of the land mines have been used as booby traps and work on the same principle, model 93 being equipped so that it can be activated by pressures from 7 to 200 pounds. Only one or two electrically operated booby traps have been encountered so far. They operate on a low voltage and are generally attached to equipment such as radios and vehicle ignition switches. It can be expected that booby trap fuzes of more advanced design, will probably appear in the near future, as the Japanese are driven back.
c. Model 91 (1931) hand grenade.
Figure 196. Model 91 (1931) hand grenade (including propellant charge for use in grenade discharge).
(1) General description. Model 91 (1931) fragmentation grenade (fig. 196) can be thrown by hand, fired either from models 10 or 89 grenade dischargers, or fired from a rifle grenade launcher (discharger) with tail assembly added. The base contains a primer and propelling charge for use when firing from a grenade discharger.
Over-all length 4.95 inches. Fuze delay 7 to 8 seconds (approximately). Diameter 1.97 inches. Weight with propellant charge 18.8 ounces..
(3) Operation. (a)To arm. With safety pin in position, screw firing pin down into firing pin holder, with screw driver or knife blade, as far as it will go.
(b)To use as hand grenade. Hold grenade with fuze pointing downward, remove safety pin, being sure that safety cover does not fall off. Strike head of fuze against solid object such as helmet keeping hand clear of gas vent hole. Throw immediately since action of fuze is sometimes erratic.
(c)To use in grenade discharger. Remove safety pin and drop into discharger.
d. Model 97 (1937) hand grenade.
Figure 197. Model 97 (1937) hand grenade.
(1) General description. The model 97 (1937) fragmentation hand grenade, (fig. 197) is carried by all front line troops and is almost identical with model 91, except that it has no provision for a base propellant attachment and has a shorter fuze delay time. It cannot be fired from a grenade discharger.
Over-all length 3.75 inches. Diameter 1.97 inches. Weight 1 pound (approximately). Fuze delay 4 to 5 seconds (approximately).
(3) Operation. (a) To arm. With safety pin in position, screw firing pin down into firing pin holder as far as it will go.
(b) To throw. Hold grenade with fuze pointing downward. Remove safety pin, being sure that safety cover does not fall off. Strike head of fuze against solid object such as helmet, keeping hand clear of gas vent hole. Throw immediately since time of fuze is sometimes erratic.
e. Model 99 (1939) hand grenade.
Figure 198. Model 99 (1939) hand grenade ("Kiska").
(1) General description. This grenade has been identified as model 99 (fig. 198). It is smaller than the model 97 and 91 fragmentation grenades and unlike these, it has a smooth, cylindrical body with a flange at either end. It may be launched from a special launcher mentioned previously under "Rifle grenade launchers" (figures 176 and 177).
Over-all length 3 1/2 inches. Diameter 1 5/8 inches. Weight 10 ounces (approximately). Fuze delay 4 to 5 seconds (approximately).
(3) Operation. (a) To arm. Remove safety pin which is held in place by a cord.
(b) To use as a hand grenade. Strike the head of the fuze on a hard object and throw immediately. Since the firing pin is integral with firing pin holder no screwing or unscrewing is necessary, as with the model 91 and model 97 fragmentation grenades. It can be used as a booby trap by removing the safety pin and setting under a floor board or chair.
(4) Alternative fuze. It is believed that there is a variation of this grenade, known as the model 99B, which is activated by a friction igniter fuze.
f. Model 23 grenade.
Figure 199. Model 23 hand grenade.
(1) General description. This grenade (fig. 199) appears to have been designed for use either as a hand grenade or a booby trap. It has a pull type friction igniter fuze with a time delay reported as approximately 5 seconds. Because a pull (from 21/2 pounds to 5 pounds) on the fuze cord ignites the time fuze, it could easily be adapted for use as a booby trap by tying the cord to a trip wire. The lugs and rings on the side are convenient for anchoring the grenade in place when so used. It has also been found in a booby trap with a high explosive artillery shell tied to it for augmenting the power of the explosion.
Over-all length 3 3/4 inches. Diameter of body 2 inches. Weight 1 pound (approximately). Filler Granular TNT.
g. 1/2 kg. incendiary grenade. 5.3 inches long and weighing 1.1 pounds (approximately), it may be thrown by hand or projected from the grenade discharger model 89. Incendiary filling is white phosphorus.
h. Incendiary stick grenade.
Figure 200. Incendiary stick hand grenade.
(1) General description. The body of this grenade (fig. 200) is filled with impregnated rubber pellets in a phosphorus carbon disulphide solution. There are some 40 pellets in each grenade, which are scattered by a central bursting charge. It is also possible that this grenade is sometimes filled with phosphorus smoke filling. The grenade is 13.2 inches long and the body has a diameter of 2.1 inches.
(2) Operation. (a)To arm. Make sure that the safety pin is in position and that the firing pin is threaded down into the firing pin holder.
(b)To throw. With the fuze pointing downward, withdraw the safety pin. Making sure that the safety cover does not fall off, strike the head of the fuze against some hard object, such as the heel of your shoe or the top of your helmet. There should be no delay in throwing the grenade, since actual fuze delay time is not known.
i. High-explosive stick hand grenade.
Figure 201. High-explosive stick hand grenade.
(1) General description. This is the well known "potato masher" type of grenade with a pressed metal cap at the end of the handle (fig. 201). It has a smooth cylindrical body.
Over-all length 7 7/8 inches. Diameter of grenade body 2 inches. Weight of bursting charge (lyddite) 2 3/4 ounces. Total weight 19 1/2 ounces. Fuze delay 4 to 5 seconds (approximately).
(3) Operation. Remove the metal cap. A ring with a string attached will be found. This ring is slipped on the finger and the grenade thrown. The string pulls away from the grenade and starts the time fuze burning. This grenade can be used as a booby trap by attaching one end of a trip wire to the ring and the other end to a moveable object such as a door, helmet, etc.
j. Molotov cocktail incendiary grenade.
Figure 202. Molotov cocktail incendiary grenade with fuze.
(1) General description. This is a Japanese version of
the "Molotov cocktail." It consists of a standard bottle (fig. 202) filled with a mixture of oil and gasoline. (The bottle illustrated in figure 202 is a Japanese beer bottle.) The fuze is an "all-ways" type that will ignite when the grenade is thrown no matter in what position the bottle lands, for the impact drive the firing pin down into the detonator which ignites the contents of the bottle.
(2) Operation. Remove safety pin, then throw.
k. Frangible Smoke Grenade, white.
Figure 203. Frangible smoke grenade.
(1) General description. Spherical, flat bottomed glass flask 3 inches in diameter and filled with a yellowish liquid varying from 100
percent titanium tetrachloride to a mixture of approximately 60 percent titanium tetrachloride and 40 percent silicon tetrachloride. The grenade (fig. 203) is packed in sawdust in a cylindrical sheet metal container.
l. Frangible Hydrocyanic Acid (AC) Grenades.
Figure 204. Frangible hydrocyanic acid grenade, arsenic trichloride stabilized type.
(1) General description. Two different types exist. One is stabilized with copper powder and is packed in a sheet metal outer container, the other is stabilized with arsenic trichloride and packed in a cardboard container. The grenade (fig. 204) consists of a spherical glass flask about 31/2 inches in diameter containing approximately 1 pint of hydrocyanic acid. The flask is packed in a mixture of sawdust and a neutralizing agent. The outer container is approximately 51/4 inches high and 51/2 inches in diameter, it is painted khaki and banded in brown.
m. Bangalore torpedo.
Figure 205. Bangalore torpedo.
(1) General description. This is the standard bangalore torpedo (fig. 205) for the Japanese Army. It has a pull type delay fuze and is threated at each end to permit an indefinite number of tubes to be attached end to end. Because of the type of fuze, it may be used in a booby trap, with the igniter string tied to a trip wire.
Over-all length (one tube) 46 inches (approximately). Diameter 2 inches. Weight (one tube) 10 pounds. Fuze delay 6 to 7 seconds (approximately). Charge composition TNT 36 percent. Cyclonite 64 percent.
(3) Operation. (a) Remove plugs, screw together the selected number of tubes, remove the bullet shaped cap from fuze and place on one end. Screw fuze in place. When ready to detonate the bangalore torpedo, pull out the safety pin, and pull the lanyard (requires about a 13-pound pull). The fuze delay will be approximately 6 to 7 seconds.
NOTE. Another bangalore type land mine which may be an antitank mine has been found. Its characteristics are as follows:
Length 36 inches. Width 3.5 inches. Height 2 inches. Charge 6 pounds picric acid. Form Oval cross section. Color Olive drab. Fuze 4 pressure type shear wire fuzes inside base--
pressure about 300 pounds.
(b) For additional information concerning Japanese bangalore torpedoes see chapter 10, section V, paragraph 5b.
n. Model 93 (1933) mine.
Figure 20. Model 93 (1933) mine.
(1) General description. This mine (fig. 206) is exploded by pressure applied anywhere on its upper surface. It is used either for antipersonnel or antitank purposes. Fuzes are provided
with shear wires of various strengths, so the fuzes may function under pressures of from 20 pounds (Mines have been reported which function with a pressure as low as 7 pounds) to as much as 250 pounds depending on the fuze selected. Additional explosive may be placed beneath the mine to give it greater force.
o. Model 99 (1939) armor piercing mine (grenade).
Figure 207. Model 99 (1939) armor piercing mine, with fuze.
(1) General description. This mine (fig. 207) is issued to infantry units and is carried by the individual soldier. It is sometimes referred to as the "magnetic antitank bomb" or "armor piercing grenade." The magnets serve to hold the mine against a metal surface such as a tank (or iron pill box door) until it explodes.
Diameter 4 3/4 inches. Thickness 1 1/2 inches. Total weight 2 pounds, 11 ounces. Length of fuze 5 1/4 inches. Charge 1 1/2 pounds TNT.
(3) Operation. Screw fuze into fuze hole. Remove safety pin. Place by hand against object to be destroyed. Give the fuze cap a sharp blow. A time delay of approximately 5 to 6 seconds gives a man time to withdraw. It has been claimed that the mine can be thrown against the target rather than having to be placed there by hand.
p. Model 96 (1936) mine.
Figure 208. Model 96 (1936) mine.
(1) General description. This is a large, very powerful mine (fig. 208) adapted for use either on land or under water. The two lead alloy horns enclose glass vials containing an electrolytic fluid. Pressure on either of these horns will crush the vial, releasing its contents. This activates the chemical electric fuze thus detonating the mine. Several sizes of this mine are believed to exist.
Height of mine 10 1/2 inches (approximately). Diameter at base 20 inches (approximately). Total weight 106.5 pounds (approximately). Charge 46 pounds.
NOTE. Another type of underwater mine, is an 81/2-inch by 8-inch canister, total weight 20 pounds, containing 8 pounds of perchlorate explosive.
5. ANTITANK AND INFANTRY GUNS. a. General (1) The Japanese infantry is comparatively well armed. The first effort to give heavy weapons to the infantry was in 1921-1922, when the model 10 (1921) 50-mm grenade discharger, the model 10 (1921) 70-mm mortar, and the model 11 (1922) 37-mm gun were introduced. These three weapons were later replaced by the model 89 (1929) 50-mm grenade discharger, the model 92 (1932) 70-mm battalion howitzer, and the model 94 (1934) 37-mm gun. However, in some areas the older weapons are still in use.
(2) In 1936, the model 41 (1908) 75-mm mountain gun was replaced by a newer weapon in the mountain (pack) artillery units. The model 41 gun then was issued four to each infantry regiment and is known as the regimental gun. This move gave the infantry a lightweight 75-mm weapon of its own.
(3) When first issued, model 11 (1922) 37-mm gun was no doubt intended in part for an antitank role, although it could not be considered a threat today. Its successor, model 94 (1934) 37-mm gun, has a much higher velocity.
(4) It was not until 1937, however, that the Japanese produced a purely antitank weapon. Model 97 (1937) 20-mm antitank rifle is a hard-hitting mobile weapon. Model 98 (1938) 20-mm antiaircraft antitank machine cannon can also be used against tanks.
(5) With the appearance of model 1 (1941) 47-mm gun, a modern, mobile, high-velocity weapon, Japanese antitank weapons take on a much more serious aspect.
(6) The fact that model 41 (1908) 75-mm infantry gun is provided with armor-piercing, high-explosive and hollow charge AP ammunition must be borne in mind, because this gun is so widely distributed in the Japanese Army.
(7) Japanese infantry must be considered well supplied with heavy weapons; the Army is primarily an infantry army, and the weapons of the infantry have always been the first consideration of the military.
b. Model 97 (1937) 20-mm antitank rifle.
Figure 209. Model 97 (1937) 20-mm antitank rifle.
(1) General description. This is actually a single purpose, selective full or semi-automatic gas operated, antitank automatic cannon (fig. 209). Infantry can maneuver it in any sort of terrain. Two men can carry it, since it weighs but 150 pounds complete with shield and carrying handles, and it is easy to hide because of its low silhouette (161/2 inches without the shield). However, it sights do not permit accurate laying for the longer ranges, and tracking is difficult because traversing must be accomplished by shoulder control. In addition, the weapon has a very violent recoil. The Japanese markings which mean "97 Model" appear on the top of the receiver.
Caliber 20-mm (0.79 inch). Muzzle velocity 2,500 feet per second. Weight: ---Gun itself 120 pounds. ---With shield and carrying handles 150 pounds Length (without handles) 82.5 inches. Traverse (total) 1,600 miles (90°). Sights ---Front Blade type. ---Rear Peep-sight controlled by "clock" drum graduated from
0 to 1,000 meters in 100 meter graduation.
Type feed 7 round box magazine. Rate of fire 12 rounds per minute (semiautomatic).
(3) Ammunition. Armor piercing tracer and high explosive tracer ammunition has been recovered.
c. Model 98 (1938) 20-mm antiaircraft antitank automatic cannon.
Figure 210. Model 98 (1938) 20-mm antiaircraft antitank automatic cannon.
(1) General description. This is a gas-operated, semi-, or full-automatic, all purpose weapon (fig. 210), similar in mechanism, but larger and heavier than the model 97, 20-mm antitank rifle. The ammunition is not interchangeable. The carriage permits firing from its wheels. Supported on outriggers with wheels removed it has a fast 360° traverse.
Caliber 20-mm (0.79 inch). Type feed 20 round box magazine. Weight 836 pounds (without wheels). Maximum range--horizontal 5,450 yards. Maximum range--vertical 12,000 feet. Muzzle velocity 2,720 feet per second. Rate of fire 120 rounds per minute. Traverse 6,400 mils (360°). Principle of operation Gas-operated, semi- or full automatic.
(3) Ammunition. High explosive tracer and armor piercing tracer have been recovered.
d. Model 11 (1922) 37-mm gun.
Figure 211. Model 11 (1922) 37-mm gun.
(1) General description. This weapon (fig. 211) is still in use in some areas, although its place in the infantry organization has been taken by model 94 (1934) 37-mm gun and other antitank weapons. It resembles the U.S. 37-mm infantry gun, M 1916. The gun is carried by four men. This weapon is listed by the Japanese as which is translated "11th year model low trajectory infantry gun."
Caliber 37-mm (1.46 inch). Weight in action 205.75 pounds. Length (with rails folded) 90 inches. Over-all width (in firing position) 49.25 inches. Breechblock Vertical sliding wedge, which may be operated semiautomatically. Traverse 584 mils (33°) by handwheel. Elevation 248 mils (14°) by handwheel. Depression 85 mils (-4.8°). Sight Telescopic, used for direct laying.
e. Model 94 (1934) 37-mm gun.
Figure 212. Model 94 (1934) 37-mm gun.
(1) General description. This weapon (fig. 212) is referred to by the Japanese as the "Infantry rapid fire gun." It
is an infantry close support weapon firing both high explosive and armor piercing high explosive ammunition. It has a semiautomatic, horizontal, sliding type breechblock. When the shell is loaded, the rear of the cartridge case trips a catch that closes the breechblock. Recoil action of firing opens the breech and extracts the cartridge case. Sighting is by a straight telescopic sight. This weapon has marked on the barrel the following which reads "94 model 37-mm gun."
NOTE. This piece may be found mounted on wooden spoke wheels or with perforated steel disc wheels as illustrated in figure 212.
Caliber 37-mm (1.46 inch). Length (over-all in travelling position) 114 inches. Width (overall in travelling position) 47 inches. Weight 714 pounds. Traverse 1,062 mils (60°). Elevation +480 mils (27°). Maximum range 5,000 yards. Muzzle velocity (armor piercing ammunition) 2,300 feet per second.
f. Model 1 (1941) 47-mm gun.
Figure 213. Model 1 (1941) 47-mm gun.
(1) General description. This is an antitank weapon of modern design (fig. 213). The wheels are independently sprung, and a lock is provided on each wheel for locking the springs out of action. It has a semiautomatic, horizontal, sliding wedge breech mechanism. The low silhouette, wide tread, and long split trails give this gun excellent stability. Preliminary tests indicate a muzzle velocity of 2,700 feet per second. The steel disc wheels are fitted with sponge rubber filled tires. This weapon has marked on its breech the following symbols which mean "Model 1 47-mm mobile gun."
Caliber 47-mm (1.85 inch). Weight 1,600 pounds. Traverse 60°. Elevation +19°. Depression -11°. Muzzle velocity 2,700 feet per second.
(3) Ammunition. Armor piercing high explosive and standard high explosive shells have been recovered.
g. Model 92 (1932) 70-mm howitzer (Battalion gun).
Figure 214. Photograph of model 92 (1932) 70-mm howitzer (Bn. gun) showing gunner and sights.
(1) General description. This weapon (fig. 214), despite its unusual appearance, has proved to be effective as an infantry support howitzer. It has an interrupted thread type, drop breechblock mechanism. Light in weight and maneuverable, it fires a projectile of relatively large weight, and can deliver fire at ranges varying from 110 yards to 3,000 yards. The Japanese markings which read "92 model infantry gun", appear on the barrel.
Caliber 70-mm (2.76 inch). Total weight in action 468 pounds. Thickness of armor shield 0.156 inch. Traverse 800 mils (45° total). Elevation +50°. Depression -10°. Range 3,075 yards Danger area of burst 40 yards (approximately).
(3) Ammunition. The ammunition is semifixed, the propelling charge being divided into four increments.
High explosive, armor piercing, and smoke shells are fired. The standard model 88 delay and instantaneous fuzes are used.
h. Model 41 (1908) 75-mm infantry gun.
Figure 215. Side view of model 41 (1908) 75-mm infantry gun, showing unusual trail construction.
(1) General description. This weapon (fig. 215) was originally the standard pack artillery weapon, but when it was largely superseded by the Model 94 (1934) 75-mm mountain (pack) gun, it was then used as an infantry "regimental" gun. It is widely distributed throughout the Japanese Army. It has an interrupted screw type breechblock and a hydrospring recoil mechanism. There are no equalizers or equilibrators. The markings which appear on the barrel, mean "41 model mountain gun." This weapon may be easily and quickly disassembled for pack into loads, the maximum weight of each being approximately 200 pounds. Actual firing of the weapon at a range of 3,200 yards resulted in 75 percent of the rounds falling in a rectangle 20 by 30 yards. At maximum range (7,800 yards) 75 percent of the rounds fell within a rectangle 10 yards wide and 200 yards long.
Caliber 75-mm (2.95 inch). Length (over-all) 170 inches. Width (over-all) 48 inches. Weight 1,200 pounds. Traverse (total) 106 mils (6°). Elevation +650 mils (+40°). Depression -319 mils (-18°). Maximum range 7,800 yards
(3) Ammunition. Ammunition recovered included common high explosive, armor piercing, high explosive, shrapnel, hollow charge AP and incendiary. For description of incendiary shell see chapter 9, section V.
1. GENERAL. Between 1925 and 1935, all Japanese artillery pieces were either redesigned or replaced by newer designs. An examination of a majority of the designs known to exist leads to the belief that the following features will be incorporated in any newer designs produced since 1936, although no weapons over 47-mm in size and bearing a model date later than 1936 as yet have been reported:
Section III. ARTILLERY
Hydropneumatic recoil systems.
Use of equilibrators.
Increased muzzle velocities.
Improved high speed mounts on all medium and heavy pieces (using either pneumatic tires or tires filled with sponge rubber).
Since Japan has had access to German weapon designs for some years, it may be assumed that Japanese weapons embodying the following features may be encountered:
Hollow charge projectiles.
New incendiary projectiles.
Self-propelled mounts of various kinds.
2. FIELD ARTILLERY. a. Model 94 (1934) 75-mm mountain (pack) gun.
Figure 216. Model 94 (1934) mountain (pack) gun.
(1) General description. This is the standard Japanese pack artillery piece (fig. 216) which replaced the model 41 mountain gun. Designed for rapid assembly and dismantling, it breaks down into 11 units, the heaviest of which weighs 210 pounds. The weapon os normally transported by 6 pack horses. It is characterized by a comparatively long split-trail, hydro-pneumatic
recoil mechanism, and a horizontal sliding breechblock. The shield is 1/8-inch armor plate.
Caliber 75-mm (2.95 inch). Maximum range 8,000 meters (8,750 yards). Maximum elevation +45° Maximum depression -9° Traverse 40° Weight in firing position 1,200 pounds. Sight Panoramic. Barrel length 5 feet 11/2 inches. Muzzle velocity 1,300 feet per second. Maximum rate of fire 10 to 12 rounds per minute. Weight of high explosive projectile 13 pounds.
(3) Ammunition. HE, AP, shrapnel, chemical, star, and incendiary.
b. Model 38 (1905) 75-mm gun.
(1) General description. One of th early weapons of the Japanese division artillery, this weapon (fig. 217) has been subject to considerable modification, and several versions are known to exist. There is no evidence that this parent model has been employed in recent operation; probably now it is regarded as obsolete. It may be readily identified by the single box trail which, but its design, considerably limits the elevation of the piece. Other characteristics are a hydrospring recoil system, interrupted screw type breechblock, and 1/16-inch shield.
Figure 217. Model 38 (1905) gun with ammunition.
Caliber 75-mm (2.95 inch). Maximum range 8,350 meters (9,025 yards). Maximum elevation +16° 30 minutes. Maximum depression -8° Traverse 7° Weight in firing position 947 kg (2,083 pounds). Sight Panoramic. Barrel length 7 feet 6 inches. Muzzle velocity Maximum rate of fire 8 to 10 rounds per minute. Weight of high explosive projectile 13 pounds.
(3) Ammunition. HE, AP.
c. Model 38 (1905) gun improved (possibly 4th year model).
Figure 218. Model 38 (1905) gun improved (inset shows breech mechanism).
(1) General description. This is an improved version of the 75-mm model 38 (1905) field gun, which appears to have been entirely replaced. Modifications on the present model (fig. 218) consist of trunnioning the barrel further to the rear; the addition of two spring and cable equilibrators to compensate for muzzle overhang;
replacement of the old box trail by a longer open-box type through which the barrel can recoil at high elevations; change of the breech to a horizontal sliding wedge mechanism. The most significant results of the above modifications are a much longer range and an increased rate of fire. Although reports have indicated that this weapon was to be replaced by model 90, the fact that the newer gun has not been encountered in any combat areas indicates that this plan has not yet been consummated.
Caliber 75-mm (2.95 inch). Maximum range 11,600 meters (12,565 yards). Maximum elevation +43°. Maximum depression -8° Traverse (total) 7° Weight in firing position 1,113 kg (2,448.6 pounds). Sight Panoramic. Barrel length 9.2 feet. Muzzle velocity Maximum rate of fire 10 to 12 rounds per minute. Weight of high explosive projectile
(3) Ammunition. HE, AP, shrapnel, smoke, star shell, and chemical.
d. Model 90 (1930) 75-mm gun.
Figure 219. Model 90 (1930) 75-mm gun
(inset shows the weapon on a high-speed carriage with pneumatic type tires).
(1) General description. Surrounded with considerable secrecy by the Japanese, this gun (fig. 219) has been reported as the modern weapon of the division artillery. In 1936 it was believed to have been in process of issue to organizations, but to date it has not been encountered in any theater of war. The gun is equipped with either pneumatic tires for motorized towing or large, steel-rimmed wheels for horse draft. It is characterized by a split trail, a horizontal sliding breechblock, and a hydropneumatic recoil system. An unusual feature is the muzzle
brake, which so far has not been found on any other Japanese artillery weapon.
Caliber 75-mm (2.95 inch). Maximum range 15,000 meters (16,250 yards). Maximum elevation +43°. Maximum depression -8°. Traverse (total) 43°. Weight in firing position 3,300 pounds. Sight Panoramic. Muzzle velocity 2,230 feet per second. Maximum rate of fire 10 to 12 rounds per minute.
(3) Ammunition. HE, AP, shrapnel, incendiary, smoke star shell
e. Model 95 (1935) 75-mm gun.
Figure 220. Model 95 (1935) 75-mm gun.
(1) General description. The 75-mm model 95 gun is horse-drawn (fig. 220) with split trails, hydropneumatic recoil mechanism, and horizontal, sliding-wedge type breechblock. A comparison with the Model 90, designed five years earlier, reveals that this later weapon has only the apparent advantage of reduced weight. On the other hand, it suffers from loss of range and lower muzzle velocity. It is seemingly more rugged in construction than the model 94 mountain gun and yet gives a lower performance than the model 90 field gun. The possibility therefore suggests itself that the model 95 was not designed to replace either of these guns, but was to be used by some unit other than the field or pack artillery. It is possible therefore that it may be the new weapon of the horse artillery, replacing the old adaptation of the model 38 with which such units previously had been equipped.
Caliber 75-mm. (2.95 inch). Maximum range 11,000 meters (12,000 yards).* Maximum elevation +43°. Maximum depression -8°. Traverse (total) 50°. Muzzle velocity 500 meters per second (1,640 feet per second). Weight 2,438 pounds. Sight Panoramic. Maximum rate of fire 10 to 12 rounds per minute. *Also reported as 9,000 meters (9,850 yards).
(3) Ammunition. HE, AP, shrapnel, smoke star and chemical.
f. Model 14 (1925) 105-mm gun.
Figure 221. Model 14 (1925) 105-mm gun.
(1) General description. The 105-mm model 14 (1925) gun (fig. 221) is used for long-range fire. There is no
[Photos only -- have been integrated with object descriptions]
information to show that this gun is still in production, and it is felt that in all probability it has been superseded by the more modern model 92 (1932). Mounted on heavy wooden wheels, the weapon is normally tractor drawn, and is capable of being moved at a maximum speed of 8 miles per hour. As an alternative it may be drawn by 8 horses. The weapon possesses an interrupted screw breechblock, a hydropneumatic recoil mechanism, and a split trail.
Caliber 105-mm. (4.13 inch). Maximum range (with long pointed projectile) 14,500 yards (also reported as 15,000 meters (16,500 yards)). Maximum elevation +43°. Maximum depression -5°. Traverse (total) 30°. Weight in firing position 6,850 pounds. Muzzle velocity 2,040 feet per second. Sight Panoramic. Tube length 11 feet 9 inches. Maximum rate of fire 6 to 8 rounds per minute. Weight of HE projectile (long pointed shells) 33 pounds.
(3) Ammunition. Ammunition is semifixed. The following types of projectiles have been reported: High explosive (long pointed shell); high explosive; shrapnel; chemical; and armor piercing. Time fuzes are provided for the smoke, incendiary, and shrapnel projectiles. The standard model 88 point detonating (instantaneous or delay) fuzes are used with the HE and chemical shells.
g. Model 91 (1931) 105-mm howitzer.
Figure 222. Model 91 (1931) 105-mm howitzer.
(1) General description. A light weight modern field piece (fig. 222) possessing a hydropneumatic recoil mechanism, split trail, and interrupted screw breech mechanism. The weapon can be readily identified by the short barrel and long sleigh. Normally it is towed by six horses.
Caliber 105-mm (4.13 inch). Maximum range 11,500 yards. Maximum elevation +45° (also reported as +65°). Maximum depression -7°. Traverse (total) 45° (also reported as 56°). Weight in firing position. 4,250 pounds. Muzzle velocity 1,790 feet per second. Sight Panoramic. Tube length 8 feet 4 inches. Maximum rate of fire 6 to 8 rounds per minute. Weight of HE projectile. 33 pounds.
(3) Ammunition. Ammunition is semifixed. The following types of projectiles have been reported; high explosive (long pointed shell); high explosive; armor piercing; shrapnel; and chemical.
h. Model 92 (1932) 105-mm gun.
Figure 223. Model 92 (1932) 105-mm gun.
(1) General description. It is considered that this weapon (fig. 223) has superseded the model 14 (1925) 105-mm gun. Readily recognized by its long slender barrel and trail, it has been designed particularly for long-range fire. Other distinctive features are the pronounced length of the sleigh and the three step interrupted thread breechblock. The recoil system is hydropneumatic. Mounted on heavily constructed wooden wheels with solid rubber
tires, the weapon is normally tractor drawn, but may be drawn by a 5-ton truck.
Caliber 105-mm (4.13 inches). Maximum range (with long pointed shell). 18,700 meters (20,100 yards) (also reported as 16,400 yards). Maximum elevation +48°. Maximum depression -10°. Traverse (total) 30°. Weight in firing position. 6,600 pounds. Muzzle velocity 2,500 feet per second. Sight Panoramic. Tube length 15 feet 6 inches. Maximum rate of fire 6 to 8 rounds per minute. Weight of HE projectile (long pointed shell). 33 pounds.
(3) Ammunition. Ammunition is semifixed. The following types of projectiles have been recovered: High explosive (Long pointed shell); high explosive; chemical; armor piercing. Time fuzes are provided for the smoke, incendiary, and chemical shells. The standard model 88 point detonating (Instantaneous or delay) fuzes are used with the HE and chemical shells.
i. Model 4 (1915) 150-mm howitzer.
Figure 224. Two views of model 4 (1915) 150-mm howitzer.
(1) General description. One of the older type horse-drawn weapons (fig. 224) which nevertheless is still in service. For purposes of transportation the trail breaks in the middle. The barrel is removed from the cradle and placed on the rear portion of the trail, to which has been attached an extra pair of wheels. A limber is attached to each section, and each load may then be towed by six horses. The weapon possesses a vertical sliding breechblock, a hydropneumatic recoil mechanism, and a box type trail.
Caliber 150-mm (5.9 inch). Maximum range 7,000 meters (7,560 yards) (also reported 10,500 yards). Maximum elevation +65°. Maximum depression -5°. Traverse (total) 6°. Weight in firing position 6,100 pounds. Muzzle velocity 1,350 feet per second. Sight Panoramic. Tube length 7 feet 3 inches. Maximum rate of fire 3 to 4 rounds per minute. Weight of HE projectile 80 pounds.
(3) Ammunition. Ammunition is semifixed. The following types of projectiles have been reported: High explosive; armor piercing; shrapnel; and chemical. Time fuzes are provided for the smoke, incendiary, and shrapnel projectiles. The standard point detonating (Instantaneous and delay) fuzes are used with the HE and chemical shells.
j. Model 89 (1929) 150-mm gun.
Figure 225. Two views of Model 89 (1929) 150-mm gun in action.
(1) General description. A tractor-drawn weapon (fig. 225) of improved design employed for long range fire. It is designated by the Japanese Army as a heavy field artillery piece. Although manufacture was commenced in 1929, it is believed that issue was not completed until 1937. For purposes of transportation the barrel is removed from the cradle and placed on a separate carriage. The weapon has a split trail, hydropneumatic recoil mechanism, and an interrupted thread block.
[Photos only -- have been integrated with object descriptions]
Caliber 150-mm (5.9 inch). Maximum range 22,000 yards (also reported as 27,000 yards). Maximum traverse 47°. Weight in firing position. 7,500 kg (16,500 pounds). Maximum rate of fire 1 to 2 rounds per minute.
(3) Ammunition. AP, HE, shrapnel, HE (long pointed shell).
k. Model 96 (1936) 150-mm howitzer.
Figure 226. Model 96 (1936) 150-mm howitzer at maximum elevation.
(1) General description. A well designed and effective weapon (fig. 226) which is, to date, the most modern of its type known to be possessed by the Japanese. It is reported that three modifications exist. Variations, however, are believed to be extremely slight. Mounted on sturdy, rubber-shod, wooden wheels, the weapon is normally tractor drawn. One of the outstanding characteristics is the extreme elevation of 75° which can be obtained. This, however, can be used only when a deep loading pit is dug beneath the breech. It is probable that the weapon could not be fired at an elevation greater than 45° without construction of such a pit. Other features are a long split trail, interrupted thread breechblock, and a hydropneumatic recoil mechanism.
Caliber 150-mm (5.9 inch). Maximum range 10,000 meters (11,000 yards) (also reported 15,000 yards). Maximum elevation +75°. Maximum depression -7°. Traverse (total) 30°. Weight in firing position. 8,765 pounds. Sight Panoramic. Tube length 11.57 feet. Rate of fire 6 to 8 rounds per minute. Weight of HE projectile. 80 pounds.
(3) Ammunition. Semifixed; HE, AP, shrapnel, smoke, incendiary tracer.
l. Model 45 (1912) 240-mm howitzer.
Figure 227. A possible 240-mm howitzer (model number unknown).
It is reported that this piece has a maximum range of 11,000 yards, firing a semifixed round weighing approximately 400 pounds. It is broken down and transported on 10 vehicles.
m. Miscellaneous heavy artillery. In recent years the Japanese have bought 17-cm, 21-cm and
24-cm weapons from Germany and therefore Japanese copies of these may be expected. In addition to the above, the following heavy artillery pieces have been reported, but none have been captured, therefore the characteristics given below have not been confirmed.
Caliber Type Length of bore (inches) Muzzle velocity (feet per second) Type of shell Weight of shell (pounds) Maximum range (yards) Elevation Weight in action (tons) Remarks 24-cm Railway gun 3,560 HE 440 54,500 35.00 Several types reported. 30-cm Howitzer M18 196 1,310 HE 880 12,750 46° 14.72 Unconfirmed. 30-cm Howitzer M 18 324 1,140 HE 1,100 16,600 48° 19.76 Do. 41-cm Howitzer (seige) 538 1,760 HE 2,200 21,200 45° 80.00 Do.
3. ANTIAIRCRAFT ARTILLERY. a. Introduction. It has been emphasized to the Japanese soldier that effective antiaircraft defense depends on the use of all arms. Many of the weapons primarily designed for ground action and previously described under infantry armament also are designed to perform an antiaircraft role.
(1) The new basic infantry weapon model 99 (1939) 7.7-mm rifle (fig. 228) has a rear sight, with arms calculated to give the rifleman the approximate lead required to hit a low flying plane.
Figure 228. Rear sight on model 99 (1939) 7.7-mm rifle.
(2) The model 92 (1932) 7.7-mm heavy machine gun (fig. 229) is provided with an antiaircraft adapter as illustrated in figure 229, and standard antiaircraft ring sights.
Figure 229. Model 92 (1932) 7.7-mm HMG with AA adapter.
(3) The Lewis type model 92 (1932) 7.7-mm machine gun (fig. 230) has a standard mount which can be adapted for antiaircraft defense (see fig. 230).
Figure 230. Model 92 (1932) 7.7-mm machine gun (Lewis type) in position for AA fire.
(4) The model 93 (1933) 13-mm machine gun is shown in figure 231 in a dual mount for anti-aircraft fire.
Figure 231. Model 93 (1933) 13-mm machine gun (Dual mount).
(5) The model 98 (1938) 20-mm AA/AT automatic cannon and probably the 70-mm barrage mortar (Chap. 9, Sec. II) have been designed principally for an antiaircraft role.
(6) In addition to the more common antiaircraft weapons described in detail on the following pages, 120-mm and 127-mm naval antiaircraft guns have been encountered. The latter were in dual mounts.
(7) There are indications that Japanese heavy AA artillery is possibly more modern and of larger caliber than the standard 75-mm model 88, which is the only heavy antiaircraft weapon captured in quantity to date.
(8) Tabulated below are the estimated capabilities of Japanese antiaircraft weapons.
Caliber Weapons Approximate
7.7-mm Model 92 Heavy machine gun. 450 4,000 7.7-mm Model 92 (Lewis) machine gun. 600 4,000 13.2-mm Model 93 machine gum 450 13,000 20-mm Model 98 automatic cannon. 200 12,000 25-mm Model 96 naval automatic cannon. 300 14,000 40-mm Vickers type 14,000 75-mm Model 88 gun 15 30,000 105-mm Model 14 gun 10 36,000 127-mm Model 89 gun 10 40,000
Information concerning fire control equipment used with some of the weapons listed will be found in Chapter 10.
b. Model 96 (1936) type 2, 25-mm antiaircraft-antitank automatic cannon.
Figure 232. Rear view of model 96 (1936) type 2, 25-mm AA/AT automatic cannon, triple mount.
(1) General description. This (fig. 232) is a gas-operated, air-cooled, magazine-fed, full automatic, or semiautomatic machine cannon. It has been found in dual and triple fixed mounts, emplaced customarily around air strips for antiaircraft defense. However, it is capable of a 10 degree depression which makes it effective for direct fire against ground targets.
Traverse and elevation are controlled by hand wheels.
Caliber 25-mm (.984 inch). Estimated vertical range 14,000 feet. Maximum elevation +80°. Maximum depression -10°. Traverse 360°. Magazine capacity 15 rounds. Weight (single gun without mount). 246 pounds. Weight (three guns triple mount). 5,330 pounds. Sight Calculating. Cyclic rate of fire (per barrel) 300 rounds per minute. Muzzle velocity 2,978 feet per second.
(3) Ammunition. The weapon is furnished with high explosive tracer, high explosive, and armor piercing tracer ammunition.
c. 40-mm single and dual antiaircraft and antitank automatic cannon.
Figure 233. Dual mounted 40-mm Vickers type 40-mm AA/AT automatic cannon.
(1) General description. This weapon (fig. 233) is a Vickers type recoil-operated, water-cooled, link belt-fed, automatic or semiautomatic machine cannon. Several of these have been captured. Single mounted guns were marked "Vickers-Armstrongs 1931," but the dual mounted guns were Japanese-manufactured copies. Elevation and traverse are obtained by hand. The weapon is fitted with a telescopic calculating sight and an automatic fuze setter.
[Photos only -- have been integrated with object descriptions]
[Photos only -- have been integrated with object descriptions]
[Photos only -- have been integrated with object descriptions]
Caliber 40-mm (1.57 inch). Maximum vertical range 14,000 feet (approximately). Maximum elevation +85°. Maximum depression -5°. Traverse 360°. Weight in firing position (dual mounted gun). 2,500 pounds (approximately). Sight Calculating. Length of barrel 5 feet 2 inches.
(3) Ammunition. Armor piercing high explosive, high explosive with time fuze, high explosive with point detonating fuze, and tracer.
d. Model 88 (1928) 75-mm antiaircraft gun.
(1) General description. This has been the standard Japanese mobile heavy antiaircraft weapon (fig. 234). Specimens have been found on all airfields captured from the Japanese. It is a truck drawn weapon. For firing, the wheels are removed, and the gun is supported by five outriggers. During transit, the barrel is dropped back on a cradle extension and secured to the ends of two outriggers. The gun has a hydropneumatic variable recoil system and a semiautomatic horizontal, sliding wedge breech mechanism. Fire control instruments captured indicate that the older system of transmitting
corrections to the gun pointers vocally is still in use. However, evidence is on hand that an electrical data transmission system and operation by the "Matched Pointers" method is used sometimes. This gun has been used against ground targets.
Caliber 75-mm (2.95 inch). Maximum range: Vertical 30,000 feet. Horizontal 15,000 yards. Maximum elevation +85°. Maximum depression 0°. Traverse 360°. Weight,overall 5,830 pounds. Muzzle velocity 2,360 feet per second.
(3) Ammunition. High explosive, shrapnel, and incendiary.
e. Model 14 (1925) 105-mm antiaircraft gun.
(1) General description. This is the heaviest mobile Japanese antiaircraft weapon (fig. 235) in use at present. As originally designed, it was not satisfactory, and probably has been redesigned by this time. It has a pedestal mount, horizontal sliding breechblock, and a hydropneumatic recoil system. In firing position the wheels are detached and the gun rests on six outriggers. Thirty to 45 minutes are required to prepare the gun for action. The fuze setter is continuous and automatic.
[Photos only -- have been integrated with object descriptions]
Figure 234. Model 88 (1928) 75-mm antiaircraft gun.
Figure 235. Model 14 (1925) 105-mm antiaircraft gun showing detachable wheels used for transport of piece.
Caliber 105-mm (4.13 inch). Maximum range: Vertical* 36,000 feet. Horizontal* 20,000 yards. Maximum elevation +85°. Maximum depression 0°. Traverse 360°. Weight in firing position 7 tons. Muzzle velocity 2,300 feet per second. * Unconfirmed.
(3) Ammunition. High explosive.
4. NAVAL WEAPONS. a. General. In all areas captured from the Japanese,naval guns have been found installed for coastal and antiaircraft defense. These weapons have been of standard naval design, and in many cases appear to have been removed complete (including turret, mounting, etc.) from the decks of ships. It is known that the Japanese have recovered the armament from beached ships and transferred them to land positions. Since they are on pedestal mounts with wide traverse, they not only are used for coastal defense but also may be brought to bear against inland targets. On the following pages are found examples of the naval guns which are most likely to be encountered. Of these weapons the model 10 (1921) 3-inch gun has been most frequently installed. In addition to those weapons described, guns of 127-mm (5 inch) and 8 inch calibers have been captured. The 127-mm guns have been found mounted in pairs in turrets which permit antiaircraft fire.
b. Model 10 (1921) 3-inch gun.
Figure 236. Model 10 (1921) 3-inch gun.
(1) General description. The Japanese refer to this weapon (fig. 236) as the "8-cm, 40 caliber, high angle gun." Actual measurement shows it to be 76.2-mm (3 inch). A dual purpose piece on a pedestal mount, it is used for antiaircraft as well as coastal defense. To compensate for muzzle preponderance, an equiliberator is mounted in the pedestal. The recoil system
is hydropneumatic, and the breechblock is the sliding wedge type. A noticeable feature is the unusually long recoil cylinder on the top of the tube.
Caliber 76.2-mm (3 inches). Maximum vertical range 26,000 feet. Maximum elevation +75°. Maximum depression -5°. Maximum traverse 360°. Muzzle velocity 2,240 feet per second. Sight Computing type. Tube length 10 feet 81/2 inches. Rate of fire 10 to 12 rounds per minute. Weight of HE projectile 12.7 pounds.
(3) Ammunition. High explosive.
c. Model 3 (1914) 12-cm naval gun.
Figure 237. Model 3 (1914) 12-cm naval gun.
(1) General description. Guns of this type (fig. 237) have been encountered on a number of islands in the Pacific Area. No provision has been made on the gun illustrated in figure 237 to provide for use as an antiaircraft weapon, but other weapons of this caliber allegedly are mounted for such purposes, It has a hydropneumatic recoil system and an interrupted thread breechblock.
Caliber 120-mm (4.72 inch). Length of tube 17 feet 8 inches. Muzzle velocity 2,700 feet per second. Maximum elevation +55°. Maximum depression -5°. Maximum traverse 360°. Maximum range 16,000 meters (17,500 yards).
(3) Ammunition. Separate loading high explosive with a cartridge case used for obturation.
d. Model 3 (1914) 14-cm naval gun.
Figure 238. Model 3 (1914) 14-cm naval gun.
(1) General description. An orthodox type of naval gun and pedestal mount (fig. 238) which has been used as a coastal defense weapon. It has been found both with a shield and mounted in a hand operated turret (casemate). It has a hydropneumatic recoil system and a truncated cone,interrupted thread breechblock.
Caliber 14-cm (5.5 inch). Length (tube and breech) 23 feet 8 inches. Muzzle velocity 2,780 feet per second. Maximum elevation +30°. Maximum depression -7°. Maximum traverse 360°. Maximum range 17,000 meters (18,700 yards).
(3) Ammunition. Separate loading ammunition is used. The projectiles recovered were high explosive, with fuzes designed for use against vessels.
Section IV. TANKS AND ARMORED CARS
1. GENERAL. Until 1929 Japan did not produce any tanks (Sensha) of her own. As usual, her ideas were borrowed from the West, particularly from the British and French, and her first tanks were versions of early Renault, Vickers, and Carden-Lloyd models. Later she turned to Russia for new developments.
Prior to 1941 the Japanese had every opportunity to study the experience of the Allies in war, and it is also reasonable to assume that they are still borrowing freely from other nations. What influence German design will have on future Japanese tank production is still to be seen. During 1935-37 the Japanese apparently were concentrating on tankettes, light tanks, and medium tanks, perfecting one model in each class. It is probable that a few heavy tanks also were produced. Their tanks fall into four main types, divided according to weight. These are:
Classification Short tons
Tankette, Chokei Sensha. Less than 51/2 5 Light tanks, Kei Sensha Less than 51/2-11 5-10 Medium tanks, Chu Sensha. Less than 11-22 10-20 Heavy tanks, Ju Sensha Over 22 Over 20
a. Tank nomenclature. For purposes of general information, annotated photographs illustrating various items of tank nomenclature, are reproduced in figure 239.
Figure 239. Above--Model 95 light tank, illustrating various items of tank nomenclature referred to in this section. Below--A ditching tail (shown at right of photograph).
b. Horsepower. Horsepowers indicated throughout the following text are all Japanese ratings. In each instance, where engines have been examined (e.g., M 2595 Light Tank and M 2597 Medium Tank) it had been clearly shown that they are capable of developing a considerably greater degree of power than that reported. Consequently, wherever possible, theoretically indicated horsepowers, derived from computations based on engine specifications, have been shown.
c. Crews. Crew compartments so far examined are limited in size, and little attention has been given to comfort. The turret and hulls, however, have been found to be well insulated with material such as asbestos.
d. Armament. In the light and medium tanks, relatively low velocity 37- and 57-mm guns are used. There is also evidence that a 47-mm gun is used in medium tanks. Although a machine gun is normally mounted in the rear of the turret, and is of some tactical use, it is doubtful if the main turret weapon and rear machine gun can be fought at the same time. The use of armored sheaths is standard for all machine gun barrels. All machine guns are ball mounted, and the main turret armament has a limited traverse, independent of that of the turret. In both the light and medium tanks a hull machine gun is mounted.
e. Armor. Japanese tanks, so far examined, have been lightly armored, but the plates tested have been of good quality. In the arrangement of armor, use
[Photos only -- have been integrated with object descriptions]
has been made of deflection angles, but not to any considerable degree. In many cases reentrant angles have been formed, but no steps have been noted to protect turret rings or mantlets against jamming or splash.
f. Engines. Diesels are mainly used.
g. Suspension. In all these models the same basic suspension is used. This consists of bell-crank arms carrying rocking pairs of wheels. These arms are sprung by horizontal suspension springs, protected by armored casings.
h. Vision. Little use has been made of periscopes, etc., vision being dependent on slits, occasionally backed by a glass block.
i. Doors. The question of escape in case of fire or other emergency has received little attention.
j. Communication. As far as known,radio is used only on the basis of 1 set per platoon in the medium tanks, and probably not at all in light tanks and tankettes.
k. Insignia. Army tanks have a 5 point star mounted on the front, while navy tanks have the anchor insignia. Many tanks either fly or carry the national flag as an identification sign. Naval tanks usually have the small naval insignia painted on the sides.
l. Future developments. (1) General. It would be dangerous to measure Japanese tanks by models now known to exist. Evidence exists that Japan is in close touch with German development, and it may well prove that Japanese tanks will show considerable German influence. That Japanese tank design is not stagnant is clearly indicated by the recently captured new type amphibious tank described in this section. In this particular tank the coaxially mounted machine gun is considered of significance. Hitherto, there has been no evidence that the Japanese have mounted weapons in this manner, so it must be considered indicative of a new trend.
(2) Armament. High velocity antitank guns, of at least 75-mm caliber, and modern high performance armor piercing high explosive ammunition, as well as hollow charge types, may be expected. As a temporary measure, earlier model tanks, such as the medium which mounts a 57-mm gun, could be given a new lease of life in a tank vs tank role by providing hollow charge ammunition.
(3) Armor. Early model tanks may be fitted with additional plates at vulnerable points; modern tanks can be expected to have heavier armor. Armor angles can be expected to receive more attention.
(4) Performance. So far Japan has used high power weight ratios. If these are maintained, high speeds and good cross country mobility will result. Suitable preparations, depending on tactical roles, may be undertaken to increase fording ability.
(5) Communication. Radio may be introduced down to individual tanks.
(6) Other improvements. Special items, like vision aids,escape facilities, and gun fume extraction may be developed. As an illustration of the trend in tank improvements,in the new type amphibious tank, many of the objectionable features of the older designs have been overcome. Reentrant angles have been eliminated, while the hull design has been simplified and welded construction used throughout. In addition, firepower has been improved by the substitution of a higher velocity 37-mm weapon and the coaxial mounting of a machine gun.
(7) Heavy tanks. The Japanese are capable of designing an efficient, modern, heavy tank, but it is thought that they may have difficulty in its quantity production. In the past the Japanese have produced a number of heavy tanks which must now be considered obsolete.
m. Miscellaneous types. Reports suggest that Crane, Repair, and Supply tanks may exist. These are believed to consist basically of a tank chassis, less the turret, and fitted out according to requirements.
2. TANKETTES. a. Tankette model 92 (1932).
Figure 240. Model 92 (1932) tankette.
Development of the tankette has been progressive. In China it was used on a wide scale by Japan in a cavalry and reconnaissance role. In addition it is employed for towing tracked trailers carrying supplies and ammunition. Both welded and riveted construction are used throughout the hull (fig. 240). The suspension is an early Japanese development. Four point suspension of the hull is achieved by use of bell cranks, resisted by armored compression springs on each side. Four rubber tired bogie wheels, two return rollers, and outside center guide tracks are used. Front sprocket drive and left rear mounted engine are employed.
Approximate specifications Weight 3 tons. Length 10 feet 3 inches Width 5 feet 3 inches. Height 5 feet 4 inches. Clearance 131/2 inches. Crew 2 men. Armor 6 to 14 mm (0.24 to 0.55 inch). Armament 1-7.7 MG ball mounted. Ammunition 1,980 rounds. Engine, 4 cylinder 32 horsepower, gasoline. Transmission 4 forward, 1 reverse. Ground contact 6 feet. Width of track 5 inches. Track pitch 3 inches. Diam. sprocket 21 inches. Diam. bogie wheel 15 inches. Diam. rear idler 15 inches. Height to center of sprocket 25 inches. Approximate maximum performance Speed 25 miles per hour. Range of action 100 miles. Gradient 27°. Obstacles: Trench 4 feet 6 inches wide. Step 2 feet 1 inch high. Ford 2 feet deep.
b. Tankette model 94 (1934).
Figure 241. Model 94 (1934) tankette.
This tank embodies the general design of the original tankette (fig. 241). The rear idler has been replaced by a trailing idler, while the drive sprocket has been lowered accordingly. Suspension: bell crank, with armored compression springs. Rubber tired bogie wheels, and two return rollers are used. The engine is reported to be a four cylinder in line Ford tractor motor of 32 hp. Steering is the clutch brake principle.
Approximate specifications Weight 3.4 tons. Length 11 feet. Width 5 feet 3 inches. Height 5 feet 4 inches. Clearance 12 inches. Crew 2 men. Armor 4- to 12-mm (0.16 to 0.47 inches). Armament 1-7.7 MG. Traverse 360°. Ammunition 1,980 rounds. Fuel capacity 23.3 gallons. Approximate maximum performance Speed 26 miles per hour. Range of action 100 miles (estimated). Gradient 27° (also reported as 30°). Obstacles: Trench 4 feet 6 inches wide. Step No details. Ford 2 feet deep.
c. Tankette model 97 (1937).
Figure 242. Model 97 (1937) tankette.
Various specifications have been reported for a tank of this size (fig. 242). It is not certain if these refer to several different models of the M2597 or whether they relate to an even later model, the M2598 (1938). The suspension of this tank remains unchanged from that of the M2594 tankette. The hull, however, has been completely redesigned. More room has been provided in the turret to accommodate the 37-mm tank gun. As an alternative, a machine gun sometimes is mounted in place of the 37-mm weapon. Particular attention has been paid to a more simple design of the front plate and improved deflection angles. This tank is powered by a 4 cylinder, in line, air-cooled Diesel engine of 48 horsepower. Engine specifications indicate, however, that this engine would theoretically develop 105 hp at 2000 rpm.
Approximate specifications Weight 4.5 tons. Length 12 feet. Width 6 feet. Height 6 feet. Clearance 14 inches. Crew 2 men. Armor 4 to 12-mm (0.16 to 0.47 inches). Armament 1-37-mm gun. Ammunition 96 rounds. Transmission 4 forward 1 reverse. Steering Drive shaft brake. Fuel capacity 20 gallons (also reported 24 gallons). Approximate maximum performance Speed 28 miles per hour. Gradient 30° (also reported as 34°). Obstacles: Trench 5 feet 3 inches wide. Step No details. Ford 2 feet 6 inches deep.
3. LIGHT TANKS. a. Light tank model 93 (1933).
Figure 243. Model 93 (1933) light tank.
This tank (fig. 243) represents the early development of the light tank series. The box type hull is divided into three compartments. The center portion is the fighting compartment, the superstructure of which overhangs the tracks. The right hand side at the front of the fighting compartment is extended forward to form a sponson for the ball mounted machine gun. The driver sits left, while the hull gunner sits right, in the forward compartment. The 6 cylinder gasoline engine is mounted to the rear of the hull. The suspension consists of six small, rubber-tired bogie wheels mounted on three semi-elliptic springs on each side. There are three return rollers. Front sprocket drive and center guide track are employed. The turret mounts one machine gun to the front, while some photographs
show another mounted in the rear. Traverse 360°.
Approximate specifications Weight 7.8 tons. Length 14 feet 8 inches. Width 5 feet 11 inches. Height 6 feet. Clearance 15 inches. Crew 3 men. Armor Up to 22-mm (0.87 inch) (reported). Armament 1 light mg (Hull), 1 light mg (turret). Steering Clutch brake. Ground contact 10 feet. Engine 6 cylinder 85 horsepower Mitsubishi. Cooling Air. Width of track 71/2 inches. Pitch of track 31/2 inches. Diam. of sprocket 1 foot 6 inches. Diam. of rear idler 1 foot 3 inches. Height of sprocket center. 1 foot 8 inches. Approximate maximum performance Speed 28 miles per hour. Obstacles: Trench 5 feet 8 inches wide. Step 1 foot 6 inches high. Ford 2 feet 8 inches deep.
b. Light tank model 93 (1933) improved.
Probably produced in 1933-34, this tank is an improved model of the M2593 in that the suspension has 4 bogie wheels coupled together in pairs via transverse even lever. It is not clear whether the
apex is mounted to the hull by means of a bell crank or a stub shaft. Likewise it is not clear whether the armored compression spring is used at this stage of development. Two return rollers are used, as well as front sprocket drive. The hull of this vehicle is almost identical with that of the previous model.
Approximate specifications Weight 7.8 tons. Length 14 feet 8 inches. Width 5 feet 11 inches. Height 6 feet. Clearance 15 inches. Crew 3 men. Armor up to 22-mm (0.87 inch) (reported). Armament 1-37-mm tank gun, 1 turret machine gun. Engine 6 cylinder,85 horsepower air-cooled (Mitsubishi). Ground contact 9 feet 6 inches. Width of track 71/2 inches. Track pitch 31/2 inches. Diam. bogie wheel 15 inches. Steering Clutch brake. Fuel Gasoline. Approximate maximum performance Speed 28 miles per hour. Range of action 120 miles. Obstacles: Trench 5 feet 8 inches wide. Step 1 foot 6 inches high. Ford 2 feet 10 inches deep.
c. Light tank model 95 (1935).
Figure 244. Model 95 (1935) light tank.
In production from 1935 to at least 1942, there is a great deal of evidence to show that Japanese light tank design was frozen in 1935 to produce large numbers of these tanks (fig. 244). The hull has been completely redesigned. The suspension has been improved to utilize the bell crank and armored compression spring. The tank is powered by a 6 cylinder in-line air-cooled Diesel engine. The hull is constructed over an angle iron frame, with backing plates at the corners; insulation is provided by layers of woven asbestos. Ammunition for the 37-mm tank gun is carried stored in clips and racks in the fighting compartment. Two types are known. Model 94 shell--presumably HE of 1934 model, and model 94 AP shell--presumably APHE of 1934 model. 1170 rounds of 7.7-mm ammunition are stored in magazines just below the hull machine gun. 1800 rounds are carried in the fighting compartment for turret machine gun.
Specifications from actual examination Weight 10 tons (laden). Length 14 feet 4 inches. Width 6 feet 9 inches. Height 7 feet. Clearance 151/2 inches. Crew 3 men. Armor 6 to 12-mm (0.24 to 0.47 inches). Armament 1-37-mm model 94 tank gun, 1 7.7-mm rear turret mg, 1 7.7-mm hull mg. Ammunition: 37-mm 130 rounds. MG 2,970 rounds. Engine 110 horsepower at 1,400 rpm (240 theoretically indicated h.p. at 2,000 rpm based on reported engine specifications).
Specifications from actual examination--Continued Transmission 4 speeds forward, 1 reverse. Steering Clutch brake. Ground contact 7 feet 8 inches. Width of track 97/48 inches. Track pitch 33/4 inches. Diameter sprocket 21 inches. Diameter bogie wheel 221/4 inches. Diameter rear idler 21 inches. Height to center of sprocket. 32 inches. Approximate maximum performance Speed 28 miles per hour. Range of action 100 miles. Gradient 40°. 30° for long climb. Obstacles: Trench 6 feet wide. Step 2 feet 8 inches high. Ford 3 feet 3 inches deep.
d. Light tank,"Keni."
It is considered that this tank is not an obsolete model; it probably has been produced subsequent to the M2595 light tank. The 47-mm gun is a significant feature.
Approximate specifications Weight 7.7 tons. Length 13 feet 6 inches. Width 7 feet. Height 5 feet 11 inches. Ground clearance 14 inches. Crew 3 men. Armament 1 47-mm gun and 1 MG. Armor 6 to 16-mm (0.24 to 0.63 inches). Engine 140 horsepower. Approximate maximum performance Speed 31 miles per hour. Gradient 34°. Obstacles: Trench 6 feet 7 inches wide. Ford 2 feet 3 inches deep.
4. MEDIUM TANKS. a. Medium tank model 89 A (1929).
Figure 245. Model 89 A (1929) medium tank.
This tank (fig. 245) is characterized by its box type hull, short front plate with door to the right, vertical front plate above this with hull machine gun mounted to the right, and small cupola hinged to top of turret. Five small return rollers are mounted along a girder. There are 9 small bogie wheels. The leading bogie wheel is independently mounted, while protective skirting all but covers the suspension. This tank is rear sprocket driven and powered by a gasoline engine. There is a rear turret machine gun, while the main armament is a 57-mm low velocity gun. Traverse 360°.
Approximate specifications Weight 13 tons. Length 19 feet 3 inches. Width 7 feet 1 inch. Height 8 feet 6 inches. Clearance 19 inches. Crew 4 men. Armor 6 to 17 mm (0.24 to 0.67 inches), also reported as 17 to 25 nun (0.67 to 1 inch). Armament 1-57-mm. 1 Hull mg, 1 Rear turret MG. Ammunition 57-mm 100 rounds, SAA 2,745 rounds. Engine 136 brake horsepower. Ground contact 12 feet. Width of track 12 inches. Track Ditch 6 inches. Diam. rear sprocket 30 inches. Diam. bogie wheel 9 inches. Diam. front idler 36 inches. Height to center of idler. 33 inches. Fuel Gasoline. Approximate maximum performance Speed 15 miles per hour. Range of action 100 miles. Gradient 34°. Obstacles: Trench 8 feet 3 inches wide. Step 2 feet 9 inches high. Ford 3 feet 3 inches deep.
b. Medium tank model 89 B (1929).
Figure 246. Model 89 B (1929) medium tank.
Also reported as the M2592 (1932), this tank (fig. 246) differs from the M 89 A in that it has a long front which combines with the driver's front plate. The turret has been completely redesigned to include a new type of cupola and a more practical aperture for mounting the 57-mm gun. The gasoline engine has been replaced by a Diesel engine, but the armament and the armor thickness remain the same.
Approximate specifications Weight 13 tons. Length 19 feet 3 inches. Width 7 feet 1 inch. Height 8 feet 6 inches. Clearance 19 inches. Crew 4 men. Armor 6- to 17-mm (0.24 to 0.67 inches), also reported as 17- to 25-mm (0.67 to 0.98 inches). Armament 1-57-mm, 1 Hull mg, 1 rear turret mg. Ammunition 57-mm, 100 rounds, SAA 2745 rounds. Engine 120 brake horsepower. Ground contact 12 feet. Width of track 12 inches. Track pitch 6 inches. Diameter rear sprocket. 30 inches. Diameter bogie wheel 9 inches. Height to center of idler 33 inches.
Approximate maximum performance Speed 15 miles per hour. Range of action 100 miles. Gradient 34°. Obstacles: Trench 8 feet 3 inches wide. Step 2 feet 9 inches high. Ford 3 feet 3 inches deep.
c. Medium tank model 94 (1934).
Figure 247. Model 94 (1934) medium tank.
Probably produced in 1934 in quantity, this tank (fig. 247) has been extensively used in China. Comparison with the M 2589 models A and B shows that the return rollers have been reduced to four, the girder has been removed, and the skirting redesigned. The long front plate has a door on the left, above which is mounted the hull machine gun. The driver sits to the right. The Diesel engine has been increased to 160 brake horsepower. With the above exceptions the M 2594 is practically identical with the M2589 B. This tank is often seen with a ditching tail.
Specifications Weight 15 tons. Length (including ditching tail). 23 feet. Width 7 feet 1 inch. Height 8 feet 6 inches. Clearance 19 inches. Crew 4 men. Armor 6- to 17-mm (0.24 to 0.67 inches). Armament: Main 1-57-mm gun. MG 1 Hull MG.,1 Rear turret MG. Ammunition 57-mm 100 rounds, SAA 2,750 rounds. Engine 160 brake horsepower air-cooled Diesel. Ground contact 12 feet. Width of track 12 inches. Track pitch 6 inches. Diam. rear sprocket 30 inches. Diam. front idler 36 inches. Diam. bogie wheel 9 inches. Height to center of front idler. 33 inches. Approximate maximum performance Speed 20 miles per hour. Range of action 100 miles. Gradient 34°. Obstacles: Trench 9 feet wide. Step 2 feet 9 inches high. Ford 3 feet 3 inches deep.
d. Medium tank model 97 (1937).
Figure 248. Model 97 (1937) medium tank.
Probably produced in 1937-1940. Some of the design features of this tank (fig. 248) are directly due to lessons learned from tankette and light tank construction. The four central bogie wheels are paired and mounted on bell cranks resisted by armored compression springs. Each end bogie wheel is independently bell crank mounted to the hull in a similar manner. There are three return rollers, the center one carrying the inside half of the track only. Backing plates are used to reinforce hull joints and corners. Numbers of these tanks are known to have been used in Burma. Other specimens were encountered on Guadalcanal.
Specifications by examination Weight 15 tons. Length 18 feet. Width 7 feet 8 inches. Height 7 feet 8 inches. Clearance 16 inches. Crew 4 men. Armor 8- to 25-mm (0.32 to 0.98 inch). Armament: Main 1--57-mm model 97 gun. Hull 1--7.7-mm model 97 mg. Rear turret 1--7.7-mm model 97 mg. Ammunition 57-mm 80 rounds HE--40 rounds APHE, MG 2350 rounds Ball, 1350 rounds AP. Engine 12 Cylinder Diesel. Horsepower 150 (365 theoretically indicated hp at 2,000 rpm based on reported engine specifications). Transmission 4 speeds forward, 1 reverse--high low range. Steering Clutch brake. Ground contact 12 feet 8 inches. Width of track 13 inches. Track pitch 5 inches. Diameter front sprocket 23 inches. Diameter rear idler 23 inches. Diameter bogie wheel 21 inches. Height to center of sprocket. 321/2 inches. Fuel consumption 4 gallons per hour. Approximate maximum performance Speed 25 miles per hour. Radius of action 100 miles. Gradient 34°. Obstacles: Trench 8 feet 3 inches. Step 2 feet 6 inches high. Ford 3 feet 3 inches deep.
e. Medium tank (unidentified).
Figure 249. Unidentified medium tank (basically the same design as the model 97 medium tank).
Probably produced in 1939, this tank is believed to have been employed on Corregidor. Its identity (fig. 249) has not been confirmed. With the exception of the turret and main armament, it is basically the same in design as the model 2597 medium tank. The turret has been improved to accommodate a modern high velocity gun, believed to be of 47-mm caliber. As usual there is a rear turret machine gun. The long overhanging rear portion of the turret would therefore provide more room for the simultaneous firing of both these weapons. With the exception of the turret and armament, specifications are believed the same as those for the model 2597 (1937) medium tank.
5. HEAVY TANKS. a. Little is known of Japanese heavy tanks. As far as can be ascertained, they have been produced only in limited numbers, and those seen have been reported as being clumsy, lightly armored, and of poor performance. In addition, some years prior to the war, a limited number of "heavies" were bought by Japan. The majority of these (including the "Vickers Independent," weight 32 tons) are obsolete.
b. In 1939, the battle of Nomonhan clearly demonstrated the inadequacy of Japanese tanks. At the conclusion of this conflict considerable reorganization took place within the Japanese Army. It is reasonable to assume, therefore, that Japan is now in possession of a modern heavy tank.
6. AMPHIBIOUS TANKS. a. General. Little specific information is available concerning the Japanese development of this type of tank. Similar to the ground tanks, the first amphibians were purchased from foreign countries, a specific instance being the 3 to 4 ton "Vickers amphibious light tank." Several modifications of this are believed to have been produced by the Japanese.
b. Model 2594 (1934) light amphibious tank.
An unconfirmed report indicates the existence of a tank, tentatively identified as the model 2594 (1934) light amphibious tank, possessing the following specifications:
Weight 4 tons. Length 14 feet 10 inches. Width 7 feet 11 inches. Height 8 feet 10 inches. Armament 1-37-mm, 1 MG. Armor Up to 20-mm (0.79 inch).
It is considered that the armor and armament, coupled with the dimensions, are hardly compatible with a weight of only 4 tons.
c. New type amphibious tank.
Figure 250. New type amphibious tank.
The photograph illustrated in figure 250 shows the most modern trend yet encountered in Japanese tank design. No information is available to indicate the model number or date of production. The system of flotation is extremely interesting and is achieved by attachment of a bow and stern pontoon. Pontoons conform to the shape of the hull, and are attached by a series of pincer clamps, which are controlled by a handwheel situated inside the tank, enabling their quick release if so desired. The volume of the bow pontoon is estimated at 220 cubic feet, and that of the stern pontoon at 105 cubic feet. Two rudders are situated in the stern pontoons and are operated from within the hull. Two propellers are fitted to the rear of the tank. With exception of the suspension, this tank is an entirely new Japanese design, the hull being simplified, reentrant angles eliminated, and welding used throughout. In addition, the round turret is of a new type, characterized by its considerably increased diameter, giving the impression of greatly reduced height. To prevent water entering, rubber seals are fitted around all openings up to and including the turret ring. The tank hull is not divided into individual compartments. Suspension closely resembles that of the M 2594 and M 2597 tankettes, excepting that the compression springs are mounted within the vehicle. No specific details are available, but there are definite indications that the primary armament of this vehicle shows improvement. Of particular significance is the coaxial mounting of the turret machine gun. As no Japanese tank has been encountered in the past with its weapons so mounted, this fact must be regarded as a radical departure in their tank
design. The following data have been obtained from a preliminary examination:
Specifications Weight: Tank (only) 13 tons (estimated). Pontoons (only). 3 tons (estimated). Length: Tank (only) 15 feet 8 inches. With pontoons 24 feet 7 inches. Width 9 feet 2 inches. Height 7 feet 6 inches. Ground clearance 14 inches. Crew 5 men. Armor: Turret: Sides 13.2-mm (0.52 inch). Top 6-mm (0.24 inch). Hull: Front 12-mm (0.47 inch). Sides 9-mm (0.35 inch). Rear 8-mm (0.32 inch). Top 6-mm (0.24 inch). Bottom 8.5-mm (0.334 inch). Armament 1-37-mm model 1 (1941) in turret, 1-7.7-mm MG coaxially mounted, 1-7.7-mm MG in hull forward. Engine 6 cylinder air-cooled Diesel (reported to be identical with that in the model 2595 Light Tank). Fuel capacity 66 gallons (2 tanks). Suspension 2 bogies on each side of vehicle. Bogies consist of 2 wheels mounted on a transverse even lever. Rear trailing idler serves as an additional bogie. Track: Length,overall 32 feet 1 inch. Ground contact- 11 feet 1 inch. Width 1 foot. Angle of approach. 561/4°. Vision apertures and pistol ports.: Hull 1-4 x 1 inch slit for driver; 1-4 x 1/8 inch slit for hull gunner; 4 pistol ports, one on each quarter of the hull. Turret 2-3.75 inch diameter vision ports, one on each side of 37-mm gun. 2-4 x 1/8 inch slits, one on each side of turret. 3 pistol ports, one at each side and one at the rear. Safety glass Shatter proof blocks are clamped over all vision slits to prevent "bullet splash" or entrance of water. Vision ports are protected by 3-inch safety glass windows.
7. ARMORED CARS. a. Armored car model 25 (?) "Vickers Crossley."
Figure 251. Model 25 (?) "Vickers Crossley" armored car.
This armored car (fig. 251) may be classified as obsolete and is readily identified by its hemispherical turret. A small domed cupola, in two hinged halves, surmounts the turret. Traverse 360°, the turret mounts only two machine guns, although there is provision for four. Each of the weapon openings is covered with a small flap, which is closed when the gun is removed. All machine guns are of the Vickers type. Guns are ball mounted and have a limited traverse independent of that of the turret. The front wheels are single, while the rear wheels are dual. The chassis is believed to be a standard commercial type weighing 2.8 tons. In the past, this armored car was incorrectly classified as the "OSAKA" model 2592 (1932).
Approximate specifications Weight 5.4 tons. Length 16 feet 6 inches. Width 6 feet 2 inches. Height 8 feet 6 inches. Ground clearance 10 inches. Crew 4 men. Armament 2 Vickers' MGs. Armor 5.5-mm (0.217 inches). Ammunition 3,500 rounds. Engine 4 cylinder, 50 horsepower "Crossley." Fuel Gasoline. Fuel capacity 26 gallons. Cooling Water. Drive Rear axle.
Approximate maximum performance Speed 40 miles per hour. Range of action 124 miles.
b. Armored car model 92 (1932) naval type.
Figure 252. Model 92 (1932) naval type armored car.
This probably was produced in 1932. The insignia indicates that it (fig. 252) is a naval vehicle. In addition to the machine gun in the front and rear, one is mounted on each side of the hull. One is also mounted in the turret. Semi-elliptic springs provide the suspension for the 6-disc wheel chassis. Wheels are fitted with pneumatic tires. To prevent bellying, when crossing rough terrain, auxiliary wheels are mounted on the frame to the rear of the front wheels. The radiator is provided with armored shutters. Reconnaissance and guard duties constitute the chief role for this vehicle.
Approximate specifications Weight 7 tons. Length 15 feet 9 inches. Width 5 feet 11 inches. Height 7 feet 6 inches. Ground clearance 16 inches. Crew 4 men. Armament 5 MGs. Armor 8 to 11 mm (0.32 to 0.43 inch). Engine 6 cylinder,85 brake horsepower. Cooling Water. Approximate maximum performance Speed 50 miles per hour.
c. Armored car model 92 (1932) "OSAKA."
Until recently,considerable confusion has existed between this armored car and the model 25(?) "Vickers Crossley," specifications of the "Osaka" being attributed to the latter vehicle. While no details are available, it is believed that the "Osaka" is of Japanese origin, a standard commercial chassis being used for its manufacture. Wheels are fitted with pneumatic tires, the front single and the rear dual mounted. Machine guns are of the Vickers type; one is mounted in the front of the turret. As an extensive free traverse has been allowed to this gun, it is considered possible that the turret is fixed and cannot be traversed. As the design of the driver's front plate gives no indication that the second machine gun is mounted in the front of the hull, it is probable that this weapon is mounted at the rear of the vehicle.
Approximate specifications Weight 6.4 tons. Length 16 feet 5 inches. Width 6 feet. Height 8 feet 8 inches. Ground clearance 11 inches. Crew 4 to 5 men. Armament 2 MGs. Armor 8 to 11 mm (0.32 to 0.43 inches). Engine 4 cylinder, 35 horsepower. Fuel Gasoline. Cooling Water.
Approximate maximum performance Speed 37 miles per hour. Range of action 150 miles.
d. Armored car model 93 (1933) "Sumida".
Figure 253. Model 93 (1933) "Sumida" armored car.
This vehicle (fig. 253) has been used extensively in China and was specially designed to run either on railway lines or hard roads. To effect the change from rails to road, the vehicle is raised up by 4 built-in jacks. Solid rubber tires then are placed over the 6 flanged steel wheels, and the vehicle can be driven off the rails onto the road. This operation
is said to take 10 minutes. When traveling on rails, 3 solid rubber tires are attached on each side of the hull.
Approximate specifications Weight 7.5 tons. Length 21 feet 6 inches. Width 6 feet 3 inches. Height 9 feet 8 inches. Ground clearance 16 inches. Crew 6 men. Armament 1 MG mounted in turret. Slits for rifles or LMGs. Armor Up to 16-mm (0.63 inch). Engine 40 horsepower. Fuel Gasoline. Vision Drivers visor slits and gun ports. Approximate maximum performance Speed: On rails 37 miles per hour. On road 25 miles per hour.
8. ARMAMENT OF JAPANESE ARMORED UNITS. The following weapons are known to be used in Japanese tanks and armored cars:
a. Model 91 (1931) 6.5-mm MG.
Figure 254. Model 91 (1931) 6.5-mm tank machine gun. Hopper and butt are missing.
This weapon (fig. 254) is merely the infantry machine gun, model 11 (1922) adapted to tank requirements by the removal of the bipod. It is considered possible that it has now been replaced largely by the better designed and heavier calibered model 97 (1937) 7.7-mm machine gun. For detailed characteristics of the model 11, see chap. 9, sec. II.
b. Model 97 (1937) 7.7-mm MG.
Figure 255. Model 97 (1937) 7.7-mm tank machine gun. (The lower figure illustrates the armor shield normally used when this machine gun is mounted in a tank.)
This is the standard MG (fig. 255) at present used in Japanese tanks. A shoulder controlled weapon, it is fitted with conventional sights. It may readily be identified by the specially designed modified stock. When used for tank purposes, a fixed focus telescopic sight of 11/2 power x 30° field of view is usually fitted. To prevent injury to the gunner, a heavy rubber eye pad is attached to the rear of the telescope. By the addition of a bipod, this weapon may be converted to ground purposes.
Characteristics Caliber 7.7-mm (.303 inch). Principle of operation Gas operated, full automatic only. Type of feed Vertical box. Magazine capacity 30 rounds. Length of barrel 28 inches. Over-all length 46 inches. Weight 34 pounds. Cyclic rate of fire 500 rounds per minute. Ammunition Fires special model 99 rimless.
c. Model 94 (1934) 37-mm tank gun.
Figure 256. Model 94 (1934) 37-mm tank gun.
Although bearing the same type number as the field piece of similar caliber, these two weapons must in no way be confused, for each has been designed for its own specific purpose. In addition, ammunition is NOT interchangeable, as the chamber of the tank gun (fig. 256) is considerably smaller than that of the antitank gun. This gun appears to constitute the primary armament of Japanese light tanks. In addition, there is evidence that one model of tankette is similarly equipped. It is considered that this weapon has neither the performance nor armor piercing qualities of the U. S. 37-mm tank gun. Mounted in the turret, the Japanese weapon is carried by two sets of trunnions, one set allowing the gun a limited "free" traverse, while the other permits the gun to be elevated or depressed. Traverse and elevation/depression are manually applied by means of an adjustable shoulder rest attached to the left side of the cradle. The main traverse is obtained by rotating the turret. Telescopic sight, pistol type grip, and trigger are mounted to the left of the gun.
Characteristics Caliber 37-mm (1.46 inch). Muzzle velocity 2,100 feet per second (estimated). Maximum elevation +24°. Maximum depression -20°. Traverse 10° right,10° left, without rotating the turret. Breech mechanism Vertical sliding, semiautomatic in action. Recoil system Hydrospring. Ammunition APHE and HE.
d. Model 1 (1941) 37-mm tank gun.
This gun has been recovered, but detailed examination has not yet been made. However, from the length of the barrel and the size of the chamber, a muzzle velocity much higher than that of Model 94 (1934) 37-mm tank gun may be expected, and it is believed that this gun will have good armor-piercing qualities.
e. Model 97 (1937) 57-mm tank gun.
Figure 257. Model 97 (1937) 57-mm tank gun (showing its appearance from the outside of the turret).
It is believed that this weapon (fig. 257) is the standard heavy armament of Japanese medium tanks. The gun is mounted in the turret and is manually controlled. Elevation and depression are free. The weapon may be traversed also approximately 10 degrees to left and right, independently of the turret.
Although several specimens have been captured, the condition of the guns has prevented a detailed examination. Sufficient information is available, however, to indicate that it is a short barrelled, medium velocity weapon that would be more suitable for employment against ground troops. This would appear to conform to the Japanese past policy of using mainly tanks for the close support of infantry, rather than for tank vs. tank action. No information is available to indicate if this policy is still being adhered to, or whether the future trend will be to substitute a high velocity weapon similar to the model 1 (1941) 47-mm antitank gun (for characteristics see ch. 9, sec. II).
Characteristics Caliber 57-mm (2.24 inches). Weight 283 pounds. Length of tube 3 feet 1.6 inches. Length of chamber 5.1 inches. Number of lands and grooves. 20. Maximum length of recoil. 11 inches. Maximum elevation +45°. Traverse 10° right,10° left, without rotating the turret. Type of breechblock Vertical sliding. Ammunition Only high explosive rounds have been recovered to date. They are characterized by a rather short cartridge case.
f. Model 90 (1930) 57-mm tank gun. No information is available concerning this weapon. Photographs of early Japanese tanks suggest that this gun is a short barrelled piece resembling the model 97. It is probable that the model 90 was the forerunner of the latter weapon.
g. 47-mm tank gun. While no details are available, indications are that the Japanese are now mounting a 47-mm gun in certain of their medium tanks. It is also reported that a model of the light tank is mounting a weapon of this caliber. It is reasonable to assume that this gun is a modern, high velocity antitank piece, in all probability, a modified form of the model 1 (1941) gun adapted to tank purposes. For characteristics of the model 1 (1941) 47-mm antitank gun, see section II, chapter 9.
Section V. CHEMICAL WARFARE
1. GAS MASKS. a. General. All the known models of gas masks used by Japanese military forces are of the air hose and separate canister type. Rubber stoppers are provided to permit sealing of the canister when not in use to protect the contents against moisture. In general the Japanese gas masks afford good protection against the common types of war gases; their face-pieces, however, are uncomfortable when fitted to the average occidental face. The American canisters can be fitted to these masks for better protection against hydrocyanic acid (AC) and cyanogen chloride (CC) gas than the Japanese canister gives. The existence of horse gas masks of the damp mask type has been reported.
b. Army gas mask "model 95".
Figure 258. Army gas mask "model 95".
It has a khaki stockinette covered face-piece (fig. 258) with molded tissot tube and circular eyepieces with removable threaded rims. The khaki-colored canister is approximately 6 inches high, 5 inches wide and 23/4 inches thick. The carrier is a rectangular canvas bag. A rubberized hood is sometimes attached to this mask to protect head and shoulders.
c. Army gas mask "model 99".
Figure 259. Army gas mask "model 99".
Similar in appearance to "model 95" (fig. 259), it is fitted with a rubber nosepiece held inside the face-piece by a stud, and has a short canister only about 41/2 inches high.
[Photos only -- have been integrated with object descriptions]
[Photos only -- have been integrated with object descriptions]
[Photos only -- have been integrated with object descriptions]
[Photos only -- have been integrated with object descriptions]
d. Civilian gas mask type 1, model A (improved).
Figure 260. Civilian gas mask type 1, model A (Improved).
This gas mask (fig. 260), although originally designed for civilian use, also is issued to Army personnel. The face-piece is tan colored with molded tissot tube and circular eyepieces with fixed rims. The tan colored canister is approximately 43/4 inches high, 51/4 inches wide and 23/4 inches thick. The carrier is a small rectangular canvas bag with a 11/2 inch diameter hole in the bottom.
e. Navy gas mask model 93, No. 2.
Figure 261. Navy gas mask model 93, No. 2.
Gray colored face-piece, with aluminum rimmed eyepieces, (fig. 261) and a tissot tube held by two metal studs. The grey canister is approximately 51/2 inches high, inches wide and 3 inches thick. An auxiliary canister, approximately 2 inches high, can be attached to the base of the main canister to give protection against carbon monoxide. A fabric carrier bag is provided for the face-piece only; the canister is carried on the back held in a fabric harness.
f. Navy gas mask model 93 No. 3.
Figure 262. Navy gas mask model 93, No. 3.
The face-piece (fig. 262) is practically identical with that of No. 2. However, the valve housing may be made of brown plastic instead of aluminum. The canister is approximately 41/2 inches high, 53/4 inches wide and 3 inches thick. The carrier is a canvas bag tapered toward the bottom which is provided with 21/2-inch diameter hole. This model may be used with the auxiliary carbon monoxide canister provided for the No. 2 model.
2. GAS MASK ACCESSORIES. The carriers of most Army gas masks are provided with a packet of anti-fog discs (fig. 263), a container for antifreeze liquid (fig. 264), a hinged metal clamp for closing the air hose, and a cleaning rag. In addition
Figure 263. Package of anti-fog discs.
Figure 264. Metal flask for antifreeze liquid.
a small cloth bag attached to the carrying straps contains a can of decontaminant powder. The anti-fog discs are carried in a thin, black, plastic box. These discs are used to cover the eyepieces when the temperature is below the freezing point. The antifreeze liquid container is either a flat square metal flask or a black cylindrical syringe (fig. 265)
Figure 265. Syringe for antifreeze liquid.
made of plastic material. The antifreeze liquid is applied to the inlet valve of the gas mask when the temperature is below the freezing point. Navy gas mask carriers contain an anti-fog compound in a small cylindrical sheet metal container and a cleaning rag.
3. PROTECTIVE CLOTHING. a. Light protective clothing. Two types of light weight impermeable protective clothing designed to be worn over regular clothing exist:
(1) "Cellophane type" light protective clothing. Comprises jacket with fixed hood, trousers, boot covers with rubber half soles, and gloves (fig. 266). The garments are made of rubberized silk with a cellophane interlining.
Figure 266. "Cellophane type" light protective clothing.
Figure 267. "Casein type" light protective clothing.
(2) "Casein type" light protective clothing. The set (fig. 267) consists of trousers, overboots, gloves, and a carrier pouch. All items are made of casein-coated, rubberized silk.
b. Heavy protective clothing.
Figure 269. Heavy protective clothing.
Is made of heavy red brown rubberized fabric and comprises an over-all suit with fixed boots and hood (fig. 269) and a pair of gloves. This suit weighs approximately 21 pounds.
c. Protective cover and leggings for horses. The existence of these items has been definitely established. The cover is made of cotton fabric, rubberized on both sides, and has semi-spherical, plastic eyepieces. No details are available concerning the leggings.
4. DECONTAMINANTS. a. Individual decontamination kit.
Figure 268. Can of individual decontaminant.
This kit (fig. 268) is intended for use by the individual soldier in neutralizing liquid blister gas that may have come in contact with the skin. The kit consists of a fabric carrying pouch, with a tie-string containing a roll of absorbent cotton, and a green metal can (approximately 3 inches by 21/4 inches) with a small screw cap lid. The decontaminant in the metal can is a powder containing chloramine-T as the active ingredient. Decontamination is accomplished by mixing the powder with water to form a paste and applying the mixture to the skin. It is effective against both mustard gas (H) and lewisite (L).
b. Bleaching powder pouch.
Figure 270. Bleaching powder pouch.
The pouch (fig. 270), measuring approximately 12 inches by 7 inches, is made of rubberized fabric and is provided with a tie-string, carrying strap, and a pocket containing several pieces of cotton gauze. The pouch holds approximately 5 ounces of bleaching powder, presumably for use in the decontamination of articles of individual equipment.
Figure 271. Decontaminating agents, (1) No. 1, (2) No. 2, (3) No. 3, and (4) No. 4.
c. Decontaminating agent, No. 1.
A cylindrical sheet metal container, 21/2 inches high and 21/2 inches diameter, with one blue band around the casing (fig. 271) contains approximately 0.33 pounds crystalline potassium permanganate.
d. Decontaminating agent, No. 2.
A rectangular sheet metal box, 41/2 inches high and 41/2 inches square (see fig. 271) with two blue bands around the casing, contains approximately 2.25 pounds of flaked sodium hydroxide.
e. Decontaminating agent, No. 3.
A rectangular sheet metal box, 131/4 inches high, 73/4 inches wide and 53/4 inches thick, with three green bands around the casing (see fig. 271) contains approximately 15 pounds of chloride of lime.
f. Decontaminating agent, No. 4.
A cylindrical sheet metal can, 23/4 inches high, 27/16 inches in diameter, with four blue bands around the casing (see fig. 271) contains a spherical glass ampule wrapped in cotton gauze. The ampule holds approximately 1.8 ounces of a yellow liquid consisting of a 20 percent solution of chlorine in carbon tetrachloride.
g. Uses. These decontamination agents are used as follows:
Nos. 1 and 2. For decontamination of tear gases and vomiting gases. No, 3. For decontamination of blister gases. Probably used to refill the pouch. No. 4. For decontamination of blister and vomiting gases.
The effectiveness of these agents is not known, but is considered comparable with similar Allied agents.
5. GAS DETECTORS. a. Blister gas detection satchel. The square satchel, 6 inches x 6 inches, with a carrying strap, contains detector papers, a small box of calcium hypochlorite, a box containing 16 glass ampules of detector material, and a supply of small flags for marking contaminated areas. The white detector material contained in the ampules turns red in contact with blister gases.
b. Gas detector kit.
Figure 272. Gas detector.
The kit (fig. 272) comprises a light metal cylindrical barrel, 101/4 inches
long and 21/2 inches in diameter; a rubber bulb and tubing; and a set of five detector tubes. When testing for war gases the five detector tubes are placed inside the barrel and held in the holes of a rubber stopper provided for this purpose. Air is then drawn through the tubes by means of the rubber bulb. The kit is contained in a wooden carrying case.
c. Gas detector kit (Navy model).
Figure 273. Gas detector kit (Navy model).
The kit (fig. 273) comprises a rubber, bulb-actuated, metal
air pump and a set of three detector tubes. Air is drawn through the detector tubes. It is said that the presence of blister gases, choking gases, and carbon monoxide can be determined by color changes of the indicator materials contained in the detector tubes. The kit is carried in a grey metal case.
1. MARKING OF CHEMICAL MUNITIONS. Indications are that the Japanese attention to war gases has been confined largely to the well known blister, tear, vomiting, etc., gases. In addition, agents for the production of screening smokes are manufactured. The Japanese distinguish between ordinary smoke and toxic, or tear, clouds by referring to the latter as "special smoke." The type of agent contained in a chemical munition is usually identified by a color band according to the following scheme:
Color of band Choking gases Blue. Tear gases Green. Blister gases Yellow. Vomiting gases Red. Blood and nerve poisons Brown. Screening smoked White.
Chemical projectiles and most chemical aerial bombs are generally grey in color. Filled shells have a red band at the nose, followed by a blue band to indicate special handling because of the chemical filling. According to the best evidence available, the type of war gas filling is indicated by a colored band in accordance with the above scheme. This band is about twice as wide as any other band on the shell. A narrow yellow band is believed to indicate a HE burster change, while a white band indicates that the projectile is constructed of steel.
2. GAS SHELLS AND BOMBS. a. General. The 90-mm mortar and the 81-mm mortar are believed to have chemical munitions, as is a reported 150-mm mortar, but shells containing these fillings have not been captured. Likewise, the 105-mm gun and 150-mm howitzer shells probably have a chemical filling. The following shells and bomb are definitely known to be filled with war gases.
b. 50 kg aerial gas bomb. Over-all length 45 inches, body diameter 7.5 inches. Total weight 110 pounds. Filling 50:50 lewisite mustard mixture. Grey colored with one yellow and one white band between nose and lug and one yellow band between tail and lug.
c. 75-mm blister gas shell. Weight 12.5 pounds. Filling 1.4 pounds 50:50 lewisite mustard mixture. Markings; red band followed by blue band (indicating CW filling) on nose, one white and one wide yellow band on body, which indicates blister gas filling.
d. 75-mm vomiting gas shell. Weight 13.25 pounds. Filling 0.4 pounds diphenylcyanarsine. Markings, red band followed by blue band on nose. Yellow band below bourrelet indicating HE filling, then a wide red band indicating vomiting gas and finally a white band indicating a steel shell.
3. FRANGIBLE HYDROCYANIC ACID (AC) GRENADES. See section II, chapter 9, for description.
4. GAS CANDLES. Most Japanese gas and smoke candles of the stationary or hand thrown type are fired by means of a matchhead fuze and scratcher block. All Japanese self projecting gas and smoke candles (figs. 274, 275, 276, and table) are composed of an outer container equipped with a
Figure 274. Small vomiting gas candle.
sliding metal spike. Before firing the candle this spike is driven into the ground to maintain the candle at the desired angle. A matchhead fuze at the lower end of the candle is ignited with a scratcher block
Figure 275. Medium vomiting gas candle.
and sets off the propellent charge which expels the inner container (projectile) carrying the main charge. The main charge is then set off by a delay fuze ignited by the propellent charge.
Figure 276. Self projecting vomiting gas candle.
Tear gas candles
Description Approximate dimensions inches) Body color Markings Approximate total weight (pounds) Filling Notes Length Diameter Tear gas candle 7.2 2.2 Grey Green band 0.5 CN mixture Main filling nitrocellulose wafers containing CN. Small tear gas candle 5.5 2.5 do do .4 do Believed obsolete. Vomiting gas candles Light vomiting gas candle. 7.2 2.2 Grey Red band 0.6 DC Metal ring handle at bottom. Heavy vomiting gas candle. 9.8 4.4 Brown do 4.4 do Metal ring handle at bottom. Under cover 16 taped vent holes. Separate compartments for fuel mixture under smoke charge. Medium vomiting gas candle. 8.8 4.4 do do 3.3 do Metal ring handle at bottom. Fixed hinged metal prong at side. Light self projecting vomiting gas candle. 7.9 2.0 do do 1.5 do Projectile has cardboard casing. Heavy self projecting vomiting gas candle. 8.2 2.0 do do 2.2
do Projectile has sheet metal casing and wooden bottom. Considerable variation has been found in dimensions and weights of the above candles.
5. SMOKE GRENADES. a. 50-mm smoke shell for grenade discharger type 89. See section II, chapter 9, for description.
b. Rifle smoke grenade. See section II, chapter 9, for description.
c. Frangible smoke grenade, white. See section II, chapter 9, for description.
6. SMOKE CANDLES.
Figure 277. "Type 94" small smoke candle (White label).
Figure 278. "Type 99" self projecting smoke candle.
Figure 279. Type 94, model B, floating smoke candle.
Figure 280. 10 kg smoke candle and igniters.
Figure 281. Type 94, smoke candle, white band.
Designation Approximate dimensions (inches) Body color Markings Approximate total weight (pounds) Smoke mixture Notes Length Diameter Type 94 small smoke candle A. 6.9 2.2 Grey White label 2.2 Berger type Metal ring handle at bottom. Probably an early model. Do 6.9 2.2 Green or brown do 2.2 do No handle. May be wrapped in paper with printed instructions. Probably a later model. Type 94 large smoke candle A. 18 6 Grey do 44 do Hinged wooden handle at top, attached to metal band around casing. Small screw cap lid. Type 94 floating smoke candle B. 31.2 3.1 Grey or brown White label or white band. 15.4 HC type Metal ring bracket for float around upper part. "10 year pattern" hand grenade time fuze fits opening on top closed by wing screw plug. 1 kilogram smoke candle "Revision 4." 8.3 2.1 Tinplate White labels top and side. *2.2 Berger type Naval smoke candle. 1 kilogram smoke candle "Revision 7". 8.3 2.1 do White labels top and side. *2.2 HC type Naval smoke candle. Igniter removable. 10 kilogram smoke candle. 9.5 6 Grey Labels on top and side. *22 Berger type Naval smoke candle. Igniter well fitted with wooden plug. Igniters packed separately. 30 kilogram smoke candle. 9.5 10.5 do do *64 do Naval smoke candle. Igniter well closed by wooden plug. Igniters are packed separately. The candle may be fitted with a float. Experimental self-projecting smoke candle. 8.2 2.1 Grey or brown May have white band. 1.5 HC type Sometimes wrapped in paper. Projectile has cardboard casing and short igniter tube. Type 99 self-projecting smoke candle. 8.2 2.1 do White Japanese characters on side. 2.9 do Projectile has sheet metal casing. Igniter tube extends whole length of projectile. Under bottom cover match head exposed through slot.
As weight varies considerably, figures shown are merely the conversion of the indicated kilogram weight to pounds.
7. AERIAL INCENDIARY BOMBS. Army type incendiary bombs are painted grey whereas the HE bombs are black. Navy type bombs, both HE and incendiary, are painted grey. Red and silver tail struts designate an incendiary filling.
a. 1 kg smoke incendiary/antipersonnel bomb, Army type. Characteristics are as follows:
Over-all length 10.25 inches. Body diameter 3 inches. Color and markings White rubber nose, black body, white tail cone and fins. Main charge Red phosphorus.
Used in conjunction with demolition bombs as a marker. On explosion antipersonnel effect by fragmentation of cast iron body.
b. 32 kilogram incendiary bomb. Characteristics are as follows:
Over-all length 24.4 inches. Body diameter 5.75 inches. Total weight (approximately). 70 pounds. Filling Phosphorus filled steel pellets. Color Grey. Markings Silver band on nose and silver tail fin tips.
c. 50 kilogram incendiary bomb. Characteristics are as follows:
Over-all length 3 feet 9 inches. Body diameter 7.75 inches. Weight (approximately). 101 pounds. Filling Rubber pellets and phosphorus in carbon disulfide. Color Grey. Markings One yellow and one white band.
d. 50 kilogram incendiary bomb, Army type 100. Characteristics are as follows:
Over-all length 3 feet 4 inches. Body diameter 7 inches. Filling Rubber pellets and phosphorus in carbon disulfide. Color and markings Grey body and tail, yellow and white bands just forward of suspension lug.
This bomb is differentiated from the 50 kg incendiary bomb described in c above by a longer tail cone with a rounded apex.
e. 60 kilogram solid oil bomb, Navy type. Characteristics are as follows:
Over-all length 3 feet 61/2 inches. Filling Normal filling mixture of paraffin wax and kerosene but a filling
consisting of pellets made of rubber-like incendiary material also exists.
Color and markings Grey body and tail, red tail struts.
f. 60 kilogram incendiary thermite bomb, Navy type. Characteristics are as follows:
Over-all length 3 feet 4 inches. Body diameter 8 inches. Filling Electron containers filled with thermite. Color and markings Grey body and tail, red tail struts.
g. 250 kilogram HE/incendiary bomb. Characteristics are as follows:
Over-all length 5 feet 9 inches. Body diameter 12 inches. Weight (approximately). 550 pounds. Filling HE and about 750 small metal cylinders filled with incendiary substance. Color and markings. Painted grey with a red band on tail and a silver band on end of nose.
8. OTHER INCENDIARIES. a. One-half kilogram incendiary grenade. See section II, chapter 9, for description.
b. Incendiary grenade "Molotov cocktail". See section II, chapter 9 for illustration and complete description.
c. 90-mm mortar projectile. Characteristics are as follows:
Weight (approximate). 11.5 pounds. Filling (approximate). 2.2 pounds phosphorus in carbon disulfide and rubber pellets. Markings Red band followed by blue band on nose, one yellow and one white band on body.
d. 50-mm grenade discharger projectile, incendiary. See section II, chapter 9, for description.
e. 75-mm Incendiary Shell, for model 41 (1908) infantry gun.
Weight (approximate). 14.5 pounds. Filling (approximate). 22 oz. rubber pellets impregnated with a solution of phosphorus in carbon disulfide. Markings Blue--grey projectile, red band below fuze.
f. Incendiary stick grenade. See section II, chapter 9, for description.
9. FLAME THROWERS. a. Flame throwers, type 93.
Figure 282. Flame thrower, type 93.
The fuel unit comprises 2 fuel tanks and a nitrogen pressure cylinder. Ignition of fuel jet is effected by flash from a blank cartridge, ten of which are loaded in the revolving cylinder located at nozzle end of flame gun (fig. 282). The firing mechanism is actuated by operating handle which controls fuel ejection valve. Characteristics are as follows:
Maximum range 25 to 30 yards. Duration of continuous discharge. 10 to 12 seconds. Fuel capacity 3.25 gallons. Total weight, charged About 55 pounds.
b. Flame thrower, type 100. Very similar to type 93 flame thrower. The fuel units of the two types are identical as are range and duration of flame. The differences are found in the flame guns as follows:
Type 93 Type 100 Over-all length 471/8 inches 351/2 inches. Weight 10 pounds 81/2 pounds. Nozzle outlet tip Fixed Removable. Diameter of cartridge 0.44 inch 0.484 inch. Chambers of revolving cylinder. 10 10.
c. Pyrotechnics. See chapter 10.
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