More effective Japanese armored fighting vehicles, incorporating
heavier armor, wider tracks, two-way radio, and a modern
high-velocity 75-mm weapon, are likely to be encountered in the near future.
There is every reason to believe the Japanese are conversant with
details of modern German tank design, and that they have also had
opportunity to study Allied armor.
Much heavier armor plate, or the addition of spaced armor to the
present armor of Japanese tanks, is to be expected. To conform to
modern European tank standards, it will have to be up to 40-mm thick
on light tanks, up to 75-mm on medium tanks, and up
to 100-mm on heavy tanks.
Among other developments anticipated are the use of wider tracks,
employment of a modern, high-velocity 75-mm field piece as a tank
weapon, two-way radio communication, improved vision, escape doors,
and gas-fume extraction.
It must be remembered, however, that while the Japanese are
considered capable of designing an efficient modern heavy tank, they may
have considerable difficulty in producing such a tank in large
At present there are four main types of Japanese armored fighting
vehicles: tankette (Keisokosha) up to 5 tons, light tanks (Kei
Sensha) 5 to 10 tons, medium tanks (Chu Sensha) 10 to 20 tons, and
heavy tanks (Ju Sensha) over 20 tons.
Few tankettes have been encountered since the 1942 Burma
campaign. There is nothing to indicate, however, that this type has been
abandoned and it will no doubt be encountered in operations in open
terrain. It is important to realize that the tankette is not intended
primarily for fighting but is essentially a light, full track
The Japanese light tank most often encountered is the Model 2595
(1935), the design of which seems to have been frozen about 1937 to
permit mass production. It was built to operate over the varied
terrain of east Asia where roads are few and poor, and where
maneuverability is the essential requirement.
The only Japanese medium tank so far encountered is Model 2597
(1937) and its improved versions. Like the Model 2595 light tank, this
design also was frozen several years ago to permit mass production.
Model 2597 armor is too light for tank-vs.-tank combat, but the vehicle
has fair striking power, good cruising radius, and is conspicuously
maneuverable. Although the Japanese describe it as "the main striking
power of the Army," it has given a poor account of itself in close
combat with allied antitank weapons and tanks on various Pacific
Another type now being encountered in the Pacific theater is a light
amphibious tank, described in detail in Tactical and Technical
Trends, No. 50. General characteristics of Japanese tanks may be
summarized briefly as follows:
Only air-cooled Diesel engines are employed. These are 4, 6, and
V–12 types, all of which employ the German (Robert Bosch) type of
Basic designs are good, but the tanks are difficult to produce in large
numbers. The cooling systems used are likely to give trouble after
prolonged use in hot climates.
Transmissions are conventional in design and of sturdy construction.
A comparatively large number of nonfriction bearings are used.
The same basic suspension is used in all types so far encountered.
Four-point hull suspension bogies are bell-crank mounted to armored
compression springs. A trailing idler appeared in later models, resisted
by a compression spring. A single bogie roller with unarmored
compression spring has been added to each corner of medium-tank
Tracks are of conventional design and rather narrow. However,
loading is light, generally in the neighborhood of 7 to 8 pounds per
square inch. Power-weight ratios are excellent throughout the line.
ARMOR GOOD, BUT LIGHT
Japanese armor so far encountered has been of good quality but
comparatively light by European or American standards. Arrangement
of the armor is poor by modern standards of design. Little use is made
of angles and, in many case, reentrant angles are formed. No steps
have been noted to protect turret rings or mantlets against jamming or
Hull design can be considered good by modern standards, and the
latest models have shown improvement. In some cases crew compartments
are very cramped and little attention has been paid to crew
comfort. Turrets and hulls are both well insulated with some material,
such as asbestos.
For several years all Japanese turrets were circular. More recent
models have turrets of oval shape and in some of them a machine gun
is mounted coaxially with the main armament. No evidence of
power-operated turrets has yet been found.
Periscopes are not frequently used, vision being dependent on slots,
occasionally backed by glass blocks.
Apparently little thought has been given to providing the crew with
a quick means of escape in case of fire or other emergency.
These weapons have been found in Japanese tanks: Model 91 (1931)
6.5-mm tank machine gun; Model 97 (1937) 7.7-mm tank machine
gun; Model 94 (1934) 37-mm tank gun; Model 98 (1938) 37-mm tank
gun; Model 1 (1941) 37-mm tank gun; Model 90 (1930) 57-mm tank
gun; Model 97 (1937) 57-mm tank gun; and an adaptation, model
unknown, of Model 1 (1941) 47-mm antitank gun.
Model 91 is a variation of the standard light machine gun of
the same caliber, fitted with telescopic sights, special stocks, etc. All
other weapons listed are low-velocity types, with the exception of
Model 1 (1941) 37-mm tank gun and the new 47-mm gun, which are
mounted in the newer light and medium tanks. However, these low-velocity
models may be given a new lease on life by providing them
with hollow-charge ammunition, which is reported under
development. Weapons are usually arranged in a conventional manner, with
one machine gun fore in the hull and the other in the turret opposite
the main armament.