Imperial Japanese Army - Armor / Sensha - Design
Japanese tanks were classified into four types according to their weight. These are tankettes which weigh less than 5/2 tons; light tanks weighing from 51/2 to'l 1 tons; medium tanks with a weight range from 11 to 22 tons; and heavy tanks over 22 tons.
By 1939 Japan had one of the largest tank fleets in the world. But it was overflowing with tiny tankettes which had quite limited utility in battle. Their main battle tank had a weak major weapon. All Japanese tanks in the early years suffered from a too small turret, suitable for only a single soldier, which turned out to be too great a burden, with too many tasks for one man to accomplish.
In the years after the Great War, the Japanese empire began the formation of its armored forces. The experience of the Great War showed the prospects of tanks and the Japanese took note of it. The creation of the Japanese tank industry began with a thorough study of foreign machines. To this end, starting in 1919, Japan bought small lots of tanks of various models from European countries. 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. In the mid-1920s, the French Renault FT-18 and the English Mk.A Whippet were recognized as the best. In April 1925, the first Japanese tank group was formed from these armored vehicles. Subsequently, the purchase of foreign samples continued, but not in particularly large numbers. Japanese designers had already prepared several of their own projects.
Until 1929 Japan did not produce any tanks (Sensha) of her own. Prior to 1941 the Japanese had every opportunity to study the experience of the Allies in war, and they were still borrowing freely from other nations during the War. During 1935-37 the Japanese apparently were concentrating on tankettes, light tanks, and medium tanks, perfecting one model in each class. Only a few heavy tanks were produced.
The tropical rain forests of Southeast Asia were generally not suitable for tanks. The terrain is often mountainous and difficult to access. The isolated location of Japan contributed to the idea of the Japanese military leadership that planes and ships were more suitable weapons for carrying out expansion policy. The aforementioned factors caused the Japanese Imperial Army to refrain from spending a lot of money on tanks.
Japanese tanks were lightly armored, but the plates were of good quality. In the arrangement of armor, use was made of deflection angles, but not to any considerable degree. In many cases reentrant angles have been formed, but no steps were taken to protect turret rings or mantlets against jamming or splash.
In the light and medium tanks, relatively low velocity 37- and 57-mm guns were used. A 47-mm gun is used in medium tanks. Although a machine gun was normally mounted in the rear of the turret, and was of some tactical use, it was doubtful if the main turret weapon and rear machine gun can be fought at the same time. The use of armored sheaths was standard for all machine gun barrels. All machine guns were ball mounted, and the main turret armament had a limited traverse, independent of that of the turret. In both the light and medium tanks a hull machine gun is mounted.
Diesel engines were mainly used. In all the tank models the same basic suspension is used. This consisted of bell-crank arms carrying rocking pairs of wheels. These arms are sprung by horizontal suspension springs, protected by armored casings. Little use was made of periscopes, etc., vision being dependent on slits, occasionally backed by a glass block. The question of escape in case of fire or other emergency has received little attention. Crew compartments were 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.
The Japanese produced their first modern light tank in 1935. This vehicle, the Type 95 (1935), subsequently was standardized and manufactured in large numbers. With its improved suspension and hull, and its turret-mounting of a Type 94 (1934) 37-mm highvelocity gun, it represented a considerable advance in Japanese design, which prior to 1935 was preoccupied with the production of imitations of 4- to 15-ton tanks purchased from other countries. Yet, in common with all early Japanese tanks, the protective armor of the Type 95 was made extremely light, with a maximum thickness of only 0.5 inch. From 1935 to 1942, in addition to the Type 95 light tank, the Type 97 (1937) medium tank, in both the original and improved versions, and the Type 2 (1942) amphibious tank were also developed and produced in considerable numbers.
The medium tank, known as the Type 97 (1937) and weighing approximately 15 tons, was produced in 1937. Its general design was satisfactory, but, as engagements With U. S. tanks have shown, its maximum armor thickness of only 1 inch was inadequate to withstand high-velocity projectiles. Furthermore, the turret-mounted 57-mm low-velocity gun, which was its primary armament, was unsuited for tank-versus-tank fighting.
Since the original Type 97 was produced, however, it was modified by substitution of a high-velocity 47-mm gun in place of the 57-mm piece, and this new weapon proved more satisfactory. Tanks of this new design were encountered in Burma and in the Pacific theaters. Although the installation of the high-velocity gun necessitated the redesigning of the turret, the armor was not increased, nor was any other major improvement effected. Combat reports indicated, however, that the quality of the 47-mm AP projectile had been improved. Previously, tests showed that the metal was brittle and tended to break up.
Apart from the improved version of the Type 97 medium tank, the Type 2 (1942) amphibious tank, first encountered on Kwajalein, was the latest and only other known modern Japanese tank. While the method of flotation by means of detachable pontons was extremely interesting, the most significant trend in this type is the coaxial mounting of the Type 1 (1941) 37-mm gun and the Type 97 (1937) 7.7-mm machine gun in the turret. In no other vehicle hade the Japanese been known to mount coaxially the primary and secondary armament. In addition, the chamber capacity of the 37-mm gun was increased, indicating that it would have a somewhat higher muzzle velocity than previously encountered Japanese tank-mounted guns of this caliber. The hull design showed considerable improvement, particularly in the elimination of re-entrant angles. Yet the armor was consistently light, the maximum thickness varying from 0.47 to 0.52 inch on the sides of the turret.
From 1938 to 1944, Japanese engineers were engaged in the modernization of a number of serial tanks, but for the most part the matter did not advance further the construction of one or several prototypes. So, on the basis of the light tank "Ke-Ni" a new sample was created - Type 2 "Ke-To", built in just a few copies. In 1943, on the basis of “Ha-Go”, a light tank “Ke-Re” with a 57-mm gun in the new turret was designed. This car also released only a small series. In 1944, work on the new light tank Type 5 "Ke-Ho" was completed. According to the test results, the tank was recognized successful, but they did not have time to adjust its mass production before the capitulation in Japan.
In 1943, the Osaka arsenal developed a new Type 75 mm gun, equipped with a muzzle brake. This instrument equipped a new medium tank, which was put into service in 1943 under the designation Type 3 "Chi-Nu". Until the end of the war, only 60 tanks of this type were built. All of them were stationed on the Japanese islands and did not take part in the hostilities. However, against the background of other Japanese serial machines of the time, the Type 3 "Chi-Nu" was the most powerful armed tank.
Although Japanese tanks did not compare unfavorably with armored vehicles used by the Allies in their speed-weight ratios, they lose speed more appreciably on cross-country runs. Japanese tanks were bulkier in proportion to their weight than comparable Allied vehicles because of their smaller armor basis. This feature was a direct resultant of the fact that, tactically, the Japanese relied primarily upon their infantry to neutralize hostile antitank weapons.
The Type 95 light tanks and the Type 97 "medium" tanks soldiered on until the end of the war, even though they were outclassed by the M3 Stuarts, M4 Shermans and T-34s. Japanese tanks were inferior to those utilized by Axis and Allied armies in Europe and North Africa. Their armor was too thin, although of good quality, and insufficient attention was given to the utilization of deflection angles. In many cases reentrant angles had been formed, and no effort apparently had been made to protect turret rings or mantlets against jamming or splash. No tanks, with the exception of a negligible number of heavy vehicles, had been armed with weapons heavier than 57-mm guns.
Crew space was cramped, and no escape doors or hatches have been provided. Visibility has been poor. Radio equipment has been installed on an extremely meager basis judged by the standards of the armored forces of other armies.
The Japanese wanted to equip its mechanized infantry with the fully-tracked Type 1 Ho-Ki armored personnel and the Type 1 Ho-Ha halftrack, but the industrial capacity of Japan dictated that those men will mostly rely on trucks. In the end the Japanese had to stick with outdated tanks in small numbers, used piecemeal or wasted in fixed positions. Limitations on the productive capacity of Japanese industry imposed the necessity of freezing tank models in order to attain a reasonably large volume of production.
|
NEWSLETTER
|
| Join the GlobalSecurity.org mailing list |
|
|
|
