Japanese anti-tank artillery … Japan entered the Second World War with an ocean-going fleet, which fully corresponded to the highest world standards. Also, by the beginning of the 1940s, in the Land of the Rising Sun, mass production of combat aircraft was established that were not inferior, and sometimes even superior to fighters, bombers, torpedo bombers and seaplanes that were available in the same period in the United States and Great Britain. At the same time, the Army of the Great Japanese Empire, financed on a leftover basis, was equipped with equipment and weapons that largely did not meet modern requirements. The combat capabilities and numerical strength of Japanese artillery and tank units made it possible to successfully fight against poorly trained and poorly equipped Chinese units, colonial British and Dutch troops. But after a series of successes on land, the Japanese ground forces, under pressure from the American-British troops, equipped with better equipment and weapons, were forced to first go on the defensive and subsequently retreat from the conquered positions. In the course of defensive hostilities, the shortage and low combat characteristics of Japanese anti-tank guns fully affected. The attempt by the Japanese command to strengthen the anti-tank defense with anti-aircraft guns can be considered partly successful, which, however, could not stop the advance of the allies.
Anti-tank guns, caliber 37-47 mm
The creation of specialized anti-tank guns in Japan began later than in other countries. Until the end of the 1930s, the 37 mm Type 11 infantry gun was the main anti-tank defense weapon of the front edge. It was a typical example of a "trench cannon" based on the French Canon d'Infanterie de 37 modèle 1916 TRP gun. The Type 11 also fired a 37x94R shot.
The design of the Type 11 gun was very simple, which made it possible to achieve minimal weight and dimensions. The recoil devices consisted of a hydraulic recoil brake and a spring knurler. Weighing 93, 4 kg, the 37-mm gun could be carried by 4 people. For this, the carriage had brackets into which the poles were inserted. In total, taking into account the ammunition carriers, there were 10 people in the calculation. Disassembled, the gun was transported in packs on horseback. To protect the crew from bullets and shrapnel, a steel 3-mm shield could be installed on the gun, but the weight increased to 110 kg.
A gun with a manually-opened vertical wedge gate could make 10 rounds / min. A fragmentation projectile weighing 645 g was equipped with 41 g of TNT. With an initial projectile speed of 451 m / s, the effective firing range at point targets did not exceed 1200 m. Also, the ammunition load included a cast iron armor-piercing tracer projectile, which made it possible to fight light armored vehicles at a distance of up to 500 m.
Serial production of the Type 11 lasted from 1922 to 1937. Each regiment of the imperial army in the state was supposed to have 4 37-mm infantry guns. The cannon performed well in the early stages of the Second Sino-Japanese War, providing fire support to the infantry and hitting various types of targets, such as pillboxes, machine gun nests and lightly armored vehicles. 37-mm infantry guns were first used against Soviet armored vehicles and tanks in 1939 during the hostilities on Khalkhin Gol. Several of these weapons became trophies of the Red Army. After the appearance of tanks with an armor thickness of 30 mm or more, the 37 mm Type 11 guns became completely ineffective. Due to their low ballistic characteristics, the frontal armor of the American light tanks M3 Stuart turned out to be too tough for them, even when firing from a short distance. In addition, armor-piercing shells cast from cast iron in most cases shattered against armor.
The weak projectile and short barrel of the Type 11 infantry cannon made it impossible to effectively deal with armored vehicles. Already in the first half of the 1930s, it became clear that the Japanese army was in dire need of a specialized anti-tank artillery system. In 1936, the serial production of the Type 94 anti-tank gun began. The design of this 37-mm cannon largely repeated the Type 11 infantry gun, but 37x165R ammunition was used for firing it.
A 37 mm projectile that left a 1765 mm barrel with an initial speed of 700 m / s could penetrate 40 mm armor at a distance of 450 m along the normal. At a distance of 900 m, the armor penetration was 24 mm. The mass of the gun in the combat position was 324 kg, in the transport position - 340 kg. A well-trained crew of 11 people provided a combat rate of fire of up to 20 rds / min.
However, there are certain doubts about the declared value of the armor penetration. So the German 37-mm anti-tank gun 3, 7 cm Pak 35/36 with a barrel length of 1665 mm and ammunition 37 × 249R, firing an armor-piercing projectile 3, 7 cm Pzgr weighing 685 g, with an initial speed of 760 m / s, at a distance of 500 m normally could penetrate 30 mm armor. Apparently, when assessing the armor penetration of Japanese and German anti-tank guns, various methods were used, and objectively the 37-mm Japanese gun did not surpass the German anti-tank gun 3, 7 cm Pak 35/36.
Possessing good ballistic data and rate of fire for its time, the 37 mm Type 94 cannon had an archaic design in many ways. The unsprung travel and wooden, iron-studded wheels did not allow it to be towed at high speed. The gun could be disassembled into four parts, each of which weighed less than 100 kilograms, which made it possible to carry out transportation in four packs on horseback. A fairly low profile facilitated camouflage on the ground, and sliding beds with openers contributed to a significant angle of horizontal shelling of the gun and its stability during firing. To protect the crew from bullets and light shrapnel, there was a 3 mm shield.
During the battles on the Khalkhin-Gol River, 37-mm Type 94 anti-tank guns easily penetrated the armor of Soviet light tanks at real firing ranges. However, 37-mm shells were unable to penetrate the frontal armor of the American Sherman medium tanks. However, the Type 94 remained the most widely used anti-tank gun in the Japanese army and was used until Japan's surrender. In total, army representatives received 3400 guns until the second half of 1943.
In 1941, a modernized version of the 37-mm anti-tank gun known as Type 1 was adopted. The main difference was the barrel extended to 1850 mm, which increased the muzzle velocity of the projectile to 780 m / s. The mass of the weapon also increased.
As in the case of the Type 94, the Type 1 gun had a very low profile and was intended for firing from a sitting or lying position. Until April 1945, Japanese industry produced about 2,300 Type 1s. Upgraded 37-mm Type 1 guns were used alongside the Type 94. Typically, each infantry regiment had six to eight Type 94 or Type 1 guns, and they were also equipped with separate anti-tank battalions. …
In the late 1930s, within the framework of military-technical cooperation, documentation and several copies of 37-mm German guns 3, 7 cm Pak 35/36 were delivered to Japan. Compared to the Japanese Type 94 gun, it was a much more advanced artillery system. According to archival data, Japan produced its own version of the 3, 7 cm Pak 35/36, known as the Type 97. But very few such guns were handed over.
Taking into account the weak mechanization of the Japanese army and in connection with the specific conditions of hostilities in the Pacific theater of operations, where the firing range in the jungle in most cases did not exceed 500 m, it was very tempting to increase the armor penetration of the 37-mm guns. Until the summer of 1945, work was underway in Japan to create a new light 37-mm anti-tank gun. Although already in 1943 it became clear that the 37-mm guns had practically exhausted their potential, Japanese designers did not abandon their attempts to improve their armor penetration until the very end of the war. In particular, on the basis of the 3, 7 cm Pak 35/36, prototypes with an elongated barrel were created, in which projectile cases with an increased weight of gunpowder were used. Field tests showed that an all-metal armor-piercing projectile with a carbide tip, leaving the barrel at a speed of about 900 m / s, at a distance of 300 m could penetrate a 60 mm armor plate, which made it possible to hit American medium tanks. However, the survivability of the barrel was only a few dozen shots, and the gun was not put into mass production.
Soon after the end of hostilities on Khalkhin Gol, the command of the Japanese army initiated the development of an anti-tank gun, superior in its capabilities to the Soviet 45-mm guns. A number of sources have information that when creating the 47-mm Type 1 anti-tank gun, the designers of the Osaka Imperial Arsenal used the German 37-mm cannon 3, 7 cm Pak 35/36 as an initial sample, proportionally increasing it in size.
The prototype 47 mm gun completed trials in early 1939. Since the original version, designed for transportation by horse-drawn traction, no longer met modern requirements for mobility, in March 1939 the gun received a sprung suspension and wheels with rubber tires. This made it possible to provide towing with mechanical traction, and in this form the gun was presented to the military. Simultaneously with the 47-mm, the development of a 57-mm anti-tank gun was carried out, which had high armor penetration. At the end of the 1930s, the creation of a powerful anti-tank gun was not among the priority programs of the Japanese army, and therefore the 47-mm anti-tank gun was adopted in order to save money.
The mass of the 47-mm gun in the firing position was 754 kg. The total length of the barrel is 2527 mm. The muzzle velocity of an armor-piercing tracer projectile weighed 1.53 kg was 823 m / s. According to American data, at a distance of 457 m, a projectile, when hit at a right angle, could penetrate 67 mm of armor. An armor-piercing sabot projectile with a tungsten carbide core was also created, which pierced 80 mm homogeneous armor during tests, but it was not mass-produced. A well-trained crew provided a combat rate of fire of up to 15 rds / min. The total number of gun servants was 11 people.
The staffing table and tactics of actions of the Japanese anti-tank artillery
Serial production of the 47 mm anti-tank gun began in April 1942 and continued until the end of the war. In total, about 2300 Type 1 guns were fired, which clearly did not meet the needs of the Japanese army in anti-tank artillery. The Type 1 cannon entered separate anti-tank companies or battalions that were attached to divisions. In the case of deployment in a fortified area, one division could receive up to three battalions. Each separate anti-tank battalion had 18 47-mm guns. The motorized anti-tank battalion, which was part of the tank division, was also supposed to have 18 anti-tank guns in the state. Separate anti-tank companies attached to motorized rifle regiments included three to four platoons of two guns each. The infantry regiments were supposed to have an anti-tank company, consisting of three fire platoons, each with two anti-tank guns. Given that the Japanese industry was unable to produce a sufficient number of 47 mm guns, 37 mm guns were used in many units. Depending on which divisions and regiments the Type 1 anti-tank guns were attached to, trucks, tractors or horse teams were used to tow them. To facilitate camouflage and reduce weight, armor shields were often dismantled from the guns.
Widespread use of the Type 1 began in the summer of 1944 during the battles of Saipan and Tinian. A significant number of 47-mm guns were also used in hostilities in Southeast Asia. Approximately 50% of American armored vehicles in the Philippines were destroyed by 47mm guns. By the beginning of the Battle of Iwo Jima, the Japanese troops had 40 Type 1s at their disposal on the island.
In the battle for Okinawa, the Japanese garrison had 56 Type 1. However, the Americans suffered the main losses in tanks from mines and ground kamikaze. On the island of Guam, the US Marine Corps captured 30 47mm guns.
In the initial period of hostilities in the Pacific theater of operations, 47-mm Type 1 anti-tank guns easily hit M3 / M5 Stuart tanks at real battle distances. However, the effectiveness against the frontal armor of the M4 Sherman medium tank was significantly lower. According to American data, the Type 1 could hit the forehead of the M4 only from a distance of about 150 m. In one of the battles on Luzon, the Sherman received six hits at such a distance, with five penetrations, while the armor-piercing effect was modest and the tank was quickly returned to service … According to some sources, a distance of less than 500 meters was required to confidently defeat the M4's side armor.
The lack of effectiveness of the 47-mm anti-tank guns forced the Japanese to use ambushes and other methods to hit the side or stern armor of the M4 and fire from small distances, at which the frontal armor also became vulnerable. Japanese instructions prescribed to wait for the tank to reach close range by opening fire in order to increase the chances of hitting it for sure. According to the memoirs of the American military, the Japanese troops were extremely adept at placing and sheltering anti-tank weapons, and were flexible in using terrain and artificial barriers. Japanese tank destroyers, taking into account the location of the minefields of anti-tank obstacles, placed anti-tank guns so as to expose the sides of the tanks under their fire. To protect against 47-mm armor-piercing shells, American tankers hung additional armor plates on the Shermans, as well as cover the hull and turret with spare tracks. This partly increased the security of combat vehicles, but overloaded the chassis, reduced cross-country ability on soft soils and reduced speed.
Unrealized projects of Japanese anti-tank guns
In the interwar period and during the Second World War, the Japanese leadership directed the main resources to the needs of the fleet and the improvement of combat aviation. The ground army was financed on a leftover basis, and many promising types of anti-tank weapons were produced in very limited quantities, or did not leave the aisles of the test ranges at all. Fortunately for the American and Soviet tank crews, the Japanese did not consider it necessary to establish mass production of 57 and 75 mm anti-tank guns. Artillery systems of these calibers were tested at proving grounds, demonstrating significant superiority over 47-mm Type 01 cannons. Armor-piercing 57 and 75 mm shells at a distance of 700-1000 m could confidently penetrate the frontal armor of M4 Sherman and T-34-85 medium tanks. Apparently, the rejection of the serial construction of anti-tank guns, whose caliber exceeded 37-47-mm, was explained not only by their higher cost and metal consumption, but also by an acute shortage of mechanized traction equipment in the Japanese army. Also, 81 and 105 mm recoilless guns were not brought to mass production.
Soon after, at the beginning of 1945, Japanese specialists got acquainted with the captured 57-mm American M18 recoilless recoillers, an 81-mm recoilless gun was transferred for testing. The Japanese recoillessness for this caliber was unprecedentedly easy. The body weight of the gun was only 37 kg, the American 75-mm M20 gun, which appeared at about the same time, weighed 54 kg. Initially, the 81-mm gun was mounted on the carriage of a Type 97 20-mm anti-tank rifle, but after the first firing it was transferred to a simple tripod.
A cumulative projectile weighing 3.1 kg left the barrel at a speed of 110 m / s, and penetrated 100 mm armor along the normal. The effective range did not exceed 200 m. When fighting in the jungle, this would have been enough, but the downside of the low weight was the low strength of the barrel. After several people died as a result of barrel ruptures at the test site, they refused to further refine the 81-mm recoilless gun, and the designers concentrated their efforts on the 105-mm recoilless gun. At the same time, a number of sources based on the memoirs of Japanese veterans say that a small batch of 81-mm recoilless vehicles still got to the front and were used in the battles for Okinawa.
In February 1945, the first prototype of the 105-mm Type 3 recoilless gun was submitted for testing. With a mass in the combat position of about 350 kg, the gun could be rolled onto the battlefield by the crew. A charge of smokeless powder weighing 1590 g threw out 10, 9 kg of a projectile with an initial speed of 290 m / s. This made it possible to hit mobile armored targets at a distance of up to 400 m.
The 105-mm cumulative projectile was able to penetrate normally an armor plate with a thickness of more than 150 mm, which was a mortal threat to all serial tanks produced in 1945 without exception. Although there is no information about the creation of high-explosive fragmentation projectiles for a 105-mm recoilless gun, a sufficiently powerful cumulative grenade containing more than 3 kg of powerful explosives could be effectively used against manpower. In general, the 105-mm Type 3 recoilless gun had good characteristics, but the protracted refinement and the overload of the Japanese industry with military orders did not allow it to be adopted.
