The Japanese military was ultimately delivered a series of shortcomings that became readily apparent as World War 2 progressed. One such limitation was in the category of anti-tank guns. Even before the war proper, the Japanese Army lacked anything in the way of a capable, indigenous tank-killing weapon for her troops and, as such, the Gun Type 34 was introduced in 1934 to rectify the situation. However, the gun system was already being reviewed for its limitations, giving rise to the Type 97 - another 37mm weapon system though this gun with origins in the fine German 3.7-cm Pak 35/36 anti-tank system. Like the Type 34, the Type 97 was still viewed as a design with inherent limitations lacking the needed battlefield performance. Interestingly, Japanese authorities believed that they would be facing enemies fielding light armored equipment - including those that America might offer - and were more interested in delivering an adequate product that could content with such.
As early as 1939, a new towed anti-tank gun was in the works. By 1941, the gun was introduced formally as the "47mm Anti-Tank Gun Type 1" and went on to see production out of the Osaka Arsenal in at least 2,300 examples between 1941 and 1945. The weapon entered service with the Imperial Japanese Army in 1942 and saw first combat action in 1943. The Type 1 would be the only indigenous Japanese-designed anti-tank gun of the war but made its presence felt across many fronts where possible.
At its core, the Type 1 was of a highly conventional design layout utilizing a barrel attached to a breech system, a two-wheeled carriage and an integrated shield protection plate. The breech, carried over from the German PaK 35/36 design, was semi-automatic in nature, allowing for an above-average rate-of-fire - a trained crew could fire about 15 projectiles within a 60-second window. The semi-automatic breech took care of ejecting spent casings and closing automatically upon insertion of a fresh projectile. The personal shield plate was well-sloped to help repel small arms fire and artillery "splash" and was larger in surface area towards the top edge. The weapon system sat on a split-trail carriage and was portable enough that a crew could easily move the system from position to position and begin firing. The carriage attached to vehicles by the ends of its trail arms for transportation. The arms were used for stabilization when firing, opening out at 60-degree angles. The steel disc wheels were simple sponge-filled rubber tires. Once in operational service, the Type 1 succeeded in proving to be a very portable and reliable system - be it by vehicle or "pack" animal.
The Type 1 weighed in at approximately 1,760lbs and featured a barrel length of 8.3 feet. The featured cartridge was listed as "47x285mm R" in official caliber (1.85 inches) and the weapon sported a muzzle velocity of 2,723 feet per second. Maximum range was out to 7,546 yards with aiming accomplished via a "straight" telescope. Traverse range was +- 50 degrees with elevation capable between -10 and +20 degrees.
The Type 1 was cleared to fire two distinct projectiles, these being the Type 1 Armored Piercing, High Explosive (APHE) round and the Type 1 High-Explosive Round (HE). The APHE projectile weighed in at 3.37lbs and was the primary shell to be used against armored targets. At 500 yards, the APHE shell could penetrate flat facing armor up to 2.75 inches thick, this degrading to 1.6 inches at ranges of 1,500 yards. Conversely, the HE shell was used against "soft" targets such as infantry positions and weighed in at 3.08lbs.
In the end, however, production of the Type 1 was never at the levels required to make much of an imprint in the Pacific Theater. Allied gains in the region were such that Japanese Army personnel often used whatever became available to them in terms of stopping tanks. Additionally, Allied tanks were becoming heavier with their thicker armor by late in the war and the arrival of the M4 Sherman soon proved American tanks impervious to any low-caliber anti-tank system the Japanese could field. Despite its shortcomings, the Type 1's barrel system was earmarked for production as the main gun in the Type 97 Chi-Ha light tank - the Japanese were "done in" partly by their centering production on such light armored systems and, with Allied gains made on a seemingly month-to-month basis, a clear Japanese victory was evermore in doubt by early 1945. A "favorable surrender" would be pursued by the end of the war instead.