Type-5 15cm Anti-Aircraft Artillery - Development
On 20 November 1943 US Army Air Force XX Bomber Command was officially activated with HQ at Smoky Hill AAFld - the first Army Air Force command to fly the giant B-29 Superfortress against the Japanese. Following the 20 November 1943 amphibious landings on Tarawa and Makin Atolls, Seventh AF resumed operations against the Marshalls, in support of the base-development phase of GALVANIC (Gilbert operations) and in preparation for invasion of the Marshalls (Operations FLINTLOCK and CATCHPOLE), which would eventually gain the Americans islands from which B-29s could bomb Japan.
On 22 November 1943 Roosevelt, Churchhill and Chiang Kai-shek met in Cairo. Talks lasted until 26 November and concerned various topics, including and future operations against Japan. It was decided to make amphibious landing and offensive in Burma (CHAMPION) and to base B-29’s in CBI - China-Burma-India Theater (TWILIGHT). Stalin agreed to commit Soviet forces against Japan after Germany’s defeat. The Cairo Declaration, the public statement by Allied leaders, laid out the goal of defeating Japan and liberating the territories it occupied.
Under such circumstances, the Type-5 high altitude gun was developed. An emergency project was initiated in December 1943 to address this issue. To save time, the existing Type 3 design was scaled up to 15 centimeters in caliber, with a corresponding increase in range and firepower. Since there was already a development experience of the Type-3 12-cm anti-aircraft gun at that time, the relevant authorities believed that as long as the gun was enlarged, the new anti-aircraft gun could be developed in a short period of time.
In order to address the shortcomings of the Type 88 75 mm AA Gun, the Army Technical Bureau had developed a larger version with superior range, designated the Type 3. It was one of the few weapons in the Japanese inventory capable of reaching the USAAF B-29 Superfortress bombers that posed a potential future threat to cities and other targets in the Japanese home islands. However, by late 1943 it became apparent that the B-29 was capable of flying at altitudes in excess of 10,000 meters, beyond the effective ceiling of the Type 3 12 cm gun.
The development task was officially issued in December 1943, and was completed in April 1945, creating the first gun. The artillery development director was a technical consultant who has played a huge role in the development of the 12-cm anti-aircraft artillery. The design draftsman was the army technician, Hehe Tedaro [the names of the principals of this project are obscured by too many transliterations]. Since the drawing work of such a huge artillery is very large, it is indeed very difficult to complete it in a short period of one year.
In April of 1944, the production draft was completed. According to the draft, the most labor-intensive body material was first ordered. The gun body was produced by the Osaka Artillery Factory and the Japanese Steel Works. At the same time, the design classes for the parts of the gun body, the gun frame, the sight, and the gun bed were also assigned. Simultaneous development Once the design drawings of these main components are completed, they can be immediately released to the factory for production.
During this period, the designers personally went to the factory to carry out research and development guidance, through their efforts day and night, to the six months of October 1944, the total number of design drawings reached more than 500. This is in the history of the design of Army weapons, and its design speed is unprecedented.
The Marianas fell in 1944, and in November 1944 the United States started a raids on the mainland of Japan based there.
The Army Institute of Technology completed the design in April 1944, and in 1945, the Osaka Steel Corporation and the Japan Steel Works Hiroshima Plant completed two cannons, one each. At the same time, observation and shooting directors jointly developed by the Japan Optical Industry (now generally referred to as Nikon), Tokyo Optics, Hitachi, and Tokyo Instruments, etc., have also been developed by surprise and completed on time.
In the face of US bombers flying at high altitudes, the old-style anti-aircraft guns were totally helpless. For this reason, the Japanese Army made a concerted effort to complete the Type-5 15cm cannon. But in March 1945, the American General Curtis LeMay initiated the low-level firebombing of Japan, although these missions were antithetical to the fundamental principle of daylight, precision bombing.
Through unremitting efforts in all aspects, in April 1945, the Osaka Warship Factory delivered the first gun on time, and on the Hamamatsu coast, the shooting test was completed by Kuroyama Daisuke [Dazu?] and Nakamura Nakasuke, and various shots were collected. The initial speed of the test reached 930 meters per second, the maximum shooting height reached 20,000 meters, the launch speed reached 15 rounds per minute, and achieved good results, fully meeting the plan requirements. It seemed a miracle that the artillery of this size can be completed and tested in just one year.
|
NEWSLETTER
|
| Join the GlobalSecurity.org mailing list |
|
|
|
