Other Exchange Items

50mm Bordkanone 5 (BK-5) aircraft cannon

This cannon, used operationally by the Ger­mans in the Me410A-l/U4 and Me410A-2/U4 heavy fighters for anti-bomber missions, gar­nered interest from the Japanese who saw the weapon at a Luftwaffe airfield in Posen in the Warthegau. There is no evidence that an example was sent to Japan.

A4 ballistic missile

Better known as the V-2, the A4 was the first ballistic missile to be used operationally in combat. In an OSS (Office of Strategic Ser­vices) report from September 1944, it was said that the Japanese had purchased the design plans for the A4. Another OSS report added that in February 1945 a Doctor Yamada of the Chemical Research Institute brought the plans to Japan. It was surmised that the Japanese were building the missile in Muk­den (Shenyang) in Northern China for use against targets in the Philippines and the Chi­nese interior. However, the OSS reports remained unverified and it was believed by other intelligence agencies that the Japanese would not have had much interest in the A4, let alone that they could construct it. Other sources say the Germans had no intention of releasing information on the A4 to the Japanese.

Blohm und Voss BV 246 Hagelkorn glider bomb

The BV 246 Hagelkorn (meaning ‘hailstone’ in German) was a radio-guided glider bomb. 1,100 examples of the BV 246 were built from December 1943 through February 1944 before the factory producing them was destroyed by bombing. Using a radio receiver, the bomb also used a smoke gener­ator to assist the operator in guiding the bomb onto the target. Despite good results, it was felt the guidance system could be too easily

jammed and production was not resumed. Allied intelligence believed that information on the BV246 was made available to the Japanese prior to April 1944.

Donau-60 Bolometer

The Danube-60 was an infra-red detection system used to control coastal guns. It used four thermal sensors in parabolic dish arrangements with a bolometer at each focal point. These dishes would detect the heat given off by ships, for example, through their funnels, and the data was then transmitted to gun layers who would bring the guns to bear on the target. Zeiss produced the system at the rate of 20-30 a month but how widespread it was in service is unknown. That the Japan­ese may have been interested in this bolome­ter can be seen in their developments of the Ке-Go (see the chapter on Japanese bombs for more information).

Fieseler Fi 103 guided bomb

Better known as the V-l or ‘buzz bomb’ (among many nicknames, German and Allied alike), the Fi 103 was a crude cruise missile first used in action against England. Intelligence reports claim that documenta­tion on the Fi 103 was provided to the Japan­ese in October 1943, and in November 1944, the Japanese acquired a Fi 103A. These reports also suggest that the Japanese were far more interested in air launching methods than ramps, and data was provided to the Japanese on the methods for air launch tech­niques as practiced by III/KG 3 and I/KG 53, who fired the Fi 103 from Heinkel He 111H-22 bombers.