Although the Germans were carrying out research at centimeter wavelengths at the start of the war, the work was abandoned as it was decided that the war would be over before the research & development could be completed. In February 1943 a RAF Stirling bomber was shot down over Rotterdam and a damaged H2S system was recovered. The Germans started a crash development program to use the information deduced from the captured system. Although a range of prototypes were produced, very few reached front line troops. Due to the device being recovered near Rotterdam, the Germans used that name in several code names for the Centimeter (9 cm) systems, such as "Rotterdam Device".
