After Operation Chastise, German forces discovered in some woods, an Upkeep bomb that had failed to explode. Subsequently, a 385 kg (850 pound) version of the bouncing bomb, codename Kurt, was built at the Luftwaffe Experimental Centre in Travemünde.[7] However, the importance of backspin was not understood, and in trials, dropped by an Fw 190, it proved to be dangerous to the delivering planes as the bomb matched the speed at which it was dropped. Attempts to rectify this with booster rockets were ultimately a failure, and the project was discontinued in 1944.[