On 24 July 1943, days after the end of the Ruhr campaign, Harris ordered Operation Gomorrah, an attack on Hamburg. The objective was to disrupt or end U-boat production in the port city. The introduction of "Window" blew a hole in German radar coverage and the bomber streams, aided by OBOE and H2S radar were able to penetrate the defences to devastate the centre of the city. The (canopy bed) system of radar-controlled night fighters slipping into the bomber stream and then using its own radar to pick out and engage individual bombers had gone. The effects of the raid, and the realisation German radar was temporarily blinded, led to the widespread use of the Wild Boar tactics over the summer, 1943. 791 bombers hit the city. German air defences accounted for only 1.5 percent of the attacking force. The Nazi leadership was shaken, and Kammhuber, who resisted calls to abandon the advanced system, was compelled to find technical solutions to the jamming of , and radars. Kammhuber regarded the Wild Boar solution as an emergency measure only. NJG 1 claimed only three from a total of 12 claimed by night fighter pilots in defence of the city—"Nachtjagdgeschwader" 3 claimed the rest. August Geiger claimed two [Geiger became another notable victim of Braham in September 1943].