The largest use of the weapon was against the PEDESTAL convoy to Malta on August 12, 1942 when ten Savoia-Marchetti SM.84s of 38 Gruppe's "32 Stormo" launched them against the convoy south of Cape Spartivento, Sardinia. This made the ships of the convoy alter course, which allowed conventional attacks to penetrate the convoy's defences. This date was barely over a week after Japanese submarine "I-30" had arrived at the German U-boat Base in Lorient, France on August 2, to bring the technology for the IJN's Type 91 torpedo to Nazi Germany. The Type 91 air-launched torpedo ordnance was the design used in the IJN's aerial attack on Pearl Harbor in December 1941.