English: Combat bulletins CB n°57: Activities in ETO—Disney swish - The Disney Rocket-Assisted Bomb was a World War II device to be used against U-boat pens and other super-hardened targets. Thought up by Royal Navy Captain Edward Terrell, it had a streamlined hardened case bomb weighing 4,500 lb (2 tonnes). The bomb was dropped from 20,000 ft (~6,000 m). At 5,000 ft (~1,500 m) a barometric fuse fired the rocket in the tail to give it a velocity at impact of up to 2,400 ft/second (730 m/s). It was first used by the 92nd Bomb Group on 10 February 1945 on U-boat pens at IJmuiden, Netherlands, one bomb under each wing of 9 B-17 Flying Fortress. On that occasion a single direct hit was scored. A total of 158 "Disney Bombs" were used operationally by the end of hostilities in Europe.