Steam Catapult Development

As part of the British development and qualification of the steam catapult, a platform containing the hardware was added on top of the flight deck of HMS Perseus.

After catapulting deadloads at dockside in mid-1951 in initial development tests, the carrier proceeded to at-sea trials in the outer Firth of Forth, beginning with deadloads and then the catapulting of six surplus, unpiloted Seafire 47s which had the wings removed at the fold joint and just enough fuel for start, warm-up, and the launch. One reportedly took umbrage at being sacrificed in even a worthy cause and managed to climb and turn back toward the ship before crashing into the sea short of the carrier. A video survives of the testing (the Seafires were not, as stated, radio controlled):

https://www.britishpathe.com/asset/51657/

Perseus was subsequently sent to the U.S. for demonstrations of the steam catapult in February 1952, first dockside at the Philadelphia Navy yard and then at sea. The steam catapult allowed the successful launch of a Douglas F3D Skyknight with a 10-knot tailwind. The existing Navy hydraulic catapult required a 30-knot headwind for the same airplane weight. The Navy immediately began planning to require steam catapults in its new aircraft carriers and retrofit existing carriers that had enough service life remaining to justify the conversion. As a result, bigger airplanes with higher performance could now be carrier-based.