How can such launching speeds are attained with the referenced system. Something along the lines of a steam piston pumped up in pressure until a specially designed part breaks Flower Girl Dresses  and the aircraft is flung into the air. There are two aspects left out that seem pertinent to me (as both an engineer and retired Navy engineer):

1. the launching valve is a very fast opening-closing valve.

The combination of the accumulator and launching valve is what delivers a large amount of high temperature and high pressure steam to the pistons in a very short time. There is definitely a quick acting launch valve, length of time the valve is open is calculated based on take off velocity and weight of the aircraft. The "holdback device" is the part that breaks. The aircraft carrier carries a literal truckload of the holdback devices for the duration of the ... Read more »