Tourist,
Nice explanation of the way the ramp works - it took me some years to 'get it' like you have. For Sea Harrier, the ski-jump essentially gave the aircraft around three quarters of a mile 'runway in the sky'. It's the nearest thing I have ever come across to being 'something for nothing'. And it was another Royal Navy invention. (We're quite good at this lark.)
The subtlety of ski-jump with a STOVL aircraft is that it can vector its thrust through its CG so that on leaving the ramp, while not capable of wing borne flight, it can use some of its thrust to support itself while still accelerating. The other 'not so subtle' part is that a STOVL aircraft has a control system that can work well below flying speed. Taken together, these allow the STOVL aircraft to maximise the benefit of the ramp (ski-jump) by scheduling thrust vector with airspeed to fly away safely. Ramp launches are also an extremely easy task for the pilot to carry out. And as I said previously, pointing at the sea, not the sky, is a simply massive safety win.
Ski-jump will be used on QE2 class to reduce the amount of deck used for launch and ease handling aircraft for launches. What will be interesting is if they stick with using JBDs for launch.
JF, thanks for that excellent explanation of nose leg loads. I was involved with early analyses at Fort Worth and yes, it was leg closure that was the issue, not leg loads. Ramp profile design is actually quite a complex area, with some interesting variance in ideas on opposing sides of the pond. The USN have never put ramps on LHD class ships due to USMC insistence that the entire deck be left clear for mass helo launches.
Best Regards as ever
Engines