Wow, great replies.
Mark, you are a gent and I definitely owe you a pint.
Guy, what kind of steam pressure do you run the engine at?
I assume that if the engine likes to rev, then smaller props are the order of the day. I remember when the Proteus was launched, they had it turning a 75mm prop at speed and boy did it move that launch. I think they also used to run it with a 100mm prop, at lower revs and it would still go well.
I have another project to finish before I start on the Brooklyn. I am currently converting a big twin prop tug from electric to steam, using a Proteus boiler and a Pegasus V4 engine. Once it's all sorted I'll post some pictures.
Anyone else have a Gemini, we know they like to rev and they don't bounce, but It'd be good to hear from more owners.
Neil