Ok, so I'm on a steep learning curve and reading everything I have time for. An amazing amount of information here. Thanks everyone who contributes. Launching (pun intended) a new project... Long term my goals are the Trojan Mk II vertical engine and hopefully Minnie traction engine but I need a simpler engine as a starting point. Plans for both Trojan and Minnie are on the way and the workshop is nearly complete. While I'm waiting I thought starting plans for a 1/12th scale 21ft Steam launch might be a good idea. Full-size displacement 3467 lbs = 1572.6 kg 1/12th scale model 1572.6/12/12 = 10.92 kg (I think, please correct me if i'm wrong) or is it 1572.6/12/12/12 = 0.91 kg? My first problem to solve is a suitable scale looking engine and vertical boiler. In photos of full-size steam launches of around this size the engine seems to be fairly imposing and taking up a fair bit of space in the hull. I intend to build the engine and later might build the boat to put it in. Any suggestions for a suitable engine/boiler to build?