Fitting the feathering to a small boat, with the complexity it entails, would be a major task. Plus the added width might make life difficult, not least for transporting the boat on land. Hence I assumed (perhaps wrongly) that it wouldnt have feathering paddle wheels. I wouldnt be in favour of electrical powered boiler. If it is going to be used, may as well fit an electic motor! Alan On 17/03/2012 12:54, Clifton wrote: > Hi All, > > For the best efficiency of paddles they need to feather. This means that > each paddle enters the water vertically, travels backwards through the water > then exits again vertically. This avoids the loss of efficiency by the > paddles first slapping the water then trying to lift a load of water > > To achieve this it means that each paddle has to pivot individually with a > linkage to a fixed offset point. Rather like a loco eccentric. > The biggest snag is that you need a set of sponsons outboard of the paddles > to carry the fixed eccentric point. > > Just recently I think in EIM there was a article on a model boat with a > electronically controlled Flash steam boiler. I see no reason why it could > not be scaled up. > > Regards > > Clif > ----- Original Message ----- > From: "stepney"<alan@xxxxxxxxxxxxxxxx> > To:<modeleng@xxxxxxxxxxxxx> > Sent: Saturday, March 17, 2012 11:11 AM > Subject: [modeleng] Re: Thoughts on future projects.... > > >> Coming back to the steam options that Chris mentioned, >> >> I know someone who has done a lot of research on steam bikes. An >> ex-university lecturer, he has written an interesting paper on them plus >> a comprehensive survey. There was one running at the St Agnes rally a >> few years ago. >> >> Generally, they werent too successful as motorbikes, but could be good >> fun. >> >> >> As for steam boats, there was an interesting flash steam boiler at... I >> think it was Donnington, a few years ago. I have photos and details >> somewhere. >> It made a compact unit that provided lots of steam. >> Plus, of course, no actual pressure vessel to test. >> That would be my choice for such a vessel. The other option is a >> vertical boiler, which is common and for which there are numerous >> designs available. >> >> For the engine, and without doing any calculations, I would guess that 3 >> or 4hp, would suffice. >> (Paddles being less efficient than a screw, and to raise the efficiency >> of paddles means quite complex paddle design, so I assume they would be >> fairly basic=less efficient.) >> There are lots of engines that would provide that power. Some of the >> Leak designs would do, but for a paddle steamer, I would go with an >> inverted V, much like the model that Tel built last year (or was it the >> year before?). >> An enlarged version of that would give a low CofG, and take up little >> space. >> >> Alan >> MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.