The float valve actually serves to keep the hotwell level constant... the operators needs to see that the boiler water level has dropped due to steam leaks (largest is usually the whistle) and then manually admits more water into the system. Note that we generally don't use automatic boiler water le...

Wow - neat! You guys are making progress! For a condensing compound, you can basically assume 30-35 BMEP on the big cylinder depending on 150-225 psi steam pressure... so that engine w/ a 10"x6" can produce 33 * .5 * 78.5 * 400 /33000 or about 15 HP at 200 rpm. That boiler will produce enough steam ...

My boat is the one that Bart mentioned with the monotube and clutch. It is I believe what many people would call a "dog" clutch. I will see if I have any pictures, as the boat is in winter storage now... Dog clutches: http://en.wikipedia.org/wiki/Dog_clutch You have a multiplate clutch, I think. - ...

What I do with the Otter to introduce make up water is to switch the pump suction from the hot well to the makeup tank. This causes the hotwell to start filling immediately; if I forget to switch it back the hotwell spilling over on my leg reminds me :). If I used a vacuum pump I'd likely just use a...

Note that the impact of this difference is quite small for hobby scale steamboats, and most of the parts that are working in close proximity (such that the small size change could be important) are subject to roughly the same temperatures..... Any design where this was critical would probably be muc...

I would use the vacuum pump to pull the condensate from the condenser into the hotwell. The feedwater heater should come after the feedwater pump; otherwise the hotwell can get too hot and the pump won't pump hot water (vapor lock). The float valve bypass just returns the water from after the pump a...

Also note the great economy (even when exhausting to the atmosphere, 15 psia) at say 65% cutoff: MEP Factor = (0.9300 x 115) - 15 = 91.95 MEP. 35% less steam by volume for a pressure decrease of only 8.05 psi. This works well... but keep in mind that the more expansion is done, the bigger the impac...

I think the relationship you're using for expansion of steam is wrong for adiabatic expansion. Bart: You are correct. I'm assuming isothermal expansion, which is the relationship I've found in two books so far (at least for the initial rough estimates at the very theoretical level). . Isothermal (c...

I think the relationship you're using for expansion of steam is wrong for adiabatic expansion.
Compare your estimate with values from a steam table.

- Bart

Put me on your "buyer" list as I've been looking and haven't been able to find 6" cleats...I need four. The shiny polished ones with some sort of varnish don't fit the character of our boat. I've been happy w/ the Herreshoff bronze cleats; very traditional, and they weather to a nice color. I found...