Engine and Boiler Update

I haven't been doing much work on the hull lately and have been concentrating on the mechanical systems. I haven't started shaping any metal yet but have been working to finalizing the designs for the boiler and new engine. But before I get to that, some hull work has been done. Mostly that it's complete. All the structural parts are now on. Earl has been working on the trim and has made some really fine step pads. He's going to put some more trim around the wheel cowlings and such and has said he's going to make some seating for the front. I have some mahogany from the old 50 footer that I was hoping to incorporate into the boat and this seems a fine opportunity. No pictures of the boat today as it hasn't changed except in the details which get lost in the big pictures and the detail pics don't make a lot of sense out of context. You'll just all have to wait to see it live.

The trailer is in the back yard, but after close inspection it was decided that it needs an overhaul before it can be used, namely a new axle and springs. It would suck royally if after all of this the boat wound up as splinters on the highway after the axle snapped. I'm still anticipating that she comes it at ~2500 lbs and nothing has changed that so far. She'll probably have to travel with the boiler and tanks empty though. We'll see.

Now for the fun bits, the engine. In an early post I showed the design for the engine when she was to have only one that was chain linked to the wheels. Going over this for some time, I decided that two engines would be not only so much cooler, but more reliable and make the boat much more maneuverable. So I took the full rotary design and split it in half. It adds about 150 extra pounds for the extra plumbing and frames but it seems to me that it will be quite a coup to pull it off. I have yet to make even one, so I'm trying to count my chickens, but wow! will it be cool.

So this is the new design. Its hard to see much except the cylinder assemblies and the rotary valve in this picture because the nifty bits are hidden behind that big plate behind the valve. Those plates (there's a matching one on the back of the frame) are probably the most essential elements in the design. They're for aligning the shaft bearings which I can tell you is a very very tricky business. There are all kinds of places for things to go out of alignment and I need those to make sure that the thing doesn't seize up after the first few revolutions. To give you an idea of the size, it's about 24X30X15 inches squared off. Probably closer to 18 after the plumbing goes on. I'm hoping each one to develop about 3 horsepower @ 75 psi of steam. That's the theory anyway. The torque isn't that high because the pistons are skinny but once it gets going it should be all right.

I also made this nifty movie of the tricky parts, namely the drive yokes and the crank shaft. I don't know how well it will play on the web, but take a look anyway. No boiler pics or diagrams. I sent the drawings off to have the sheet metal water cut so I'll have pictures when I get that back. Until then.