A Real Start

[Brenton Baker]

I posted here some time over a year ago, with great and ambitious plans to build one of the several steam launch plans I had drawn up in my spare time. These were interrupted by reality, as my father and I had to move, and I came to the realization that we were not ready to pursue any project with most of the house still in boxes.

After a year, we are a little more settled, and most of the major house projects are out of the way. Most importantly, my father has become interested in the project.

Trying to keep things simple for the first time, I have purchased a 15' Coleman canoe off Craigslist, intending to make a simple conversion. An inspiration here was Fred Rosse's Scanoe conversion, and that method seems almost ideal, as old/antique outboard motors seem to be everywhere out here in Phoenix. Additionally, any launch we own will have to fit through the 3'-6" side gate, which seems to make the traditional canoe-style launch our only option.

With the hull already bought, the remaining items are the boiler (including feed), the engine, and the propeller.

The boiler we're not too sure about - Fred used a monotube made from 304SS and Swage-Lok fittings, and we will probably go a similar route if I can get an idea of how much steam we need, and how much tubing that will require. If that doesn't work out, the next option is to simply buy a boiler from Beckmann, as we have neither the equipment nor the skill to safely build/weld a more traditional boiler ourselves. We have a casting kit for a hand feed pump from Pearl Engine Company; I will take a look at that after we get the engine going, to see if we can't machine it ourselves.

Since we will be buying an old/antique outboard from Craigslist (there are many, in good condition, for a song) for the propeller anyway, I will take a look at the engine in the outboard to see if a simple conversion to steam is possible (we have the solenoid setup from before, as well as the possibility of bash-valve conversion, and other methods, and are keeping possibilities open).

If a conversion proves impossible, we have the casting group from Tiny Power.


So, that is the plan. I am confident that real progress will be made this time around, as the situation is much more conducive to work on the project (we have more time to work during the week, and a few months' time before the temperature starts getting into the triple digits).

[mtnman]

Ambition is the most important thing in starting a project. About the Canoe, are you proficient in canoeing? I ask this because, from experience I have found a canoe to be very unstable and capsizes easily. If you add an outrigger they become very stable.

[Brenton Baker]

We are both proficient, having spent years canoeing as part of BSA outings, including a week-long trip on the Colorado. Stability was never really an issue, but then we mostly used somewhat heavier aluminum canoes.

If stability proves to be a significant issue, we can look at some kind of outrigger that can be bolted on during launch. At the very least, the canoe has enough floatation so it shouldn't be completely lost if it ever does capsize.

[fredrosse]

With a monotube boiler you will need an engine driven feed pump (in addition to the manual feed pump) because the monotube boiler needs continuous feed. Fuel feed should also be continuous, so I used propane. For the canoe, 5 to 10 square feet heat transfer surface area (HTSA) is required, based on the surface exposed to hot flue gasses.

My scanoe boiler had 5 square feet HTSA, and the center steam/water separator was made from 1-1/2 inch schedule 40 pipe. The arrangement was designed to keep all of the steam generating coils wet (steam and liquid water two phase flow) which avoids possible overheating. 100 MPH Steam hydroplanes with high superheat coils can perform much better, getting several horsepower from a boiler much smaller than mine, but with shorter life and much more excitement. The steam hydroplanes virtually all use gasoline vaporizing burners, which are noisy.

Conversion of an outboard to steam is not too complicated, and bash valve arrangement will work for several engines. The devil will be in the details here. There have been some other successful steam outboards made, correspond with the Northwest Steam Society for further details. From what I have seen, the original outboard vertical shaft, (and crankshaft I think) has been retained, with steam cylinder added.