Sailboat to Sidewheeler Conversion?

[DetroiTug]

I've laid out water lines (boot stripes) on hulls using a piece of string and a lamp. As long as three points are known i.e. at the transom, stem and one amidship on the hull. Darken the shop, then just hang the string over two saw horses, Put the lamp behind to project the line on the hull. Line up all three points and whallah.. start marking it out, turn the lights back on and start masking it off. Would work the same for what you are contemplating. Use strong string and make it very tight.

-Ron

[Lopez Mike]

In the case of a Cal 34, after the two halves of the hull are glassed together, it will be necessary to install a shaft log and a rudder post. If the deadwood includes the shaft log and a strap from the dead wood to a bottom rudder bearing, it should work.

I blow hot and cold on this idea. I suspect I will cobble stuff together and just enjoy steaming.

Mike

[fredrosse]

My first steamboat, a 15 ft Coleman Scanoe, car top mounted, with the "drop in" power unit mounted on a 2ft x 4 ft plywood board, carried in the back of the SUV. Stability was OK, and used an outboard lower unit to creat an I-O drive. See "Steam Scanoe" on Radow's website.

I have seen similar setups where the steam power unit, including sidewheels, drops into the canoe type hull before launching. Somewhat easier because drive shafts and the Inboard-Outboard setup does not need to be made. Space is at a premium, one, at most two persons, and difficult for the Fitch indian paddle configuration.

[Lopez Mike]

I am surprised that there doesn't seem to have been much work in adapting water power principles to paddle wheel steamers. In designs like the Pelton Wheel, there is flow across the surface of the blades rather than being stalled. Anyone who has stalled an airplane knows instantly that here is much more force to be had with attached flow.

I suppose a Pelton Wheel needs a high velocity jet to work but the principle is worth thinking about. I've often wondered if the Greenland kayak paddle with their narrow blades might be getting more attached flow and thus better efficiency.

Of course, this asks the question of whether attached flow is more efficient. I don't have a clue but it seems likely.

Maybe something like the stages in a low pressure turbine with one paddle blade passing the flow to a fixed blade and thus to another blade . . . .

I think one of you has really missed the boat (pun intended) by not naming a paddle wheel steamer The Anachronism. The again, that might apply to all of our craft.

Mike

[fredrosse]

Actually there has been significant study of hydrodynamics of paddle propulsion.

In high speed planing paddlewheel boats the floats are indeed shaped to achieve flow directing similar to the Pelton wheel practices. The float is shaped like a 180 degree piece of pipe, about 3 or 4 inch diameter, and enters the water only 1/4 to 1/2 submerged. The water is scooped up by the float, and thrown out the aft end of the boat with relatively high velocity. The 180 degree reversal of direction increases effective thrust. This refers to paddle boats that have been studied by professors and students of naval architecture, I can send you some papers on this subject if you would like.

For the relatively low speeds of our steamers, paddle design falls into another realm of technology, which has also been studied very well. For the moderate (non-planing) speeds of typical steamers, there is just not enough room within the wheel to achieve this flow reversal effectively. The head requirements to scoop up the water become a significant fraction of the power required, this is a parasitic loss. Also to throw a sufficient quantity astern requires big dimensions of the astern "jet", which typically interferes with the trailing float. As a result, low speed paddle designs favor basic "Drag" technology, which can get fairly close to propeller efficiency numbers with articulated floats that have the proper shape.

Of course, on Youtube you can find several high speed planing paddle boats, where some guy hooks up an automobile engine to a simple paddlewheel and scoots his Jon boat about at relatively high speed. I am not writing about those types of "designs", which often have no real engineering basis, other than "big engine-probably go fast" .

Paddlewheel technology has certainly been eclipsed by screw propellers, except where shallow draft governs, or, in the case where nostalgia governs. Screw propellers cost less, take up less room, are more efficient. And screws allow docking!

[Lopez Mike]

I had no idea there had ever been a 'high speed planing paddle wheel boat'. The mind boggles.

I have watched small sea birds paddle along on take off and sometimes just on short flights. I can't imagine they get that much push from their feet. Probably more lift.

My five liter hydroplane propeller used a two blade that ran hub deep at speed. Maybe 8 thousand rpm and 600 hp to a 12 x 12. I always assumed that it wasn't acting as a paddle wheel but I have not a clue how much attached flow was involved. The blades were razor sharp on the leading edge and square on the trailing edge. My prop experts called them Super Cavitating (more likely super ventilating). It was, indeed, a case of big engine-go fast! Even with the open exhaust of the engine, the bystanders said that they could hear the prop noise coming from the water at their feet. The probable efficiency would not bear thinking about.

[fredrosse]

Somewhat off topic, but interesting...........

Personal watercraft often have over 100 horsepower, and can go pretty fast. Then the snowmobile people, running late in the season, ran over some big puddles, and found the snowmobiles could "fly" over water. Of course, boys will be boys, and soon they were racing snowmobiles on lakes, (not in winter on ice, but summertime on lake water). One chap added extra fuel tanks and drove one across lake Michigan!

Finally a personal watercraft magazine arranged a "shootout", the baddest Yamaha personal watercraft against the baddest Yamaha snowmobile, both 100 HP plus little devils. The snowmobile won hands down, faster around the multi-turn lake course. If you look on youtube there are drag races for snowmobiles across a lake, they can get up on the water and go! Of course, don't slow down, they sink like a rock.

As far as I can see, the snowmobiles are essentially paddle boats (with no net positive buoyancy), yes?

[Lopez Mike]

I have often opined, while sitting around a camp fire, that there is NO human activity that has not been pursued to absurdity.

I rest my case.

Mike

[guyvapeur]

http://s1360.photobucket.com/user/guyva ... sort=3&o=0
Here is a photo of a sailboat converted to steam. You can not have more fun than this. I added 3 feet to the stern to give it a fantail look. This boat has served me well.

[Lopez Mike]

What make and size of boat was it? Length, beam and draft now? Any pictures of the construction project?

Mike