Pedal Powered Boats

I did that with my wife's Audi cabriolet on a rainy day, over brand new, oil slick pavement. It didn't end well. Steering was a b!♧<h.

-Will

 

Maybe adding flywheel to the drivetrain is some solution.It's additional weight but I think is a thing to consider in pedal powered boat propulsion.I think that will be difficult to beat existing record ,drivetrain and boat propeller is the biggest challenge. Foils setup is also important but this worry me less.

 

It was quattro or not ? And which quattro , there are totally different drivetrains.Friend of mine aquaplanned in some old v8 quattro on the highway straight way during rain . He was strong quattro beliver .His drivetrain was Torsen I belive.Happily Nobody hurt , it happend at 9something mph or less .

 

Couple weeks ago somebody paste dirt bike with some boards attached . Boards for hydro lift . It was amphibious bicycle with some offroad limitations
But going strong .


going offtopic

 

Yeah, kind of off topic to human power which goes to just above one kilowatt for a couple of minutes at Peak. But questions were asked about 1,000 horsepower?

 

I believe the numbers are more like just over 1/2 hp for less than 1 minute by an elite athlete.
100 watts sustained by the average Joe.

 

The Rise of Cyclors: The high-wattage cyclists who power America's Cup teams https://www.cyclingnews.com/features/cycling-meets-sailing-the-rise-of-cyclors-in-the-quest-for-the-americas-cup/

 

Why would it only work at low speeds? If you have a drive shaft with strong magnets in a stretch of its length, you can then have another set of magnets in a cylinder turning around it, while the length of that section and number of magnets in it can be increased to provide whatever strength of connection is required, which should be low for pedal power in any case, and the main use of it would be for relatively gentle sustained effort. The part of shaft with the propeller could simply be plugged in whenever it's needed, and be easy to stow. Simplicity and low losses.

 

You are forgetting the whole context...this is field strength through a hull in water. There is the magnetic permeability and induced field issues besides the arrangement problems. If you think it can be done cheaper, lighter, smaller, and more reliable than existing through hull fittings for high speed...<shrug>...go make yourself a fortune.

 

Maybe some drawing to explain your idea ? Watertight magnetic torque connection is possible , thin composite or aluminium as a seal. High torque need big diameter , that could be problematic with horizontal shaft .

 

I've heard about these solutions. The regulations have caused funny technical solutions. Cyclor. Of course, this is part of racing and there is no joking. So cyclor drives the compressor without a flywheel. Interesting.

 

Why would you want to try to make the magnetic connection through the hull? Within the boat you would have a tube containing the propeller drive shaft with neodymium magnets embedded in it, while that tube's only opening would be where it exits the hull at the bottom of the transom (or a skeg to take it deeper and shorten the extension of the shaft to the prop), so no leak and no seals needed. Around that tube and within the boat, a cylindrical drive shaft with magnets embedded in it rotates, causing the drive shaft inside the pipe to rotate with it while the magnets in both parts would be in close proximity.

Note: I'm not talking about high power, high speed stuff for setting records, but ordinary people who want efficient pedal power for sustained travel (far better than rowing) with low losses and minimal stuff taking up space in the boat.

 

It would need to be a darn stout tube - strong enough that you could slide a shaft into it and then bend the shaft into a pretzel. You need to think about the way conventional shafts tolerate collision damage and prop strikes and make sure you can provide an equally capable connection.

And it would be a hoot to sand and bottom paint the insides. Let it sit for a week in the Florida Bay and it would be locked tight with oysters and Goose Barnacles.

 

That is still "through the hull". There is an air gap, physical hull material, and water, between the driving and driven magnets.

 

Don't leave your pedal-powered boat sitting in salt water. That said though, when you've removed the propeller and its extension shaft, you could shove a bung in there and pump the water out to keep the pipe dry.

Stout tube? What's the problem there? A section from the transom to some way forward can be extremely stout, reaching a place where it's locked firmly in place. Beyond that it can have a fragile, thin-walled section of tube around it where the magnets are, and around this is the other set of magnets in a collar that rotates around it, while this collar has a robust exterior that's hard to damage, but the tube between the two sets of magnets could be half a millimetre thick along this stretch. The tube could also have a much wider diameter here to allow the magnets to stay together with higher accelerations, and to fit more magnets into a shorter stretch. The fatter the better, up to the limit of how much space is convenient. The shaft running through all of this can then go on into a bearing even further forward where it's again held firmly in place. An extremely robust system with a fragile section well protected where the magnets get close together.