"In general, tractors can only exert as much drawbar force as the machine itself weighs. This is typically limited by the amount of traction the...
Seems rather outdated at least for asphalt and concrete. In EU passenger car tires get the worst energy rating, if they have more than 0.0121. For...
Sounds like a friction coefficient, not rolling resistance. That would be valid for dragging a rubber ship on wet asphalt, not for any kind of...
0.25 sounds a lot. The ship on the video seems to weight 410 tons:...
You should be able to do much better with a sailboat hull or similar. E.g. Swan 65 S&S (50' LWL) is about 32 tonnes and should do 6.5 knots in...
Interesting. I had calculated the forces on individual sheaves, but not really thought about moments. I have to try rerunning the line. I haven't...
Just to update I made some new measurements with a bit changed backstay system. Two years ago the first block in the cascade (not the one attached...
Pricey? Axopar is a cheap new generation of this XO Boats - Design by sea https://www.xoboats.com/ , which cost 2-3 times more. Same group of...
Torqeedo claims are totally BS. It has been shown in many tests that 2 kW Torqeedo is not even close to any 4-5 hp outboard in performance. It is...
Regarding prop rpm: E.g. you can take an engine from VP D1-series and fit it with a standard 2.63-2.74:1 transmission. The recommended max rpm is...
Why? Most electric motor installations have a gearbox just like combustion engines, which also could use a higher gear ratio, if found necessary.
Here we go again! You are still writing about "onset of lift", Kutta condition, no lift with backflow although in previous threads your theory...
Obviously there is no reason why a folding propeller should have a better efficiency than a fixed one, which can have equal shape. There is a...
2 kW or 48V and 21 A, which is 1 kW? 1 kW would be very low power, but 2 kW is about what I would expect for a 2300 kg 7.5 m sailboat at 5.5...
But you still haven't corrected the errors regarding Kutta condition, onset of lift and no lift while there is backflow at the trailing edge. I...
