Human powered hovercraft, but changed to electric power

Hi everyone,

I've recently been toying with this idea I had. I was looking at a couple of human powered hovercraft, that is, powered by the hovercraft driver pedalling, like this very impressive one here: http://steamboatwilly.org/ , and this UH plan here : http://www.hovercraft.com/content/index.php?main_page=index&cPath=5_38 .

According to Wikipedia, an adult of good average fitness averages between 50 -150 watts cycling power output for an hour of vigorous exercise. So as you can probably guess, I was wondering if it would be possible to swap the pedal power for electric power. To me it seems that there is no obvious reason why not, but maybe I am missing something. Yes you would add weight with adding an electric motor and batteries, but perhaps this could the same weight or lighter than the pedals/gears/chains.

It seems absurd, but if we take 100 watts to be the required power, then a fairly small and cheap model aircraft motor, and a lightweight lithium battery, could supply that power.

What do you folks think? Thanks for any replies. It seems incredible that a 100 watt motor could hover a human, when most 1 person hovercrafts use a few horsepower, but maybe this is a result of the extremely lightweight design of these human powered hovercraft. Also, there are model aircraft motors that can far exceed 100 watts power.

Any thoughts?

You could easily power a small hovercraft like SBW with a few hundred watts of electrical power, but it probably still wouldn't be a very practical craft; it would prove that it is possible. A few Kw would make a practical craft though.

I made a small part of SBW-the propeller one way clutch housing. I didn't really get on with the main builder but he is a clever builder who has been involved in human power devices for decades.

Hi Milo

Your numbers are unprecise its depending on the wight of the cyclist.

On firm, flat ground, a 70 kg (150 lb) person requires about 30 watts to walk at 5 km/h (3.1 mph).[citation needed] That same person on a bicycle, on the same ground, with the same power output, can average 15 km/h (9.3 mph), so energy expenditure in terms of kcal/(kg·km) is roughly one-third as much. Generally used figures are

1.62 kJ/(km∙kg) or 0.28 kcal/(mi∙lb) for cycling,
3.78 kJ/(km∙kg) or 0.653 kcal/(mi∙lb) for walking/running,
16.96 kJ/(km∙kg) or 2.93 kcal/(mi∙lb) for swimming.

Amateur bicycle racers can typically produce 3 watts/kg for more than an hour (e.g., around 210 watts for a 70 kg rider), with top amateurs producing 5 W/kg and elite athletes achieving 6 W/kg for similar lengths of time.[citation needed] Elite track sprinters are able to attain an instantaneous maximum output of around 2,000 watts, or in excess of 25 W/kg;[citation needed] elite road cyclists may produce 1,600 to 1,700 watts as an instantaneous maximum in their burst to the finish line at the end of a five-hour long road race.

Click to expand...

From here

You can see in and on water u need much more power to move.