Jeremy
Interesting discussion about human power. Sometimes at anchor I think of how I could rig up a pedal powered anchor winldlass to raise the anchor. Perhaps with a bow mounted prop attachment to be able to slowly maneuver the boat and get a little exercise on board too. Just something to move the boat away from the mooring to get room to raise the sail. Saving the battery amps for more important maneuvers. Seems to me human power could handle some tasks on board with the right setup.
Capt. Mike
Sent from on board BIANKA
http://biankablog.blogspot.com
Those figures fit well with all the data I've seen about human power output. There is a fairly big difference (as you might expect) between the sustained power that an average person can deliver and that which an athlete can deliver. I know that I can only sustain around 90 watts (from a few checks on an exercise bike) whereas I believe that Lance Armstrong has been shown to sustain around 400 watts for over an hour - pretty amazing.
The rule of thumb I use is that most people can probably sustain between 80 and 100 watts, unless they are super fit, so this is the sort of power being used to propel a rowing boat, kayak or even a large Chinese junk propelled by a yuloh. This power figure seems to fit well with the performance from a few human powered boats where the hull resistance is known.
Interestingly, this appears to be an aerobic power limit, not a muscle capability limit, so it doesn't seem to make any significant difference whether the arms, legs or both, are used (kayak paddlers can produce the same sort of sustained power as cyclists and rowers, apparently). The limiting factor for sustained power delivery seems to be the ability of your lungs to oxygenate the blood, together with the ability of the heart to pump it around and the muscles to take advantage of it. It's probably this aspect of health that training for stamina improves the most, rather than outright physical strength.
Jeremy
--- In electricboats@yahoogroups.com, "Andrew Gilchrist" <andrew@...> wrote:
>
> Tour de France vary between about 150 and 350 watts in a time trial -
> however in sprints Mark Cavendish can pout out over 1000w - at least he did
> this year according to commentators who have access to these telemetry on
> the riders bikes
>
>
>
> Andrew Gilchrist
>
> www.fastelectrics.com
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> 612 4982 5481
>
> Australia
>
> _____
>
> From: electricboats@yahoogroups.com [mailto:electricboats@yahoogroups.com]
> On Behalf Of "hanermo" - CNC 6-axis Designs
> Sent: Wednesday, 14 September 2011 5:22 AM
> To: electricboats@yahoogroups.com
> Subject: Re: [Electric Boats] Re: 1000w per ton?
>
>
>
>
>
> I thought human olympic athletes could at best produce 100W for short
> periods, on bikes.
> Any comments ?
>
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