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HP boats

Posted: 2 Sep 2020, 3:09pm
by SRV
Does anybody have any experience of human powered screw driven boats, specifically prop design and gear ratios?

Re: HP boats

Posted: 2 Sep 2020, 3:46pm
by pjclinch
SRV wrote:Does anybody have any experience of human powered screw driven boats, specifically prop design and gear ratios?


I don't, if I wanted to know I'd start asking at the British Human Power Club, http://www.bhpc.org.uk/

Re: HP boats

Posted: 2 Sep 2020, 4:01pm
by [XAP]Bob
Coventry university was racing a sub I think last time I was there.

Re: HP boats

Posted: 4 Sep 2020, 7:51pm
by Trikeyohreilly
A subject I'm interested in also. I have always fancied a HP boat for the inland waterways.

No experience myself.

Only read about it in "Pedalling to Hawaii" which was the first book to be written about a attempt by one of the two that set out to circumnavigate the world by human power. Stevie Smith.

The other man, Jason Lewis, went on to complete it, not "just" get to Hawaii. He went on to write three good books on the trip.

They were the first to cross the Atlantic from Europe to North America by human power. Their boat Moksha I think I remember correctly was set up in the recumbent cycling position.

Though I don't think they went into gear ratios, and think they were propeller driven, you may find some useful information there. All the books are worth a read anyhow.

Hope that helps.

Re: HP boats

Posted: 5 Sep 2020, 4:58am
by OldBloke
I have a vague memory of reading somewhere that flipper propulsion was more efficient for a pedal powered boat.

An internet search for pedal flipper kayak will return quite a few results. Here in Oz eBay has some for sale.

OB

Re: HP boats

Posted: 5 Sep 2020, 9:22am
by Mike Sales
SRV wrote:Does anybody have any experience of human powered screw driven boats, specifically prop design and gear ratios?


I have been looking into building an HPB for some time.
There is much on the net about it.
I have concluded that long and thin, like a canoe, is the hull form to go for.
Semi-recumbent and possibly with an outrigger for stability sounds right. (No paddle to trim balance)
I have not looked much at screw questions, but I have seen some discussions.
Please post if you make any progress.

Re: HP boats

Posted: 5 Sep 2020, 11:56am
by recumbentpanda
Pedal power is interesting, but there is a huge gap between the needs of racers, where hydrofoil canoes are probably the way to go, and the pedal power of touring boats (which interests me). Gear ratios , prop angles etc, and not least how you get the drive from pedals to prop.

Re: HP boats

Posted: 5 Sep 2020, 12:52pm
by OldBloke

Re: HP boats

Posted: 5 Sep 2020, 1:11pm
by Mike Sales
recumbentpanda wrote:Pedal power is interesting, but there is a huge gap between the needs of racers, where hydrofoil canoes are probably the way to go, and the pedal power of touring boats (which interests me). Gear ratios , prop angles etc, and not least how you get the drive from pedals to prop.


I would still want to minimise resistance in a cruising boat.
Hydrofoils are completely other though, and only for sprints.

Re: HP boats

Posted: 28 Sep 2020, 8:56pm
by yostumpy

Re: HP boats

Posted: 29 Sep 2020, 11:14pm
by [XAP]Bob
Mike Sales wrote:
recumbentpanda wrote:Pedal power is interesting, but there is a huge gap between the needs of racers, where hydrofoil canoes are probably the way to go, and the pedal power of touring boats (which interests me). Gear ratios , prop angles etc, and not least how you get the drive from pedals to prop.


I would still want to minimise resistance in a cruising boat.
Hydrofoils are completely other though, and only for sprints.



Don’t know, if you can get a fairly high lift foil then you might be able to sustain the foil, not for extreme speed as much as for smoothness and much reduced drag.

Watched some kite surfers this summer, one of whom had a foil board - crazy low drag, basically zero wake.

Re: HP boats

Posted: 30 Sep 2020, 10:04am
by Grldtnr
I have a recollection of something called the Winsome,a tandem pedalled boat ,long & thin, about 17'.
Google Winsome, Swallowboats,the Prospectory you may find what you are looking for.
It's not in production anymore, but Matt Newland of Swallow boats might be able to help you.

Re: HP boats

Posted: 3 Oct 2020, 10:07am
by SRV
Whoops! Took my eye off the ball for a bit there.
Some interesting responses.
I'm after something which I can take out for a bit of a tear about, but in displacement mode - no foils for me, just long and narrow. I want something that will be fast but seakindly.
It's the propeller and gearing I'm interested in and possibly how they compare with the Hobie Mirage Drive - which seems to be a benchmark.
Anyway I now have some useful leads to follow. Thanks everybody.

Re: HP boats

Posted: 3 Oct 2020, 10:33am
by DaveP
I believe that the specs for commercially available propellors include recommended rpm which might be something to look into, but I can't help thinking that for a small diameter lowish speed job you might need a special!
And if your thinking of inland waterways, don't forget the weed problem.

Re: HP boats

Posted: 3 Oct 2020, 11:34am
by Jdsk
SRV wrote:It's the propeller and gearing I'm interested in and possibly how they compare with the Hobie Mirage Drive - which seems to be a benchmark.



Jonathan

PS: Yes, I do know that winning a tug of war might not be the only requirement! : - )