Now, here is a video that really intrigued me.
In the world of proas, outriggers and such other, considered exotic multihulls, the Harryproas are of a modern breed. Rob Denney researches and experiments with modern, more rational construction methods, often considering easily built panels, flat laminated, and then bent. Seems quick and cheap. The arguments for the weight distribution of his proas are simple and logic. They are "weight-to-windward" proas.
Just like in monohulls, there are a dozen or more possibilities to distribute the different elements of a multi-hulled boat, like; weight, length, volume, rig, rigtype, rudders, ballast, overhangs, symetry and such. It makes you really think about the factors that drive performance.
The harryproa chooses to use a slim long hull where the rig is located, and a shorter hull to windward, which carries most of the total weight. Accomodations, tanks, batteries engine are located in this "outrigger hull".
If you think about it, the concept makes lots of sense. The idea of the shunting boat is exactly to be able to have a slim hull, with an element of rightning moment, dedicated to be used to windward. Precisely where your overturning force comes from. So why not putt all the weight that you need to carry to achieve the rightening moment you need in there?
In the video, a Harryproa shunts over a conventional catamaran. Looks nice and easy. But, towards the end of the video, the cat seems to sail higher and faster. Accounting for the fact, that the proa needs to accelerate from a standstill, in relatively light winds, after shunting, it still seems odd. And the time indicated, at the end of the video, is not as positive as one might think. Why???
Are there lenght differences I can't recognize? Is the crew getting used to the boat or are the sails maybe not too well cut? The video owner profile informs that the owner is from Denmark. I am not aware of a Harryproa in Denmark. Does somebody know about it? I'd like to know more about it.
Click here to visit the Harryproa site, and see Rob's designs.
5 comentários:
Thanks, I've not yet seen this. I'm just theorizing, but perhaps the light wind is not in this proa's favor. The cat has more sail area (though is likely heavier). But also, the cat will have more of it's weight supported by the lee hull because the weight is central, as apposed to the proa. The idealized multihull is always sailing on just one hull, with the other just flying. Neither cat or proa are close to that ideal, but the cat is not dragging as much windward hull through the water as the proa. I'd suggest that this W2W proa would benefit from more sail area to take advantage of the increased righting moment.
Cheers, Michael
Yes, Mike, I agree that the proa would benefit from more and better sails. The cat's fat top main looks very good either.
To really grasp the effects of having a hull, an outrigged hull, dragging along aside of the driving force of the boat, that intrigues me. I wonder how my boat will perform in a similar case. I really are.
Cheers,
Peter
Hej Peter.
Jeg var fotograf af den rystende dårlig kvalitet "rangering Harry". Beklager, men jeg står op i en lille jolle. Jeg var medlem af racing commity i IMM 2009. Harry's ejer er fra Finland / finsk og båden hed Uno. Der er lidt flere billeder fra IMM på WWW.multihulls.dk-gå til IMM2009-"Billeder".
Jeg tror ligesom Michael. For lille sailarea til dette særlige forhold og mangel på spiler på dødt løb. Men i nogle øjeblik Uno viser en god hastighed.
Sorry above.It is Danish !
Hello Peter. I was photographer of "shunting Harry" video. I know is shaky and bad quality. I was member of the race commity and stand up in a tiny dinghy. Harry´s owner is from Finland/Finnish. Boat name Uno. Ther are few pictures more om www. multihulls.dk-
go to IMM 2009- "billeder".
I agree with Michael. Too small sailarea for this particular conditions and lack of a spinnaker on the dead run.
Hi Dan!
Many thanks for you comment. It was a cool surprise to receive your message in Danish. I actually only noticed seconds after the surprise effect, that you actually sent a translation too.
I think the images are not bad. If you did this form standing on a dingy... congratulations. Thats not easy.
So, this is Uno, from Finland. I had suspected so. Thanks for clarifying. The owner, Artho (or Arttu) occasionaly posts on the proa-file.
I agree with your comment about the sails and sail area.
Cheers,
Peter
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