Hydrofoil rowing
Eberhard Nabel
recently I found
http://pantheon.yale.edu/~jbm42/Hydrofoil.htm
and
http://www.youtube.com/watch?v=9BXxL9gztO8
Amazing! I wonder whether it is known.
Eberhard
Mike Sullivan
changes, and boat speed
variations, but there it is....
"Eberhard Nabel" <ebn...@aol.com> wrote in message
news:3c082ca2-70b9-4a8b...@d4g2000yqa.googlegroups.com...
zeke_hoskin
Allow me to change my conjecture that sliding riggers may work with
hydrofoils to an assertion.
I note that in the brief accompanying exposition, the designer
mentions less speed variation as
one of the reasons it works. As Carl Douglas has pointed out, sliding
riggers in boats significantly
lighter than the crew almost certainly have *worse* speed variation
than sliding seat rigs. However,
the lack of weight shift is probably crucial. Their rower looks
skilled enough to scull a sliding seat
single without burying the ends . . . //Zeke
Carl Douglas
Anyone interested in early attempts at hydrofoil sculling should seek
reports of the work of James Grogono - surgeon, speed sailor (Icarus),
sculler & unstoppable enthusiast.
James added hydrofoils to a single around 1980 & was one of the first to
achieve foil-borne sculling. He used a simple type of depth control,
for what is always going to be a bit of a problem in a rowing action.
The Yale guys' plans for some kind of surface-sensing foil controls make
obvious sense.
I was intrigued by the amount of elevation they considered necessary -
not just clear of the water but well clear - since that would seem to
amplify the difficulties caused by the inevitable change in ride height
from normal immersed sculling & foiling. However, with foils like that
you no longer need trestles!
I, like Zeke, was impressed by the lack of porpoising seen in that film,
suggesting that, in effect, moving the foils relative to the CofG during
each stroke cycle was not such a problem.
To see how foils might possibly transform sculling, see those Youtube
films of the foil-borne Moth sailing dinghy. That is really quick &
twitchy!
Cheers -
Carl
--
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David Henderson
'Learning to Fly'.
Not sure that 'coming down is the hardest thing'. I would have
thought that staying up was even harder.
Dave H
Groovin' with Mr Petty in Brussels, Belgium
ben
My impression was that this had actually been done before but the
problem was that they could find anyone who could sustain the "flying"
for any length of time to make it worth while. It seems to me it was ?
Eltang the lightweight Danish sculler who was the model. If you could
get to work it seems pretty clear that it would be faster although
certainly would get you disqualified. The video is beautiful to
watch. The fun thing to do would be to sneak the boat onto the water
at a regatta and race down the course with it.
As for the sliding rigger, it is the obvious choice for this
application for the reasons stated in the link. I don't know if they
were able to try previous incarnations of the hydrofoil with a sliding
rigger or not but this may have contributed to previous failures.
Anyway, would be very cool to have one although I suspect not very
practical othe than for 10 strokes at a time.
Jake
Great video. i tried to build something similar a couple of summers
back. i thought that the mechanism of the Aquaskipper
http://www.youtube.com/watch?v=9FXuBkAVU6g&feature=fvw which has a
spring which allows the user to transfer weight rhythmically on and
off a main foil might be possible to integrate into a single scull
with sliding seat- that way the transfer of weight to the bow would be
used to help propel forwards rather than be wasted. Due to the drag of
the mechanism off the foils I was unable 'to get it up' but still
think it could have worked if it had got up. I used a recreational
sculling boat and aquaskipper mechanism with reduced and adjustable
spring.The main foil of an aquaskipper describes a similar route
through the water as a whale or dolphins tail, which is quite pleasing
but if you're over 80 kilos it's pretty frantic work to keep it on the
foil.
Tinus
is that it would generate a class in which lightweights are faster
than heavyweights by nature (resistant force scales with mass as power
1 instead of 2/3).In that way the philosophical objections of
different weight classes become redundant.
Carl Douglas
Going back to the historical perspective:
I received the following a short while back from noted RSR correspondent
and good friend, Tim Wise, which I think he may have intended to post
direct to RSR:
"Very difficult to find any information of Mr James Grogono's foil borne
sculling boat on the net, however
the River and Rowing Museum at Henely will tantalize us
"I've seen it plus a picture in flight, alloy hull and frame. Legend has
it that it disintegrated in flight while being sculled by a young
sculler called Steve.
"The whole thing was amazing, except sitting right next to was the Glyn
Locke (Spelling) Hydrofoil for a lightweight assault on the Montreal
Olympics.
"This assault never eventuated as it was difficult to control at speed.
"Tim Wise"