sailing, speed record

[sjlaka]

hi,
being a dedicated windsurfer I ask myself this question?
Isn't it an illusion to think the record can be held by a windsurfer (don't believe in it myself). There has been some attempts to break the Yellow Pages record lately which were quite succesfull ( about 45 knts avg over 500m, about one knot under the standing record) using conventional boards and rigs. What is the main problem in building boats this fast?

[tspeer]

Minimizing all sources of drag. Including cavitation. And the windage of the crew.

I would also add that control is an issue. With my hands acting as sheets, I can control the sail very rapidly. In a larger vessel, response time is slower. This is important when considering how much power (sail) can be utilized.

As far as I know wind surfers sink under the weight of 'the captain' until under way, when they can plane on the water. Obviously this gives them a huge surface area to power ratio. It would be very difficult to operate a yacht similarly designed. Half way across the sea wind is lost and everybody has to swim or sink. Anyone else comment?

Another point. Wind surfers have a huge percentage of 'moveable ballast', the 'ballast' weighing far more than the entire boat. Imagine a 20 ton racing yacht with 50 tons of moveable ballast that can be hung out well over the weather rail. Not only is the 'ballast' able to 'hang out' over the weather rail but the centre of gravity can be adjusted to suit wind conditions.

[foxxaero]

http://foxxaero.homestead.com/indsail_001.html

[tom28571]

Not mentioned so far is the ability of the windsurfer to heel the rig to windward, thereby reducing the displacement and increasing speed potential. All of the usual sailboats heel to leeward which increases displacement, reducing speed potential. I think the fastest speed sailer will need to use a windward tilted sail to reduce drag and maximize speed. The ultimate rig would approach the "wing in the air and wing in the water" set forth 40 years ago by the author and experimenter of "The 40 Knot sailboat". I forget his name.

Kite sailers already use this concept but they are a different breed and aren't really boats.

Originally Posted by tom28571

Not mentioned so far is the ability of the windsurfer to heel the rig to windward, thereby reducing the displacement and increasing speed potential. All of the usual sailboats heel to leeward which increases displacement, reducing speed potential. I think the fastest speed sailer will need to use a windward tilted sail to reduce drag and maximize speed. The ultimate rig would approach the "wing in the air and wing in the water" set forth 40 years ago by the author and experimenter of "The 40 Knot sailboat". I forget his name.

Kite sailers already use this concept but they are a different breed and aren't really boats.

The book was by Bernard Smith in the early 1960s. I think the US Navy paid for some of his work, it may be possible to get a copy of the source material from them. The Baker Manufacturing Company did the best stuff; also I think for the US Navy, but I have never seen a write up on that work.

[Kiteship]

Originally Posted by tom28571

Kite sailers already use this concept but they are a different breed and aren't really boats.

Some here will understand why I cannot just let this go by. I've designed built and sailed kite powered "boats" for 27 years--from a pair of water skis to 80', 25 ton America's Cup yachts.

Please, Tom, why are kitesurfers not "boats?" In your answer you might address windsurfers, their "boat-ness" and potentially why one is a "boat" while the other isn't?

Cheers,

Dave
www.kiteship.com

[Kiteship]

Originally Posted by Robert Gainer

The book was by Bernard Smith in the early 1960s. I think the US Navy paid for some of his work, it may be possible to get a copy of the source material from them. The Baker Manufacturing Company did the best stuff; also I think for the US Navy, but I have never seen a write up on that work.

Bern Smith did his seminal work while working for the Navy, but in his spare time. His older book is out of print, but his latest "Sailoons and Fliptackers" is available to anyone from the AIAA website. Smith is writing a new book as well. There is a website chronicling these types of boats--there have been many built. See: http://www.geocities.com/aerohydro/home.htm

Worth a look

Dave
www.kiteship.com

[Sean Herron]

Hello...

I don't know if any one here has been following these guys - but they have been making claims towards 70 knots plus...

See http://www.monofoil.com/monofoil/monofoil.php ...

Crazy fools want your money too...

Well - at least they do tricks for treats...

Also - a boat as I believe and as my faith in Freya dictates - is something that displaces its own weight in water per Archimedes and thus will float while at rest - but heh - I am just a Sean...

However is a biycycle on a kickstand still a biycycle - or is a Sean full up on whisky and walking like a dog still a Sean...

Symantic arguement is for those who feel the need to argue - go sailing however you bloody want or go take out a $60,000 student loan and become one of those wank pysychologists...

Or go get a drink...

SH.

[foxxaero]

Well, Sean ... I'd be careful of writing John Howes off as some kind of lunatic. Although his design is somewhat divergent to general thinking, methinks he is far from being classed as an idiot! We shall see...

http://foxxaero.homestead.com/news_howes.html

[Kiteship]

Originally Posted by Sean Herron

Hello...

I don't know if any one here has been following these guys - but they have been making claims towards 70 knots plus...

See http://www.monofoil.com/monofoil/monofoil.php ...

Crazy fools want your money too...

Well - at least they do tricks for treats...

Also - a boat as I believe and as my faith in Freya dictates - is something that displaces its own weight in water per Archimedes and thus will float while at rest - but heh - I am just a Sean...

I gotta agree with Foxxaero; I know Jon, spent an intereesting afternoon having this model explained to me. I think he's for real, though they're claiming a *goal* of 70 kts, not actively sailing at that.

"Something that displaces its own weight in water" would include a working definition for a stone, too. Perhaps we've missed something here? ;-)

Dave

[Sean Herron]

Hello...

I said crazy fool not lunatic - perhaps I need to define my vision of crazy fools vs. lunatics...

A crazy fool is a guy who as a kid built 6 foot high snow ramps to jump his toboggan over in minus 40 degree weather - a lunatic is a crazy guy...

Now hold in mind that kid who was building 6 foot snow ramps probably suffers psychologically from the ear cuffing he got from his mother - when she found out why he snapped the $60.00 snow sled...

I also said 'displaces its own weight in water such that it floats' - no equal mass - ie: 64 pounds per cubic foot pushing against something that is something that displaces something - I mean - something...

I think my feelings are hurt - you assuming that I would call such a crazy group of research lunatics to be out of their skulls - being out of your skull is a lot more fun than doing the 9 to 5 - I love all the development in speed sailing that has been going on since the 60's including the work with hydrofoils on military fast patrol craft...

I think my feelings are hurt - I can't tell - no obvious bruising - maybe I need the psychology degree...

Anyway I am just now trying to remember a book that I picked up years ago with some lunatic crazy ideas in it - it was not Jack Holt - he did the Enterprise - some pedal boat and weird rotating blade sail boats - I think he ended up designing for Freedom - just can't remember his name or the book..

Anyway I am not slamming anyone or anything - just having fun with words - cause I can - if I have offended anyone - well just go make yourself feel better by ignoring me - passing me off as the raving lunatic (and 60 WPM typist) that I can be...

Best of...

SH.

[tom28571]

Originally Posted by Kiteship

Some here will understand why I cannot just let this go by. I've designed built and sailed kite powered "boats" for 27 years--from a pair of water skis to 80', 25 ton America's Cup yachts.

Please, Tom, why are kitesurfers not "boats?" In your answer you might address windsurfers, their "boat-ness" and potentially why one is a "boat" while the other isn't?

Cheers,

Dave
www.kiteship.com

Dave,

I can see that I may have gone too far. I've only watched a couple of kitesailers at the beach so my exposure is slight. What I meant is that separating the floating part from the driving part by long string(s) just seems to get outside what I'd call the definition of a boat where all the parts are intimately connected .

I appologize if I stepped on anyones ideas but my personal prejudice still gripes at lumping kites with the others. The earliest kites were fixed to the tip of a mast and I had no problem with their boat qualifications. Oh well, I don't eat beets either.

Bernard Smith it was and what a stimulus to thinking about speed in sailing it provided as I read and reread it many years ago.

Now I'm going to take a look at the monofoil link.