Would 11 tonnes become airborne????

> 10 years ago
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padbury
padbury
WA
20 posts
WA, 20 posts
22 Dec 2004 12:41pm
I know this is a kite forum not a yachtie forum but this is a cross between the two actually.

From the Age newspaper:
A secret weapon unveiled by Team AAPT could smash the Sydney to Hobart race record.

A $25,600 kite which increases their downwind speed by up to 20 per cent.

The 420sqm kite flies 150m from the boat reaching winds up to a third stronger than normal mast heights giving Team AAPT a hope of beating the 1999 race record

Team AAPT skipper Sean Langman said the kite technology, officially named Outleader Kite Mark II, allowed his 66 foot yacht to compete with the 100 foot maxis like Skandia, Konica Minolta and Nicorette.

The kite, helps lift the bow out of the water making the boat lighter and faster.

"I believe the kite gives us a chance (to win) that we did not have," said Langman.

"Our downwind speed is quite remarkable. "I have been told we may actually get this boat airborne."
"If we can get those (north-east wind) conditions again the record will definitely fall."

Langman, a 14-year veteran of the Sydney to Hobart race, said he found the kite on the NASA website.

"(If the win blows) we will just leave it on til it breaks."

"It is a big risk (to use it) but also it enables us to prove it is legal," he said.

"When people don't understand how somethings work they say let's make them illegal.

"I am no convert by any means. It is yet to be proven.

Team AAPT have less than three weeks to learn how to use the new kite and admit the adjustment is difficult to learn.

"We actually have to learn how to sail again," said Langman.

"You have to forget everything you normally think."

Type: OutLeader™ Kite Mark II

General Appearance: Measures as a spinnaker but looks like half a parachute. Designed to fly outside a yachts existing rigging.

Size: 420 square metres - this is the largest OutLeader kite built and delivered to date.

Dimension: Single surface and only 3 flying lines

Material: AirX nylon spinnaker fabric

Designer and builder: KiteShip™ Corporation, California USA

Flying Height: Normally flown between 50 - 150 feet

Winds at kite altitudes: 115 - 130% as high as winds at the surface according to analysts, Multihulls

Tactics: Kites are often 'swooped' or flown in zig-zag patterns through the air, causing them to fly often at 150 - 200% of boat speed according to analysts, Multihulls

How many kite-sails exist: Over 40 yachts from 30 to 75 feet worldwide have these Kites but APPT is the first big boat to race offshore with one in Australia.

TEAM AAPT - TECHNICAL SPECIFICATION

Construction: GRP
LOA: 20.03m
Beam: 5.59m
Draft: 4.04m
Rig: Bermudan Sloop
Fore Triangle: 95.70 square metres
Spinnaker: 389.5 square metres
No. of spinnakers: 3
No. of sails: 4
Weight: 7500kg + 3700kg of water ballast



PsYLoR
PsYLoR
QLD
927 posts
QLD, 927 posts
22 Dec 2004 7:23pm
www.kiteboat.com - Don Montague has built a 50meter kite (inflatable) & a 100m to pull an outrigger canoe.
They have been able to sail in 1 knot (thats right one knot!) of wind with the 50m kite using the resistance of the boat to create apparent wind!
The have also been riding waves and have done an actual jump off a wave with the canoe getting completely airborne.....
NeilT
NeilT
WA
139 posts
WA, 139 posts
22 Dec 2004 8:16pm
I'm no yachtie but I would have to say that there is virtually no chance of the yacht leaving the water!!! The mast would probably break first and this could prove to be a slight inconvenience!

There has been much experimenting with kites on yachts recently with most emphasis on fitting within the rules. No doubt these will change if a yacht-kite does well.

Take a look at the pics at:

http://www.boatingoz.com.au/news04/1206a.htm

There is no doubt that there is more wind at 30m above sea level than at sea level, enough to make a winning difference without the need to actually "sine-wave" the kite as kitesurfers do.

The Peter Lynn company in New Zealand were involved in serious technical discussions with an Americas Cup Team quite recently on this very subject.

It is most likely that someone will object on some obscure ruling and have it banned however the skipper of AAPT has vowed to start his yacht 2 minutes after the official start and then win the race. I like a guy with that sort of confidence!!!!

Don't miss the Sydney-Hobart race start on Boxing Day morning live on TV from Sydney.

Let's hope we get a chance to see the kite in action heading out to the ocean.

Incidentally, the colourful character Samuel Cody crossed the English Channel powered by a kite in the late 1800's. A frenchwoman yachtie crossed the Atlantic about 8 years ago powered by kites.

We are all just following in their considerable footsteps and probably having a bit more fun to boot!!

cheers

Neil Taylor








punchy
punchy
WA
98 posts
WA, 98 posts
22 Dec 2004 9:17pm
although this is not kite powered, windrush in fremantle developed a 40ft hydrofoil catamaran powered by a mast on each hull with double sided sails similar to normal pocket luff sails. according to Brett Burvill from windrush this thing could do fremantle to rotnest in a typical seabreeze quicker than your a twin 220hp powered chaseboat. i don't know if there are pictures on the internet but brett did do alot of his R&D on the moth class dinghies. have a look at www.moth.asn.au. if anyone is going to get an 11 tonne yacht airborne whilst powered by a kite, this guy is likely to do it
padbury
padbury
WA
20 posts
WA, 20 posts
22 Dec 2004 10:38pm
I guess getting "airborne" could be as simple as punching through a tallish swell and flying low over a decent sized trough before the next swell! They'd have all the regular racing sails up as well, so the available driving power would be huge. Hope their hull and rig stands up to the pounding.

Racing yachts in a strong breeze with a big spinnaker up is an awesome feeling AND a big handful, especially when things go pear shaped.

Anyway, I'd love to be out there on that boat when they fly the kite!
TimLewis
TimLewis
WA
111 posts
WA, 111 posts
23 Dec 2004 7:55am
I believe they attach the kite to the boat, not to the mast...preventing the damage to the yacht!

Bring on Boxing Day!!!

Forcast is 10 - 15 ENE - perfect
CODY
CODY
WA
56 posts
WA, 56 posts
23 Dec 2004 12:32pm
I read another article on DON MONTAGUE who with Naish attached a 100m2 kite (100 m of line)to a 47foot 15,000 pound carbon fibre catamaran...with a crew of 11...he said conventional sails push the bow into the water where as the kite lifted it up.

STUART
wrex
wrex
86 posts
86 posts
23 Dec 2004 2:32pm
Conservatively A 10sqm kite can lift a 100kg man so in theory a 420sqm kite could lift 4200kg
PsYLoR
PsYLoR
QLD
927 posts
QLD, 927 posts
23 Dec 2004 5:03pm
No, it depends on the design of the kite.
With 4 line inflatables it comes down to the arc of the kite, the apect ratio and the drag that is created by those(aspect and the arc)
So you can have a kite that is 10sqm thats very high aspect (really thin and relly long) with a slight arc. This kite would create huge lift, power and hangtime but would realy flop around in the gusts and be unstable in the air because it has not real structure to hold it there.
Or you can have a 10sqm thats low aspect (so its not as long but really wide) with a really curved arc. This would be really stable in gusts but have nowhere near as much hangtime or power, It would be a more solid pull from the kite also.
You can also talk about the amount of drag that is created by the kite when it turns in the air, and how if you go to one extreme you eventually lose performance in the kite.
So in inflatables all these must come together to create a kite that will perform best for beginner, intermediate and pro, in x amount of wind for x weighted rider.
richo
richo
QLD
337 posts
QLD, 337 posts
23 Dec 2004 8:10pm

A 420sq kite that is putting a upward force on the bow of the boat! Would it be possible for this kite to boost the boat? maybe not, but what if the boat was climbing a wave and a freak gust happened just as it punched through the crest. Maybe you would get some hang time. Might cause a loss of control. As long as there is a vertical force vector involved you got the chance to leave old mother earth, but surely something else would break first!
dachopper
dachopper
WA
1807 posts
WA, 1807 posts
24 Dec 2004 8:54am
well, my dads boat gets half out of the water with a normal spinnaker out the back of rottnest, surfs...... so i recon hell yeah it could get airborne
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