New Age Trawler/Motorsailer; Kite assisted PowerYacht

[eponodyne]

Ow You got math in my eye!

[brian eiland]

Lots of activity here !!...haven't had time to keep up

video I was referenced to:
Sit-down kiting
http://www.skytoys.co.nz/Kite%20videos.htm

[eponodyne]

Video showing stability of a Peter Lynn kite.

This is promising, my experience with traction kites is that they have to--have to-- be flown all the time. Apparently the model shown is water-relaunchable as well.

Hmmmmm.

[Guillermo]

Very interesting that statically stable Peter Lynn's kite. Member of this forums Dave Culp has developed a long time ago also 'anchor type kites' for marine propulsion.
See: http://www.kiteship.com/

Cheers.

[brian eiland]

Either this French group has been reading my posting,

...or I've been reading their site,

...or many of us are thinking along the same lines.

... and Dave Culp was way ahead of us all

[Guillermo]

That "Trawlivarius" seems to be flying an SkySails' kite.

Cheers.

[brian eiland]

Video shot

...click on "english version" and check out the competition...first a windsurfer, then a kite sailor.

[Munter]

Epo - before taking on such a big project as a 5.5m kite monohull I would strongly recommend that you learn to kitesurf. The lessons you learn there will help ensure that your design is practical and workable. It will also help you understand the dynamics of kite flying which will be important if the project is to be successful.

Cheers,

Munter.

[Guillermo]

SkySails first flight on the "Michael A."
http://s2.streamingfarm.tv/streaming...m_02_1000k.wmv

When 'zenithing' the kite, net propulsion force is zero. SkaySails' developers say you can use this feature to put the kite in 'stand by' mode, useful when trawling and other fishing manoeuvres.

Cheers.

[FAST FRED]

"and if I keep everything balanced to *just* before the keel stalls, then that should net me a greater windward moment than without a trailing edge flap."

Most cruisers head up till the HULL stalls , the keel on a cruiser just makes it happen at a bit higher angle.

A racer with a huge draft will sail on the keel's angle of attack , mostly as a tactical manuver , as the drag is higher with all the lifting force coming from the keel, and the hull doing little for lateral resistance.

Remember the plots of Nelson showed 90 deg tacking , and no keels as we know them today.

FF

[eponodyne]

Munter, thanks. As it stands, I have several 2- and 4-line kites and have hundreds if not thousands of hours flying them. I built a kiteboard last summer using ideas gleaned from the old zeroprestige.com site (and didn't pay attention to what they had to say about volume, this thing is way too thick and too heavy. But it sure looks sharp.), and have been out several times. I could waterski and wakeboard about the same time I learned to pee by myself so it wasn't too hard to integrate the ideas.

Fred, good point on the hull stalling. I hadn't thought of that. I wonder if I could build a kite-powered ekranoplan.....

LOL

[sigurd]

Some older references, my dinghy with a 4 line winch, and cristofa's mini 650: kite dinghy

On my Tornado 20' cat I used a line with pulley between the bows instead of a track. The rudder was controlled with pedals via ropes.

This is Peter Lynn's system for launching an Arc kite on one line. As the four other lines are tightened, the first line will be slack, and the kite will fly in its normal shape.

[sigurd]

check out some older news on www.peterlynnkites.com .
He has a 6m (?) mono with a system for eliminating heeling - a bow mounted pivoting pole. He used or proposed tandem rudders to eliminate centrifugal heeling, I think.

[brian eiland]

...just saw this news from Sail-World.com, and being that it relates to 'supplemental wind power' I felt it belonged in this subject thread


Advance to the Past: Fishermen Start to use Sails

Commercial fishermen in the UK are reverting to wind power in response to soaring fuel prices, as skippers rig their boats with auxiliary sails to cut the amount of diesel they use.

The move comes as a new generation of vessels is being developed that will rely almost exclusively on sails.

Higher fuel costs threaten to force many fishermen out of business. The price of the red diesel the industry uses has doubled in less than a year, while fish prices have remained relatively stable.

Deas, chief executive of the National Federation of Fishermen's Organisations, said a number of skippers were now using sail power to help them travel the long distances between port and their fishing grounds.

'Skippers are putting on foresails while steaming to fishing grounds offshore,' he said. 'The whole cost structure of the industry has shifted so dramatically as a result of fuel price rises, and in response, vessels are looking at what they can do to reduce costs.

'Fleets are going to have to find ways of reducing fuel dependency. Everyone is looking for the optimum steaming speed and people are looking at a whole range of measures, including sail.'

Auxiliary sails were once commonly used by fishermen to pick up extra speed, but they died out in the 1980s as engines became more powerful. 'These sails might sound a bit Heath Robinson and a bit of a throwback, but in other ways they are the future,' Mr Deas added. 'We used to have windmills in this country. Now we are building windfarms.'

At the wheel of his boat, the 36ft Sardia Louise, Roly Kirby, a fisherman from Helford River, Cornwall, said he had saved up to a fifth of his weekly fuel bill since fitting a sail to the 20ft mast. He uses the sail while steaming to and from fishing grounds up to 20 miles from his home port, where he lays nets for monkfish.

'We are steaming for about three hours out and three hours back every day, but with the sail, we can cut the revolutions back on the engine from about 1,300 to 900 and still make the same speed,' he said.

Mr Kirby, 33, steamed along the sheltered Helford River while crewmate Perry Roger, 28, tied a spinnaker sail to a mast at the bow. Once out into Falmouth Bay, the potent northwesterly filled the sail and the throttle was eased back to save on fuel as the Sardia Louise stormed towards the Lizard.

'We have been using another sail, which is bigger, but this one seems to be doing the job today,' said Mr Kirby. 'You have to be careful in case the wind is too strong for the sail, but in these waters it just gives you the right helping hand.' Since October last year, the cost of red diesel has risen from 30p to 60p a litre, and Mr Kirby now spends about £1,000 a week on fuel. It is his biggest single expense and means that after paying wages, insurance and leasing a quota, he must catch fish worth at least £6,000 every week to make a profit. 'The fuel prices are terrifying, so the savings I can make are a real boost,' he added.

'Of course, it depends on the direction and strength of the wind, but these are pretty good results using an old spinnaker from a racing yacht on a traditionally built fishing boat. It looks like the future. I'm sure this will catch on more and more.'

Kevin Bennetts, a former fisherman who now runs an oil firm selling diesel to fishermen in Cornwall, said: 'A lot of people are dragging old bits of sails out of their lofts and hoisting them up. It can make a difference, supplementing the engine.'

Although the use of sail is currently limited to small and medium-sized boats, there are plans to harness the power of the wind for Britain's biggest and most powerful fishing boats, such as beam trawlers, which use up to £12,000-worth of fuel a week.

A German company is developing a system that would allow larger trawlers to be powered by a computer-controlled kite flying off their bows. The technology is already used on two cargo ships and can provide up to 35 per cent of their power.

In a separate development, an Essex boatyard is developing a new generation of sailing vessels for fishermen. Gemini Workboats in Colchester has designed a 30ft catamaran which uses its small, 14-horsepower engine only to enter and leave harbour and in emergencies. Boats of a similar size would normally require an engine of about 200bhp and would use around £600 of fuel during a week's fishing.

Plans for the catamaran, which will cost about £60,000, are to be announced this week, and work on the first boat is expected to start in October. Although it would not be suitable for trawling, the vessel could be used for laying nets and pots and for trolling - dragging baited lines behind the boat. Andrew Craig, of the company, said: 'This is the first boat of its kind really since the 1930s. But it is time to go back to them. They are cheap to build and cheap to run. We think there will be huge demand. Sailing's time has come again.'

by Jaspar Copping, Telegraph/Sail-World
_________________________________________________
Of course I've tried promoting the idea of 'Sportfishing Under Sail' for quite some time:

...and at one point I commented, "Several times I’ve put this idea into hibernation, particularly the ‘Gamefishing Under Sail’ idea. My comment at the time was something like, “I just spent 18 years in the sailboat business trying to convince sailors of the virtues of multihulls, and now I’m going to try and sell a fishing guy a boat with sails on it. I’ve got to be crazy!”
http://www.boatdesign.net/forums/sho...41&postcount=3

http://www.runningtideyachts.com/gamefishing/

[masalai]

Slowly, the world is getting there.... One can only hope that the changeover is more expeditious than the supply of diesel expiring....