by Judgie » Sat 28 Jun 2008, 06:25:28
$this->bbcode_second_pass_quote('7-Zark-7', 'T')here is already a working 36' catamaran with a windmill as its means of generating propulsion - Revelation II.
Looks weird at first, but it works.
http://news.bbc.co.uk/2/hi/uk_news/1507825.stm http://www.treehugger.com/files/2007/02 ... sailbo.phpSeems several people have tried this concept on a small scale.
http://uk.geocities.com/fnsnclr@btinter ... /hist4.htmSo if the technology scales up then maybe ships could harness wind power.
In a moderate to heavy seaway, sailing vessels, whether turbine or sail, must contend with rolling and pitching. In these conditions, sail can maintain it's power output, whereas the turbine is continually in and out of it's powerband.
My advice. Don't believe in the stereotype that all sailing vessels, especially tall ships, get around at 5 knots. Remeber that the cargo carrying sailing vessels of 1850 through to 1950 (yes, large 4 to 5 masted sailing vessels were still moving wheat, wool and guano until 1950) averaged 12 - 13 knots in 24 hour periods, with many vessels known to have averaged over 17 knots, and some clippers making 20+ on the rare occasion for protracted periods of time.
Why mess around with the "propeller coupled to a propeller" solution when sail is much more efficient, and yes you can sail a square-rigger backwards. I've volunteered as unpaid crew with the One and All (
www.satallships.com.au) for 7 years now, we've done so on many occasions with her. It's also suprisingly simple to enter or leave berth under sail, even into the wind with tacking and the intelligent use of mooring lines as pivots, etc.
As an added, plus, you'll find sails (the ones used on tall ships, mostly Dupont Dacron these days, not the expensive "one season and they're stuffed" kevlar and carbon fibre jobs on racing yachts) are VASTLY cheaper than you're average wind turbine, ship for ship. Believe me, sails are not a step backwards. Partcularly with the availability of CAD
That's just my 0.2 cents
P.S.
Ocean Shipping efficiency in a modern capitalist economy, is basically "moving as much as you can, as fast as you can, on time".
To do so and obtain the speeds necessary on your average modern container vessel of 75,000 through to 180,000 tons, your wind turbines will need to make anywhere from 70,000 shaft horsepower to 125,000 shafthorsepower (the output of the large Wartsila/Sulzer diesels that dominate the market, which are now being supplied with cogeneration, using the exhaust gases to drive a large gas-turbine generator, and a heat-exchanger to power a steam turbo generator and provide heating for the accomodation. Their electrical output is supplied to a large electric motor on the main-engines shaft to boost output to 180,000 horsepower approx, the most prominent application is in the Maersk/Sealand "E class" container vessels), to maintain economical service speeds of 25 to 30 knots. You'll have to use the main diesel engine anyway to maintain those speeds OR you can put them on a much smaller vessel, 60 to 100 meters or so by which time sail comes into it's own.
"That the cream cannot help but always rise up to the top, well I say, <censored by peakoil.com> floats"
Jarvis Cocker - "Running the World"