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  #31  
Old 10-17-2011, 06:06 PM
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sabahcat sabahcat is offline
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Quote:
Originally Posted by High Tacker View Post
There's actually less rigging than on a conventional rig, and thus less parasitic drag,
Looks to me like you have 2 pipe sections and some pipe sections as spreaders, none of which are foil shaped.

Thats more than the 1 foil shaped mast section with foil shaped spreaders which a conventional rig has
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  #32  
Old 10-17-2011, 08:48 PM
High Tacker High Tacker is offline
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Hello sabahcat,

Have a look at Greenpeace's new Rainbow Warrior rig. The A-frame masts are essentially identical to mine, but are 50 meters tall whereas my A-frame is 20 meters. Their new ship is 840 tons, and my Catbird Suite is 20 tons. Their designers did extensive wind tunnel testing before deciding to go with this rig, and they found it to be very efficient. That has held true in sea trials. See the following page in this forum:

WishBone Sailing Rig

Scroll on down that page and you will see that the mast sections in the new Warrior rig are elliptical.

My sections also are elliptical. For effective streamlining, your "foil shaped mast section" would need to be at least 3 times as long as it is wide. Cruising boats don't usually have such. If they did, they'd be sailing all over the place when at anchor, very annoying to neighbors. And even a 3 to 1 section is not effective streamlining if it doesn't rotate, weathercock, into the wind, indeed, that's why it acts as a sail when slightly off the wind. It has more drag at any angle to the wind than does a shorter oval. And it's not effective in front of a sail unless it over rotates.

If by "pipe section" you mean round, that would actually be better for my A-frame in terms of drag. Have a closer look; the sections are not round. I chose an oval section for the increase in fore and aft strength, and I think it looks better than a round section.

Shorter than 3 to 1 foil sections, and foil sections in general that don't rotate, are really only about looks. Oops, I take that back; some might have more fore and aft strength. But the much shorter and unrotatable "foil" sections that you often see are mainly about looks, or about sailors fooling themselves, or, rather, being fooled about drag and effective sailing.

Another point: a single mast that could support 4 furling sails (which are, after all, sails on wires, and thus put a lot of compression loading on a mast) would have to be a very big section with thick walls and lots of very heavy and thick rigging. Or, another conventional way to do it would be two masts, like a schooner or ketch rig. Still, the sections would have to be bigger than in my rig and there would be much more and heavier wire involved.

Renowned multihull designer Malcolm Tennant, and his assistant Tony Stanton, did the engineering calculations on my rig, and I think that most knowledgeable readers of this forum would agree that Malcolm knew his business. He also showed me the numbers for a conventional rig for the boat. This A-frame rig has better ratios of strength to weight, strength to section size, strength to windage, strength to complexity and strength to cost.

Four furled sails do indeed present some windage. But the mainsail and staysail are on soft furlers and are very easily dropped and stowed away below decks. For that matter, it's not all that difficult to take down the genoas, too.

Everything about a boat is a compromise. And she's not intended to be a motoryacht. When she's moving, most of the time 3 of those sails are in use, and quite often all 4 of them. Nowadays all the big cruising sailboats I see, monohull and multihull, all have at least two furling sails. The furling sail is the single greatest invention in sailing in the past couple of centuries.

Last edited by High Tacker : 10-19-2011 at 02:14 PM. Reason: addition
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  #33  
Old 10-17-2011, 09:17 PM
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sabahcat sabahcat is offline
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Quote:
Originally Posted by High Tacker View Post
Renowned multihull designer Malcolm Tennant, and his assistant Tony Stanton, did the engineering calculations on my rig, and I think that most knowledgeable readers of this forum would agree that Malcolm knew his business.
Totally agree.
If this type of rig is so good one has to ask why he never had this A Frame rig on the many designs he has in his portfolio.

Ah, I get it.
Having googled "Malcolm Tennant A Frame rig" the only thing that crops up are the many advertisements of your vessel for sale and your comments regarding it here.
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  #34  
Old 10-17-2011, 10:02 PM
High Tacker High Tacker is offline
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Malcolm died not long after the rig was done. And part of why it doesn't appear on any of his other boat designs is probably because it was my idea, specifically for my boat. I gave him sketches of the rig, and he and Tony did the calculations and construction drawings and specs. They suggested modifications, but it was very much a joint effort by 5 of us, including my then boat partner and also the builder of the rig. Of course, we all deferred to Malcolm's judgment.

The original design of my boat, with wind turbine rig, is still on his website.

www.tennantdesign.co.nz

The boat was then named Revolution and is listed under Sailing cats of 15m and bigger. The A-frame rig was Plan B, in case the turbine turned out to be not completely satisfactory, which indeed was the case. Malcolm took that into consideration in the design of the boat structure. He apparently never got around to adding the A-frame to his catalog. Tony Stanton went to work elsewhere, I think at High Modulus, after Malcolm's death, but I think he is still involved in managing Malcolm's website and selling the catalog. As far as I'm concerned, he can still sell plans for the A-frame if you want one. Hey, maybe I'll get a royalty! You could easily add an A-frame to that powercat you're building, and it would come in handy when you're no longer able to get diesel. And you could claim some green-ness even before that.
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  #35  
Old 10-17-2011, 10:20 PM
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sabahcat sabahcat is offline
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Quote:
Originally Posted by High Tacker View Post
You could easily add an A-frame to that powercat you're building,
I doubt I could ever re-coup the expenditure as I would imagine the cost of the rig would provide decades worth of fuel in a zone that has little wind and relatively cheap fuel.

Quote:
and it would come in handy when you're no longer able to get diesel.
And when will that be?

Quote:
And you could claim some green-ness even before that.
I have claimed "greenness" on the last 5 boats I have had and I will do so on this as well as it will use relatively small quantities of fuel with 65hp engines compared to other vessels in its class.
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  #36  
Old 10-17-2011, 11:22 PM
High Tacker High Tacker is offline
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sabahcat,

That's a pretty pale shade of green. But I think I get it about you now. You're not interested in sailing, so I should ask why are you poking at my boat? You're taking me and my boat on in order to promote your own boatbuilding and powercats in general, that's why, since this is not the first time you've touted the idea that the cost of sailing rigs will buy a lot of fuel. Hey, if we keep wasting time on this tit for tat, you'll never finish the boat you're building and I'll never get mine sold. If you're in Australia, it's the middle of a work day there, isn't it? Don't you have anything better to do? You'd better hurry up and get her built, and sold, and let somebody else worry about the cost of diesel.

I have two diesels, too, 80hp each, and she gets about a nautical mile per liter at 8 knots, and she's 20 tons, so there. Malcolm got it right when it came to designing easily driven hulls.
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  #37  
Old 10-17-2011, 11:40 PM
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sabahcat sabahcat is offline
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Quote:
Originally Posted by High Tacker View Post
sabahcat,

That's a pretty pale shade of green. But I think I get it about you now. You're not interested in sailing,
Really?
How do you explain my previous 5 sailing boats and the fact that I still sail on other peoples boats?

Quote:
so I should ask why are you poking at my boat?
Where have I done that?
The boat looks to be a fine vessel with a good pedigree.
I have questioned whether an A frame rig is the be all and end all as I have seen several over the years and none seemed to work as well in real life as touted.
Quote:
You're taking me and my boat on in order to promote your own boatbuilding and powercats in general,
Unlike some, I am not trying to sell a boat, therefore, what interest would I have for promotion?

Quote:
that's why, since this is not the first time you've touted the idea that the cost of sailing rigs will buy a lot of fuel.
And its true.
The cost of a sailing rig does by a lot of fuel.
Do you deny this?

Quote:
Hey, if we keep wasting time on this tit for tat, you'll never finish the boat you're building and I'll never get mine sold. If you're in Australia, it's the middle of a work day there, isn't it? Don't you have anything better to do?
I am currently on holidays no where near the boat

Quote:
You'd better hurry up and get her built, and sold, and let somebody else worry about the cost of diesel.
Like I said, I have no interest in selling her, especially as I believe the concept to be sound.

Quote:
I have two diesels, too, 80hp each, and she gets about a nautical mile per liter at 8 knots, and she's 20 tons, so there.
Cool. so I should expect similar from 65hp x 2 @ 8700kg fully loaded.
Thanks for the confirmation that the cost of rig and sails will get me many decades of motoring.

Quote:
Malcolm got it right when it came to designing easily driven hulls.
That he did and I never said he didn't.
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  #38  
Old 10-18-2011, 01:10 PM
High Tacker High Tacker is offline
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Another long range cruiser with A-frame sailing rig

The SMG 50 catamaran "NumberOne" with A-frame rig and furling sails has proved her general sailing efficiency, and windward ability in particular, in racing against other substantial cruising boats.

http://www.sail-the-difference.com/h...an/smg_50plus/

http://www.sail-the-difference.com/f...up_results.pdf


Quote: 'The innovative SMG 50plus NumberOne performed surprisingly at the first regatta she took
part – Kornati Cup,May 2009 in the Adriatic Sea. This was the first time also for her owner,
Richard Malits, to skipper her in a regatta. The Kornati Cup is one of the most popular sailing
events in Croatia so the fleet is limited to 100 participants.
The catamaran class was easily won by NumberOne. In the 3 longer distance races (all
together about 9 hours) she was 1h 24min in front of the next best catamaran. Such a
convincing win of the catamaran class could hardly have been expected, in this competitive
class. Impressing all, NumberOne was able to tack better than many of the fast monohulls
taking part at the regatta. Reaching in 18 knots of true wind she achieved 11-12 knots and
whilst beating her VMG (velocity made good) was 6.5 knots. During the tacking procedure,
her VMG never fell below 3.5 knots. Cruising catamarans are often regarded as yachts
without good upwind sailing characteristics. This is definitely not true for the SMG 50plus.
Confirmed by Peter Czajka - the very experienced and notorious Austrian competitor and
skipper of YR-Salona – the catamaran was faster than the Salona. He never before
considered that this could be possible.
The Austrian sailing magazine yacht revue is quoted as commenting that “Richard Malits
steered the Schein-design SMG 50plus surprisingly fast upwind and at times outstanding fast
(on the) broad reach.”
Notably NumberOne recorded her new speed record during this event in 19.3 knots with 25
knots of true wind on her beam. This was with the genoa only and they didn’t need more sail
up at the time.
High speed record 19.3 max – the SMG 50plus record
NumberOne’s tacking angle less than 90 (including leeward drift) during the 5th race.
NumberOne’s track in 20 knots of true wind shows her tacking angle of 90 over the
ground – that includes her leeward drift' -end quote.

http://www.parasailor.co.za/dyn_docu...lor__smg50.pdf

There's a video of the SMG 50 sailing, at:

http://www.sail-the-difference.com/home/english/video/
Attached Thumbnails
the perfect long range cruiser-smg50.jpg  the perfect long range cruiser-smg50-2.jpg  

Last edited by High Tacker : 10-18-2011 at 05:21 PM. Reason: addition
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  #39  
Old 10-18-2011, 02:45 PM
pool pool is offline
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Smg 50

She has been for sale for some time now in the Med, if i recall correctly ...
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  #40  
Old 10-18-2011, 03:08 PM
High Tacker High Tacker is offline
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A real superyacht long range cruiser

For more detail on the 840-ton Rainbow Warrior III, with two 50-meter A-frame masts and 5 furling sails:

http://www.superyachttimes.com/edito...rticle/id/3960

http://www.ship-technology.com/projects/rainbow-warrior

www.damsl.com

In this forum, see the following thread:

WishBone Sailing Rig
Attached Thumbnails
the perfect long range cruiser-dsc8169.jpg  the perfect long range cruiser-17092011084.jpg  

Last edited by High Tacker : 10-18-2011 at 03:09 PM. Reason: spelling
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  #41  
Old 10-21-2011, 05:17 PM
High Tacker High Tacker is offline
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A couple of links to videos of Rainbow Warrior III:

http://www.youtube.com/watch?v=IjncCTnpPSc

About a minute into this second video are some scenes of her sailing:

http://www.youtube.com/watch?v=hhuSpD81FOQ
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  #42  
Old 03-18-2012, 09:10 AM
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The Loftsman The Loftsman is offline
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The perfect Cruiser

Hi
I would say one that stays afloat and convays its passengers and crew safely at sea for more than 50 years you will see one just such vessel at out website just look for the pages on the Annabella

Cheers
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  #43  
Old 06-17-2012, 01:21 PM
Wavewacker Wavewacker is offline
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LOL, Option One, cruiser, 300 mile range, trailerable.....now we're over a hundred feet at how many tons?
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  #44  
Old 06-25-2012, 07:22 PM
masalai masalai is offline
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My fav is what I own, "CNO" and the build is partially recorded here - My little piece of peace - I cannot post a "WWW" link as it is not available??????

WTF and it is "windows 7 Professional" what bloody rubbish... and having only yesterday bought a new laptop - I AM BLOODY DISGUSTED - MS actually means IT HAS A TERMINAL DISEASE.... and if the seller cannot delete the affliction on this "toshiba" notebook it is being returned for a full refund - - - I am disgusted...
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  #45  
Old 06-26-2012, 06:51 PM
pdwiley pdwiley is offline
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Originally Posted by masalai View Post
My fav is what I own, "CNO" and the build is partially recorded here - My little piece of peace - I cannot post a "WWW" link as it is not available??????

WTF and it is "windows 7 Professional" what bloody rubbish... and having only yesterday bought a new laptop - I AM BLOODY DISGUSTED - MS actually means IT HAS A TERMINAL DISEASE.... and if the seller cannot delete the affliction on this "toshiba" notebook it is being returned for a full refund - - - I am disgusted...
Buy a Macbook and be a happy owner of a system that works. I just rebooted mine for the first time in over 14 months yesterday after needing to edit some of the system memory settings to install the latest version of Postgres database.

I spent many, many years rubbishing Apple for their POS operating system and then Steve Jobs brought out a unix o/s with a functional GUI. I'd always wanted a unix laptop, I bought one and no way am I going back to Windows. Just yesterday I was trying to connect to a Solaris server from a Windows machine on a site - WTF, no ssh client! Plug my laptop in and I can connect straight away.

FWIW I'm a software designer, Java programming working with database engines on big servers. My laptop is a work tool, I use the best tool I can afford. If I wasn't using a Mac, I'd be using linux on a high quality laptop; Windows would be my last choice.

PDW
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