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12ft skiffs develop a new boom vang setup |
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carshalton fc
Really should get out more Joined: 26 Jan 05 Location: England Online Status: Offline Posts: 2337 |
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Topic: 12ft skiffs develop a new boom vang setup Posted: 06 Mar 06 at 8:18pm |
what is the differnce detween this and a gnav? cos they both seem to be the same but this vang is under the boom?
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International 14 1503
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Isis
Really should get out more Joined: 01 Sep 05 Online Status: Offline Posts: 2753 |
Post Options Quote Reply Posted: 06 Mar 06 at 8:20pm |
....look a bit closer luke lad.
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laser47
Far too distracted from work Joined: 11 Feb 06 Location: United Kingdom Online Status: Offline Posts: 349 |
Post Options Quote Reply Posted: 06 Mar 06 at 9:28pm |
i think thats pretty much the diffence. looks dead interesting though
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redback
Really should get out more Joined: 16 Mar 04 Location: Tunbridge Wells Online Status: Offline Posts: 1502 |
Post Options Quote Reply Posted: 06 Mar 06 at 11:28pm |
Hey if there is too much strain at the root of this strut thing you could run a wire to an anchorage further back on the boom to take the forces! Better still go for Gnav and with some good engineering you could get it to support the weight of the boom and lessen the leach tension in light winds.
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JimC
Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6649 |
Post Options Quote Reply Posted: 07 Mar 06 at 12:26am |
That would rather miss the point. There are quite a few disadvantages to the compression vang setup (most of which don't apply to a one design to be fair). I'd need a lot of persuading to use one. |
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Blobby
Really should get out more Joined: 07 May 04 Location: Australia Online Status: Offline Posts: 779 |
Post Options Quote Reply Posted: 07 Mar 06 at 3:23am |
Care to elaborate?
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Chris Noble
Really should get out more Joined: 26 Nov 04 Location: Scotland Online Status: Offline Posts: 710 |
Post Options Quote Reply Posted: 07 Mar 06 at 7:17am |
yeh what are the disadvantages?
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Competitive Boat Insurance From Noble Marine
FOR SALE: I14 2 Masts 2 poles 3 Booms, Foils Kites/Mains/Jibs too many to list. |
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Blobby
Really should get out more Joined: 07 May 04 Location: Australia Online Status: Offline Posts: 779 |
Post Options Quote Reply Posted: 07 Mar 06 at 10:22am |
just for the techno-freaks this is what happens to all the loads compared to a normal kicker...
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Skiffe
Far too distracted from work Joined: 24 Jun 05 Location: Australia Online Status: Offline Posts: 220 |
Post Options Quote Reply Posted: 07 Mar 06 at 12:07pm |
Some one had far to much time on their hands |
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12footers. The Only Way to FLY
Remember Professionals built the titanic, Amateurs built the ark. |
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JimC
Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6649 |
Post Options Quote Reply Posted: 07 Mar 06 at 12:35pm |
OK, Disadvantages of the compression vang. Bear in mind that not all of these apply to every boat and the extent to which these are issues varies from boat to boat. Sailboat design is always a compromise, and doubtless there are situations where the compression vang is the best solution. On a one design many of the disadvantages are irrelevant as all boats are the same.
1) Mast is pushed forward by the vang well above the gooseneck. This will require either staying or else a very stiff mast section. On a tension kicker the gooseneck can be off the mast, and thus the forward push taken out of the mast. In any case if the gooseneck require staying then the stays are much shorter and create less drag. 2) The compression strut affects airflow round the sail reducing power and creating drag. Even the Bethwaite dual luff setup (illegal on most classes) is a compromise and is also a pain to rig. 3) The arrangements nevcessary to stop the vang pushing the boom off the gooseneck are a nuisance 4) Its possible to arrange mast support with a tension kicker so that lowers are unnecessary, for instance with the mast stump used by some 12s and Cherubs, or the gooseneck on the front bulkhead like Moths. This reduces drag still more and makes it easier for the crew to position in front of the shrouds. For balance, the chief advantages include room under the boom the boom can be as low as desired no concerns about clearance for the kicker in internal layout. RS300 is an example where the advantages probably outweigh the disadvantages, as the bend issues are less of a concern on an unstayed spar, and the very low boom with its aerodynamic advantages is made practical. Edited by JimC |
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