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Masts |
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winging it
Really should get out more Joined: 22 Mar 07 Online Status: Offline Posts: 3958 |
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Topic: Masts Posted: 12 May 09 at 3:18pm |
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Now, I attempt to coach sailability sailors in their unstayed single sail, fully battened challenger trimarans. Apart from the fact that the masts are of variable quality, are there any rules of thumb for downwind sailing in a blow? And how does all this affect batten tension?
I'm afraid unstayed fully battened multi hulls are something I have little experience of, so any advice gratefully received. Tack' ho, do you have a link for the vid? I looked on the Byte site and couldn't find it. |
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the same, but different...
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Post Options Quote Reply Posted: 12 May 09 at 3:27pm | |
As I know you know, but others possibly don't, the NS14 has sliding shrouds so that the leeward one can be let forward on a run. Coupled with a fully battened square head mainsail, over-rotating wing mast (often with tapered carbon tip) I reckon that makes it a fairly advanced non-spinny rig. PS Tack'ho - that is Dan's own design Punk. |
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tack'ho
Really should get out more Joined: 08 Feb 06 Location: United Kingdom Online Status: Offline Posts: 1100 |
Post Options Quote Reply Posted: 12 May 09 at 3:53pm | |
Hi, this should work the link on the UK website is wrong http://ps2000.biz/classes/byte/pg_tech/manuals.php If not go to the international website and look for the coaching manual, link on front page a couple of items down. For a quicker explanation have a look on youtube, just pop in Byte class Ian Bruce.
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I might be sailing it, but it's still sh**e!
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Isis
Really should get out more Joined: 01 Sep 05 Online Status: Offline Posts: 2753 |
Post Options Quote Reply Posted: 12 May 09 at 7:36pm | |
Nobody said that the class rules should be changed to allow other rigs - only that there are no classes where both options are allowed and unstayed rigs have proved competative.
IF? Well thats the challenge, isnt it... |
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zailor
Far too distracted from work Joined: 10 May 09 Location: Penparc Online Status: Offline Posts: 249 |
Post Options Quote Reply Posted: 15 May 09 at 12:38pm | |
not seeing the point in making another thread.
Is there a performance diference in track masts or the luffpocket masts. (eg Blaze track mast VS Laser pocket mast) |
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laser193713
Really should get out more Joined: 13 May 09 Location: United Kingdom Online Status: Offline Posts: 889 |
Post Options Quote Reply Posted: 15 May 09 at 1:11pm | |
you cant have a sleeve sail on a boat with spreaders and shrouds etc, that is the main problem, well not one that you can take down without the whole mast being taken apart. Sleeves should in theory be more efficient though, just more awkward having to take the mast out all the time especially on boats which keep their mast up in the dinghy pound. Wing masts are the attempt at making an efficient mast that works like a sleeved sail without needing to take it down all the time, mainly depends what type of boat its for. Some sleeves have zips so they can be taken down for example but this still cant get round a set of spreaders! |
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Guest
Newbie Joined: 21 May 04 Location: United Kingdom Online Status: Offline Posts: 0 |
Post Options Quote Reply Posted: 15 May 09 at 1:22pm | |
I remember that; I was looking for a photo but couldn't find one ... I thought it was a great innovation and it was a shame the ratings knobbled it; innovation should be rewarded. 747 wings don't need stays to hold them in place; aircraft have long since done away with stays. |
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JimC
Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6648 |
Post Options Quote Reply Posted: 15 May 09 at 2:28pm | |
It wasn't much of an innovation - more an attempt at a rule cheat. The idea was to have a mast that rated as a very long section fixed mast (ie lots of drag) but twisted so that it behaved much more like a rotating mast drag wise. They hoped to get a rating allowance for much more rig drag than was actually present. The measurer, quite correctly according to the rules, elected to give it a rating partway between a fixed mast and a fully rotating mast, and as a result the owner threw his toys out of the pram and went off in a huff because he'd spent a fortune on this stick and was no better off rating wise than if he's kept a standard one. That particular rating rule aspired to do exactly that - rate any innovation on the exact effect it had on boat speed. That's the big difference between a measurement handicap rule and a box rule. Edited by JimC |
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JimC
Really should get out more Joined: 17 May 04 Location: United Kingdom Online Status: Offline Posts: 6648 |
Post Options Quote Reply Posted: 15 May 09 at 2:35pm | |
Not really no. A sleeve sail doesn't address the main problem of a round section mast, which is that a constant radius leading edge - ie a round tube - isn't the cleverest of sections as the airflow splits in advance of the blunt leading edge. A good wing mast, by contrast, will have something like a hyperbolic curve section on the leading edge which, when correctly aligned to the airflow, will in theory have both much lower drag and create lift as well. |
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tgruitt
Really should get out more Joined: 02 Dec 04 Online Status: Offline Posts: 2479 |
Post Options Quote Reply Posted: 15 May 09 at 3:12pm | |
The Moths seem to manage just fine... |
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Needs to sail more...
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