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Centre Main

  • Emma Barry
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13 Feb 2007 16:42 #19698 by Emma Barry
Centre Main was created by Emma Barry
I noticed from the pictures that there is a cleat for the centre main. Does this mean that a cleat will be allowed for transom mains as well?

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13 Feb 2007 17:27 #14379 by Trevor Lloyd
Replied by Trevor Lloyd on topic Centre Main
Need to clarify that Emma, there is also an additional purchase on the mainsheet. That'll be good for the smaller helms like Martina, but an awfull lot of mainsheet!

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  • Sinker
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14 Feb 2007 19:59 #14384 by Sinker
Replied by Sinker on topic Centre Main
Are there any words available from ISAF or anyone else that define what we can or can't change?

What is the wisdom on the suitability of the present mast step design, given that an awful lot of load currently taken through the kicker anchorage on the bulkhead will now go through the mast step?

Sinker.

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14 Feb 2007 23:45 #14386 by Trevor Lloyd
Replied by Trevor Lloyd on topic Centre Main
Jon

ISAF have not posted the amendment on the website as yet. very interested to read a copy myself. Will post as soon as I see a copy.

Trevor

PS Hope your all well.

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  • Rupert
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10 Mar 2007 20:44 #14511 by Rupert
Replied by Rupert on topic Centre Main
<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
I noticed from the pictures that there is a cleat for the centre main. Does this mean that a cleat will be allowed for transom mains as well?


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Transom mains would be somewhat of a liability with a cleat - I think you'd find yourself going swimming alot, as the angles are such that it would be very difficult to free off.

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  • LevanteIRL67592
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12 Mar 2007 11:05 #14524 by LevanteIRL67592
Replied by LevanteIRL67592 on topic Centre Main
Not necessarily, if a swivelling ratchet block with attached cleat were used, the cleat would always be facing towards the helm.

Plus you should never realoly have to spill the main in a mirror anyway, and if the worst comes to the worst, free off the jib and feather the boat, like in a single-hander.

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  • HannahJ
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12 Mar 2007 20:10 #14533 by HannahJ
Replied by HannahJ on topic Centre Main
Some of us have to free the main...

64799 "Dolphin"

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  • abeach
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12 Mar 2007 21:13 #14535 by abeach
Replied by abeach on topic Centre Main
Centre mains for a mirror are a great idea. I rember proposing the idea to the committee about 10 years ago when I was racing mirrors in my late teens. It should allow you to get the boom on the centreline upwind. Which in turn may change sail shapes slightly, all making upwind progess better.

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  • BearHunter
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13 Mar 2007 09:02 #14538 by BearHunter
Replied by BearHunter on topic Centre Main
Does anyone know who supplied the stainless steel fitting for the centre main on the Mirror shown at the Dinghy Show?

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  • Jacksonac
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13 Mar 2007 20:31 #14543 by Jacksonac
Replied by Jacksonac on topic Centre Main
Has the centre main been tested to make sure that it doesn't change the performance of the boat?

abeach suggests that it would improve pointing ability, is this true, or just guess work?

Andy J

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  • Simon Lovesey
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13 Mar 2007 20:46 #14545 by Simon Lovesey
Replied by Simon Lovesey on topic Centre Main
Yes the centre main has been tested, as suggested by Alex the ability to centre the main can help. To give the same advantage to transom main boats you will also be able to fit a bridle.

This can be a short length of rope, so virtually no cost

MCA Secretary

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  • Jacksonac
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14 Mar 2007 09:58 #14548 by Jacksonac
Replied by Jacksonac on topic Centre Main
Thanks Simon,

Is this bridle change detailed anywhere? and can we start using it yet?

Andy

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  • LevanteIRL67592
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14 Mar 2007 19:14 #14551 by LevanteIRL67592
Replied by LevanteIRL67592 on topic Centre Main
We were always taught to sail with the boom below the centre line, you usually have the leeward part of the mainsheet perpendicular, except when it's really breezy. The centre main shouldn't affect this, should it?

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14 Mar 2007 23:35 #14559 by Trevor Lloyd
Replied by Trevor Lloyd on topic Centre Main
The centre main allows you to sheet closer to the centre line of the boat without increasing leech tension and allowing you to maintain twist. If you sheet a transom sheeted mirror beyond the leeward perpendicular you start to increase leech tension and reduce twist.

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  • Sinker
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15 Mar 2007 14:42 #14561 by Sinker
Replied by Sinker on topic Centre Main
Trev,

In the absence of any written rules about the centremain, what is the consensus about how to route the main sheet.

(i) off the transom (from a bridle?) to the outer end of the boom, then to the centre of the boom & down to the main block on the thwart, may be via a 2:1.

or

(ii) From the thwart to the centre of the boom and back again to the main block on the thwart. Allowing the end of the boom to flex off and ensure no excessive leach tension, as all the pull is in the centre of the boom. Or will the booms bend too much?


Do we know if main block jammers will be legal or not?
-My view is not to permit jammers as it can compromise the ability to right the boat after a capsize, plus those capsizes for the inexperienced or forgetful who leave the main cleated whilst tacking. I also believe it will change the dynamic of sailing the boat too much, especially in windy weather.
Plus a small harken swivel/jammer is about £80!


Cheers
Jon

Edited by - sinker on 15 March 2007 15:04:09

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