National 12

General Boards => General National 12 chat => Topic started by: jamesmorley on 08 Apr 2006, 08:42

Title: centre main
Post by: jamesmorley on 08 Apr 2006, 08:42
Hi
Could someone please tell me if it is possible to turn a national 12 into centre main.
Thanks a lot James
Title: Re: centre main
Post by: sinker24 on 08 Apr 2006, 02:41
hi,
i spent some time in the winter converting mine to centre mainsheet because i feel more comfortable with it. i've made the system similar to the laser with the main block on the end of the centreboard box. seems to have worked ok when i went out today with it.
ta, ben
Title: Re: centre main
Post by: tom (Guest) on 09 Apr 2006, 10:00
surely its better straight off the boom, skiff style??
Title: Re: centre main
Post by: sinker24 on 09 Apr 2006, 04:17
hi tom,
the only problem with the skiff style is that if the rope slips out of your hand or you absent-mindedly drop it to pull the centreboard down then the whole thing flies out to the boom and then you tend to go swimming. with a deck block at least the rope stays nearby.
ta, ben
Title: Re: centre main
Post by: Jimmy Whitehead on 09 Apr 2006, 07:30
hi,
    Thats why you tie a piece of shot cord to the end of the main sheet,this keeps it near by. The best set up i have seen is on Chris Bishop's boat , master of puppets( 3474)

cheers

Jimmy
Title: Re: centre main
Post by: Mikey C on 09 Apr 2006, 09:58
Sailed with it in Jimmys boat off the boom - rubbish for manoevers....
Title: Re: centre main
Post by: Master of Puppets (Guest) on 10 Apr 2006, 12:52
for all of those who wish to stay dry when gybing I suggest they go to off the boom sheeting. At the recent Gill event we never swam during the gybes when the more mighty members of the 12 fleet were seen admiring the centre main technique from the comfort of their centreboards (it was the straight lining on the broad reaches that did us and the mast in!!).
There are two ways of doing the of the boom set up-either one2one using a split end mainsheet or a two 2 one puchase at the end aka 49er/B14 style. One to one does make getting leach tension by use of mainsheet more difficult, but having used it now for the last 4 years its a very small price to pay for the benefits (I challenge all to a gybing duel for the non believers!!!). The two to one system involves alot of rope and the loads on a 12 mainsheet are low enough not to need it. :P
Title: Re: centre main
Post by: Barry on 11 Apr 2006, 06:20
Is that just a normal pulley off the boom or an auto ratchet?

Barry
N3364
Title: Re: centre main
Post by: JimC (Guest) on 11 Apr 2006, 11:10
Unless you have some kind of superhuman crew taking the mainsheet up the beats and shy reaches (possibly called Alex Windsor (old in joke)) experience with Cherubs suggests that a ratchet is essential with the one to one mainsheet.
Title: Re: centre main
Post by: Jimmy Whitehead on 12 Apr 2006, 04:33
ok ok, so my set up isnt quite right yet! no need to be quick to judge, it is up to the helm and crew ( yea the crew can get trapped in by the main sheet) to decided

tata

Jimmy
Title: Re: centre main
Post by: jamesmorley on 13 Apr 2006, 05:54
I was thinking more of a set up similer to the one on a merlin.
James
Title: Re: centre main
Post by: John Meadowcroft on 14 Apr 2006, 08:33
Kevin Driver did this very successfully 10 years ago.  All subsequent owners of his boats reverted to aft main though.  Key to this I think was that Kevin and Adam May spent a lot of time practising and were able to overcome the disadvantages of the hoop - eg which way round it do you go when you need to move back? and get the benefits of the advantages too.

This was before carbon masts had really taken off and the rig set up was very merlin style.  They sailed light and used a lot of rake to depower.  

However, take note - it definitely worked.
Title: Re: centre main
Post by: BrianWhitmey on 18 Apr 2006, 01:09
42 had a 'traditional' centre main set up when I bought her. The biggest problem I found with it was sailing inland on gusty days; the crew needs to move pretty sharply back and sideways and the mainsheet was just getting in the way. I tried transom style but got fed up with force of habit causing me to face the wrong way on crucial gybes. so, i went for the 'skiff style' set up and I'd swear by it...