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Jamie Thompsons Rig Concept
Being someone who is interested in new concepts, I am wondering what Jamies rig concept is. Is it in the set-up or is it new sail plan? Looking at the new high performance sails around it could be a positive step to 'update' to more efficient sail plans.
Greg31-Dec-2007    Edit    Delete 
Re: Jamie Thompsons Rig Concept
Hi Greg,
the starting point of my thinking is that the boat is generally underpowered...hence, need to keep the mast pretty straight and the boat powered up.
The mast is a relatively soft section, although the new thicker walled James Glass masts are noticeably stiffer so the battle is to keep it from bending too much, compressing between the hounds and base and losing forestay tension.
Now you have to think about keeping mainsail leech vang or mainsheet..
If you use vang and end-boom sheeting the mast will bend alot low down..especially just when you are trying to carry maximum leech tension, i.e: when you are fully hiked, crew on wire and not easing sheets yet.
To combat this you could use an internal stiffener an/or lower spreaders.
Lower spreaders save weight but then you lose some control on the upper section of the mast.
Stiffeners add weight where you don't want it..far from the centre of gravity of the's similar to sailing with half a kilo right on the bow..would you want to sail like that?? in a chop??
So...i didn't want a stiffener, and want to control as much of the mast as possible with the spreaders ( as high as allowed..which is close to half way up the mast)...but still get adequate mainsail leech tension.
Solution: use a central boom traveller along the thwart.
I sail by setting the mainsail leech tension with the mainsheet cleated off to the centre case behind the thwart, then play the traveller ( it's usually sheeted to windward).
I have perfect control over leech tension, and control power by playing the traveller in and out for the gusts/lulls.
I only ever use vang if it's blowing REALLY hard, and downwind.
My rig is noticeably light if you pick it up.
Gybing is also a sinch with centre sheeting.
Tacking is easy with regard to the tiller extension.
Drawbacks are learning to tack efficiently picking up the new windward side of the traveller, and making sure the main stays cleated while playing the traveller ( just have to be careful not to flick it out of the cleat accidentally)
It could be said to be more expensive, but i save on the stiffener, plus labour, and extra purchases/pulleys for the vang and cleats ( i only have a simple 4:1 cleated with a simple jamb as.
So there you have it..
Jamie Thomson8-Jan-2008    Edit    Delete 
Re: Jamie Thompsons Rig Concept
Jamie's notes are now included on the Sail Faster pages of this site.
Keith Merkley9-Jan-2008    Edit    Delete 
Re: Jamie Thompsons Rig Concept
Thanks Jamie. I have center sheeting with traveller but finding it difficult to set up traveler cleats. What purchase do you have on traveler and where do you cleat it off? I have spreaders at midway between upper and lower limit with long stiffener on new mast section in WA. Our rake is about 6130 (47kg crew with 72kg old skipper)and we get over powered easily! Should we drop mast back and ditch the stiffener?
Any suggestions?
Greg20-Jan-2008    Edit    Delete 
Re: Jamie Thompsons Rig Concept
Jamie's reasoning behind his boat setup parallels what I have been doing with some success for 30 years. When I was fitter (and younger) the traveller playing in excess of 18 knots was magical. Alas not easy. I first had the cleats on the inside edge of the deck. Not good as you could not cleat when hiking. Moved to gunwale with a very low profile cleat that did not damage the backside. Good spot for many years. However when the hip started to restrict leg lifting I found it difficult to climb over the "room divider" to get excessive weight forward in light and medium winds. Welded a plate to the traveller carriage and mounted good cleats there. Works very well especially for the ability to sheet the carriage to windward in light stuff with decreased leech pressure. Centre boom sheeting definately makes the boat easier to sail and can be just as fast as end boom. It is interesting to see people questioning the best way to do things and not just following like sheep. The ability to rig a 125 to suit the sailor is a very important principle of the class.
Don Barnett SA
Don Barnett21-Jan-2008    Edit    Delete 
Re: Jamie Thomsons Rig Concept
Greg, i reckon you should definitely get rid of the stiffener, especially with your crew weight. Spreader height as it is may be okay with the light crew weight..try it. The mast rake you are on is okay..pretty much the same as mine..and i never change it.
I tried cleats on the traveller car itself and they work well but they were wearing out the traveller lines too quickly. Now i just have the cleats on the inner edge of the seat tops at the thwart. I only cleat off on reaches with the kite up anyway, or in the pre-start.
I have 3:1 purchase because yes, it is quite hard work in a breeze to play 2:1.
jamie thomson22-Jan-2008    Edit    Delete 
Re: Jamie Thompsons Rig Concept
Thanks Jamie for your help. I will try it for next race.
Greg22-Jan-2008    Edit    Delete 

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