Spilling the wind with a cabin top mainsheet

You have a big First n'est ce pas? Does yours have a cockpit or a coachroof traveller? Our coachroof one is full width and lets the sail right out like when I sailed OKs, not quick though doing that.

I forget that newer designs have tichy jibs and big mains, I much prefer masthead I must say.
 
That's me alright. Mine is a cockpit traveller. You raise an interesting point though. The boom on my boat is quite long and it carries a largish main 60m2 odd. Normally when cruising one reefs conservatively and when racing one reefs to the lulls relying on the mainsheet trimmer to keep the boat on it's feet. Many times the traveller when eased to the limit does not fully do the job. It is then necessary to loosen the mainsheet and the boom rises as the kicker cannot keep the leech tight enough which is not optimal. A coachroof system would give the angles for a more sustantial range - I never thought of it that way but can't argue with it. I guess one needs to balance that against the increased forces on the coachroof. I guess there is no perfect solution.
 
We never let the mainsheet off upwind because with the traveller right down the main (fully battened 34sqm) is 2/3rds backwinded, in any case it is attached not far from the kicker so that would need dumping as well! The trouble is the slot is firmly shut with the traveller right down, hence as I say it is not at all quick! In practice we use the traveller for nearly all (angle) trimming out to pretty well a beam reach, with the mainsheet and kicker controlling the leech tension. Bear in mind we are a crew of two only!
 
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read my replies. I never said the Dufour 40 is a rocketship either. How could I?
But you did imply that it would require a well crewed rocketship to squeeze by the Dufour. Ahem.

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Er, no I didn't......? Did I......?
I only chose the dufour as a comparison after I knew we were comparing to a 41 footer. My regular ride at the moment is a Jboat, bit smaller though!

Fact is, in terms of sail control mid boom sheeting is inferior. It has come about as a compromise to keep the sheet out of the cockpit which some people regard as safer. The location of the mainsheet is a key indicator of the intended use of the boat.
 
Looks like Robin and dom in the discussion above beg to differ. Seems like you aren't having much agreement on this thread. Still, there are others. /forums/images/graemlins/grin.gif
 
Mechanical question

My suspicion is that most of the force coming through the mainsail to the sheet is coming down the leech. Therefore, the further the leech is from the sheet (as in midboom sheeting) the greater the moment of leverage applied to the boom, implying a meatier boom, or a broken one.

Make sense to any engineers out there?
 
Re: Mechanical question

Indubitably, and especially in the case of a loose footed main.
Force x Radius is halved if the point of rotation is the gooseneck and there is a coachroof mounted sheeting /traveller positioned, as opposed to being near the boom end.
Of course the kicker is more closely coupled also to the next point of restraint, the sheeting point, which aids the boom height control forces.

Therefore it follows that the forces required to control the sail at the boom mid point are higher than those at the boom end.

However, the more reefs you have in, the better the coachroof setup becomes, as the forces are concerntrated more along the boom toward the mast, and thus the sheeting point, which aids the bending moments. My 3rd reef boom hardpoint is probably only 400mm from the sheeting position.
 
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With coachroof mainsheet you simply go boating with assistance of rags

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Any other little pearls of wisdom you'd like to share with the swineheard hereabouts?

And a Dufour 40 as a shining example!

You're aving a larf, no?
 
I rather agree with all your points, however, applying the auto pilot would prove difficult when the yacht was on its side the wind was in every direction and was futher held down by the wave/swell. I know the skipper had to hold onto the pushpit rail with one foot on the binnicle whilst his dog was getting a soaking but was tied on. The dan bouy framework was bent up with the bouy and light in the water. I know this because it was me. I have read all the comments and agree and disagree as one would expect. I will add one thing to those that have mentioned what to do. This all happened in a flash and if i was not holding on for grim death, i would have been MOB with the dog but only the dog was clipped on. My first thought was 'what the **** was that'. Happy sailing.
 
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