OK to have mainsheet behind the boom?

Otter

Otter

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I'm trying to change the boom - still looking for a second hand one but Z Spars have quoted £300 so it's a goer either way.

I want to have a slightly shorter boom as the end bashes a fitting on the wheelhouse. This means the mainsheet purchase will be about 6 inches behind the end of the boom. Does this mean the mainsheet will be trying to pull the gooseneck apart? It's not practical to move the mainsheet traveller as it's in a custom fitting.

Thanks.
 
Yes and it drives me wild! At some stage in the past, TG's mast was moved forward about a foot apparently to counteract weatherhelm. The mainsheet position remained as it was to the back of the cockpit so there is quite an angle on the sheets. I don't see that as a problem on the gooseneck but it does make controlling twist more difficult - to the extent that I am increasing the power of the kicking strap this winter.

6" doesn't seem that much of a problem though particularly as yours is (I think) quite a high aspect mainsail? Mine on the other hand is typical 1960's low aspect (long foot).
 
Also Standard fitting on a Hurley 22, Track was probably 6"-12" Aft of the end of the boom.. I never had a problem in 10 years of ownership, it didn't seem to make any difference to sailing ability but then the H22 is not a racer anyway.It did make for a clear cockpit and no trouble going below, but obviously not applicable in OP case.
 
When you're sheeted-in as hard as (reasonably!) possible, what's the approximate length of the sheet from the fitting on the boat to the fitting on the boom?

On the face of it, I wouldn't be bothered by 6" on most boats.
 
My Vivacity 650 had the mainsheet traveller about 6" or so behind the end of the boom and it was not an issue. End of the boom fitting was angled to correspond so the fitting was not being pulled at an odd angle when sheeted in. The topping lift and mainsheet attached to a component of the fitting which swivelled anyway so pull was always through the centre axis of the boom. (It was like that to support the round the boom mainsail furling).
 
Most Twisters have the mainsheet horse behind the boom end (mine included) it doesn't cause me any problems and I'd much rather have it there than across the companionway.
 
Is it not the case that when sheeted in and beating that the boom will be transmitting power from the sail into the gooseneck?
 
When I got my last boat some 25 years ago, two problems that I had to solve pdq were:
1 Boom could catch on the backstays when gybeing - no kicking strap due to boom roller reefing.
2 When going about, if I wasn't careful the main sheet would try to take my head off!
I solved the problem by cutting 6" off the end of the boom and moving the mainsheet from a sliding bar mainsheet traveller on the transom to a sliding track across the forward width of the cockpit sole.

If you can't move, or as I did make a new mainsheet traveller, then you will just have to keep the mainsheet at an obtuse angle and keep an eye on the fittings.

PS - Can't you cut the end of your boom down rather than fork out you a new one?
 
Last edited:
Lazy Kipper said:
About three inches!
Click to expand...

Eeeek! Ok I take it all back - I think you probably have reasonable grounds to be worried! That's less than 30 degrees to the horizontal, so the majority of the tension in the sheet will, as you said, be trying to pull the boom off the mast at the gooseneck. The kicker will, of course, react against this to an extent, and the tension in the foot of the sail (depending on where the tack is attached and how), but I think I'd be inclined to so something about it if it were ours. I was imagining something more like a couple of FEET!
 
So the mainsheet attachment is on the coachroof/cabin only a few inches lower than the boom then if its 3 inches when sheeted in! I was assuming it was at least a couple of feet or more below the level of the boom. If it is that close then it ought to be level with the fitting point where the mainsheet attaches to the boom to avoid unnecessary forces.

How about removing/relocating the fitting it hits instead if you can't move the mainsheet fitting.
 
Thanks for the replies, yes the end of the boom is directly above the mainsheet track and when sheeted in tight there's no room - the end of the boom bashes against the track fitting which can't be moved. The boom is an old roller reefing one so one of the reasons for changing is to have a slab reefing boom with lines down the centre and rams horns etc.

If I go for a shorter boom it would mean the sheet will run backwards a short distance to the track.
 
I haven't thought this through, but is there room for some sort of snatch block arrangement whereby the sheet goes from the back of the boom down to a snatch block (as a single line) directly below it on the coachroof, and then the tackle goes from the end of that line (horizontally) to it's original fitting? (Although, I suppose if the coachroof is strong enough to take the snatch block there, it would also be strong enough to take the original fitting)!
 
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