Loose footed sail problem

J

Joe_Cole

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This season I fitted a new loose footed mainsail on my boat. The improvement in performance has been superb but I do have one problem with it.

My previous sail was conventional (i.e. fixed to the boom with a bolt rope) and when the mainsheet was hard on there was no problem. With my new sail when the mainsheet is hard on the boom inevitably is pulled down a bit and it tends to get in the way. In some conditions the boom fouls the top of my sprayhood. Of course, this happens mainly when I am close hauled. Apart from the fact that it a nuisance, I suspect that I am loosing some of the efficiency of the mainsheet/outhaul.

With the current arrangement the outhaul goes from the sheave at the end of the boom straight to the clew on the mainsail. Tightening the outhaul helps of course, but it's not possible, and probably not desirable, to pull it hard enough to correct the problem.

I am thinking of fitting the clew slide from my old sail and effectively making my sail "loose footed, fixed clew"...if that makes sense! (The clew will still slide)

Any thoughts from any of the sail experts out there?

Joe

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My initial thought is that there'll be so much pressure on the single clew slide, she'll blow or pop out of the track or similar and I'm not sure it will solve the problem. If the halyard and outhaul, cunningham and all are set properly it sounds like the leech of the sail is a bit too long and you may need the sailmaker to sort it out.

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This is a problem that all of us with in-mast roller reefing have considered, I'm sure. Not the fouling of the sprayhood though, that is a matter between you and your (sail)maker!

You say that you are worried about tightening the outhaul too much. Surely if you fit the slidearrangement you will have a 2:1 purchase and therefore seriously increase the possibility of damage to the sail? Personally I wouldn't worry on this score as a good sail should easily take the tension you are likely to be able to apply to it. All RR mains have this arrangement and it is possible - if required - to get good foot tension without riskng the sail's stitching.

Since your main difficulty seems to be with the sprayhood, I would seriously talk to the sailmaker, although I think he will probably claim that his main priority is sailing performance NOT your personal comfort!

"Oh you wanted the CRUISING version sir, why didn't you say?"

Steve Cronin

<hr width=100% size=1>The above is, like any other post here, only a personal opinion
 
I agree with salty, a slightly shorter leech would solve all your problems, or a kicker, to hold your boom above the sprayhood, but I think the sail would not set correctly. Leech has it for me. IMHO

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The sail will set better if the clew is secured to the boom but, as salty says, a slider will probably not be strong enough. The solution I have seen most often is a webbing strop round the boom and through the clew. If you are disinclined to make one yourself, the sailmaker will (indeed, I m surprised he didn't supply one).
Once you have the strop in place, if the boom still fouls the sprayhood, get the sailmaker to shorten the leech. You will lose very little sail area. Assuming the sailmaker worked to your (correct?) dimensions or measured up himself, this shouldn't have happened so he should make the adjustment without charge.

<hr width=100% size=1>JJ
 
In less than hour 3 helpful responses! Thanks.

I won't have a go at the sailmaker (I took the measurements!) I'll try the strop idea first and, being lazy, I'll talk to him at the boatshow and see if I can get him to make me one.

Joe

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Standard practice

on loose footed gaff mainsails is indeed to have a strop round the boom, as James describes. Been that way for the last couple of hundred years.

If you don't have this you cannot ease the foot, which negates many of the advantages of a loose footed sail.

<hr width=100% size=1>Que scais-je?
 
Re: Standard practice

I did some racing on a J105 where the strop was a velcro strip. Very stong velcro strip mind, and wrapped round three of four times on itself... It worked well though and made it a doddle to take the main sail on and off after each race.

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Slide on the clew.

I've gone with this arrangement on my loose footed boomed staysail, and it works well. A hoop did not slide freely enough, and having nothing was hopeless, as Mirelle says you loose all the advantage of being loose footed.

Obviously it needs to be a steel not a plastic slide. Any sailmaker can provide one, and they are cheap enough. Lash it onto the clew with webbing stitched with whipping twine. The loads are high, but not too high assuming you will normally have the sail pulled well out to the clew in strong winds.

Don't shorten the leech until you have tried this arrangement. Two wrongs won't make a right.

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Re: Slide on the clew.

Can't help thinking that the loads on a staysail will be lower than the main. I've seen a gust rip a whole set of (plastic) slides out of the mast track, and another time where the slot in the boom has opened up for (metal) slides to pop out. If the boom is aluminium you're as much at risk of the slot not taking the strain as the slide itself. I'd agree getting the leech recut is a last resort, but the strop would be my vote for the best interim solution, IMHO.

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My loose-footed main has a slide on the clew working in the old bolt-rope groove and has done about 3000nm during last season.

It hasn't broken apart and the outhaul (which comes back to the gooseneck) makes the foot-tension dead easy to alter.

A temporary mitigation would be a strop from the clue around the boom, but I feel that your sailmaker has supplied an incomplete sail.

So I'd take it back to him and demand he finishes the job.

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I have a loose footed main with the clew 2 feet from the end of the boom so it is esential that the clew is fixed to a slider that moves along the boom. In my case the large metal slider runs in the bolt rope grove and ensures the boom stays at exactly the right hight all the time. A strop round the boom will achieve the same but I would talk to the sailmaker or rigger and try to find a suitable slide of the right size and strength to do the job.

Yoda

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Re: Slide on the clew.

I also have in mast reefing, so have a loose footed main, I know its not the same for you, but we have a block on a slider along the top of the boom which insures that the clew is always kept tight down to the boom when reefed, you dont need a slider but a fixed block close to where the clew comes along the boom when fully tight, so the outhaul goes through the block then onto the clew, tentioning the foot of the sail and holding it down to the boom at the clew, so now you can adjust this tention for differwnt wind strengths and points of sail, but I would have thought that you should be useing your topping lift to support the boom, and your kicker to hold it down tight against the topping lift, that way when you are close hauled and have the main sheet traveller to windward and the boom amidships you do not change the shape of your main, eg flat for high winds and full for light winds. This way providing the leach is not too long your boom should not come down far enough to touch the spray hood.
Mike

<hr width=100% size=1>www.sailingforfun.co.uk
 
You can keep your assumption, Charles

Which assumption sunshine, or do you mean all of them? Fact is, beating into rotten weather, the loose footed main which was held in place by a bloody great metal slug blew out of the track because the slot distorted under the pressure. Thinking this was a one off, the owner got everything fixed only for it to happen again next time the weather blew up. Hence the arrival of the velcro strip referenced above and no more problems.

So you may be able to assure me that my assumption is ill-founded and state that I have a vivid imagination, but having had it happen twice, both times in the middle of the night in manky weather I'll take my experience over the supercilious tone of your opinion anytime Charles.
 
Re: Vivid imagination

Slightly different problem with loose footed mains - does the kicker still have any effect on the shape of the sail? Is there any point really tightening it in hard or is it now just stopping the boom fron lifting?

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Re: You can keep your assumption, Charles

I have just ordered a new loose fitted main (which I believe will be supplied with a metal clew slide/slug) and have therefore been watching these posts with much interest, not least because I have time to change my mind!

Now to the questions. My existing main has a metal clew slide/slug fitted and also has a very light shelf foot fitted via bolt rope into the boom groove. There is a clew outhaul led through the boom to a mast mounted winch. There has never been a problem with this and unlike on my previous smaller boats I have not felt the need for any extra lashing around the boom end. My previous boats did not have adjustable outhauls or metal clew slides. Surely there was very little extra strength added by such a light (and now UV affected fragile) shelf foot? Actually in practice except in VERY light winds the outhaul was tensioned to the black bands, collapsing the shelf foot and surely therefore all the load was on the clew plus clew slide?
Secondly in stronger winds, whatever the design of sail,as the slab reefs go in then there is no bolt rope option possible, the loads being taken by the tack and clew reef fittings and the reef line which on ours at least does pass round the boom?

Maybe the belt and braces answer therefore is to have a metal clew slide in the boom grove plus treat the clew outhaul as a reef line. By that I mean instead of attaching it directly to the clew, taking it through the clew ring and around the boom just as is done for reefs 1, 2 & 3? The only problem perhaps being that the extra friction would make it more diificult to ease the outhaul in light winds?



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Re: Vivid imagination

An interesting question! My thoughts, and we have a very powerful gas strut kicker, is that apart from a very slight bend in the boom which might flatten a normal sail (or crease it) very locally, all the load is transferred by the boom to the leech where it should be, loose foot or regular foot.

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Re: You can keep your assumption, Charles

Robin,

Our approach was belt and braces simply because we'd had the set-up fail when less over-engineered. Admittedly it was a race boat so the strains and stresses might be greater than on a cruising yacht, but my principal is that if it can break on a race boat it can break on cruiser too! And probably at the worst possible moment.

Your reefing point is true, but bear in mind the pressure is then being taken by a line going round a pulley wheel and through the boom, not a strong vertical force being exerted between metal on metal (in the case of the slug).

The scenario of when you have full sail and a lot of outhaul tension is interesting - there can't be much, if any, support from the foot of the sail as you say and I suppose this must bear the same risks as just loose footed with a metal slide.

Rather than put more friction in the outhaul system, the belt and braces answer for me would be a strop as mentioned by several people in the thread -as opposed to the strop I threw when accused by Charles of having an over vivid imagination ;-)



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