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Old 27-05-2013, 19:23   #1
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Storm tri-sail percentage

Is their a certain precentage of mainsail area a tri sail should be? What's the best way to determine the proper size?
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Old 27-05-2013, 19:36   #2
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Re: Storm tri-sail percentage

That's really going to depend on the boat. Smaller on a tender boat. But you want the sail to be able to maintain headway to weather, so too small a sail is not going to do what you may need it to do.

A good starting point would be to figure the square footage of your third reef.
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Old 27-05-2013, 19:40   #3
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Re: Storm tri-sail percentage

One starting point would be the Offshore special regulations . . . which for a trysail are:

"
a storm trysail which shall be capable of being sheeted independently of the boom with trysail area not greater than 17.5% mainsail hoist (P) x mainsail foot length (E). The storm trysail area shall be measured as (0.5 x leech length x shortest distance between tack point and leech). The storm trysail shall have neither headboard nor battens,
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Old 27-05-2013, 19:45   #4
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Re: Storm tri-sail percentage

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Originally Posted by estarzinger View Post
One starting point would be the Offshore special regulations . . .
OK I'll bite - What are "Offshore special regulations"?
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Old 27-05-2013, 19:54   #5
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Re: Storm tri-sail percentage

^^

They are a set of requirements for boats participating in offshore racing. Worthwhile reading for anyone sailing offshore.

link: Offshore Special Regulations
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Old 27-05-2013, 20:07   #6
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Re: Storm tri-sail percentage

Thanks for quoting the offshore regs. I think that will work as a start, now i just need to remember my high school algebra.
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Old 28-05-2013, 05:16   #7
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Quote:
Originally Posted by FSMike View Post

OK I'll bite - What are "Offshore special regulations"?
Also applys to all new zealand cruising yachts leaving nz waters. they also require all metal slides/slugs and a indepent track if you have batt cars
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Old 28-05-2013, 06:46   #8
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Re: Storm tri-sail percentage

^^Metal slides.. Yuk, I still have bad memories of trying to haul down Blizzards main to put in a reef, with freezing hands half way between NZ and South America. Those damned metal slides jamming and fighting every inch of the way even with the sail luffing. Though I have seen some HDPE coated ones that might just work for a while until the coating wears off. Do they allow the metal stem/plastic slide type, some of these look very strong.

A friend blames his knockdown/capsize (and dismasting) partly on a poorly set trysail that he couldn't get good luff tension on due to sticky slides. He ended up reaching rather than forereaching/dodging.

Size is tricky, too small, and it could be very hard to set, as by the time it's right for the boat it's blowing great guns. To big and it's useless in a blow. To really get an idea you need to sail with a third reef in a decent blow and get a feel for the boat. Some boats will forereach quite well with just a headsail, making one almost redundant, in this case a small one would be fine, as it is a supplement rather than a necessity. Others really need a trysail of a decent size to hold the head up, and are stiff enough to carry them in a good blow.
Like evans I think the offshore racing guidelines are a good starting point, though they make no allowance for mast height, ie a racing boat often has a huge mast height for it's length and displacement.

I'm pretty happy with a third or fourth reefed main for most stuff. This is as long as the main is strong, well made and looked after. A spare main below is a good backup. But trysails certainly can be useful, Ie for reducing wear on an expensive main, or to enable an old worn out main to have the last of it's life carefully extracted, by switching to the trysail when it starts to blow.

Still not sure the easiest way to deal with lazy jacks, boom bags and weird shaped masts (making separate tracks angle to one side) on a bigger boat, maybe just dropping the lazyjacks forward is the best bet.

On a lot of larger lightly crewed boats a trysail starts to get pretty unmanagable. I can't even remember if the 60 foot yacht I ran to Antarctica had a trysail? certainly there was never any question of using it unless the main was shredded.
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Old 28-05-2013, 19:30   #9
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Re: Storm tri-sail percentage

Quote:
Originally Posted by Snowpetrel View Post
^^Metal slides.. Yuk, I still have bad memories of trying to haul down Blizzards main to put in a reef, with freezing hands half way between NZ and South America. Those damned metal slides jamming and fighting every inch of the way even with the sail luffing. Though I have seen some HDPE coated ones that might just work for a while until the coating wears off. Do they allow the metal stem/plastic slide type, some of these look very strong.

A friend blames his knockdown/capsize (and dismasting) partly on a poorly set trysail that he couldn't get good luff tension on due to sticky slides. He ended up reaching rather than forereaching/dodging.

Size is tricky, too small, and it could be very hard to set, as by the time it's right for the boat it's blowing great guns. To big and it's useless in a blow. To really get an idea you need to sail with a third reef in a decent blow and get a feel for the boat. Some boats will forereach quite well with just a headsail, making one almost redundant, in this case a small one would be fine, as it is a supplement rather than a necessity. Others really need a trysail of a decent size to hold the head up, and are stiff enough to carry them in a good blow.
Like evans I think the offshore racing guidelines are a good starting point, though they make no allowance for mast height, ie a racing boat often has a huge mast height for it's length and displacement.

I'm pretty happy with a third or fourth reefed main for most stuff. This is as long as the main is strong, well made and looked after. A spare main below is a good backup. But trysails certainly can be useful, Ie for reducing wear on an expensive main, or to enable an old worn out main to have the last of it's life carefully extracted, by switching to the trysail when it starts to blow.

Still not sure the easiest way to deal with lazy jacks, boom bags and weird shaped masts (making separate tracks angle to one side) on a bigger boat, maybe just dropping the lazyjacks forward is the best bet.

On a lot of larger lightly crewed boats a trysail starts to get pretty unmanagable. I can't even remember if the 60 foot yacht I ran to Antarctica had a trysail? certainly there was never any question of using it unless the main was shredded.
The length of the slide/slug has a lot to do with how it behaves, and how well it fits the mast, if they are to small they jam. I've seen a couple of cases where all the plastic slides have blown off a main in 40+ knots leaving it only attached at the head/clew and tack, the result was catastrophic for the sail. Haven't seen any of the plastic w/metal bail slugs break, I don't think they make the flat slides in this configuration tho.

We have a 9oz spectra main with a deep 3rd reef. The regulation trysail we needed to leave NZ is made to maximum size as the only time I intend to use it is if the boom breaks or the main is disabled in some manner... NZ trysails also have to be dacron, and orange.... In NZ there is 100 pages of regs the inspector has to check off before your allowed to leave the country in a sail boat!!
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Old 28-05-2013, 20:34   #10
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The Offshore racing regulations have been critised for recommending too large a try sail. , my suggestion is that it should be smaller then a third reef in your main .

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Old 28-05-2013, 20:44   #11
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Re: Storm tri-sail percentage

Ha.. Them damned cat 1 regs. I registered my 26 footer in the UK so I could get out of NZ without having a fight with a cat 1 inspector... Saying that I fully think these regs are a good starting point for outfitting for offshore, things like securing the mast base and adequate ventilation are important, and on a racing yacht with the lightweight exotic mains a trysail is a very important sail.

On slides, these where the metal and plastic one's I was thinking of from ronstan


They might just satisfy a reasonable cat one inspector. Most of the failures of plastic slides I have seen have been on the older un UV inhibited ones, sunlight slowly weakens them and then one day they peel off the mast. Well worth having a few much stronger ones in the mix (like at the battens and headboard) to act as a rip(zip?) stop.

What would be nice would be a better system for equivalent solutions that address the same issues. I remember my father having the odd argument with stubborn Cat1 inspectors. I decided not to ever register a boat in NZ, and now live in Tassie where the regs are pretty sensible and limited to basic minimum equipment.

Interesting to see this

MoMu0,1,2 ISAF OFFSHORE SPECIAL REGULATIONS
Category
Page - 51 -
i) A trysail track should allow for the trysail to be
hoisted quickly when the mainsail is lowered
whether or not the mainsail is stowed on the main
boom.
It is strongly recommended that a boat has either a

dedicated trysail track permanently installed with the
entry point accessible to a person standing on the
main deck or coachroof, or a permanently installed
stay on which to hank the trysail
.

Note that this is only strongly recommended, and nowhere does it mention metal slides, It might be worth arguing the case with the inspector.

Maybe this is a possible solution to the difficulty of installing a second track that can be used to port or starboard on some masts profiles. A dynex dux stay that it can be hanked onto with soft hanks! Prehaps even a small backstaysail/riding sail like a storm jib that can be hanked onto the backstay? Or maybe even hanked onto a lower shroud. That would get a cat one inspector shaking their head but it could work well and gets around many of the problems with the boom being in the way, but it might make tacking slow.
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