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Old 23-07-2017, 01:58   #31
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Re: Square top mainsail

i am yet to be convinced square top provides better overall performance than classic shape because one loses ability to trim by boom topper. In most conditions adds around 1/4 kn, and this increases in light winds to 1 kn or so.

If I got both - square top and ability to manipulate boom height, that would be something to think about. Tacking boom topper with square top seem like PITA as one need to reef, tack and unreef.

Going vang route seem like serious modification that I am not prepared to take.
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Old 23-07-2017, 04:46   #32
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Re: Square top mainsail

I've written on the matter of trimming in light wind conditions using the topping lift....

Topping Lift - Mainsail Trim - Light winds...

That being said, there are several caveats:
1. Its is only generally useful in very light conditions that fail to generate twist at the the sail head
2. If you have a main with a large roach (aka most traditional multi boats) then the topping lift will invariably be on one side of the sail and getting it to the other side after a tack or gybe is very difficult. Lots of slack and the biggest whip action to the line might just do it, but not always.
3. If you don't have this problem, you don't have a big roach
4. You can overcome this by having two topping lifts, one either side, but not too many would see this as a genuine "advantage" as opposed to a hindrance.
5. By its very design, the square top main has less tendency to close off the sail head in light winds and as a corollary, is of course, more willing to twist off in high wind conditions.
6. From a topping lift perspective, positioning from side to side will be difficult with both the square top and a very roachy mail, with the square top virtually impossible and the roachy main very difficult.
7. Needing to use the topping lift for a square top is much less likely, due to sail geometry and leach tensions and a inherant willingness to twist.
8. If it remains an issue to you use the two topping lift option....
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Old 23-07-2017, 05:40   #33
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Re: Square top mainsail

Quote:
Originally Posted by 2Wind View Post
I've written on the matter of trimming in light wind conditions using the topping lift....

Topping Lift - Mainsail Trim - Light winds...

That being said, there are several caveats:
1. Its is only generally useful in very light conditions that fail to generate twist at the the sail head
2. If you have a main with a large roach (aka most traditional multi boats) then the topping lift will invariably be on one side of the sail and getting it to the other side after a tack or gybe is very difficult. Lots of slack and the biggest whip action to the line might just do it, but not always.
3. If you don't have this problem, you don't have a big roach
4. You can overcome this by having two topping lifts, one either side, but not too many would see this as a genuine "advantage" as opposed to a hindrance.
5. By its very design, the square top main has less tendency to close off the sail head in light winds and as a corollary, is of course, more willing to twist off in high wind conditions.
6. From a topping lift perspective, positioning from side to side will be difficult with both the square top and a very roachy mail, with the square top virtually impossible and the roachy main very difficult.
7. Needing to use the topping lift for a square top is much less likely, due to sail geometry and leach tensions and a inherant willingness to twist.
8. If it remains an issue to you use the two topping lift option....
yup, that is where I got sailtrim idea from, thanks 2wind

However, I found topping lift to be useful in stronger conditions as well when seas not calm and boom is dancing, hence changing sail shape and robbing boat of speed. It limits movement of mainsail, and on average sail keeps better shape more of time, hence creating additional speed.

Also works when mainsail reefed, even 2x reefed. Presume in this case 'could' tack even with square top. So it is really an issue only with full mainsail and one side only.

2 topping lifts seems a bit too much mess and am just a bit too lazy to attempt that.

So, I guess will live with that
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Old 23-07-2017, 09:41   #34
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Re: Square top mainsail

You don't need a topping lift with a square headed sail. The sail is pulling up and the sheet is pulling down.

If these guys can get by without one, and I promise their sail is trimmed better than yours, you don't need one.

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Old 11-11-2017, 03:42   #35
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Re: Square top mainsail

thanks everyone. Decided for square top mainsail after lots of research.

My white sails will be replaced after 19k nm and will also move to square top.

see if there will be noticeable improvement in performance.
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Old 11-11-2017, 03:45   #36
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Re: Square top mainsail

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Originally Posted by Stumble View Post
You don't need a topping lift with a square headed sail. The sail is pulling up and the sheet is pulling down.

If these guys can get by without one, and I promise their sail is trimmed better than yours, you don't need one.

do these guys actually have fun ? Looks like every wave they pass sends them lots of water in theit face. In cold waters of southern ocean that is unbearable ?
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Old 11-11-2017, 11:42   #37
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Re: Square top mainsail

I really like the square top, it really provides added power up high in better wind area, but also is quite forgiving in gusts as it flicks off nicely to de-power.
The catching of batten tips on lazy jacks is a lazy jack problem - not the sail. You can get a lazy jack retraction set up that pulls them forward to the mast (simple and cheap), or you can steer the boat more accurately into the wind and be more patient with your raising (which is what we do). We have an electric halyard winch which I tail by hand, allows for easy halyard slacken and tighten when it looks like a lazy jack may foul - makes a big difference - but not cheap. When the top batten gets close to the topping lift we turn slightly so the wind blows the mainsail slightly to port of the topping lift, by this time it is clear of the lazy jacks, then hoist it up the rest of the way. If you let it go to starboard then the halyard will rub against the topping lift at the mast head. Depending on how many reefs we have and wind angle I adjust the topping lift so as not to interfere with sail shape. Remember to reset topping lift to original setting when dropping the main (put a mark on it) . Our topping lift is 12mm spectra, for use as an emergency halyard and bosuns chair (I don't like two to one halyards for the bosuns chair cos I can't see the connection at the top of the mast)

The Incidences square top for the Lagoon has a patented spectra tensioner built in so when the mainsail is raised the tensioner pulls the square top head into the mast and vice versa, makes it no problem for stacking. There are other devices out there that do the same sort of thing.
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Old 11-11-2017, 15:57   #38
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Re: Square top mainsail

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Originally Posted by Bean Counter View Post
I really like the square top, it really provides added power up high in better wind area, but also is quite forgiving in gusts as it flicks off nicely to de-power.
The catching of batten tips on lazy jacks is a lazy jack problem - not the sail. You can get a lazy jack retraction set up that pulls them forward to the mast (simple and cheap), or you can steer the boat more accurately into the wind and be more patient with your raising (which is what we do). We have an electric halyard winch which I tail by hand, allows for easy halyard slacken and tighten when it looks like a lazy jack may foul - makes a big difference - but not cheap. When the top batten gets close to the topping lift we turn slightly so the wind blows the mainsail slightly to port of the topping lift, by this time it is clear of the lazy jacks, then hoist it up the rest of the way. If you let it go to starboard then the halyard will rub against the topping lift at the mast head. Depending on how many reefs we have and wind angle I adjust the topping lift so as not to interfere with sail shape. Remember to reset topping lift to original setting when dropping the main (put a mark on it) . Our topping lift is 12mm spectra, for use as an emergency halyard and bosuns chair (I don't like two to one halyards for the bosuns chair cos I can't see the connection at the top of the mast)

The Incidences square top for the Lagoon has a patented spectra tensioner built in so when the mainsail is raised the tensioner pulls the square top head into the mast and vice versa, makes it no problem for stacking. There are other devices out there that do the same sort of thing.
looking forward to test it out. not too worried about lazy jack and topper line. Regretting bit loss of 'wang' functionality as topper cant be tacked but hope this to turn to non-issue.

how do you determine length of tensioner as sail stretches over time : too tight may damage the sail, too loose probably does not function right ?
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Old 11-11-2017, 16:08   #39
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Re: Square top mainsail

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Originally Posted by arsenelupiga View Post
Regretting bit loss of 'wang' functionality
Sorry to hear of your loss.

I suspect Mrs Arsenelupiga is devastated.
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Old 11-11-2017, 17:35   #40
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Re: Square top mainsail

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Originally Posted by Seaslug Caravan View Post
Sorry to hear of your loss.

I suspect Mrs Arsenelupiga is devastated.
LOL, Don't worry, he'll be OK. Arsenelpugia managed to keep his mast upright and finctioning at sea on the same day that another cat had an embarrassing "droop" in Port Hacking.

I'd be adjusting sail outhaul tension after each of the first few sails.
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Old 11-11-2017, 18:38   #41
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Re: Square top mainsail

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LOL, Don't worry, he'll be OK. Arsenelpugia managed to keep his mast upright and finctioning at sea on the same day that another cat had an embarrassing "droop" in Port Hacking.

I'd be adjusting sail outhaul tension after each of the first few sails.
thanks mr tuskie for moral support and advice

Learned that L 400 is very strong construction in my 3 k nm in rather windy & wavy area. No breakages yet. I abused sails and improved my sailing with old/worn nonsquare top sails, time to get new ones and reach new plateaus of sailing proficiency.

cant wait
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