mainsail trim after tack

bkw · #1 (**permalink**) 05-08-2009

trimming the main on a ben 36.7
on a beat to the windward mark.
i was told by a fellow crew to bring the traveler up to full trim right after the tack. especially after a bad tack.
is this sound advise ?
any comments appreciated.

AdamLein · #2 (**permalink**) 05-08-2009

Well, I'm no expert, but if "bad tack" means "turned too far and lost speed", the most important thing should be to build up speed right away. When you're not close-hauled, you want to let the main out a bit for speed, and bring it in as she heads up.

Also, the optimal position of the traveler depends on wind conditions. Close-hauled, you want the boom on the centerline, but in lighter winds, you want raise the boom to twist the sail and give it a fuller shape. Boom tension is the job of the mainsheet, and the traveler is used to pull the boom to the centerline as the sheet is paid out.

What were the conditions and what exactly happened after the boat passed head to wind?

Faster · #3 (**permalink**) 05-08-2009

I'd say if you're down speed coming out of a tack you'd be better off to ease the traveler briefly to "free" the sail a bit to build speed and then come up to close hauled and retrim as you settle into your target speed.

bkw · #4 (**permalink**) 05-08-2009

conditions were 12knt wind and light chop. the tack wasn't the greatest but nothing unusual. was about two minutes off the line with another boat pretty close to starboard.

AdamLein · #5 (**permalink**) 05-08-2009

For such conditions I'd probably have the sheet eased a bit and the traveler slightly above dead center... but your best bet is to watch the sail and make your decision based on that. The main trimmer's job is to get the main driving as soon as possible after the tack. If your main has leech telltales, watch them (especially the uppermost one in moderate winds) and keep them streaming aft.

OsmundL · #6 (**permalink**) 05-09-2009

Quote:

Originally Posted by bkw

conditions were 12knt wind and light chop. the tack wasn't the greatest but nothing unusual. was about two minutes off the line with another boat pretty close to starboard.

Technically, follow Faster and AdamLein. But that boat to starboard, is it ahead? Stealing your wind? You'd aim to keep your right-of-way at the next mark, and if easing the main gives you the acceleration to edge ahead of him, try. However, you do have to sail closer eventually, so it is a trade-off. Sailing close-hauled in his wind shadow is a pretty doomed strategy unless you plan to eventually pass him on starboard.

Beware of using "dinghy" techniques on a boat your size and in 12 knots. Sending the traveller all the way out sounds extreme unless your boat had truly stalled. * Correction: Misread your "traveller" note - forget the last bit.

nolatom · #7 (**permalink**) 05-11-2009

Excellent advice above. All I'd add is if you've lost speed during the tack, the apparent wind will be more aft as you start off on the new tack (so you may ease out a little, especially if it's choppy). Then, as you gain speed, the apparent wind creeps forward, and consequently your main comes in, in response.

You can probably accomplish this with just the mainsheet, it's only a few seconds before you're back up to speed.

OsmundL · #8 (**permalink**) 05-11-2009

Quote:

Originally Posted by bkw

trimming the main on a ben 36.7
on a beat to the windward mark.
i was told by a fellow crew to bring the traveler up to full trim right after the tack. especially after a bad tack.
is this sound advise ?
any comments appreciated.

P.S. There could be a slight misunderstanding here? If the boat is crewed to afford a man on the main, then the main is brought to full trim at the beginning of the tack so as to catch the wind as long as possible. By the time you pass the eye of the wind, the main should already be at full trim, and the next move is to ease off to match the new course. Yes? If by "bad tack" you meant "stalling before the turn is complete" then you'd need to keep the full trim a bit longer, but the way you put it, it sounds as though the mistake happened earlier, not after the tack.

jackdale · #9 (**permalink**) 05-12-2009

I have raced a couple of Beneteau 36.7s and taught on one several times. That lengthy traveller is great. I would tend to leave the mainsheet alone on a tack and play the traveller more. I would ease it up as the boat accelerated and the apparent wind shifted forward. You can then trim to the main in conjunction with the genoa to get the desired helm. I am assuming that you have a fairly large genoa driving the boat with the main used primarily for balance and secondarily for drive.

In those conditions, I would hope that genoa trimming is playing the sail constantly and so should the mainsail trimmer.

Jack

zz4gta · #10 (**permalink**) 05-12-2009

Assuming the boat, main and jib, are in perfect trim before the tack, tell the driver to crack off no more than 5* after the bad tack. The outside tell tales on the jib will start to luff just a bit. Ease the main and jib about 2-4" and then trim them back in while the driver comes up to his correct course. By driving a little low, you'll make more power and should accelerate back up to full speed faster than just strapping everything down tight right off the bat. Get all the weight on the rail (except for one trimmer) and the last guy up to the rail does final tweaks. Final tweaks includes ALL sail controls, not just the sheet.

In winward/leeward racing, the main is played to keep the boat flat, the driver will steer to the jib tell tales. On a 36'+ boat, playing the jib sheet would kill your trimmers, not take advantage of any lifts, and continually get knocked by headers.

In point to point racing, playing the main and jib sheet will win you the race. Driving down in the puffs, and up in the luls. This keeps your average speed up.