Twisting main sail near the spreaders.

Rhylsailer99

Active member
Joined
19 Jun 2020
Messages
717
Visit site
When sailing downwind I'm noticing a lot of twist at the top of the sail. Could this be caused by not pulling the sail up tight enough? I'm not sure if its something I'm doing wrong. My old sail was not battened, and was attached all along the boom, whereas my new sail is loose footing. Ps I'm still a novice, and solo sailing learning by my mistakes.
 

Attachments

  • Screenshot_20230428-095202_Video Player.jpg
    Screenshot_20230428-095202_Video Player.jpg
    608.4 KB · Views: 45

fredrussell

Well-known member
Joined
24 Mar 2015
Messages
3,471
Visit site
If you haul in the kicker/vang that should pull the sail taught and away from the spreaders. But to some extent with swept back spreaders (assuming that’s what you have) the sail will sit on spreaders sooner or later going deep downwind
 

dunedin

Well-known member
Joined
3 Feb 2004
Messages
13,954
Location
Boat (over winters in) the Clyde
Visit site
Twist in the sail is corrected by tightening the kicking strap (often easier to do before you bear away and ease the sail out).

A loose footed sail is not an issue at all - most modern boats, raising and racing, have loose footed sail. Just needs a very strong attachment to the boom at the outer end (clew) - in our case using a webbing strap covered in Velcro.

Halyard tension is important, but typically need tighter going upwind and not an issue downwind unless really really slack.
 

Rhylsailer99

Active member
Joined
19 Jun 2020
Messages
717
Visit site
I have just tightened 2 of the inner forstays,as last night I noticed my mast was vibrating. It has now stopped making the noise, so hopefully that might help somewhat.
 

penfold

Well-known member
Joined
25 Aug 2003
Messages
7,729
Location
On the Clyde
Visit site
Twist in the sail is corrected by tightening the kicking strap (often easier to do before you bear away and ease the sail out).
Putting a lot of tension on the kicker before bearing off is not a good idea, on some rigs it could break the mast, especially in strong wind.
 

Laser310

Well-known member
Joined
15 Sep 2014
Messages
1,381
Visit site
you don't want to eliminate all the twist anyway - some twist is good.

but your main is not at full hoist - is there a reef in?
 

Laser310

Well-known member
Joined
15 Sep 2014
Messages
1,381
Visit site
Yes one reef, I think maybe I didnt hoist the sail high enough up.

The luff does _not_ look too loose.., especially for sailing downwind.

If I were on the boat looking at it I might feel differently.., but it doesn't look bad.

As I said - you want some twist.., and anyway, as others have mentioned, the main way to reduce twist is to tension the vang, not increase the halyard tension.

Increasing luff tension with the halyard mostly just brings the draft forward - and you really don't want it far forward going down wind.

One of the first things the crew on a race boat do when rounding the weather mark, is to ease the main halyard for the run.
 

Laser310

Well-known member
Joined
15 Sep 2014
Messages
1,381
Visit site
actually.., the more i look at the picture, the more I think it might have more halyard tension than is ideal for a run.
 

oldbloke

Well-known member
Joined
24 Jun 2018
Messages
453
Visit site
If your previous sail had no battens then the leach would have been made with a concave curve. The battens support a convex curve giving a larger, better shaped sail. That leach beyond the straight line between the head and the clew will twist away , unlike the concave leach on your old sail. Judicious amounts of kicking strap tension will support the leach and let it stand up.
How much is enough?... It all depends.
As Laser 310 observes , increased luff tension pulls the fullness forwards and gives more twist. This may or may not be a good thing... It all depends
As Roaringgirl says the amount of twist may not be excessive....It all depends on the circumstances
Time to get a book or look on a sail maker's website and learn how to use your nice new sail
 

Buck Turgidson

Well-known member
Joined
10 Apr 2012
Messages
3,423
Location
Zürich
Visit site
Looking at the lower stripe the camber is right at the front of the sail so I would say the luff is a little too tight if anything. The sail is on the lower shroud as well as the spreader which is what is causing the distortion. Where is your traveller? Do you have the kicker on?
 

dunedin

Well-known member
Joined
3 Feb 2004
Messages
13,954
Location
Boat (over winters in) the Clyde
Visit site
Putting a lot of tension on the kicker before bearing off is not a good idea, on some rigs it could break the mast, especially in strong wind.
Perhaps on a racer with a very powerful / hydraulic vang and a very spindly mast?
On a cruiser like the OP the kicker has often got very little purchase so hard to pull on. And can't think of any cruising boat rigs that would be brought down by bearing off with kicker on. Definitely would be a design or build fault.
 

William_H

Well-known member
Joined
28 Jul 2003
Messages
13,988
Location
West Australia
Visit site
As said the kicker or vang may not have much power to pull boom down. If he has a traveeller that can get main sheet well out then pull down on main sheet this will aleviate some pressure of the sail on the spreaders. I think some pressure on the cap shroud and spreaders is inevitable when running down wind. My battened main sail get pressure wear on the batten pocket at cap shroud contact point. A stick on patch might be the best prevention of sail damage. ol'will
 
Top