Top batten tension

gbr1918 · 25 Feb 2019, 10:05

Hi, does anyone think it would be a good idea to de-tension the top batten a bit when the wind is very light? It occurs to me that it might be good to get the top of the sail a bit flatter, and maybe make the batten a little easier to pop through when tacking and gybing. The pic shows what conditions were like on Sunday.

I guess you can easily tell from what boats we've got around us how much we were struggling in this one! Dave Cooper

TimL2 · 26 Feb 2019, 05:17

Quote from: gbr1918 on 25 Feb 2019, 10:05
Hi, does anyone think it would be a good idea to de-tension the top batten a bit when the wind is very light? It occurs to me that it might be good to get the top of the sail a bit flatter, and maybe make the batten a little easier to pop through when tacking and gybing.

It's definitely something worth looking at. The whole leach looks very tight - are you sure the crew isn't leaning their weight on the boom!?

In a drifter it may be worth having a slack kicker all the time (mainsheet to control twist upwind). There's an optimum amount of slack - too much and the batten won't pop on tacks and gybes. Also if you have let off the leeward shroud this will tighten the leech, so the kicker needs to go off more (and/or let off the windward one too in those conditions).

Europes are pretty quick too in light airs! Which club are you at? The Europe class is trying to trace as many active boats as possible so if you could direct the helm to https://www.ukeuropeclass.com/boat-survey.html that would be great.

NTOACertification · 26 Feb 2019, 07:25

Yes you could ease the top batten in light winds, but only to allow 3mm of movement more than this starts to allow creasing at the top batten. However looking at the sail it does not seem that full at the top batten to warrant easing the tension.

As Tim says getting enough twist in the sail in light winds is the secret, the Kicker should be slack enough to allow the boom to lift 200mm at the clew before the kicker limits the twist. Also a heavy aluminium boom can be too heavy in very light winds, preventing the leech from twisting open.
I have always thought that having a carbon boom in light winds is a great in light winds. In these conditions a carbon boom is a better investment that a carbon mast!

In the 70's I tuned up with a then top sailor at Rutland in light winds. We started a test race and I sailed away left the other boat standing - re started with the same result. sailed back to look at his boat and realised the kicker looked too tight. Asked him if it was all the way off? The answer was yes. I then asked if he had a spare shackle, which he did have, and he inserted it at the boom attachment point of the kicker.
After that we never saw him -- he went on to win the Burton Race and was 2nd in Silver National series that year.

Kevan Bloor

Chris Troth · 26 Feb 2019, 08:23

While we are discussing top battens... I seem to have to apply quite a lot of kicker to maintain the correct shape of the top batten, especially if the wind is light. The batten is especially keen to invert - it is impossible to sail with the kicker slack. The main is quite full, and the mast (selden S3) is really quite stiff fore-aft. I have quite a lot of spreader deflection to try and match the curve of the mast to the luff curve of the sail. P and B changed the batten for carbon to try and force the mast to bend more towards the top but this has just caused the sail track to crack. Any ideas?

gbr1918 · 26 Feb 2019, 10:19

Many thanks for the responses. The kicker is slack (but the boom is heavy!), and both the shrouds are off. I'll play around with batten tension and see what I discover! The Europe is pretty quick: helmed by a junior called Joseph who weighs in at about 50kg. I'll point him at the boat survey if he hasn't heard about it. The club is Ouse Amateur at King's Lynn. There's a useful gaggle of Europes quite close at Overy Staithe, so maybe Joseph will do some sailing with them this summer. Dave Cooper

gbr1918 · 03 Mar 2019, 07:04

Well, another light wind day at OASC (plus continuous drizzle, lovely!) and i have to state that easing off the top batten seems a pretty good idea! Getting the batten to pop through was loads easier and I thought we were quicker too. It makes me think I've had the batten too tight for the year I've owned this sail!

.Thanks for the help and advice! - now for a carbon boom. Dave