Dart 15 Forums

Can anybody tell me whether the top batten should curve when the sail is powered up? I've noticed that when sailing all the other battens take on a
nice curve but the top one stays virtually straight and does not look right to me.

Thanks
Andy

Hi Andy,

Yes the top batten should curve.

One year I broke that batten and replaced it with a bit of an old broken one, I used the end that goes into the pocket protector by the mast and I found that the batten didn't curve anymore. After going to a windless TT at Grafham at which Brian Phipps gave an impromptu tutorial ,whilst we were lounging on the grass , he used my boat for demo purposes and indicated said top batten! (amongst lots of other things that were loose or not quite right ) Apparently you need to use the other end of a broken batten for it much more flexible. When I got home I used the correct end of another broken batten to make its replacement up.

Martin S.

Martin

Are you sure that explanation is the right way around?

The inner end of a full length batten is more flexible but tend to break on the shrouds in gybes with too loose a mainsheet, so top battens are often made up from the outer ends of longer battens which makes them stiffer since people aren't prepared to spend £25 on 2' of batten.

Some people sand down stiff top battens to make them flex, I'm not sure whether this is technically permitted under the rules, but it's certainly a cheaper option than buying a new batten.

Charles wrote:Martin

Are you sure that explanation is the right way around?

The inner end of a full length batten is more flexible but tend to break on the shrouds in gybes with too loose a mainsheet, so top battens are often made up from the outer ends of longer battens which makes them stiffer since people aren't prepared to spend £25 on 2' of batten.

Some people sand down stiff top battens to make them flex, I'm not sure whether this is technically permitted under the rules, but it's certainly a cheaper option than buying a new batten.

maybe its the flexible end you need! I used one of my stock of broken battens to make the replacements.

Martin S.

I've looked at my top batten and it appears to be an original one rather than a long one that has been cut down. It was suggested to me at the weekend by a fellow Dart owner that I might not have enough tension on the top batten so that it is lying limp rather than popping across, I'll try it when I'm next out.

Andy

Andy
Next time you are at the club, we can compare two sails side by side, I also have a new top batten I haven't used yet, so we can also check against a new one for length, flex etc.

Mark 1431

Hi Andy B,

I was at Brian Phipps's Teach In at Stewartby earlier this year, and I also was at most of Brian's voluntary impromptu tutorial at the windless Grafham Traveller.

At the Teach In, Brian pointed out that the battens are all made to fit with the thin flexible end next to the mast. If you think about it, if all the red battens are tensioned similarly then the sail will have more or less the same curve from top to bottom as you move out from the luff towards the leach; this curvature similarity up and down the sail will drop away as you move towards the leach, more quickly starting from the top. There will be less curve in the top batten than the one below it and so on, with most curve in the longest battens. Given that the short battens are on average thinner than longer ones, you may find this surprising, but it has to do with the length factor. The battens get thicker as you move out towards the leach to help hold the "optimum" sail shape nearer to the leach - especially so for the longer battens. The battens will hold the sail shape better in medium to strong breezes if they are tensioned more. When the wind gets stronger still, reducing the tension will allow the sail to be blown back more by the wind nearer the leach, effectively depowering the sail - useful if it's gusty. Best qualified suggestion I've heard is to reduce tension starting from the top downward. I've even heard of lighter helms reversing battens so as to be able to sail in strong winds. Brian also said that if you want stiffer battens there is nothing to stop you from cutting off some of the thinner end as well as/rather than the thicker end, but remember what I wrote above about sail shape.....

But many Sprinters seem to break battens - I used to but I haven't broken any for years (I didn't break any doing a bit of a cartwheel at Grafham last October). When there is a usable amount of batten that can be salvaged from the broken one, it is always advisable to retain it for spare, but remember that if it's not the thin end you've been able to salvage it will be very stiff, probably over stiff. In this respect, as well as breaking battens against shrouds (near the middle - per Charles's contribution) battens can also break at the open end of the plastic batten end holder next to the luff; then you've got a batten that is going to be a little bit stiffer, but only a little after the first break, more stiff if it happens again (and again?)....

If you've bought a boat 2nd hand, it may be that one or more of the shorter battens are salvaged replacements after previous breaks, and so be thicker and stiffer than other battens. I thought that Brian identified an over-thick top batten for Martin at Grafham - but I also thought the batten looked thicker at the luff than the leach.....

Mark's offer to Andy B to compare sails and battens is well worth taking up. If someone else reading this thinks they may have a batten problem, then comparison with another more experienced local Sprinter's sail and battens is a really good idea.

I have bought some new battens in recent years, because it seemed to me that Brian Phipps's quality control had resulted in battens from Catparts that produced better sailshape than the poor quality battens that Laser Centre peddled, seemingly without regard to specification.

I have also briefly tried some alternative battens of the kind that some have pushed for on this website. I am not convinced that they produced the right sailshape, which I think was the finding of some (but not all) others who also tried them.

I appreciate this is a well-worn subject, but could someone please clarify the correct batten tensions for the following conditions.

Light winds, F1-2

Medium winds, F3-4

Stronger winds, F5 and above.

Please assume weight of helm is 12-13 stones.

Andrew,

I don't think there is such a list.

It's all trial and experience, depending not only on helm weight but other things - such as (and not a fully comprehensive list) the helm's ability to hike, the way the rig is set up (mast rake, rig tension, etc), the sea state in which you will be sailing, etc etc.

Thanks George.

It is a question I'm often asked. My usual grunt, "that looks about right......!"