Page 1 of 3

Batten Tension Article

Posted: Tue Jan 20, 2009 1:33 pm
by Grahame Smith
what is that all about? Any one got the answers to the question. Personally I dont run enough batten tension to worry, more that just enough to get the wrinkes out, but not enough to stop them popping with a light tug in light airs. Too much tension and you have to be super alert to keep every thing working alright for some hot shots but more than I can cope with, I have had other issues with the mains but none that I can associate with batten tension.

Re: Hyde sails

Posted: Tue Jan 20, 2009 1:49 pm
by Rick

Re: Hyde sails

Posted: Tue Jan 20, 2009 1:55 pm
by Grahame Smith
Hi Rick

yes is there any other on this subject ?

Re: Hyde sails

Posted: Tue Jan 20, 2009 1:59 pm
by Rick
We always try and work with our key suppliers to address any issues.

Some people have been massivly overdoing the batten tension which has lead to failiures.

Some people have had faliures due to a change in the plastic fittings which Chris Henderson has been replacing at major events acting for Hyde.

Either way the article just points out that if you are not sure about batten tension get one of the top guys to help rather than just crank them in bar tight.

I have seen people with battens so tight that the batten has been snaking up the pocket as it twists out of column.

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 2:06 pm
by Grahame Smith
One onf the top guys did set mine up with much more tension than I can cope with as I have described many of the people I have met and discussed this with are running tensions which cause the bottom batten to significantly S and require a aquired techique in light airs to get the rest to pop.

Perhaps the issue is actualy driven by the faster guys in a quest for a winning edge ?

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 2:29 pm
by Rick
People will always push their kit to the limit in the quest for speed.

My personal view is that if the batten is snaking in the pocket it is in too tight. It's also a pain to hoist ...

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 2:38 pm
by Grahame Smith
Your view is clear would be good to have views from some others lets hope they will put them on here along with any other sail related issues

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 4:19 pm
by SELSBowbitch
OK, I'll try and explain my logic (this may be painful)

Current set up - I use max tension on the bottom and 2nd one up usually, however I found with my new sail at Silvaplana that that didn't work and it had a snake (as Rick explained) in the batten and I had to back it off a bit. I can only assume that there was a difference in the batten length, sail, or fittings on the ends. I might check that out!

I use enough on the 3rd batten to take the wrinkles out and then as much as possible on the top batten without preventing the ability to pop it in the light stuff.

However...........

This does depend on the set up you have on your mast and the way you shape the sail using the controls.

If you sail with a bit of prebend you can get away with more tension as the mast bends and that allows the battens to pop easier, if you have a straight rig the opposite applies. But.....if you use a lot of cunno it can allow you to carry more tension and vice versa as well.
So if you look at Stens set up he uses a load of tension on a straight rig with loads of cunno in all conditions, this makes the boat really twitchy which is fine for Sten but he is super human and it doesn't suit us all!

Looking at the logic behind it I guess it will make the whole sail stiffer and allow the main to blade off easier in the gusts rather than over twisting and losing the leech tension and therefore pointing ability / ability to have control as you foot off. Same principle as windsurfer sails use.

Personally I haven't had any issues with my sails (although the batten ends were changed before Silv. on a new main). My training sail was new from the same batch and has been through the mill big time last year (including the big day at the nats) with no issue.

As Grahame says, I think this is a personal thing, minimum required is to take the wrinkles out of them all and as you get better slowly increase as necessary.

That's my best guess anyway

cheers

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 4:35 pm
by Grahame Smith
hI Grahame

How would you define max tension in the lower battern does the snaking occur in the batten in a static state in most cases the batten will tend to curve uniformaly over length due to the fact that the batten is not tappered, it is common to see large S shapes in light air in the mps fleet when the cunno is applied with no/ little kicker, one sailor has remarked he belives that this shape is benificial to the air flow over the sail in light airs however this clearly is using more tension than is being suggested here. I assume that the batten tension in the lower battens is to create depth in the camber of the sail which can then be drawn out with the use of the cunningham.

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 4:49 pm
by SELSBowbitch
My max tension has always been as much as I could get on the tensioner up until my recent main. With that one I wound it on as much as possible and then it started to snake so I wound it back until it didn't. I did the tensioning with the sail up and no boom attached.

There is no sensible reason for having the snake there as far as I can see, aerofoil theory sees to that one!

You are right with the assumption that it forces the shape into the sail, the reason for that is that the mast has to be straight to allow for the induced bend by both the sail and kicker tensions (otherwise we'd all be prebending), if we don't have enough batten tension the sail will not set properly on the straight mast.

I'm sure Sten will kick in soon with some better theory!

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 4:58 pm
by Grahame Smith
Graeme

what shape do you get with max conno and min kicker which I am lead to belive would be the sort of setting for light air

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 5:22 pm
by Rick
When I refer to no snaking I am talking about the sail not up ... when it's up and you set for light airs I have noticed some get an S bend in that batten.

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 5:31 pm
by Grahame Smith
do you think that tyhis could be an indication of batten being over tightened

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 5:45 pm
by Rick
I have only really noticed that when the sail is not set; i.e. hanging around at the start, I can't ever see an S bend in a batten being any help when actually tring to sail.

Re: Batten Tension Article

Posted: Tue Jan 20, 2009 9:37 pm
by SELSBowbitch
What I meant by the snake was that the front 1/3 of the batten seemed to be twisting in the sleeve as well as inverting, when I backed it off a bit it was fine.

The shape I look for in the light stuff is to make the top batten flat or with a slight bit of shape. The sail needs to be flattened as it is very full when you have no cunno / kicker on. you also need to add more outhaul. The traveller tension is quite important as well.

cheers