Shellgrit Posted February 6, 2017 Report Share Posted February 6, 2017 Have just started using a square top main. The boat, as is, has done well under the previous owner in competitions. I am sailing cat rigged and the sail feels like a wet blanket; unresponsive. Sail tell tales unresponsive to sheet tension. Middle leach tell tales constantly hooked forward. So boat does not keep up with the fleet. I think my problem may be basic. Any suggestions on what to check? One fellow sailor I checked with says he doesn't look at his tell tales so should I be looking for some other guide? Link to comment Share on other sites More sharing options...
Prince Planet Posted February 6, 2017 Report Share Posted February 6, 2017 Continuing on from the post on the Australian Catamaran Forum.. The main issue is probably a combo of too soft battens / mast rake - and possibly a too loose rig... The thing to do is to hop on someone else's boat - and they sail yours for a while - trading tacks etc - so that a comparison can be made... if you can get a 3 or 4 boat 'swap' going - this is enlightening for all concerned - and will highlight any faults in your own boat... Or, send some photos here - taken from behind the boat; sail sheeted on tight with traveler centred - or very close to centre with enough luff tension to remove all creases from the leading edge... Link to comment Share on other sites More sharing options...
Shellgrit Posted February 7, 2017 Author Report Share Posted February 7, 2017 Thanks again Prince, Am getting some confidence in what the problem is and how to tackle it. if I go for stiffer battens what grade/rating/description would you suggest ? Shrouds are set at 3rd hole from the top. Rake the must back a bit? Luff tension should be just tight enough to remove all creases? Link to comment Share on other sites More sharing options...
Prince Planet Posted February 7, 2017 Report Share Posted February 7, 2017 You should be just shy of block-to-block when sheeted on hard in a strong breeze - 15 knots + So, mast rake is determined by that... and the less 'slop' you have in the rig - the more responsive she will be... Luff tension should always be 'full-on' - and even more so in a strong breeze - give it heaps. Of course, off-wind reduce luff tension according to wind strength and the set of your sail... Take your battens (and sail) to a local sailmaker - he will show you the curve in them - (basically, put one end against a wall or something solid - and push) - and then get some stiffer/heavier ones ordered... Make sure the maximum draught (camber) is no further back than 35% - 40% along their length - in other words you want the drive 'forward' - and a 'clean' aerofoil exit to the shape. Generally the top 3 battens should have less 'depth/camber' than those below. You get power from the bottom 2/3rds of the sail going upwind, and the top 1/3 should really be laying off and 'feathering' - especially in stronger breezes where it just adds to healing, and doesn't add to speed... Downwind the top 1/3 is being utilised for even more drive - but the balance must be found carefully, as too much power can quickly lead to a pitchpole on a broad or close reach... too much 'fun' - huh? Anyway, there are plenty of articles online talking about cat sail / batten shape - just do some research... Of course, these are just general guidelines... you really MUST get some 'boat-to-boat' comparisons happening... Link to comment Share on other sites More sharing options...
Shellgrit Posted February 9, 2017 Author Report Share Posted February 9, 2017 Prince, Will have to get some more practise. Have contacted the previous owner who says he did replace original battens with stiffer ones issued by Windrush. With a pin head sail flatness is achieved by sheet tension. Is it the same with a square top? Link to comment Share on other sites More sharing options...
Prince Planet Posted February 9, 2017 Report Share Posted February 9, 2017 There's really nothing more I can add... sorry. if you sail with a racing fleet - this kinda basic question can be answered by anyone who's prepared to listen to your concerns... and put your boat next to theirs and 'play' around with things... PP Link to comment Share on other sites More sharing options...
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