Hi,

another simple question while I get myself sorted out... in the absence of similar boats for comparison, what are the basic rules of setting an effective rig tension?

What effect is observed if the rig is too loose, or too tight, and what impact does this have on performance?

Thanks!

too loose: rig slats around when boat goes through waves, so that disrupts flow across the sails

too tight: mast won't rotate, so you will have trouble setting the mast effectively

Available here at this very website: CATAMARAN SAILING FOR THE 90's. Well worth the purchase.

To loose... risk demasting.. or damage from rigging slamming around in waves...also less responsive when you NEED to depower (heavy gusts).

Loser rigging (not sloppy) is ok for light air, but the saying is.. the harder she blows... the tighter it goes... this is true with the main sheet and the shrouds.

tighter rigging should allow you to point higher too. Mast rake (and rudders) are a big part of the rigging too... I recommend the book mentioned by tami, and read through old posts... also talk to people with the same boat...

I'm with you so far, but what about fine tuning?

The more you learn what works for your type of boat, and your rigging, and wind, and crew weight, and sail shape, and waves and skills, the more fine tuning comes into play.

I would talk with others who own the same boat for general advice, crew for them as often as you can... read all you can get your hands on, but most of all sail EVERY day... and that should be a good start to understand all the different fine tunings.... (hehe... kidding, kind of)

I have been sailing for over 30 years... cats for 10... and have sailed seriously for the past 3 years (over 100 days a year). I feel i am JUST getting to understand fine tuning, apparent wind, vmg and the biggest lesson i EVER learned.... NEVER, EVER, EVER pop the chute with my girlfriend onboard.... hehe... the 2 just dont work well together.

On the Tornado we run fairly high rig tension, especially in lighter air. The reason is that you want to keep the forestay from being too slack, which hurts jib & pointing performance going to weather. In the light, the main stay ligtly sheeted, so there's not much left to pull on the forestay.

We use a Loos gauge and typically run 25-30 on the new black gauge (pretty near the high end for 3.5mm rigging).

any idea what that is in lbs? I know my mystere needs to be around 400

I'd suggest you look on the Shadow forum for specific tips for the boat.

Found this on the web:
North Sails
It has a chart mapping the old Model A, & Pro gauges to pounds of tension. My numbers are from a Pro Loos...so I'm at/above the 390 lbs mark.

cool thanks... i was just curious.. i am actually at 420... but feel i should have a little extra as i almost always sail solo.

Thanks for the feedback... I get that "loose" equals sloppy rig, and lost power, and therefore tight is better, unless it prevents mast rotation when you need it. Beyond that, your feedback suggests it is a "set and forget" thing - but sailing never seemed that simple! I figured there must be some benefit to small or moderate changes from the average.

I have asked the same on the Shadow forum, but again no numbers are given (yet)!

Simon, your question requested ... "simple" and "basic rules". Everyone has provided that... and even more in depth data.

Of course small changes effect performance... look at what the outhaul and downhaul do... they make small adjustments to the sail the improve or depower your sails.

Since every boat, sail, crew and wind condition is different... you need to apply these general rules of thumb and test the thousands of variables to your conditions... and then try to remember what effect they had.

in rick's "cat racing for the nineties", previously mentioned, hobie alter jnr writing about the hobie 18 says he runs tight diamonds but not a tight rig. i'm not up with current thinking but i'll probably be happy enough with a medium rig and loose diamonds on my boat until i've built up enough hours to actually tell what the changes i make are doing

1st up for experimentation will be mast rake