question on trimaran handicap

Pascal,

 

The SCHRS rule will deal with this; However, we do not have any factors to try and differentiate Cats from Tri's - however, I'd think we would get fairly close to an appropiate handicap and would welcome your feedback on the numbers generated.  Go to www.schrs.com and download the calculation routine and have a play around.  Please feel free to contact me for any guidance.

 

Cheers

Simon

One comment - by sitting on the windward float, wouldn't you be creating a similar righting force to a person on a trapeze?




Edited by mrzen

One comment - by sitting on the windward float, wouldn't you be creating a similar righting force to a person on a trapeze?

You can't really sit on the windward float, just on the trampoline. I guess doing so would be equivalent to sitting on the trampoline next to the windward float on a catamaran.

On a catamaran with a trapeze the righting force is higher as you're standing outside the boat.

Regards,
Pascal

Edited by Pascal

I think you are probably right pascal - here's another comment - (and I'm not an engineer to please feel free to correct me)

the pivot point on a trimaran would be different to that of a cat and in fact would move accoridng to the forces on the boat. The pivot point on a cat is around the leeward float, but the pivot point on a trimaran would be similar to a monohull - around the main hull when upright, and then would move towards the leeward float as pressure on it increases...

this would mean that using the cat handicap would disadvantage you in lighter winds as you will essentially be sailing a monohull with a bit of extra stability...

tricky - what do others think...?

Well I am an engineer. But mostly I just bluff. This may be one of those occasions.

Doesn't it depend  on how the plane of the hulls is arranged? Most tris have their floats slightly higher than the centre hull so that only one is in the water at one time. But because the rig is on the centre hull any increase in wind strength will depress the leeward float rather than lifting the centre hull. So the drag increases with the wind

You also have the problem of tacking. It's hard enough to get two long straight lines to turn a circle, let alone three. On cats you keep the weight on the "inside" hull as far as possible to help the outside one (which has further to go) skim across the water. At least that's the theory I work to.

I sail under the auspices of the Irish Multihull Association. I have no idea what would happen if someone turned up anything other than a cat but in theory it's possible. Incidentally, how would foiling tris such a the TriWave and the Rave fit into the handicapping equation. And if lifting foils take such craft outside the remit of SCHRS then what about stabilising foils such as on F16 rudders?

Over to you Scooby!