Aft Stay

[EllisElectric]

Catamarans seem to have a disadvantage not having a backstay, especially going down wind. Are there any with a backstay?

[Sailmonkey]

Catamarans have the advantage of not needing a back stay. Cats that sail well, don't cover the most ground dead down wind anyway.
Are you asking from a mast stability perspective or from a sail trim perspective?

[EllisElectric]

I would think both because the boom can't get perpendicular to the centerline of vessel, therefore impeding downwind performance by mainsail and having 360 degree points of attachment should be better for stability than lets say 200 degrees.

[Stu Jackson]

The general idea is that cats sail so fast the wind is always abeam for further forward.

Look at the America's Cup boats, for an extreme example.

[Sailmonkey]

Stability wise, the shrouds are usually swept aft so that the stays fully support the mast in all directions.

As far as running, generally, on a cat your VMG will be higher by reaching off rather than running.


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[Training Wheels]

Catamarans seem to have an advantage of not having a back stay. Big roach or square top main!


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[StuM]

I know that older Prout / Broadblue 45/46s have backstays to both sterns. They don't have a big roachy main so it can swing under them freely.

[Snowgoose35]

All Prouts from the UK have back stays - the 33, 34, 35, 37, Elite, etc - big headsail , tiny main , twin back stays - very useful in the Med for running under spinnaker without needing the main up to support it (as Lagoon insist you do, for example)

[44'cruisingcat]

Originally Posted by Training Wheels

Catamarans seem to have an advantage of not having a back stay. Big roach or square top main!


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Exactly. You could fit backstays if you really wanted to, but would have to sacrifice the nice roachy sail shape for a hollow leached, much smaller triangle.

[UNCIVILIZED]

A lot of the catamaran designs out there are a too fat & overloaded in order to gain sufficient VMG when sailing at say 120 degrees AWA. Vs. being able to sail deeper angles, in order to get better VMG.
This can be due to their/his; displacement, hull shapes & underwater profiles (foils), lack of sufficient sail area vs. weight or wetted surface, & or aerodynamic drag of the vessel, making a design slow when it comes to downwind work.
So that may be what the OP is referring to.

In theory, you might be able to move your aft most stays forward, & add a set of full strength running backstays. So that they'd take the load in the place of a fixed backstay. But you'd need a professional (NA) in order to do the math, & make such design changes. As such a change would significanly alter where the loads are on the boat, as well as the rig.
Also, by switching to runners such as this, if you goof (when handling them), on a tack or gybe, then down comes the rig.