Inverted Vee Mast?

[HomeyD5]

Has anybody ever made a rig with a double mast in the shape of an inverted
vee? Simple idea, two smaller masts deck-stepped where the shrouds would
normally be anchored, and joined at the top. Forestay and backstay would
provide the tension to compress the split mast to the deck. Pros: eliminates
the shrouds, stays, etc; spreads the compression load to the sides of the boat;
no need for keel-stepped mast to occupy valuable centerline space in the
cabin; could run two mainsails, one each on each mast; mainsail on lee mast
would be vertical when the boat heeled. Cons: more windage, though the
lack of shrouds and the smaller mast diameters would keep it to a minimum;
turbulence created by the weather mast would reduce the efficiency of the
sails downwind. Seems like a straightforward idea, I'm sure it's been done
before.

[SeaSpark]

This rig is know as Bipod or A-mast.

Example of a boat equipped with it was the Procyon Project:
http://boatdesign.net/forums/showthread.php?t=10771

[messabout]

The bipod rig has been in place for centuries. Some of the Polynesion boats used that method. If well executed the system has some merit. One of the advantages is that the "masts" can be fairly short. These rigs usually have a main that is similar to a lateen as the sail will necessarily have a raked leading edge. Marchaj and others have postulated that lateens are considerably less efficient than other types. Sunfish sailors belabor that point. The lateen has some plusses nonetheless. Among those are the ability to change the balance of the rig quite easily.

If one makes the bipod tall enough to join at the head of the sail, the luff can be near vertical. The disadvantage is weight aloft. I would argue that such a rig is appropriate for puddle duck type play boats but not the best choice for large boats. Yes Procyon has such a system, but it costs megabucks to do it as well as they have done.

[Skippy]

Crab Claw Cat

[Wellydeckhand]

Have anybody seem an old Indonesian Jung sail in Borobodur wall carving? they reproduce the similar sail boat with wooden v -inverted sail frame I will scan picture and post later.

WDH

[sharpii2]

[quote=messabout]The bipod rig has been in place for centuries. Some of the Polynesion boats used that method. If well executed the system has some merit. One of the advantages is that the "masts" can be fairly short. These rigs usually have a main that is similar to a lateen as the sail will necessarily have a raked leading edge. Marchaj and others have postulated that lateens are considerably less efficient than other types...[quote]

But you can almost as easily hang a dipping lug from that same mast. Except now you won't have to dip it to change tacks. The mast will have to be slightly higher, but I see no reason that it can not be made to work.

I do agree, however, that such things should be tried in smaller scale first (such as in cheap Puddle Duck Racers) where this risk in failing is least expensive.

Bob