Bart wrote:

What is the purpose of this rig?


To make the boat sail, of course. Hopefully with some advantage over
other possible rigs the designer could have chosen for this boat.

It is not a rotating mast!


Are you sure? Looks like a rotator to me.

http://www.yachtworld.com/core/listi...?&photo=7&boat...

http://www.yachtworld.com/core/listi...jsp?boat_id=16...



Martin Baxter wrote:
Good grief! The environmentalists will be complaining that it's a
hazard to migrating birds, what a cluster-****. Bet it's a whole heap
o'fun tuning that mess.


Sure. Lots of people enjoy tweaking the stringy parts.

All the jumpers do is convert torsion to compression. The skinny mast
can be very strong in compression as long as it's held in column,
within boundaries, it doesn't have to take any torsion. If you think
this triple-jumper arrangement is a cluster-****, consider the
alternatives....

1- a simpler arrangement of standing rigging, necessitating much less
sail area

2- a much much stronger mast section which would be heavier & bulkier;
overall stability would certainly be reduced and windage may be just
as bad or worse. And no control over the bend of the rig.

So, while I *hate* jumper struts as much or more than anybody (and why
in the world does the Thistle still have them (triple diamond stays,
actually), other than the nostalgic thrill of tearing your spinnaker
on them), sometimes the alternatives aren't so great either. IIRC
there are a couple of scow classes with rotating masts and big sets of
diamond stays too.

A big problem I've seen with rotating masts is that the bearing in the
mast step wears out much quicker than anybody thinks.

Fresh Breezes- Doug King