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post #4 of Old 05-24-2004
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Fractional vs. Masthead Rig

I''ve sailed a good deal on both (and more) types of rigs. There are advantages to both.

First, from a performance standpoint, a masthead rig is faster in almost all points of sail. Suprising? Not really. But it''s superiority comes at a price. It has a VERY narrow performance envelope for a given sail combination. As such, it requires a great deal of "gear shifts" as the wind changes. As an example, how about the optimum racing inventory for my 37'' IOR masthead sloop: Main, Storm Tri-sail, Drifter, Light #1, Heavy #1, #2, #3(reefable to #4), Storm Jib, 1/2oz Radial, 3/4oz Tri-Radial, 1.5oz Tri-Radial, 1.5oz Starcut, Staysail. Whew... where is the crew to sleep? Plus it takes a bunch of crew to make all these "gear shifts" happen. To give you an idea of the size of these sails, my 3/4oz Tri-Radial is over 1,400sf!

This is in a racing scenario. But when cruising, you could get by with a Main, 150%rf genoa, 110% rf genoa, and an asymetric spinn. In general terms, you can "reef" a roller furler genny by about 20%. After that the shape is pretty much worthless. I actually feel that you can''t roller furl a genny at all and maintain anything resembling a decent shape.

The masthead rig also works well for the set-and-forget-it crowd in that the mast doesnt respond too much in the way of rig tension beyond headstay sag. (My bendy rig uses an adjustable baby-stay to help control mainsail shape, but that is one more thing to worry about when racing, it has to be struck when flying the chute)

The fractional rig benefits from the metioned smaller headsails, and a smaller inventory to cover the anticipated wind range. Smaller chutes are easier to handle. My masthead rig does dip-pole gybes, while a similar sized frac-rigged boat can do end-for-end. The fractional rigged mainsail responds to tuning very well, and is very easy to de-power. But it also needs more sophisticated controls and knowledge. Things like running back stays need to be tacked, and the backstay tension is critical for mainsail shape. The fractional rigged boat just requires a more knowlegable crew to maximize it''s potential.

In one-design racing, almost every one is a fractional rig, as the limitation of a fixed sailplan requires one that can handle all wind conditions.

I raced on Atlantic Class sloops (31'' mini "J" boats) out of Cedar Point Yacht Club. These lovely old designs were able to sail at remarkable speeds in light air, and the same sailplan would be re-tuned to handle 30+ kts. I don''t know of any masthead rigs that can handle that kind of wind range with only two sails.

There are pluses and minuses everywhere in sailing. Just like the search for the "Perfect Cruiser/Racer/Circumnavigator/Shorthanded/Livabord" will require compromises, so will a skipper''s choice in rig.
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