Crowther hulls

[rustyrusty]

Any one got a comment on the angle of the hulls on this Crowther. Nice old ish boat for sale in Oz I would think it would go OK He isnt sure what the hulls and deck are I think maybe foam core. They were using that in the mid 90's Appreciate your comments..

[Sand crab]

Crowther was famous for asymmetric hulls just like that and they work great. He designed the early Catanas. Here's a C401.

[tamicatana]

The XX1 Catanas are NOT Crowther.

Christophe Barreau began designing Catanas at Crowther's death in 1993

[catsketcher]

I know of three designs from the 80s, 90s and 2000s that used Crowther hulls as the basis for a "new" design. Lock drew some nice hulls, although his bulbs were not copied much because other designers just drew fuller bows to get a better result.

The outward stance was used by Lock, IIRC, to reduce the length of the interior beams, allow easier access into the hulls (early Spindrifts were a real pain to enter) and get the leeward hull more symmetrical in the waterline as it was depressed.

Lock writes about this effect of uneven waterlines in Robert Harris' book on tris. When hard pressed a leaning hull has uneven waterlines and this helps cause the hull to turn away from the lean (or into the wind when heeled causing a broach). Tri designers reduced this effect by canting the floats out so they were vertical when pressed. Lock may have been doing the same with his cat hulls - starting with Bagatelle, which was a successful race boat.

I don't think the torque effect is large on cats and other cat builders (apart from Catana) did not copy his ideas. But the cant angle is small and so any ill effect is small too.

cheers

Phil

[tcpbob]

very unlikely to be a disadvantage. the crowther name is quite venerated in OZ for good reason. as long as the boat was built properly, and to design, it is a good boat.