In the olden days before big space or skeg mounted rudders were common the steering forces generated by keel hung rudders were marginal. So the hull shapes had to balance as they heeled or the weather helm would be uncontrollable.
Here are two deck views to show how the lines were typically balanced.
Notice how the point of maximum beam is well forward compared to modern designs. The forward volume kept the distribution of volume centered about the same point as the wind forces built and the boat heeled.
Another example of the same approach.
There are several negatives to this distribution of volume. First, the full bows react more to waves than would be the case if the point of max volume were further aft. Second, in many situations this is a slower configuration (more drag) than you could achieve with a different approach.
But these types of designs have an easy motion and track well.
Posted by Steve Dashew (January 12, 2010)
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on Tuesday, January 12th, 2010 at 2:00 pm and is filed under Dashew Logs.
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Comments or Questions?
September 25th, 2010 at 12:48 am
I have a 28′ catamaran designed by Norm Riise, built by Bud Platten/R/D for Hobie
I am interested in history of this vessel named Mahitabel; I’m close to launch date.
Anyone interested in sharing information may post to Anydaypest@att.net
Specs, 29′ overall by 12′ beam, 550 sq. ft. of sail and a hard flybridge.
Built w/ fiberglass and kevlar reinforced. Circa 1961.
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