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Best aft edge of Bilge Keel

Posted: Wed December 8th, 2010, 3:50 pm
by Hugo Plokker
Dear gentlemen, ladies. I was very (very) surprised to read that the aft edge of Rosy’s bilge keels, were vertical. Also on the pictures of Brimwilm, it seems she has also a vertical aft edge, while all nearly other WW’s have “positive” edge’s. However, it looks like when looking to these ones that even the positive’s edge’s of some are a slighty different angle’s: the Phoenix and Longevity aft edge’s like more vertical then those of Dougaljo and Andy Nelson Raptide 31 “Harryson”. On the other hand Phoenix, all the Eventides, Beth Anne and Ermintrude have even “negative” edges. Also motorboat’s which has short deep bilge keels fore roll damping, have negative aft edge’s. While most twin keel sailing yachts, like Westerly’s, Sadlers, etc all has positive edges. Also the bilge keelers Golden hind, Raptide’s, etc, are positive. However nearly all fin keels nowadays, have all vertical edges.
At the moment I’m making two bilges keels (in combination of a center keel). I tried for about three month’s to find out what is the best aft edge’s: vertical, a positive edge or a negative edge.
I’m looking with very great interest if any of you could help me further with this matter or had experience as with Rosy’s vertical edge against the other WW’s or even a negative edge.
In advance very many thanks for your help end I remain with kind regard, Hugo Plokker, Hellevoetsluis, Holland.

Re: Best aft edge of Bilge Keel

Posted: Sat January 15th, 2011, 2:12 pm
by Fiddler's Green
Hello there,

The reason the aft edges of the bilge plates were extended aft in many of our boats is explained fully in the 'Weatherhelm' article in the 'Hints and Tips' section of the main site.

It is an option builders have used when they perhaps did not want to fill in the area between main keel and skeg or rudder. It does help,

Regards,
John

Re: Best aft edge of Bilge Keel

Posted: Wed May 15th, 2013, 2:59 pm
by Wooden Boat Fittings
Exactly what John said. Sanderling's bilge keels are raked on the forward edge, primarily to avoid snagging warps --

Image

If I were building them from scratch I'd rake both ends for that reason.

Mike