Re: T&T: Bilge keels and skegs
Outer Reef, a 36' trawler with sails, has bilge keels
or rolling chocks. Like the Defever owner, they were
on her when we acquired her, so I cannot say how
effective they are. I can say that, as much as she
rolls in a beam sea, I would hate to not have them, if
they help at all.
Like you, I would be interested in hearing about the
experiences of others with strakes, bilge keels, or
rolling chocks.
Larry and Peggy,
Bilge keels are used infrequently in the US but they are common in many parts
of Europe with wide tidal ranges. Their primary use in these conditions is
not to stop roll but to prevent the boat, either power or sail, from falling on
its side in drying out mooring situations. They do add some roll damping but
no more than a single keel of comparable area. Many European sailboat builders
make the same hull in single keel and twin keel formats. Performance is
comparable. In one of a kind sailing races, single keel boats are slightly faster in
light wind conditions because of less underwater frictional drag. In high
wind conditons where form resistance is a much greater factor, they perform
equally. Both types roll about the same.
I have owned a twin keel sailboat since 1966 and can testify to the
effectiveness of bilge keels in permitting the boat take the ground and remain level. I
can store it for the winter without stands or a cradle since it will sit flat
on its keels and reinforced rudder skeg. It also can be towed on a flatbed
trailer. It rolls just about as badly as any other 26' sailboat.
Michael Kasten has written extensively about the roll damping effects of
bilge keels. Check his website:
http://www.kastenmarine.com
It is a treasure trove of useful information.
Larry Z
Get a sneak peak of the all-new
AOL at http://discover.aol.com/memed/aolcom30tour
I struggled with the question of getting active fin stabilizers or not in
designing and now building our 53 foot aluminum trawler. I vacillated back
and forth between fins or paravanes for stabilization. For a lot of reasons
I finally decided to have twin bilge keels and paravanes. Michael Kasten
designed the boat and it is being built in Halifax by YachtSmiths
International. You can see what the bilge keels look like at their web page
showing our boat under construction:
http://yachtsmiths.com/valdemar_52_gallery_01.htm
To give you an idea of size, you can get to the fins from the engine room
and they are wide enough and deep enough to physically stand in. The floor
of the engine room comes to a little below mid chest when you stand in the
fins. The guys at YachtSmiths are going to turn the space a storage area --
for what, I haven't decided yet.
Alan F. Wagner
Tampa, Florida
Building Passage of Time
-------Original Message-------
From: LRZeitlin@aol.com
Date: 7/15/2007 9:29:43 AM
To: trawlers-and-trawlering@lists.samurai.com
Subject: Re: T&T: Bilge keels and skegs
Like you, I would be interested in hearing about the
experiences of others with strakes, bilge keels, or
rolling chocks.
Michael Kasten has written extensively about the roll damping effects of
bilge keels. Check his website:
http://www.kastenmarine.com
It is a treasure trove of useful information.
Larry Z