We have a 45' Defever pilot house that we enjoy very much. The one down
side is the rolling of the displacement hull when we are off shore in
the Pacific North West. I recently visited with a commercial fisherman
friend who operates a 60' steel trawler. He installed "anti rolling
chalks" of approximately 20' in length that stick out and 18" to 24"
inches from the hull. He has had good luck with these especially when
traveling off shore from Oregon to Alaska.
Dose anyone on the list have experience or knowledge of this type of
stabilization?
I would appreciate the input.
Dave Davis
Florence, Or
45' Defever
Hi All
I am not familiar with the term "chalk" in this context.
Are we talking bilge keels?
Regards
Roger Bingham
France
I am not familiar with the term "chalk" in this context.
Proper spelling for this term is its homonym "chock".
-- Jim
I am afraid we are continuing to abuse this term. A chock is used to
control the location and lead of a line, an anchor stowed on deck or a boat,
often a small boat, that is out of water. As other listees have noted, this
thread refers to bilge keels.
Regards
Wesley
wpeldred@comcast.net
----- Original Message -----
From: "Jim Ague" ague@usa.net
To: "Roger Bingham" rjbingham@orange.fr;
trawlers-and-trawlering@lists.samurai.com
Sent: Tuesday, February 10, 2009 8:19 AM
Subject: Re: T&T: Anti-Rolling CHOCKS for 45' Defever
I am not familiar with the term "chalk" in this context.
Proper spelling for this term is its homonym "chock".
I've got a 44 DeFever and she's rolly. My concern with bilge keels (and
I got a degree in Naval Architecture back when we used slide ruls. No
Computers!) all cargo ships and most Naval vessels had bilge keels, even
tankers, though I always wondered why you would even worry when your
hull looked like a 2 x 4 floating on its side.... but if you're getting
hauled out by a carry all, wouldn't a great proporation of the weight of
the boat (in my case 22 tons!) be carried in the sling on those 2 x 4's
glassed onto the turn of the bilge, right where you would want a bilge
keel. That's why I never followed up, because putting them on was the
first thing I thought about when I took a stiff wake on the beam. I'm
looking at a picture of my boat up on the hard and I've always wondered
where I would put them? She's realllllllly round!
I just thought of all the internal structure I would want to beef up the
bilge and dropped the thought. The only other option would be to make
the bilge keel discontinous and establish a " put slings here" area.
That's two breaks in the keel. Not too sure what it would do to crusing
speed or fuel consumption but it couldn't be good.
A steel hull would be no problem, I would think.
I sure want to see Bob's setup.
John Blackburn
44 DeFever "Yak Rack"
Deale, MD
"Wesley & Patty Eldred" wpeldred@comcast.net writes:
I am afraid we are continuing to abuse this term. A chock is used to
control the location and lead of a line, an anchor stowed on deck or a boat,
often a small boat, that is out of water. As other listees have noted, this
thread refers to bilge keels.
For what it's worth, this may be a regional thing. I live on the east coast
and have always known bilge keels as "bilge keels". However my boat (a 60
foot DeFever) is on the west coast, and everybody there, from the surveyor to
the guys in the shipyards, refer to the bilge keels a "rolling chocks". In
fact, they were even referred to as "skookum rolling chocks", which is how I
discovered that "skookum" is not a fancy type of bilge keel but is in fact
something that is extra-special heavy duty.
Scott Welch
Product Manager, Open Text Collaboration Solutions Group
www.firstclass.com
"Things turn out best for people who make the best of the way things turn
out." - John Wooden
Some interested in this topic will find this site usefull as there are
examples of stability solutions and discussion regarding relative
effectiveness.
http://www.brayyachtdesign.bc.ca/
Note especially the Amnesia article and the article on stability.
Richard