Boat Building Forum

Find advice on all aspects of building your own kayak, canoe or any lightweight boats

Re: Catmaran kayak? I have one --- almost
By:Carl Delo
Date: 5/27/2008, 12:03 pm
In Response To: Re: Catmaran kayak? I have one --- almost (Mike Savage)

: Hi Carl,
: Nice concept and design. It will need a rudder for sure with that draft but
: it should be very quick.
: The individual hull torsional strength can be fixed by an internal trellis,
: the torsional effects between the hulls would be low with the narowness of
: the hull spacing.

: There are two schools of thought on crossbeam-hull rigidity. One is that they
: should be rigidly connected.
: This works well with cabin-decked catamarans where weight isn't as critical.
: The other is based on the traditional Pacific multihulls where there is a
: small amount of flex allowed in the connections. This allows for a lighter
: structure.

: Mike Savage
: South West Cork

Hey Mike - thanks for the feedback - I did use internal diagonal bracing on the model - bamboo skewers improved the torsional rigidity of the hulls in a major way. It should work at full size as well, but I hope it won't add too much weight. I suppose I could use Kevlar roving instead, but don't really want to. At some point when I settle on a final hull design I plan to make a version from heat-molded Divinycell foam over bulkheads, which should remove the need for the bracing (well, maybe). I'm going to try a light-weight connection between the hulls and only make it more rigid if it seems necessary. My goal is for the thing to go on the roof of my Mini Cooper, so light is good.

You're probably right about needing a rudder for turning. When I gave the model a good push in a 4' wide tow tank with surface chop (that I introduced), it coasted dead straight for about 30 feet with a 4 pound load. When I shifted the weights laterally, it did carve a (very) gentle turn, so edging should be possible. I plan to increase the foreward rocker from the model to the prototype somewhat. I assume 10 minutes on the water in the boat should settle the issue of a rudder.

Messages In This Thread

Seeking: catmaran kayak?
Bill Hamm -- 5/18/2008, 1:26 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/21/2008, 1:43 am
Re: Seeking: catmaran kayak?
Mike Savage -- 5/21/2008, 6:35 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/22/2008, 1:25 am
Catmaran kayak? I have one --- almost *LINK*
Carl Delo -- 5/27/2008, 1:30 am
Re: Catmaran kayak? I have one --- almost
Chris Ostlind -- 5/29/2008, 9:11 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/30/2008, 1:18 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/30/2008, 10:23 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/1/2008, 2:54 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 6/1/2008, 11:41 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/2/2008, 1:53 am
Re: Catmaran kayak? I have one --- almost *LINK*
Carl Delo -- 6/2/2008, 9:36 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/2/2008, 3:26 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 6/2/2008, 5:43 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/2/2008, 5:54 pm
Re: Catmaran kayak? I have one --- almost
Mike Savage -- 6/3/2008, 3:26 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/3/2008, 5:55 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/3/2008, 3:51 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 6/2/2008, 6:43 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/3/2008, 1:58 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 6/2/2008, 1:45 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/30/2008, 11:08 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/30/2008, 11:23 am
Re: Catmaran kayak? I have one --- almost------Web
Dan Caouette (CSFW)------WebKitFormBoundaryqtsCtZA -- 5/30/2008, 11:57 am
Re: Catmaran kayak? Floatation
Carl Delo -- 5/30/2008, 10:28 pm
Re: Catmaran kayak? I have one --- almost------Web
Bill Hamm -- 5/30/2008, 1:21 pm
Re: Catmaran kayak? I have one --- almost *LINK*
Dan Caouette (CSFW) -- 5/29/2008, 1:55 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/30/2008, 12:02 am
Just Curious.
John Monroe -- 5/29/2008, 4:38 am
Re: Just Curious.
Bill Hamm -- 5/30/2008, 10:46 am
Re: Just Curious.
Carl Delo -- 5/30/2008, 11:32 am
Re: Just Curious.
Bill Hamm -- 5/30/2008, 1:24 pm
Re: Just Curious.
Bill Hamm -- 5/30/2008, 1:08 pm
Re: Just Curious.
Carl Delo -- 5/30/2008, 10:48 pm
Re: Just Curious.
Bill Hamm -- 5/30/2008, 11:06 pm
Re: Just Curious.
Carl Delo -- 5/30/2008, 11:45 pm
Re: Just Curious.
Bill Hamm -- 5/31/2008, 9:24 am
Re: Just Curious.
Mike Savage -- 5/29/2008, 7:09 am
Re: Just Curious.
Bill Hamm -- 5/30/2008, 10:37 am
Re: Just Curious.
Mike Savage -- 5/30/2008, 2:53 pm
Re: Just Curious.
John Monroe -- 5/30/2008, 5:26 am
Re: Just Curious.
Mike Savage -- 5/30/2008, 6:37 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/28/2008, 1:43 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/27/2008, 5:37 pm
Re: Catmaran kayak? I have one --- almost *Pic*
Carl Delo -- 5/27/2008, 11:55 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/28/2008, 1:43 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/29/2008, 12:28 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/28/2008, 1:51 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/27/2008, 5:27 pm
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/27/2008, 6:15 pm
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/28/2008, 1:47 am
Re: Catmaran kayak? I have one --- almost
Bill Hamm -- 5/27/2008, 6:32 pm
Re: Catmaran kayak? I have one --- almost
Mike Savage -- 5/27/2008, 7:04 am
Re: Catmaran kayak? I have one --- almost
Carl Delo -- 5/27/2008, 12:03 pm
Re: Seeking: catmaran kayak?
Scott Shurlow -- 5/20/2008, 6:36 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/21/2008, 1:22 am
Re: Seeking: catmaran kayak? *Pic*
Tom Yost -- 5/18/2008, 8:05 pm
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/19/2008, 1:28 am
Re: Seeking: catmaran kayak? *Pic*
Tom Yost -- 5/19/2008, 2:02 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/20/2008, 1:21 am
Re: Seeking: catmaran kayak? *Pic*
Tom Yost -- 5/20/2008, 2:35 pm
Re: Seeking: catmaran kayak?
Randy Ricchi -- 5/19/2008, 9:34 pm
Re: Seeking: catmaran kayak?
Tom Yost -- 5/20/2008, 2:26 pm
Re: Seeking: catmaran kayak? *Pic*
John Monroe -- 5/18/2008, 4:46 am
Re: Seeking: catmaran kayak?
Bill Hamm -- 5/19/2008, 1:26 am