View Full Version : New Ribs
07-09-2007, 08:48 PM
Back in the 1920's my Beetle Cat was originally built with half ribs throughout. I had Beetle Inc. bend me new ribs on their original mold. These are full ribs giving me the option of going with the original method or using them as full ribs. I believe they started using full ribs in the 1940's - nobody knows for sure.
My question; is there an advantage to using full ribs as oppose to half-breadth? Is one method stronger than the other?
It would be much easier to install half ribs as they would slide neatly under the sheer clamp.
07-09-2007, 09:11 PM
You've answered the question yourself. Full length FRAMES (people have ribs, boats have frames) are stronger because they transfer the stresses over a larger area, although not by much if the floor fastenings are proper. Half frames are easier to install if your replacing them. You should be able to pop most of them in full size on a Beetle cat. Have you tried canting them in by tipping forward or aft and then pulling them upright under the clamps?
07-09-2007, 09:20 PM
I would say that since your boat was originally framed using half frames and seeing as that it lasted till now I don't see a good enough reason to change that. Plus your clamp I assume is in good shape, why risk possibly damaging it and surrounding material while removing for just a few frames. (I assume it's a few frames and not all the frames) If it were the later then maybe removing the clamp would be worth it. I like the idea of full frames but it seems that that was some thing that is best done during initial construction as a time saver in production building. Most keeled boats don't have full frames and they seem to be plenty strong. Then again I am new to the forum and have only worked on one beetle cat perhaps some one with more experience with them would give you a different opinion.
07-09-2007, 09:34 PM
Rather than edit "ribs" for "frames"in original post, I'll remember it next time.
I'm replacing all frames aft of the centerboard trunk. The original frames were notched into keel. I assume this was done for additional strengh.
07-09-2007, 09:54 PM
Oh Darn! I thought we had a barbeque somewhere.......:o
07-09-2007, 11:28 PM
Myself I like half frames. There easier to handle and generally a lot easier to get along with. I set them back about 3/8” to 1/2” from the keelson to make a good water way and tie them together with a floor made from framing stock. I run the floor out over top of the half frames about two to three plank widths either side of the keelson. I lag the center of the floor down through the keelson and into the keel, the over laps are then bolted or riveted to the frames up through the planking. This makes for very light but strong construction. If you go with the half frames you only have to build half a steam box. I just use a standard size electric kettle from “Lee Valley” to fire my little box, works great.
Frame or rib ? I’ve worked with old shipwrights and fisherman, some call them ribs some call them frames. Cheer’s
07-09-2007, 11:37 PM
Boats AND people have ribs ... :rolleyes:
07-09-2007, 11:47 PM
Actually a boat is the closest to a living thing a man can build.
07-09-2007, 11:50 PM
Isn't ribands called ribands because it bands the ribs? Or is it Rib Band? Can you call them frame bands?
Best I've been able to tell is that on the west coast they are all frames. Here on the east coast, sawn are frames and bent are ribs (or at least that's the way it was on the Jersey shore for longer than people knew there was a west coast. :D )
07-10-2007, 01:01 PM
You've answered the question yourself. Full length FRAMES (people have ribs, boats have frames)
Joe Trumbly, legendary instructor at a boat school in Tacoma, had the same reaction when one used "ribs" when they meant frames.
Joe would say "COWS have ribs, boats have frames!"
Though in the scheme of things...hardly the largest sin to be observed lately.
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