The discussion about a ribless/glueless boat (here) got me thinking. If frames/ribs are going to be used how could you reduce hard points in the bottom panel without removing frame structure? 

So here is my thought. Instead of having limber holes have one large space or flex gap. This gap would allow the bottom to flex without creating hard points.

Note: Chine Log is pictured but not labeled.

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Neat idea,I may be wrong but when the floor goes up don't the sides have to come in? The floor frames wont allow this.Or maybe it will give I'm not sure.

The goal is to get the energy from a impact to spread across the bottom panel into its fasteners and through the rest of the hull structure. At what point does the energy of impact overcome the fasteners ability distribute it? I don't know but its fun to think about.

When the bottom flexes upward it seems like there would be lots of stress on the fasteners holding the bottom to the chine log...

How about no bottom frame at all?

There is a fairly long history of traditional boats built without the bottom of the frame. And you are right, the fasteners  would take some stress. Does the stress increase or decrease with the horizontal frame there, gone, or lifted off the bottom? How much of the stress is spread through the bottom fasteners to the chine log and the rest of the hull structure? I really don't know but its interesting to think about.

The frameless boats Ive built and others that ive rowed you can feel the impacts right through the oars,the whole boat shakes.Its been awhile since Ive been in  framed boat so I cant compare.

My knowledge of this comes from working on fiberglass whitewater kayaks, so take it with a grain of salt...

The issue with the hulls of those boats was that when something that stiffened the interior of the boat (bulkhead, seat bottom) it caused a stress riser in the hull. I think this is similar to one of Sandy's objection of frames, and the genesis of this thread. The problem with the kayaks was in the difference in stiffness between the reinforced and non-reinforced areas of the hull. One way to work around this, rather than eliminate the frames,  would be to stiffen the bottom in order to avoid creating areas with markedly different flex - and by eliminating flex as much as possible in the bottom, seems like stress on the fasteners to the frames and chine log would be reduced. 


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