E Barnacle - I wonder, in mort clinker built boats Ive seen the edges of the laping planks have not been fastened, relying on the bow of the wood and the fastnings of the planks to the ribs and stringers. I have seen roves used to hold scarfed joints together, but to be candid my wood butchery skills depend more upon GRP and Epoxy than skilled work.

I concur that planking could not be held in lap together with trunnels, for the reasons you gave, and that there would be insufficient length of wood for an interfrence fit to hold. But the framimg structure, ah! that a different story.

Gareth