Correct term needed

[foggytown]

Watching a show about uncovering an ancient Roman barge and the diggers were excited about the fact that the floor boards were joined (along the lengthways edge) by "mortice and tenon" joints. I'll try to describe. Assume 18" X 2" planks maybe 15' long running along the bottom of the barge from side to side. Every 2' or so there is an arrangement whereby a mortice about 1" X 6" is cut into the side of each adjoining plank, a piece of wood a touch smaller than 1" X 12" was slipped into one plank then the next plank was slipped over the other half of the piece. Then holes were bored through each plank about 3" from the joined edge and two dowels were driven in to hold the two planks together. Very neat! But the question is whether this is actually a mortice and tenon joint. (Can you have a floating tenon?) Would it be possibly more properly called a double spline? Actually, come to think of it, it was really very like a rectangular biscuit joint! 2000 year old biscuit joints. Those clever Romans.

FoggyTown

[stoutman]

That's what I was thinking. sounds like a biscuit joint.

I find it fascinating that the ancient Egyptians use to make dovetail joints. So I have read...

[Joe Barta]

According to my sources it's a "Roman Biscuit Tenon". Really. Would I lie?

Ok, maybe I lied. It's a floating tenon...

Barta

[fredfighter]

Yes, they are called loose tenons. A Chesapeake Bay area boatwright used a similar method to make hulls resembling large dugout canoes.

Or more accurately, a biscuit joint is a type of loose tenon joint.

[Gordon Airporte]

Since no one else has, I'll just point out that pretty much every tenon used in boat making is a floating tenon.

[Doug Brown]

[Enoch Root]

I spose you'll be here all week?

er

[foggytown]

OK, I'll bite. Which tenon on a boat ISN'T a floating tenon (assuming the boat hasn't sunk, of course)?

FoggyTown

[Upscale]

Those tenons above the waterline?

[fredfighter]

Well, the ones below the waterline aren't floating but they're trying hard to float. The ones above the waterline aren't floating, they're supported by something else that is floating.

Are you sure he didn't mean , "Damn near", " pretty close", or "absolute"?

[Bugs]

I believe it would be called a spline joint. The benefit is that the spline can be made with the grain at right angles to the planks, adding strength to prevent cracking the joint under stress. Those storms at sea can get ferocious! Bugs

[Robert Bonomi]

*all* of them -- while the boat is still on the ways, and under consturuction.

Or, while it's on a trailer, on the highway, or in dry storage,