What is Flam?

[ChaseKenyon]

ample flare, but it will be noticed, no flam.

looking at Atkin's designs and descriptions.

He often mentions flare and flam but google can't tell me what "flam" is.


:confused:

[Nicholas Scheuer]

Flam is a CONVEX section in the topsides.

Flare is CONCAVE.

Moby Nick

[htom]

Google books (http://books.google.com/books?id=VLg6Lx5yRP0C&pg=PA125&lpg=PA125&dq=flare+flam+tumblehome&source=bl&ots=jwkzMhw59m&sig=BSjZP_njr0C_gP2dMp6dJHxDGCg&hl=en&ei=7h-zSdyVGZuqMsyRvOgE&sa=X&oi=book_result&resnum=1&ct=result)

Atkin's Navarana (http://www.boat-links.com/Atkinco/Cruisers/Navarana.html) has flam.

[Bill Perkins]

Does flam become tumble home when it crosses inboard of the waterline ?

[htom]

I would say that flam becomes tumblehome where the hull is inboard of the beam.

Think of the side of a dory, perfectly straight but at an angle. No flare, no flam. Now, holding the bottom fixed at the same angle, flex the side moving the gunwale outward a bit: flare, or inward: flam. Flex it so far inwards that the gunwale is inboard of the beam: tumblehome.

[N. J. Harris]

I've seen a few sources that give an alternate definition: flare (and tumblehome) is degree of variation from the vertical, and flam is degree of curvature (i.e. variation from a straight line between waterline and the sheer); the main advantage of this definition is that it is much easier to say "concave flare" and "convex flare" than it is to explain what you mean by degree of curvature.

That said, the definition given in the preceeding posts is by far the more common one, and many boat terms have multiple possible meanings depending on the times and regional usage.

Edit: incidentally, even though its pretty rare anymore, we should remember that tumblehome in not inherently convex; old sailing warships, Indiamen, and so on are an obvious example.