Many thanks for your response Glenn. I do have a set of figures from
the architect, but all the mast manufacturers want to give me a mast
that I feel is far heavier and stiffer than I would prefer for my type
of sailing.
Obviously I am not going to argue with the architect or the mast
suppliers, but I just wanted to have an idea of the whole concept
(about which I have no knowledge at all) so I can maybe get the mast I
want without compromising any of the architects intentions - well not
too much anyway!

To make it a bit tougher for me I'm trying doing this in French, so
I'm struggling a bit to make sure I am completely understood and I
completely understand them. "Knowledge is everything" is never more
true then when your a stranger in a strange land. I have a seven page
questionnaire from the manufacturers full of technical terms that
would make my head ache in English let alone French!

Thanks, Pete

On Thu, 13 Oct 2005 07:57:32 -0400, "Glenn Ashmore"
wrote:

There is no simple explanation. Brion Toss's "Rigger's Apprentice" and Dave
Gerr's "Nature of Boats" have a fairly straight forward explanation. Both
have charts to help you estimate the RM. Larsson & Eliasson "Principles of
Yacht Design" has a much more complete explanation but requires more math.
Read all three in that order and you will have a pretty good grasp of the
subject.

Best way to get accurate numbers is to send your hull dimensions to a spar
maker and ask them to specify a mast. They all have computer programs that
can crank out a report in seconds.