We did agree on rules for wooden craft some time ago, but unfortunately (a) I didn't have a copy on my harddisk, and (b) the rules were not transplanted in the first move from the design board to aowwt's board, and thus not here either.
As I recall, the rule was as follows:
Wooden vessels 200 tons and smaller, 150ft and smaller, can be constructed at a number of 1 per month for every whole three factories a nation possesses. Constructing such craft does not require use of the slips or docks in a players infrastructure, as long as no more than 1 craft per month per whole three factories, is constructed, but constructing such craft still requires an amount of materials equal to its light displacement out of the nations war-materials production, in the month the vessel is constructed. For the purposes of the sim, the construction of such a craft is assumed to last exactly one month, all of it on slip. Repairs do not occupy any capacity, but are still paid for in materials. Shake-down cruise is assumed to last 1 month for full effect.