In order to manufacture the correct coupling for your vessel we need to know the following.
Gearbox OUTPUT Flange Diameter.
Number, size and Position of holes ( P.C.D.) ( Pitch Circle Diameter )Register details, i.e. male / female size etc, this can be obtained either from the manufacturer/ supplier of the gearbox, or the owners handbook.
Shaft Taper if any:-i.e. 1:10 / 1:12 / 1:16 Etc.
Length of coupling is useful but not critically essential, If you do not know, we would manufacture the coupling to suit the shaft taper allowing for "The Draw" on the shaft.
Please feel free to contact us for further information