of course they do. for example DNV for fishing vessels:
you do need to have lines plan because of calculations. for load cases just follow procedure that class prescripts.
as far as i know, weight of lightship is summary of weights of hull, machinery complex, equipment (cranes and similiar things) and project reserve...
Hi, I'm graduate student of Naval Architecture and for my M.Sc. thesis i have to project this type of fishing vessel (maximum lenght 30m). I was...