Creating frames, stringers, concentrated masses etc. with Freeship / Delftship

you need to divide the hull shell into layers. 1 layer for each develop-able plate. Then select "develop plates" from the menu and it will lay them all out for you.

The dimensions can be anything as the plates can be welded together from many sheets of metal to form any size/shape. The size, shape and how you break the hull into flat or single curve plates is dictated by the size and how the hull is intended to be built in practice - theres no hard and fast rules, only what is easiest in practice and achieves the shape designed is best.

 

FWIIW: Carene is a bit more limited for designing hull shapes and has fewer tools than FreeShip, but it handles masses and panel densities easily with its Hydro tool and will calculate the draft and waterline directly from that data. Carene is a nice easy program to start a design in and will export a .XYZ file that can be imported directly into FreeShip, but the file contains far too many points to be modified easily in FreeShip and benefits from pruning with a text program.