Crossmembers, bulkheads, and stringers can all be added in Freeship software with the information in this tutorial. I go at a slow pace so that a first time user can easily follow along while watching.
FreeShip Download:
https://sourceforge.net/projects/freeship/
FreeShip Manual Version 2.6:
https://www.boatdesign.net/attachments/freeship-manual-2-6-pdf.92896
