In the same manner as port lines, ship lines can also be unlocked by the faction founder for faction members to attempt to find ship recipes within. Each ship line has a specific purpose, from attack ships with damage increasing equipment to recon ships with extended scanning range. In total there are 30 different ship lines with each ship line containing 5 different marks of ship to discover.
Your faction founder can unlock a new weapon line by building ship research centre and paying to unlock a line.
To begin, deposit your ship parts into the hold of a shipwright. Once that is done, you can open the crafting window and select the option for "craft ship", this will open a recipe window, where you can place parts from the shipwright hold into a recipe in an attempt to find a viable outcome. A recipe consists of four different parts, and pressing the add button next to any part will add it to the recipe. Once the recipe as 4 parts, the "craft" button will become active and pressing this will tell you the outcome.
If the outcome is successful, you will have discovered a new ship for your faction which will be sold at all faction shipwrights. In all cases the ship parts are consumed.