Want to design a physically capable steam-age (1850-1950) warship? Then Springsharp is the game/program for you! Designing anything from coast defense ironclads with low freeboard to ridiculous twenty turret monsters, it works very well for any alternate shipbuilder.
Some caveats are in order. First, it’s just a weight simulator. This is why it doesn’t really work for volume-dependent missile age ships. Second, it works better for large (by the standards of the time) ships than small ones. Third, you have to know the basics of naval design and ship dimensions to really put in the right numbers for a viable ship.
But with this in mind, it’s an excellent simulation that can create the fleets of your dreams.