I really recommend Springsharp to those who want to design their own ships

While I would do somethings differently (and do, in my own warship design program), I highly recommend Springsharp to anyone who wants to design their own warships. I don't really have any interest, right now, in designing ironclads, but you could with Springsharp. My own program is geared up for 1903 to 1945 ships (primarily 1903 to 1927). I have not attempted to get very far into ironclad design, at least to be able to actually look at design parameters. I firmly believe that my power calculations would work for 1860 to 1903, and in fact, expanded the data tables to allow for ships with very large "displacement-length" ratios. Ironclads were generally very short for their displacement. The speed-length ratios involved were generally pretty low. I would probably have to add Schoenherr data lower down in the table, as I only entered what I needed for more modern ships. The key parameter is the Reynolds number. That is the index into the Schoenherr table. I use a table from Morton Gertler's book, A REANALYSIS OF THE ORIGINAL TEST DATA FOR THE TAYLOR STANDARD SERIES. The Society of Naval Architects and Marine Engineers has republished the book. I bought a used copy in 2001, as Frank Fox had highly recommended the book to me. I use residual resistance data from graphs in David W. Taylor's The Speed andPower of Ships: A Manual of Marine Propulsion.