WTF is it?
IDK don't ask me...
WW II I-400 class submarine
It's obviously a platform for a single massive gun, but I don't think it is on a turret, meaning you had to aim the entire ship to aim the gun. Looks to me like between 1860-1900. It's ironclad but not really all that big. I'm thinking an experimental design that was not pursued. Where the hell did you drag this up anyway?
you can see the vents along the side and looks like periscopes on the sail.
with a 12 inch gun. In theory, the gun could be fired while submerged; in practice, the boat had to surface after each shot to reload the gun. M.1 sank after a collision in 1925 in the English Channel. Apparently there was a BBC documentary on it. It was intended for coastal bombardment.
A few more pics are here: http://www.battleships-cruisers.co.uk/m_class.htm#M 1
and a description of its sinking is here: http://socyberty.com/history/the-m1-submarine-disaster/
is a link to a site that has some interesting you tube type footage of these subs.
when you consider they were made in the 1930's