the actual origin of the Laird turretships is quite illuminating :
The design of these ships two vessels originated in a proposal
by Assistant Secretary of the U.S. Navy, Gustavus Fox to build two double-turreted ironclads in Britain with which the USN could attack Charleston. John T. Howard of New York approached Lairds to seek their estimates. Resembling a New York ferryboat in that they were to have a propeller and rudder at each end, they were intended to run into Charleston harbour unharmed by the defences.
Although Lairds drew up a contract which matched Fox's requirements, nothing came of the attempts to consummate it, so that when Bulloch approached them, they had a ready-made basis to develop into his requirements for the CSN.
The Fox –Howard Ironclad
Type; Sea going ironclad floating battery
Dimensions: 231ft OA x 48ft EXS x 14ft later reduced to 12ft D, 2,218 /1,901 tons ,10 knots
205ft PP x 47ft B x 14DPH
Guns: 2 – 11" SB
Armour: 4.5" sides and turrets, backing if any not known
This evolved into the Turret ship via an intermediate stage with three fixed gun houses, from which the turret ships developed.