Central battery ship

One of the participants was the Confederate casemate ironclad CSS Virginia, essentially a central battery ship herself, albeit a low-freeboard one.

The previous Royal Navy ironclad designs, represented by HMS Warrior, had proven to be seaworthy, fast under power and sail, but their armour could be easily penetrated by more modern guns.

The Austrian SMS Kaiser—not to be confused with German Kaiser—was built along a similar design, although the hull had been converted from a wooden ship, and it was slightly smaller (5,800 tons).

[2][3] The Austrian records distinguish between the category of older broadside ironclads and the newer designs using the words Panzerfregatten (armoured frigates) and respectively Casemattschiffe (casemate ships).

[6] The first ironclad of the Greek navy, Vasilefs Georgios (1867), was also built in the UK; at 1700 tons, it was a minimalist casemate design having only two large 9in guns, and two small 20-pounders.