CSS Palmetto State, the archetypical casemate ironclad. Note the sloped deck and the low waterline.
An ironclad was a steam-propelled warship protected by metal armor plates. Originally devised in the second half of the 19th century on Old Earth, they were "re-invented" on Safehold in the Year of God 895, with some help from Merlin Athrawes.
The first four ironclads of the Imperial Charisian Navy were HMS Delthak, HMS Hador, HMS Saygin, and HMS Tellesberg. (MTAT)