ironclads CSS Virginia (ex-Merrimack) and USS Monitor here.
So let us start, then, with ironclad vessels. Also spoken of as ironcased, coated or plated, these were the ships, emerging in the 19th century, entirely encased in iron plates. The trick of making such vessels seaworthy was one that led to the practice of putting plate on only specific parts that were more open to missiles until the dawn of the 20th century iron age ship.
By the 19th century, most ships had some iron parts. Iron work was the general name for these and any pieces of iron used in the construction of ships or equipment for ships. Iron bound blocks were those fitted with iron strops. The "iron horse" was the latter-day iron railing of the head attached most usually to the fore- or boom-sheet. A ship was said to be iron-sick when her iron work was coming loose from the timbers and her sheathing nails are rusted. A sorry condition that no right-thinking sailor would allow.
A coast may be spoken of as iron-bound when it is made up of rocks that are predominately perpendicular to the sea as they rise up from it. These are dangerous shores indeed, and should be avoided at all costs.
A ship may be said to be in irons when, as Admiral Smyth explains in The Sailor's Word Book:
... by mismanagement, she is permitted to come up in the wind and lose her way; so that, having no steerage, she must either be boxed off on the former track, or fall off on the other; for she will not cast one way or the other, without bracing in the yards.
Irons are the tools used by caulkers, of which my grandfather was proudly one, to hammer oakum into the wooden seams of a vessel. These are sometimes known as boom irons, probably for their loud racket while in use. Grandpa went deaf caulking. Irons were also, of course, the bilboes that would be fitted around a miscreant sailor's ankles to keep him both in place and in discomfort. Sailors, with their sarcastic wit, might euphemistically refer to same as "iron garters."
And a ship might be lovingly spoken of as having "iron-sides" when she seemed immune to the blasts of enemy cannon. Here in the U.S., we still know one of our first frigates, USS Constitution, as "Old Ironsides."
Thus ends another addition of SMS. Fair winds and following sees, Brethren, until next we meet...
Header: Hudson River Under the Moonlight by M. F. Hendrik de Haas via American Gallery