Layout
As built, Concord was 244 feet 5 inches (74.50 m) in length and 36 feet (11 m) abeam. Her steel hull had an average draft of 14 feet (4 m), which was expected to give her the ability to escape from larger ships into shallow water. At the waterline was a turtleback deck of ⅜-inch (9.5 mm) steel that formed a watertight seal over the lower spaces. The deck had a crown at the level of the waterline and curved downwards to 3 feet (0.91 m) below the waterline at the sides of the ship. Below this armored deck were twelve compartments separated by watertight bulkheads; the spaces above were equipped with watertight doors intended to be closed during battle.
Above the armored deck, Concord had forecastle and poop decks with an open gun deck that spanned the length of the ship between them. The conning tower was located forward on the forecastle deck and was oval-shaped to deflect shot. It was outfitted with a steam-powered steering wheel, a telegraph, and speaking tubes; it was protected by 2 inches (51 mm) of steel armor plate.
Read more about this topic: USS Concord (PG-3), Design and Construction