Stevens Battery - The 1854 Design

The 1854 Design

The Stevens brothers succeeded in getting Congress to overrule Bancroft and Skinner, and set about radically redesigning the Stevens Battery. The new design was ready by January 1854. It called for a great increase in the ship's size and capabilities. She was now to be 420 feet (128 m) long, 53 feet (16 m) in beam, and displace 4,683 tons. She was to be proof against 125-pound (56.7-kilogram) shells, with armor made up of 6.75-inch (171-millimeter) iron plates sloping upwards from 1 foot (0.3 m) below the waterline to the main deck and running along the entire side of the ship from stem to stern. She was to have bulwarks to make her more seaworthy when steaming which could be lowered to reduce her freeboard in combat, making her a smaller target. Again, the ship was to semisubmersible, able to submerge herself down to the gunwales, also to make her a smaller target.

Her armament was to consist of two 10-inch (254-millimeter) rifled guns mounted on pivots fore and aft and five 15-inch (381-mm) smoothbore guns mounted on the deck above an armored casemate. The 15-inch (380 mm) guns were to fire 425-pound (193-kilogram) shells. The gun crews, protected by the casemates, would load the 15-inch (380 mm) guns from below through holes in the deck protected by armored hoods; the gun's muzzle would be pointed into the hole, and a steam-powered cylinder would use a ramrod to load the gun for the next shot, allowing a high rate of fire. Water was to be injected into each gun automatically after it fired, to cool the gun and prevent it from being damaged by extended, rapid firing.

The ship was to have eight steam engines generating 8,600 ihp (6,400 kW) to drive two propellers and give the ship a maximum speed of 20 knots (37 km/h), breathtakingly fast for the time. She would have consumed a lot of coal, and her 1,000-ton coal capacity suggests that she would have had a very short operating range. She was to be the first ship equipped with fan-driven ventilation, to increase crew comfort by extracting fumes and hot air from below decks.

The Stevens brothers made significant progress on the newly designed ship between January 1854 and September 1855, but then work slowed again. When Robert Stevens died in April 1856, worked stopped entirely, and did not resume until 1859.

The Navy by then was losing interest in the ship. By 1861, it had spent $500,000 (U.S.) on the project, and the Stevens family had spent another $228,435 (U.S.). That year, Edwin Stevens and his brother John C. Stevens offered to pay for completion of the ship themselves if the Navy would agree to pay for the ship if it was completed and proved successful, but a Navy board rejected the offer, finding deficiencies in the project. It was not clear when the ship would be completed, and in 1862 Edwin Stevens estimated that it would take another $730,484 (U.S.) just to complete the ship enough for to be launched.