They were basically improved Passaics, modified in accordance with war experience. The four ships not commissioned during the war were built on the Ohio River, three at Cincinnati, and Manayunk as far up as South Pittsburgh.
Design
The hull lines were improved and designed speed is given as 13 knots (24 km/h) but there was no hope of getting near this. The 5 in × 1 in (127 mm × 25 mm) side armour was backed by two iron stringers 6+1⁄2 in (165 mm) deep and 6 in (152 mm) thick for 70 ft (21 m) from the bows, but 4 in (102 mm) elsewhere, and the armour lower edge was 3 in × 1 in (76 mm × 25 mm). The turret, of 21 ft (6 m) internal diameter, had 10 in × 1 in (254 mm × 25 mm) plates as did the pilot house above, and the funnel base was also armored. The turret skirt was protected by a 5 in (127 mm) thick and 15 in (381 mm) high ring fixed to the turret, and as in other later monitors the 15 in guns were longer than in the Passaic class and fired with their muzzles outside the turret.[citation needed]
Tecumseh was sunk during the Battle of Mobile Bay by a mine. Canonicus, the last survivor, was decommissioned 31 years before being sold. Catawba and Oneota were both sold to Peru, on 2 April 1868, without ever entering service in the US Navy.[1] Renamed by the Peruvian Navy as Atahualpa and Manco Capac respectively, they participated in the War of the Pacific, which lasted from 1879 to 1883.
Friend, Jack (2004). West Wind, Flood Tide: The Battle of Mobile Bay. Annapolis, Maryland: Naval Institute Press. ISBN978-1-59114-292-8.
Olmstead, Edwin; Stark, Wayne E.; Tucker, Spencer C. (1997). The Big Guns: Civil War Siege, Seacoast, and Naval Cannon. Alexandria Bay, New York: Museum Restoration Service. ISBN0-88855-012-X.
Roberts, William H. (2002). Civil War Ironclads: The U.S. Navy and Industrial Mobilization. Baltimore, Maryland: Johns Hopkins Press. ISBN0-8018-6830-0.
Silverstone, Paul H. (2006). Civil War Navies 1855–1883. The U.S. Navy Warship Series. New York: Routledge. ISBN0-415-97870-X.
Silverstone, Paul H. (1984). Directory of the World's Capital Ships. New York: Hippocrene Books. ISBN0-88254-979-0.