Second South Dakota class

Construction of the second South Dakota-class battleship began shortly before World War II. Built with Fiscal Year 1939 appropriations, they were more compact and better protected than the preceding North Carolina class, but had the same main battery of nine 16 inch (406 mm) 45-caliber guns in triple turrets. Their innovative hull design featured an internal armor belt, to protect the ships' vitals against 16 inch (406 mm) shells, and outboard propeller shafts that extended further aft than the inboard ones. They also had improved anti-torpedo side protection and more powerful engines, the latter being necessary to drive their shorter hulls at the designed 27 knot (50 km/h) speed. Compared with her three "sisters", South Dakota had extra command facilities and two fewer 5 inch (127 mm) twin gun mounts.

These ships were all completed between March and August 1942, providing a welcome reinforcement to the Navy's surface battle fleet at a critical stage of World War II. In 1942 and 1943, they stood guard in the Atlantic against possible sorties by German battleships, took part in the invasion of North Africa and in operations around Guadalcanal. During the latter campaign, South Dakota was damaged in a gunnery engagement with a Japanese force that included the old battleship Kirishima. As the U.S. went on the offensive in the Central Pacific, they joined in escorting the fast carrier task forces, a job for which their heavy anti-aircraft gun batteries were well-suited. They also employed their main battery guns in shore bombardment, and were kept ready to form battle line in case their Japanese opposite numbers should appear.

All four South Dakota-class battleships went into reserve after World War II and saw no further active service. When they were disposed of in the early 1960s, USS Massachusetts (BB-59) and USS Alabama (BB-60) became museum ships. The other two were sold for scrapping. These ships are considered the best "Treaty" battleships ever built, and quite possibly the finest battleships ever built on a ton-for-ton basis, especially because of their excellent fire control. They were considered for many conversion schemes, including guided missile battleships and satellite control ships, but all were eventually discarded.

Ships

 * USS South Dakota (BB-57)
 * USS Indiana (BB-58)
 * USS Massachusetts (BB-59)
 * USS Alabama (BB-60)

General Characteristics

 * Displacement: 35,000 tons (standard)
 * Length: 680 ft (207 m)
 * Beam: 108.2 ft (33 m)
 * Powerplant: 130,000 horsepower (97 MW) steam turbines
 * Speed: 27 knots (50 km/h)
 * Armament
 * Main: Nine 16 inch (406 mm) 45-caliber guns in three triple turrets
 * Secondary: Twenty five inch (127 mm) 38-caliber guns in ten twin mountings (South Dakota had eight twin mountings)