South Dakota-class battleship (1920)

South Dakota-class battleship (1920). The South Dakota-class was a group of six battleships planned for the United States Navy in the immediate aftermath of World War I. Designed to be the most powerful capital ships in the world, they were intended to counter new naval threats from Imperial Japan and the United Kingdom. However, their construction was halted and ultimately cancelled by the Washington Naval Treaty of 1922, which imposed strict limits on naval armaments. The class never advanced beyond the laying of keels, and their names were later reused for the successful South Dakota-class battleship (1939) of World War II.

Design and description

The design of the South Dakota-class emerged from the General Board of the United States Navy's post-war requirement for a fast, heavily armed battleship capable of operating with the new Lexington-class battlecruisers. Naval architects, including the noted constructor John H. G. McGrory, sought to create a vessel superior to foreign contemporaries like the British HMS Nelson (28) and the Japanese Nagato-class battleship. The primary armament consisted of twelve 16-inch /45 caliber Mark 1 gun mounted in four triple turrets, a significant increase over the eight guns of the preceding Colorado-class battleship. Secondary battery plans evolved but settled on sixteen 6-inch /53 caliber gun in casemates to defend against destroyer attacks. Protection was formidable, with an internal inclined armor belt up to 13.5 inches thick and extensive torpedo bulkheads designed to withstand hits from contemporary torpedoes. Propulsion from General Electric turbines and Babcock & Wilcox boilers was intended to deliver 23 knots, a speed compromise between the fast battlecruisers and slower standard-type battleships. The design pushed the limits of displacement (ship) under existing treaty considerations, directly influencing the negotiations at the Washington Naval Conference.

Construction and cancellation

Authorization for the six ships came with the Naval Act of 1916, a massive building program championed by proponents of a "navy second to none" like Josephus Daniels. Keels for the lead ship, USS South Dakota (BB-49), and her sisters were laid down at major yards including Newport News Shipbuilding, New York Shipbuilding Corporation, and Mare Island Naval Shipyard between 1920 and 1921. Work progressed slowly due to post-war economic adjustments and shifting strategic priorities. The decisive blow came from the international diplomatic effort to prevent a renewed naval arms race, culminating in the Washington Naval Treaty. Signed in February 1922, the treaty mandated the cancellation of all capital ships under construction for the signatory powers, which included the entire South Dakota-class. The unfinished hulls were subsequently scrapped in place, with some materials recycled. The treaty's limitations directly led to the development of the subsequent North Carolina-class battleship in the 1930s under a new treaty framework.

Proposed ships

All six planned vessels were named after U.S. states, continuing the naming convention established for American battleships. USS South Dakota (BB-49) was assigned to Newport News Shipbuilding in Virginia. USS Indiana (BB-50) was allocated to the New York Shipbuilding Corporation yard in Camden, New Jersey. USS Montana (BB-51) was to be built at the Mare Island Naval Shipyard in Vallejo, California. USS North Carolina (BB-52) was also slated for Newport News Shipbuilding. USS Iowa (BB-53) was assigned to the New York Navy Yard in Brooklyn. USS Massachusetts (BB-54) was to be constructed at Fore River Shipyard in Quincy, Massachusetts. None of these specific hulls were completed, though the names USS Indiana (BB-58), USS Massachusetts (BB-59), and USS North Carolina (BB-55) were famously carried by battleships of the later South Dakota-class battleship (1939) and North Carolina-class battleship.

See also

* Lexington-class battlecruiser – A contemporaneous U.S. battlecruiser class also cancelled by the Washington Naval Treaty. * Colorado-class battleship – The preceding U.S. battleship class, the last of the "standard-type" designs. * Treaty battleship – The generation of battleships built under the constraints of the Washington Naval Treaty. * South Dakota-class battleship (1939) – The later, entirely different class of fast battleships that reused the South Dakota name.

Category:Cancelled battleships of the United States Category:World War I battleships of the United States Category:Ship classes