South Dakota-class Battleship

1. Lead

The South Dakota-class battleship was the United States Navy’s fast battleship of the Second World War, and the most successful American battleship design of the war. Built under the limits of the Washington and London naval treaties, the four ships of the class — USS South Dakota (BB-57), USS Indiana (BB-58), USS Massachusetts (BB-59) and USS Alabama (BB-60) — packed the armament and protection of a much larger ship into a hull only 680 feet long, on a standard displacement of 35,000 tons.

Armed with nine 16-inch guns, protected by a 12.2-inch belt of armour, and capable of 27.5 knots, they fought in every major Pacific campaign from 1942 to 1945, escorted the fast carriers, bombarded Japanese-held islands, and fought the last battleship-versus-battleship action of the war in the dark off Guadalcanal. Two of the four survive as museum ships, and the class remains the standard by which American treaty battleships are judged.

The South Dakota class was a compromise, and a brilliant one. The treaty limit of 35,000 tons forced the designers to choose: a longer hull would have given more speed, a larger hull would have given more protection, and a heavier armament would have given more firepower, but the treaty allowed only one of those things at a time. The designers chose protection.

They shortened the hull, crowded the machinery into a smaller space, and used the weight they saved to thicken the armour, producing a ship that was slower than the Iowa class that followed it but better protected than any battleship the United States had built before. The compromise worked: the South Dakotas were the ships the Navy sent when it needed a battleship that could take punishment and keep fighting.

2. Key Facts

Type	Fast battleship
Origin	United States
Designers	Bureau of Construction and Repair
Builders	New York Shipbuilding (Camden), Newport News Shipbuilding, Bethlehem Steel (Quincy), Norfolk Navy Yard
In service	1942–1962 (US Navy)
Produced	1939–1942; 4 completed
Ships	USS South Dakota (BB-57), USS Indiana (BB-58), USS Massachusetts (BB-59), USS Alabama (BB-60)
Displacement	About 35,000 tons standard; about 37,970–44,500 tons full load
Length	680 ft (207.3 m)
Beam	108 ft 2 in (33.0 m)
Draught	About 36 ft (11.0 m)
Propulsion	4 steam turbines, 130,000 shp; 4 shafts
Speed	About 27.5 knots
Range	About 15,000 nautical miles at 15 knots
Crew	About 1,793–2,500 (wartime)
Armour	Belt 12.2 in (310 mm); deck 5–6 in; turrets up to 18 in; conning tower 16 in
Armament	9 × 16-in/45 guns; 20 × 5-in/38 guns; 40 mm and 20 mm anti-aircraft guns
Most famous action	USS South Dakota and USS Washington at Guadalcanal, 14–15 November 1942; USS Massachusetts at Casablanca, 8 November 1942

3. Background and Development

The treaty limit

The South Dakota class was born of the Washington Naval Treaty of 1922 and the London Naval Treaty of 1930, which limited new battleships to 35,000 tons standard displacement and guns of 16 inches. The United States Navy’s previous battleship class, the North Carolina class, had been designed to the same limit, but it had been laid down when the treaty still allowed only 14-inch guns, and it had been completed with 16-inch guns only after the treaty’s escalator clause was invoked.

The South Dakota was designed from the start for 16-inch guns, and its designers had the advantage of knowing exactly what the North Carolina had got wrong: the North Carolina was long, fast and lightly protected for its size, and the Navy wanted the next class to be better protected, even if that meant giving up speed and length.

The result was a ship that was 40 feet shorter than the North Carolina, with the same armament and the same speed, but with armour thick enough to resist its own 16-inch shells at battle ranges.

A shorter, better-protected hull

The key to the design was compression. The designers shortened the hull by moving the machinery spaces closer together and by placing the three 16-inch turrets closer to each other, which shortened the armoured citadel — the part of the ship that had to be protected by the belt and deck armour — and allowed the weight saved to be spent on thicker armour.

The belt was 12.2 inches thick, the deck armour was 5 to 6 inches, and the turret faces were up to 18 inches thick. The ship’s underwater protection, against torpedoes and mines, was also improved, with a system of liquid-loaded compartments and bulkheads designed to absorb the shock of an explosion.

The price was cramped machinery spaces, which made maintenance harder, and a hull that was wetter in heavy seas than the longer North Carolina, but the Navy accepted those costs in exchange for protection.

Building the four ships

The four ships were ordered in 1938 and 1939 and laid down in 1939 and 1940, at four different yards: South Dakota at New York Shipbuilding in Camden, New Jersey; Indiana at Newport News in Virginia; Massachusetts at Bethlehem Steel in Quincy, Massachusetts; and Alabama at the Norfolk Navy Yard.

All four were commissioned in 1942 — South Dakota in March, Indiana in April, Massachusetts in May and Alabama in August — at the moment when the United States most needed battleships, after the loss of the battle fleet at Pearl Harbor and the sinking of the British battleships Prince of Wales and Repulse.

The class was the last American battleship class built to the treaty limit: the Iowa class that followed it was built after the treaty system had collapsed, and it was 10,000 tons heavier, 200 feet longer and 5 knots faster.

4. Design

Armament: nine 16-inch guns

The South Dakota’s main armament was nine 16-inch/45-calibre guns, in three triple turrets — two forward and one aft — each firing a 2,700-pound armour-piercing shell to a range of about 36,000 yards (about 33 kilometres). The guns were the same type carried by the North Carolina class, and they were among the most powerful naval guns in the world: a single broadside of nine shells weighed more than 24,000 pounds, and the shells could penetrate the armour of any battleship then in service at ordinary battle ranges.

The secondary armament was twenty 5-inch/38-calibre dual-purpose guns, in ten twin turrets, which could fire at surface targets and at aircraft, and which became the standard secondary gun of the American fleet. By the end of the war, the ships also carried dozens of 40 mm Bofors and 20 mm Oerlikon anti-aircraft guns, added in successive refits as the air threat grew.

Armour and underwater protection

The South Dakota’s armour was the best the United States had yet put on a battleship. The belt was 12.2 inches of Class A armour, inclined at 19 degrees from the vertical to increase its effective thickness, and it protected the machinery spaces and magazines — the ship’s vitals — from the waterline to the main deck.

The deck armour, 5 to 6 inches thick, was designed to stop shells falling from long range and bombs dropped from aircraft. The turret faces were up to 18 inches thick, the barbettes up to 17.3 inches, and the conning tower 16 inches.

Underwater, the ship was protected by a system of three longitudinal bulkheads and liquid-loaded compartments, designed to absorb the shock of a torpedo hit and to contain flooding. The system was tested in combat: South Dakota was hit by a torpedo in 1942 and survived, and Indiana survived a collision with another battleship that would have sunk a less well-built ship.

Machinery, speed and habitability

The South Dakota was powered by four steam turbines, of 130,000 shaft horsepower in total, driving four shafts, and it could make about 27.5 knots — fast enough to keep up with the fast carriers, which was the battleship’s principal wartime role.

The machinery was crowded into a short space, which made it harder to maintain and harder to repair in action, and the ship’s short hull made it wetter in heavy seas than the longer North Carolina or Iowa. The crew, about 1,793 men in peacetime and up to 2,500 in wartime, lived in conditions that were cramped but, by the standards of the time, comfortable — air-conditioned, with a proper galley, a bakery, a laundry, and a sick bay.

The ship’s fire-control system, with its Mark 8 radar and its analog computers, was the best in the world, and it allowed the South Dakota to fire accurately at night and in bad weather, when the enemy could not see to reply.

5. Variants

Ship	Laid down	Commissioned	Fate
USS South Dakota (BB-57)	July 1939	March 1942	Decommissioned 1947; scrapped 1962
USS Indiana (BB-58)	November 1939	April 1942	Decommissioned 1947; scrapped 1963
USS Massachusetts (BB-59)	July 1939	May 1942	Museum ship at Fall River, Massachusetts
USS Alabama (BB-60)	February 1940	August 1942	Museum ship at Mobile, Alabama

Four sisters, four careers

The four ships of the class were built to the same design, and the differences between them were small: which yard built them, which radar and anti-aircraft fittings they received in successive refits, and which campaigns they fought in. South Dakota fought the hardest battles, at Santa Cruz and Guadalcanal, and was the most decorated battleship of the war, with 13 battle stars. Indiana served in the Pacific throughout the war, bombarded Japanese-held islands, and survived a collision with USS Washington in 1944 that killed several men and damaged both ships. Massachusetts fought in the Atlantic first, at Casablanca, and then in the Pacific, where she bombarded Iwo Jima and Okinawa. Alabama served in the Atlantic and then in the Pacific, escorting carriers and bombarding islands, and she was the last of the four to be decommissioned.

The class’s uniformity was a strength: a crew trained on one ship could serve on any other, and a spare part made for one ship fitted them all.

Wartime refits

All four ships were refitted repeatedly during the war, and the refits changed their appearance and their capabilities. The most important change was the addition of anti-aircraft guns: the ships commissioned with a handful of 20 mm guns and a few 1.1-inch guns, and by 1945 they carried dozens of 40 mm Bofors and 20 mm Oerlikon guns, in quad and twin mounts, which made them formidable anti-aircraft platforms.

Radar was also improved, with the Mark 8 fire-control radar and the SK air-search radar replacing earlier sets, and the ships’ fire-control systems were upgraded to allow them to fire accurately at night. The refits added weight, and the ships’ displacement grew from 35,000 tons standard to about 44,500 tons full load by the end of the war, but the Navy accepted the weight because the air threat had grown faster than any other threat.

Post-war service and reserve

After the war, all four ships were decommissioned in 1947 and placed in reserve, and they remained in reserve through the Korean War and into the 1960s, when the Navy considered reactivating them and then decided against it. South Dakota and Indiana were scrapped in 1962 and 1963, but Massachusetts and Alabama were saved by the states whose names they bore, and they survive as museum ships. The class’s post-war career was short, but its wartime career was long and hard, and the ships’ record — 13 battle stars for South Dakota, 9 for Massachusetts, and the respect of every sailor who served in them — is the measure of a design that had been right from the start.

The reserve years were not idle years for the ships’ memory. The Navy kept the four battleships in a state of preservation, with caretaker crews, because it believed that a future war might need them again, and the ships were inspected regularly and maintained against corrosion. When the Navy finally decided, in the early 1960s, that the battleship era was over, the decision to scrap South Dakota and Indiana was taken with regret, and the campaigns to save Massachusetts and Alabama were, in part, a response to that regret.

6. Operational History

Massachusetts at Casablanca

USS Massachusetts fought the class’s first action, and she fought it in the Atlantic, not the Pacific. On 8 November 1942, during Operation Torch, the Allied invasion of North Africa, Massachusetts bombarded the French port of Casablanca, where the incomplete French battleship Jean Bart — armed with four 15-inch guns in a single turret — was moored as a floating battery. Massachusetts fired her 16-inch guns at Jean Bart from a range of about 22,000 yards, hit her several times, and silenced her guns, and she also sank a French destroyer and damaged a cruiser and several other ships.

The action was the first time an American battleship had fired her main guns in anger since the First World War, and it showed that the South Dakota class could fight and win against a battleship. Massachusetts then sailed for the Pacific, where she spent the rest of the war escorting carriers and bombarding islands.

Santa Cruz and the night battle off Guadalcanal

The Battle of Santa Cruz

USS South Dakota fought her first major action at the Battle of Santa Cruz on 26 October 1942, where she escorted the aircraft carrier USS Enterprise and shot down a large number of Japanese aircraft — the ship claimed 26 kills, a figure that was probably exaggerated but that reflected the intensity of the air attack and the effectiveness of the ship’s anti-aircraft guns. South Dakota was hit by a bomb on her forward turret, which killed several men and damaged the turret, but she survived, and she brought Enterprise home.

The battle was a tactical victory for Japan and a strategic victory for the United States, because the Japanese lost more aircraft and aircrew than they could replace, and South Dakota‘s part in it made her famous in the Navy.

The night battle off Guadalcanal

Three weeks later, on the night of 14–15 November 1942, South Dakota fought the action that made her a legend. Sailing with USS Washington under Rear Admiral Willis Lee, South Dakota engaged the Japanese battleship Kirishima and her escorts in the dark off Guadalcanal, in the second Naval Battle of Guadalcanal. South Dakota was hit by a power failure that knocked out her radar and her fire control, and she was hit repeatedly by Japanese shells — 27 hits in all, by one count — which killed 39 men and wounded 59.

But she survived, and Washington, using her radar, sank Kirishima with 16-inch gunfire, the last time a battleship sank another battleship in a gun action. South Dakota‘s survival, after taking 27 hits and remaining afloat and able to steam, was a testament to the class’s armour and to the damage control of her crew, and it became the most famous damage-control story in the American Navy.

Carrier escort and island bombardment

For the rest of the war, the South Dakota class served principally as escorts for the fast carriers, screening them against air attack and against the rare Japanese surface force, and as bombardment ships, shelling Japanese-held islands before invasions. Indiana and Alabama bombarded Truk, Saipan, Guam and the Philippines; Massachusetts bombarded Iwo Jima and Okinawa, firing her 16-inch guns at targets ashore in support of the Marines; and South Dakota, after repairs, returned to the Pacific and bombarded islands from the Marshalls to Japan itself.

The ships’ 5-inch guns, in particular, were invaluable against aircraft, and the class’s anti-aircraft batteries were among the most effective in the fleet. By 1945, the South Dakotas were bombarding the Japanese home islands themselves, firing at factories and airfields in the last months of the war, and they were present in Tokyo Bay for the surrender on 2 September 1945 — South Dakota and Indiana among the ships that witnessed the end of the war they had fought from its first year.

Losses and damage

No South Dakota-class ship was lost in the war, but the class paid a price in men and in damage. South Dakota lost 39 men killed and 59 wounded at Guadalcanal, and she was hit by a torpedo and by a bomb in other actions. Indiana lost several men in her collision with Washington in February 1944, when the two battleships collided in the dark during a night exercise, killing six men on Indiana and damaging both ships so badly that they had to return to Pearl Harbor for repairs.

The collision was a reminder that the greatest danger to a battleship in the Pacific war was not always the enemy: it was the dark, the sea, and the ships steaming alongside her. The class’s survival, with no ship lost and with every ship able to return to service after damage, was a testament to the design’s strength and to the damage control of its crews.

7. Performance and Specifications

Specifications in full

The figures in the table below are the standard South Dakota-class figures, taken from the Navy’s design data and from the ships as completed. Displacement, speed and range varied slightly from ship to ship, because the four building yards fitted slightly different machinery and because wartime refits added anti-aircraft guns and radar, increasing the full-load displacement from about 37,970 tons to about 44,500 tons by the end of the war.

The armour figures are the design figures: the belt was 12.2 inches thick, inclined at 19 degrees, and the deck armour was 5 to 6 inches. The 16-inch guns fired a 2,700-pound shell to a range of about 36,000 yards, and the 5-inch guns fired a 55-pound shell to a range of about 18,000 yards against surface targets and to a height of about 37,000 feet against aircraft.

Specification	South Dakota class
Displacement (standard)	About 35,000 tons
Displacement (full load)	About 37,970–44,500 tons
Length	680 ft (207.3 m)
Beam	108 ft 2 in (33.0 m)
Speed	About 27.5 knots
Range	About 15,000 nautical miles at 15 knots
Main armament	9 × 16-in/45 guns
Secondary armament	20 × 5-in/38 guns
Anti-aircraft guns	40 mm Bofors and 20 mm Oerlikon (wartime)
Belt armour	12.2 in (310 mm), inclined 19°
Deck armour	5–6 in (127–152 mm)
Turret armour	Up to 18 in (457 mm)
Crew	About 1,793–2,500
Ships completed	4

Comparison with other battleships

Compared with the North Carolina class that preceded it, the South Dakota was shorter, better protected and equally well armed, at the cost of a wetter hull and more cramped machinery. Compared with the Iowa class that followed it, the South Dakota was slower — 27.5 knots against the Iowa‘s 33 knots — and shorter-ranged, but it was better protected for its size, and it was the ship the Navy sent when it needed a battleship that could take punishment.

Compared with the Japanese Yamato class, the South Dakota was smaller and more lightly armed — nine 16-inch guns against nine 18.1-inch guns — but it was faster, better protected by its fire-control radar, and far more numerous. In its own time, the South Dakota was the best-balanced treaty battleship in the world, and its balance of armament, protection and speed is the reason it is still regarded as the finest American battleship design of the Second World War.

8. Operators

The United States Navy

The South Dakota class was built for the United States Navy, which operated all four ships throughout the war and kept them in reserve until the 1960s. In American hands the ships served as carrier escorts, bombardment ships and flagships, and they were the Navy’s principal battleships in the Pacific from 1942 to 1944, before the Iowa class arrived in numbers.

The Navy’s battleship force, of which the South Dakotas were the core, was the largest and most powerful battleship force in the world by the end of the war, and the South Dakota class was its most successful design. The ships were decommissioned in 1947, placed in reserve, and considered for reactivation during the Korean War and again in the 1960s, but the Navy decided that the cost of modernising them was too high, and they were struck from the Navy list in 1962.

No foreign operators

No South Dakota-class ship ever served in a foreign navy. The class was too large, too expensive and too specialised for any other navy to operate, and the United States, which had built the ships for its own Pacific war, had no reason to transfer them. The two ships that survive — Massachusetts at Fall River and Alabama at Mobile — are American museum ships, maintained by the states whose names they bear, and they are visited by hundreds of thousands of people every year. The class’s story is therefore an entirely American story, from the treaty that limited its size to the museum ships that preserve its memory.

The absence of foreign operators also reflects the battleship’s place in naval history. By 1947, when the South Dakotas were decommissioned, no navy in the world wanted a 35,000-ton battleship: the aircraft carrier had become the capital ship, and the battleship’s role — shore bombardment and carrier escort — could be done by smaller, cheaper ships. The South Dakota class was therefore the last of its kind in American service, and the two museum ships are the last witnesses of an era that ended with the Second World War.

9. Legacy and Influence

The finest American treaty battleship

The South Dakota’s legacy is its reputation as the finest American battleship design of the Second World War. Naval historians regard the class as the best-balanced treaty battleship ever built — the ship that got the most fighting power out of the 35,000-ton limit — and its design influenced the Iowa class that followed it, which kept the South Dakota’s armament and protection but added the speed and length the treaty had denied.

The class also proved the value of radar fire control: Washington‘s sinking of Kirishima at Guadalcanal, in the dark, using radar, was the first time a battleship had sunk another battleship at night, and it showed that the future of naval gunnery belonged to the ship with the best radar, not the ship with the biggest guns.

The human legacy

The South Dakota also left a human legacy. The class’s most famous action — South Dakota‘s survival after 27 hits at Guadalcanal — became the most famous damage-control story in the American Navy, and it is still taught to young officers as an example of what a well-built ship and a well-trained crew can endure.

The ships’ crews, about 2,500 men at wartime strength, served in every major Pacific campaign, and their names are remembered on the ships’ memorials at Fall River and Mobile. The class’s two museum ships, Massachusetts and Alabama, are visited by hundreds of thousands of people every year, and they are the best-preserved American battleships of the Second World War — a living link to the war at sea that the class fought from its first year to its last.

10. Surviving Examples

Massachusetts at Fall River

USS Massachusetts (BB-59) is preserved at Fall River, Massachusetts, as the centrepiece of Battleship Cove, one of the largest collections of historic naval ships in the United States. The ship is maintained in remarkable condition, with her 16-inch guns, her 5-inch guns, her radar and her crew’s quarters all open to visitors, and she is visited by hundreds of thousands of people every year. Massachusetts is the best-preserved South Dakota-class ship, and she is the ship that fought at Casablanca, the class’s first action, and at Iwo Jima and Okinawa, its last.

Walking her decks, past the turrets that fired at Jean Bart and at the beaches of Okinawa, gives a visitor a clearer sense of battleship life than any book can.

Alabama at Mobile

USS Alabama (BB-60) is preserved at Mobile, Alabama, as the centrepiece of Battleship Memorial Park, where she is displayed alongside the submarine USS Drum and a collection of aircraft. Alabama is maintained by the state of Alabama, and she is visited by hundreds of thousands of people every year.

The ship’s preservation is a testament to the efforts of the schoolchildren of Alabama, who raised money in the 1960s to save her from the scrapyard — a campaign that is still remembered in the state. South Dakota and Indiana, the other two ships of the class, were scrapped in 1962 and 1963, but their memory survives in the two museum ships and in the battle stars they earned.

For anyone who wants to see a Second World War battleship, a visit to Massachusetts at Fall River or Alabama at Mobile is the best introduction there is.

Frequently Asked Questions

What is the South Dakota-class battleship?
The South Dakota class was the United States Navy’s fast battleship of the Second World War. Four ships were built between 1939 and 1942, armed with nine 16-inch guns and protected by 12.2-inch armour, on a standard displacement of 35,000 tons.

How many South Dakota-class battleships were built?
Four: USS South Dakota (BB-57), USS Indiana (BB-58), USS Massachusetts (BB-59) and USS Alabama (BB-60). All four were commissioned in 1942.

What happened at Guadalcanal on 14–15 November 1942?
USS South Dakota and USS Washington fought the Japanese battleship Kirishima in the dark off Guadalcanal. South Dakota was hit 27 times and survived; Washington sank Kirishima with radar-directed 16-inch gunfire.

What did USS Massachusetts do at Casablanca?
On 8 November 1942, Massachusetts bombarded Casablanca during Operation Torch, silenced the French battleship Jean Bart, sank a French destroyer and damaged a cruiser.

Where can I see a South Dakota-class battleship today?
USS Massachusetts is preserved at Fall River, Massachusetts, and USS Alabama is preserved at Mobile, Alabama. Both are museum ships open to visitors.

How is the South Dakota different from the Iowa class?
The Iowa class was larger, longer and faster — 33 knots against the South Dakota’s 27.5 knots — but the South Dakota was better protected for its size and was the best-balanced treaty battleship ever built.

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Sources

1. Wikipedia, “South Dakota-class battleship” — four ships, specifications, Guadalcanal, Casablanca, museum ships.
2. Norman Friedman, U.S. Battleships: An Illustrated Design History (Naval Institute Press, 1985) — treaty limits, armour and design.
3. Robert O. Dulin and William H. Garzke, Battleships: United States Battleships in World War II (Naval Institute Press, 1976) — service history and refits.
4. Naval History and Heritage Command, “South Dakota (BB-57)” and “Massachusetts (BB-59)” histories — Santa Cruz, Guadalcanal and Casablanca.
5. Samuel Eliot Morison, History of United States Naval Operations in World War II, Vol. V (Little, Brown, 1950) — Guadalcanal and the night battle.
6. Battleship Cove, Fall River, and Battleship Memorial Park, Mobile — museum ships Massachusetts and Alabama.