USS Michigan and her sister South Carolina (BB-26) were the first all-big-gun battleships designed. The duo was laid down some months before HMS Dreadnought, but completed more than 3 years later than the British ship. Being a pet project of First Sea Lord Sir John Fisher, the Dreadnought was produced in the then-astonishing time of a year and a day at the Portsmouth Naval Dockyard, with Fisher pushing and prodding every moment of the day and night. American timelines and technology were more laid-back, but the final product was still one to be proud of. The 16,000-ton South Carolinas packed double the 12" firepower of the Connecticuts which had preceded them. And in their very first generation of dreadnoughts, the Americans introduced one innovation that was eventually adopted by all the world's navies: the all-centerline superfiring turret layout seen here. The B and X turrets were raised 12 feet above the deck on tall armored barbette tops, in order to clear the roofs of the A and Y turrets.
Whereas the Dreadnought and succeeding classes of British and German battleships and battlecruisers placed two or more of their gun turrets staggered on the ship's beams, the American ships, and all their successors, mounted all their turrets on the centerline, with the inboard pair firing over the top of the deck-level turrets closest the bow and stern -- superfiring. This innovation was made possible by moving the sensitive gun sighting hoods from the top of the lower pair of turrets to the sides, enabling both sets of guns to fire straight ahead simultaneously. (Superfiring turrets had been tried first in the French coast-defense battleship Henri IV of 1903, but that had been with a single 5.5" turret firing over the roof of a single 10.8" gunhouse. This arrangement had not been deemed a success due to soot and debris fouling the turrets' sighting hoods.) The South Carolina class made a gesture toward the adoption of director firing with large spotting platforms atop the masts. The goal was to coordinate battery firing with instructions to the guns based on precise observation from the central observation post. Appearing for the first time in the U.S. Navy, these were the standard "cage" or "lattice" masts, woven of springy steel wire. This type of mast was standard on all U.S. armored cruisers and battleships through WWI and beyond; however, they were found to have insufficient rigidity to permit accurate observation of the fall of shot in actual combat conditions. Eventually these were replaced by heavy, rigid British-style tripod masts on surviving ships. New construction for WWII went over to fully enclosed control towers instead -- very different from the minimal superstructure that was doctrine in these early dreadnoughts.
The South Carolinas did not adopt the then-new turbine engines: rather, they were powered with conventional triple-expansion reciprocating engines, as were nearly all the USN's capital ships through the New York class, completed in early 1914. A principal reason America held back was the fact that early turbine engines were less fuel-efficient at low revs than reciprocating machines. While Britain's battleships defended a limited area close to home shores, the U.S. Navy had vast stretches of the Atlantic and Pacific to patrol and limited space for coal aboard; hence the choice of piston engines. With the adoption of geared turbines and the switch to oil fuel after WWI, fuel efficiency improved markedly, and turbines were universally adopted in the American service. Whereas the Dreadnought had four turbine engines shafted to quad screw, the first American dreadnoughts continued the tried and true twin-screw configuration except in the turbine-powered Wyoming and Florida of 1912. As for protection, the first of the pair, the South Carolina, came equipped with Krupp armor, while the Michigan premiered a new variant on KC produced by Midvale Steel. With a patent granted in 1908, this went on to be the standard armor for American warships through the end of World War II, depriving the Krupp armaments combine of many millions in U.S. royalties.
At right, the Michigan firing a broadside during target practice, 1912. The South Carolinas suffered from a 16,000-ton Congressional restriction. As a consequence they were rather crowded, though workable, ships. In the service both proved good sea-boats, but had a reputation for heavy rolling. To meet the tonnage limit, instead of having a flush deck as in the Connecticuts, the afterdeck was stepped down by one level. This was found not to reduce performance, as the sisters had suitably high freeboard forward. "A" turret had 24 ft clearance above the waves; "B" turret, 32 ft. All four turrets had a 272° arc of fire, and were worked with electric training motors and hoists. Again to meet weight requirements, the secondary battery was undersized: 3-in guns were used; these 22 guns were manually trained, but supplied by 12 electric ammo hoists. The very first dreadnoughts commonly abandoned secondary guns, retaining only a light anti-TB armament. But a 4" battery was added in 1908-09 British dreadnoughts; by the time of the Iron Dukes (comm. 1914), this was up-sized to 6" (152 mm) to match the Germans' 6"/45 secondary guns. Thus one of the original selling points of the dreadnoughts -- simplification through reliance on one calibre of main gun -- was discarded in favor of the many gun sizes that had been common in pre-dreadnought warships. With the addition of two sizes of AA gun for WWII, battleships reverted once more to four main types of gun, each with a well-defined purpose -- albeit two of these were AA flak guns, the ship had to carry four separate sizes of projectile and propellant to be fully operational.
The U.S. Navy returned to its preferred flush-deck design with succeeding classes of dreadnought. And improved dreadnoughts came thick and fast: six 2-ship classes completed before America's entry into WWI, catapulting the U.S. into third place in the naval arms race (behind Britain and Germany), and quickly rendering the undersized 1909 battleships obsolete. But both the South Carolina and the Michigan performed training and convoy escort duties in WWI, and repatriated troops from Europe after the Armistice. Both vessels were laid up in 1920 and scrapped in 1924. By then the U.S. was well on its way to a coveted title: As the nation state that built more battleships than any other in history.
Plans and Specifications
Above, schematic of the South Carolinas (for an enlarged outline plan, click here).
Specifications for the South Carolinas:
Dimensions: 457'x 80.5' x 27'6" Displacement: 16,000 tons. Armament: (8) 12"/45 cal, (22) 3" 14-pdr, and (4) 1-pdr guns; (2) .30 cal MG; (2) submerged 21" torpedo tubes. Armor - S.C., Krupp type; Michigan, Midvale type: 11"/9"/1½" belt, 12"/8" turret, 10" bulkhead, 10"/8" barbette and upper belt, 12" conning tower, 2.5"-3" deck. Fuel capacity: 900 tons of coal std; 2,380 tons maximum. Propulsion: 12 Babcock & Wilcox M1906 boilers in 3 compartments, developing 265 psi; (2) 4-cyl vertical triple-expansion engines developing 16,500 ihp, shafted to twin screw. Maximum speed: 18.5 kts @ 121 rpm (S.C. did 19.68 on trials; Michigan, 20+). Crew: 805.
Dimensions: 139m x 25.5m x 8.4m. Displacement: 16,000 tons. Armament: (8) 305 mm/45, (22) 76 mm 14-pdr, and (4) 1-pdr guns; (2) .30 cal MG; (2) submerged 60 cm torpedo tubes. Armor - S.C., Krupp type; Michigan, Midvale type: 280/229/38 mm belt, 305/203 mm turret, 254 mm bulkhead, 254/203 mm barbette and upper belt, 305 mm conning tower, 76/64 mm deck. Fuel capacity: 900 tons of coal std; 2,380 tons maximum. Propulsion: 12 Babcock & Wilcox M1906 boilers in 3 compartments; (2) 4-cyl vertical triple-expansion engines developing 12,304 kW, shafted to twin screw. Maximum speed: 35 km/hr. Crew: 805.
For comparison purposes, look at a schematic of the British Dreadnought, commissioned in 1906. Notice that the Michigan's layout allows the same broadside fire with two fewer guns than the Dreadnought. The first 4 classes of British dreadnought battleships followed the beam-turret pattern of the original ship, adding centerline turrets and eventually upgrading their artillery to 13.5" guns. Then -- following the lead of their German arch-rivals -- the British began to use superimposed turrets -- initially just at the stern, then gradually by the time of the Iron Dukes, graduating to all-centerline turrets with superfiring arrangements fore and aft. In fact, the premier WWI superdreadnoughts, the Queen Elizabeth class, adopted a turret layout identical to the Michigan's -- but with 15" guns!
A Michigan Mash-Up
The Michigan crossing the bounding main.
The Michigan raising steam at New York. Enlarge
USS Michigan dressed over all and with sides manned for a naval review, 1911. Enlarge
The South Carolina under way, circa 1912. Her armor belt stands out clearly in this shot. Enlarge