South Carolina-class battleship

The South Carolina class, also known as the Michigan class, consisted of two early dreadnought battleships built in the early years of the twentieth century. The ships were named USS South Carolina (BB-26) and USS Michigan (BB-27), after the American states of the same names. They constituted the United States' first class of dreadnoughts—powerful battleships whose capabilities far outstripped older vessels in the world's navies—with their "all-big-gun" armament.

The United States' warship technology in the opening years of the twentieth century was based on the prevailing theory of naval combat of the time, where battles would be fought at relatively close ranges and smaller, faster-firing guns would be most important. As such, the South Carolina class' predecessor (the ) had four large guns and a much greater number of medium-sized weapons. American naval theorists, led by H.C. Poundstone, began to believe that a ship mounting a homogenous battery of large guns would be more effective in battle.

As this idea began to enjoy wide acceptance, the United States Congress authorized the country's navy to construct two small 16000 LT battleships, roughly the same size as the Connecticut class and at least 2000 LT smaller than the foreign standard. The solution to this was found in an ambitious design drawn up by Washington L. Capps, the chief of the nay's Bureau of Construction and Repair. His plan featured the heavy armament favored by naval theorists and relatively thick armor—but mediocre speed—on the congressionally-limited displacement.

During construction, South Carolina and Michigan were considered to be "epoch" new warships, but they were soon surpassed by ever-larger vessels—including super-dreadnoughts, which began entering service in 1913. In addition, the class' low top speed of 18 kn, as compared to the 21 kn standard of later American dreadnoughts, relegated them to serving with earlier pre-dreadnoughts during the First World War. Both South Carolinas were scrapped soon after the end of the war with the signing of the Washington Naval Treaty.

Background
The genesis of the South Carolina class began in 1901 as an outgrowth of current battleship designs and a belief that the designs could be much more potent if significant changes were adopted. At the time, the United States Navy's capital ships were designed around the prevailing theory of naval combat—that battles would initially be fought at some distance, but the ships would then approach to close range for the final blows, when the shorter-range, faster-firing guns would prove most useful. Its premier battleship class under construction carried four large 12 in, eight 8 in, and twelve 7 in guns, a striking power only slightly heavier than typical foreign battleships of the time.

The Naval Institute's Proceedings devoted space in two of its 1902 issues to possible improvements in battleship design. The first article was authored by Lieutenant Matt H. Signor. He argued for a ship with four triple turrets, two of 13 inches (330 mm)/40 caliber and two of 10 inches (254 mm)/40, and a secondary battery of 5-inch (127 mm)/60 guns. While this paper alone did not affect the Navy's designers, it provoked enough thought that Proceedings published comments on the story from Captain W.M. Folger, Professor P.R. Alger and David W. Taylor, the former the foremost gunnery expert in the Navy, the latter an up-and-coming officer and future chief constructor. These comments expressed doubt that the proposed vessel could be modified into a feasible design, but they praised his thoughts as going in the right direction. Alger believed that Signor was on the right track in making the armament larger, though he thought that triple turrets would be unworkable and eight 12-inch guns in four twin turrets would be a much better arrangement. Naval historian Norman Friedman believes that this was one of the "earliest serious proposals for a homogeneous big-gun battery."

The direct progenitor to the South Carolina class was in the ideas of H.C. Poundstone, a Lieutenant Commander in the Navy, who would become the principal proponent of an American all-big-gun design. In a December 1902 paper written for President Theodore Roosevelt, he presented an argument for greatly increasing the size of current battleships, although he also believed that the mixed main batteries should be retained. By the time this was published in the 1903 March and June editions of Proceedings, Poundstone had begun advocating for an all-big-gun arrangement featuring twelve 11-inch guns mounted on a 19330 LT ship. In October of the same year, the Italian naval architect Vittorio Cuniberti presented a similar idea in an article for Jane's Fighting Ships entitled "An Ideal Battleship for the British Navy." He argued in favor of a ship with twelve 12-inch guns on a slightly larger displacement than the battleships in service at the time, 17000 LT. He believed that the higher weight would allow 12 inches of armor and machinery capable of propelling the ship at 24 kn. Poundstone used what he believed to be the great popularity for this idea among Europeans to justify the all-big-gun design.

In 1903, Poundstone's designs began receiving attention from American naval authorities. After being refined by Washington Irving Chambers, Poundstone's work was brought to the Naval War College, where it was tested in war games during the 1903 Newport Conference. Results from these indicated that a theoretical battleship that dispensed with the intermediate eight- and seven-inch armament was armed with only twelve 11- or 12-inch guns, and all able to fire on a single broadside, was worth three of the battleships then in service. The main reasoning for this was that the men who conducted the tests felt that the measure of effective gun ranges was directly related to the maximum length of an enemy's torpedo range. At this time, the latter was roughly 3000 yd; at that distance, the seven-inch and eight-inch guns common to American intermediate batteries would not be able to penetrate the armor of enemy battleships. Worse still, it was certain that—as the United States was developing a 4000 yd torpedo—gun range would have to rise in the near future, making the intermediate guns even less useful. However, a homogeneous main battery of 11- or 12-inch guns would be able to penetrate the armor and had sufficient explosive power to disable an enemy capital ship, and adding as many guns as possible would provide a strong defense against destroyers.

Design
Faced with this evidence, the General Board formally requested that the Bureau of Construction and Repair (C&R) draw up plans for a battleship including these characteristics in October 1903, but no progress had been made by 26 January 1904, when the General Board asked C&R for a design including four 12-inch, eight guns of 10-inch or larger, and no intermediate armament beyond 3-inch anti-destroyer guns. The move to 10-inch weaponry was the result of doubt among naval authorities that heavy weapons like 12-inch could physically be mounted on a ship's broadside. No action was taken on this request until September, when C&R began planning a ship with four 12-inch in dual turrets along with eight dual 10-inch or four single 12-inch guns.

Meanwhile, the Naval War College played three battleship designs against each other at its 1904 Newport Conference; the ships that had resulted from the 1903 conference, the new C&R design from September, and the latest battleships under construction, the Connecticut class. The non-usefulness of 7- or 8-inch guns was demonstrated again. Even the 10-inch guns were unsatisfactory; under the ideal circumstance of hitting a battleship at a perfect $$ to its belt, they could pierce only 12 inches of Krupp armor. This meant that the 12-inch gun was the only suitable weapon for countering enemy capital ships. Speed calculations were also done at this time which showed that even a 3 kn advantage over an enemy fleet would be inconsequential to the final outcome of almost all naval battles—the slower ships could simply turn inside of the faster.

Within the naval bureaus, however, there was still much resistance. In mid-to-late 1904, Poundstone continued to lobby the General Board while C&R protested that the final determinant in a naval battleship would be the light guns and in any case such a large uniform battery was not feasible. Poundstone replied with a design of his own creation, USS Possible, which fit twelve 11 in guns on a ship of 19330 LT. With support from Lieutenant Commander William Sims, who was able to cite the increasingly accurate long-gunnery of the Navy, and interest shown in the project by President Roosevelt, the bureaucratic stalling was ended.

On 3 March 1905, Congress passed a bill which authorized the Navy to construct two new battleships which would be named after the states of South Carolina and Michigan. The maximum tonnage limit was set at 16000 LT, the same weight as the mixed-battery Connecticut class of two years prior, in an attempt to stem the rising displacement—and accompanying costs—of the Navy's new capital ships. This provision was met with a mixed reception from naval designers. Some, including retired Admiral of the Navy George Dewey, thought the limit should have been set at a minimum of 18000 LT, the standard of foreign battleships. Others believed adding a significant amount of speed or firepower, something one would expect with an increase in tonnage, would require a much larger size than 18,000 tons. They argued, then, that the increase in size would buy nothing more than an increased target profile.

The Constructor of the Navy, Washington L. Capps, devised an ambitious design that could pack powerful armament and thick armor onto the small hull. He believed that future naval battles would involve fleets rather than single-ship actions, and so while the wing turrets so common in European designs were useful in the latter role for putting a maximum amount of firepower in any given direction, they were less so while operating as part of a line of battle. From this, Capps theorized that the principal concern of battleships was how much shell weight they could fire per broadside. The arrangement of superfiring turrets on the centerline would allow the hull to be as short as possible while still having the most powerful broadside possible.

As the superfiring arrangement used a great amount of space within each ship, Capps was forced to economize in other ways to stay within the tonnage limit, but the need to cut the ship down one deck created problems with volume. Machinery had to be built smaller than normal to fit in the space between the fore and aft magazines, both of which were larger than usual. Boiler rooms were moved inboard to make room for torpedo protection. The biggest drawback was in propulsion: there was no room for engines that could provide more, or even maintaining the same amount of power as previous battleships. Capps suggested cutting down the number of boilers by one-third to make room; it may have been at this point that he considered turbine propulsion, for which he would have needed the extra room. All the Bureau of Engineering could offer in response was more compact boiler rooms by eliminating centerline bulkheads. The end result was that the South Carolina class fell behind Dreadnought in top speed.

Specifications
At a design displacement of 16000 LT, the South Carolina class dreadnoughts were the same size as their pre-dreadnought predecessors. In service, they could actually be lighter: USS Louisiana (BB-19) came out to a standard displacement of 15272 LT, while Michigan was only 14891 LT by the same measurement. The South Carolina class' hull size was also comparable to the earlier ships, with a length of 452 ft overall, 450 ft between perpendiculars, and the same at the waterline. Their beams were 80 ft, and their draft was 34 ft. The South Carolina class' metacentric height was 6.9 ft normally and 6.3 ft at full load. Only the South Carolina class' beam and metacentric height were greater than the Connecticuts.

The South Carolinas had a propulsion system was comprised of two vertical triple expansion engines driving two three-bladed propellers. These were in turn powered by twelve coal-fired superheating Babcock & Wilcox water-tube boilers located in three watertight compartments. Together, they weighed 1555.308 LT, which was just over the specified contract limit. The use of the traditional and tried triple expansion engines was as opposed to the use of steam turbines, which were used in the British Dreadnought. The actual coal capacity of the South Carolinas was 2374.2 LT at full load, slightly more than the designed maximum of 2200 LT, and this allowed for an endurance of 6950 nmi at 10 kn. While both ships were able to surpass 20 kn in idealized trial conditions, in normal conditions top speeds of 18.5 kn were expected.

The class' main battery was comprised of eight 12 in/45 caliber Mark 5 guns in four turrets, with one pair each fore and aft. These were placed in an innovative superfiring arrangement, where one turret was mounted slightly behind and above the other. This arrangement meant that the shortcomings of other all-big-gun arrangements, such as the torsional stress and rolling inertia from wing turrets, were avoided. 100 rounds were carried for each gun. The anti-torpedo boat secondary armament of twenty-two 3 in guns was mounted in casemates.

Armor on the South Carolina class was described by naval author Siegfried Breyer as "remarkably progressive", despite deficiencies in horizontal and underwater protection. The belt was thicker over the magazines, 12 to 10 in, than over the propulsion, 11 to 9 in, and in front of the forward magazines, 10 to 8 in. Casemate armor was the same, 10-to-8 inches, while the deck armor varied from 100 to 40 pounds. The turrets and conning tower had the heaviest armor, with 12–8–2.5 in (face/side/roof; 305–203–63.5 mm) and 12 to 2 in. The barbettes were protected with 10 to 8 in of armor. The total weight of the armor amounted to 31.4% of the design displacement, which was slightly more than the US' next three battleship classes.

Construction and trials
The contracts for Michigan and South Carolina were awarded on 20 and 21 July, respectively. Michigan's keel was laid down on 17 December 1906, one day before South Carolina. After the initial construction periods, the ships were launched on 26 May and 11 July 1908. Michigan was also more than half complete when launched, and the ship was christened by Carol Newberry, the daughter of Assistant Secretary of the Navy Truman Handy Newberry. As befitting of what was considered to be an "epoch" new warship, the spectacle was a large amount of prominent individuals, including the governor and lieutenant-governor of Michigan, the governor of New Jersey, the mayor of Detroit, the secretary of the Interior Department, along with many naval admirals and constructors. South Carolina's launch, taking place just after noon, was attended by many prominent residents of the state of South Carolina, including Governor Martin Frederick Ansel. His daughter Frederica christened the ship, which was 51.9 percent complete at the time.

The two ships then entered the fitting-out stage, where they were completed in all respects. Before being commissioned as active-duty warships in the navy, though, they were put through sea trials to ensure they met that contracted specifications. These included being able to travel at 18.5 kn or more for four straight hours and endurance runs where the ship would be drove at 12 kn and 17.5 kn for twenty-four hours to test the machinery performance and coal consumption.

Michigan's trials were originally conducted at the navy's traditional testing grounds off Rockland, Maine beginning on 9 June 1909. Standardization trials were completed on a marked course off Monhegan Island, with the ship reaching a maximum speed of 20.06 kn and an average of 19.11 kn. On 10 June, the four-hour run was completed. This was immediately followed with the twenty-four hour 17-knot run, but they were forced to stop only a few hours in to fix a malfunctioning relief valve. During this time, a heavy fog rolled in, and Michigan ran aground on a sand bar that night near Cape Cod Light due to the reduced visibility. After being cleaned, they attempted the twenty-four hour 12-knot run on the 12th, but it was called off when a damaged propeller blade made the starboard engine run at 1,000 horsepower more than the other. Michigan was forced to put in at the Philadelphia Navy Yard, where it was found that both propellers were damaged. It took more than a month to replace them; beginning on 20 July, Michigan sailed to the Delaware Capes to complete its trials. These included additional standardization runs (21 July), the twenty-four hour 17.5-knot run (22 July), and the twenty-four hour 12-knot run (24 July). Michigan was then commissioned on 4 January 1910—making the United States the third country to have a dreadnought in commission, behind the United Kingdom and Germany but just ahead of Brazil—and its shakedown cruise lasted until 7 June.

South Carolina's trials were done off the Delaware Capes beginning on 24 August 1909 with its standardization runs, which resulted in a 19.25 kn average and 20.52 kn top speed. On the next morning, the four-hour 18.5-knot full-speed trial was successfully completed, with South Carolina attaining a speed of 18.88 kn After the trials were complete, the ship returned to William Cramp for final modifications. South Carolina was then commissioned on 1 March 1910 and departed for a shakedown cruise six days later.

Service history
After being commissioned, both ships were placed into the United States' Atlantic Fleet. Both ships operated up and down the American east coast from July until November. On 2 November, as part of the Second Battleship Division, the two ships left the Boston Navy Yard for a training voyage to Europe, where they visited the Isle of Portland in the United Kingdom and Cherbourg in France. In January 1911, they returned to the United States' naval base in Guantanamo Bay, Cuba before continuing to another base in Norfolk. After further maneuvers, the ships split; Michigan remained on the east coast, while South Carolina departed on another trip to Europe. The ship visited Copenhagen (Denmark), Stockholm (Sweden), Kronstadt (Russia), and Kiel (Germany)—the last during Kieler Woche, a large sailing event—before returning in July 1911.

South Carolina next took part in the naval review in New York, before several months of traveling to ports on the east coast, welcoming a visiting German naval squadron comprised of the battlecruiser SMS Moltke and two light cruisers, and a three-month overhaul in Norfolk. South Carolina then joined Michigan to visit Pensacola, New Orleans, Galveston, and Vera Cruz in Mexico, as part of the Special Service Squadron. South Carolina later visited Colon, Panama in January 1913. Both ships continued their previous service of visiting east coast ports before unrest in Mexico and the Caribbean caused the American government to order them away. South Carolina landed marines on Haiti on 28 January to protect the American delegation there. They returned to the ship when Oreste Zamor took power, but continued unrest later led the United States to occupy Haiti. South Carolina then joined Michigan at Vera Cruz while the United States occupied that city.

On the beginning of the First World War in Europe, both of the South Carolina class battleships were grouped with two older pre-dreadnoughts (USS Vermont (BB-20) and USS Connecticut (BB-18)) due to their top speeds, which were lower than the later Standard-type battleships. South Carolina was refitted in Philadelphia between 14 October and 20 February 1915, and both ships were kept on neutrality patrols off the eastern seaboard. After the United States' entry into the war on 6 April 1917, the ships were largely kept on the American side of the Atlantic. In January 1918, Michigan was training with the main fleet when they traveled through a strong storm. The high winds and waves caused its forward cage mast to collapse, killing six and injuring thirteen.

On 6 September 1918, South Carolina escorted a fast convoy partway across the Atlantic, becoming the first American battleship (alongside USS New Hampshire (BB-25) and USS Kansas (BB-21)) to do so. When returning to the United States, South Carolina lost its starboard propeller. When continuing with the port propeller, a valve in its engine malfunctioned; continuing with an auxiliary valve caused a large amount of vibration, so the ship was stopped just hours later for temporary repairs on the main valve before continuing to the Philadelphia Naval Yard for repairs. Michigan had the same problem when escorting a convoy in the next month; the ship lost its port propeller on 8 October, but managed to return home on 11 October without further incident.

With the war's end on 11 November 1918, the South Carolina class battleships were used to repatriate American soldiers that had been fighting in the war. The idea for using battleships in a similar role—that of transporting troops to the war zone—was actually proposed by South Carolina's executive officer in early 1918, but was not taken up:

In the years after the war, the two battleships were used for training cruises. When the Washington Naval Treaty was signed in February 1922, the class was slated for disposal under its provisions. South Carolina was sold for scrapping on 24 April 1924, and both it and Michigan were broken up in the Philadelphia Navy Yard.