The class was a class of four dreadnought battleships built for the German (Imperial Navy). The class comprised , , , and . Construction started on the ships shortly before World War I; was laid down in 1913, and followed in 1914, and , the final ship, was laid down in 1915. Only and were completed, due to shipbuilding priorities changing as the war dragged on. It was determined that U-boats were more valuable to the war effort, and so work on new battleships was slowed and ultimately stopped altogether. As a result, and were the last German battleships completed by the .
and were commissioned into the fleet in July 1916 and March 1917, respectively. This was too late for either ship to take part in the Battle of Jutland on 31 May and 1 June 1916. was assigned to the naval force that drove the Imperial Russian Navy from the Gulf of Riga during Operation Albion in October 1917, though the ship was severely damaged by a mine and had to be withdrawn to Kiel for repairs. replaced as the flagship of the High Seas Fleet, but saw no combat.
Both and were interned at Scapa Flow following the Armistice in November 1918. Rear Admiral Ludwig von Reuter, the commander of the interned German fleet, ordered his ships be sunk on 21 June 1919; was successfully scuttled, though British guards managed to beach to prevent her from sinking. The ship was expended as a gunnery target in 1921. and , both at various stages of completion when the war ended, were broken up for scrap metal. was raised in 1934 and broken up the following year.
Design
Design work on the class began as early as 1910, with great consideration given to the armament of the new vessels. It had become clear that other navies were moving to guns larger than , and so the next German battleship would also have to incorporate larger guns. The Weapons Department suggested a gun, but during a meeting on 11 May 1910, Admiral Alfred von Tirpitz, the State Secretary of the (Imperial Naval Office), decided that budgetary constraints precluded the adoption of larger weapons. The following year, in the aftermath of the Agadir Crisis, Tirpitz quickly seized on public outcry over the British involvement in the crisis to pressure the (Imperial Diet) into appropriating additional funds for the Navy. This provided the opening for more powerful battleships, so Tirpitz requested funds for ships armed with guns in mid-1911.
In August that year, the design staff prepared studies for ships armed with , , and guns; the 40 cm caliber was set as the maximum, since it was (incorrectly) assumed that British wire-wound guns larger than that could not be built. During a meeting the following month, the preferred designs were a ship armed with ten 35 cm guns in five turrets or eight 40 cm guns in four turrets. The Weapons Department advocated the 35 cm gun ship, pointing out that it would have a 25% greater chance of hitting its target. Tirpitz inquired about a mixed battery of twin and triple turrets, but after examining the gun turrets of the Austro-Hungarian dreadnoughts of the , it was determined that the triple gun turrets still had too many problems. Among these deficiencies were increased weight, reduced ammunition supply and rate of fire, and loss of fighting capability if one of the turrets was disabled.
Design studies suggested that the 35 cm ship would displace around and cost around 59.7 million marks, while the 40 cm proposal would cost approximately 60 million marks and displace , but both of these ships were deemed to be too expensive. The Construction Department proposed a ship armed with eight 38 cm guns, which reduced the cost to 57.5 million marks per vessel. This design was adopted as the basis for the next class of battleship on 26 September, and the decision to adopt the 38 cm gun was formally taken on 6 January 1912. Work continued on the design into 1912, and included further developing the armor layout that had been adopted in the previous . The ships were originally projected to be armed with eight anti-aircraft guns, though they were not completed with any. Since the development of diesel engines was proving to be problematic, the design staff adopted traditional steam turbines for the ships, though it was hoped that by the time the third member of the class was ready to begin construction, reliable diesel engines would be available.
Funding for the vessels was allocated under the fourth Naval Law, which was passed in 1912. The Fourth Naval Law secured funding for three new dreadnoughts, two light cruisers, and an increase of an additional 15,000 officers and men in the ranks of the Navy for 1912. The capital ships laid down in 1912 were the s; funding for and was allocated the following year. Funding for was allocated in the 1914 budget, while was funded in the War Estimates. The last remaining pre-dreadnought, , was to be replaced, as well as two elderly pre-dreadnoughts, and . was ordered as , as , and as ; was regarded as an addition to the fleet, and was ordered under the provisional name "T".
General characteristics
and were long at the waterline, and an even long overall. and were slightly longer: at the waterline and overall. All four ships had a beam of , and had a draft of between . and were designed to displace at a normal displacement; at full combat load, the ships displaced up to . and were slightly heavier, at 28,800 t normal and 32,500 t fully laden. The ships were constructed with transverse and longitudinal steel frames, over which the outer hull plates were riveted. The hull was divided into 17 watertight compartments, and included a double bottom that ran for 88 percent of the length of the hull.
and were regarded as exceptional sea boats by the German navy. and her sisters were stable and very maneuverable. The ships suffered slight speed loss in heavy seas; with the rudders hard over, the ships lost up to 62% speed and heeled over 7 degrees. With a metacentric height of , larger than that of their British equivalents, the vessels were stable gun platforms for the confined waters of the North Sea. The ships of the class had a standard crew of 42 officers and 1,129 enlisted men; when serving as a squadron flagship, an additional 14 officers and 86 men were required. The vessels carried several smaller craft, including one picket boat, three admiral's barges, two launches, two yawls, and two dinghies.
Machinery
and were equipped with eleven coal-fired Schulz-Thornycroft boilers and three oil-fired Schulz-Thornycroft boilers in nine boiler rooms. Three sets of Parsons turbines drove three-bladed screws that were in diameter. s and s power plant was designed to run at at 265 revolutions per minute; on trials the ships achieved and , respectively. Both ships were capable of a maximum speed of . The first two ships were designed to carry of coal and of oil, though the use of additional spaces in the hull increased the total bunkerage to of coal and of oil. This enabled a range of at a speed of . At , the range decreased to , at the range fell to , and at the ships could steam for only . The ships carried eight diesel generators; these supplied each ship with a total of 2,400 kilowatts of electrical power at 220 volts.
and were intended to be one knot faster than the earlier pair of ships. received more powerful machinery that would have produced for a designed speed of 22 knots. On , a MAN diesel engine producing was to be installed on the center shaft, while steam turbines powered the outboard shafts, but the diesel engine was not ready by the end of the war, and it was only completed in 1919 for testing by the Naval Inter-Allied Control Commission. The combined power plant would have produced for a designed speed of 22.5 knots.
Armament
The -class battleships were armed with a main battery of eight 38 cm (15 in) SK L/45 guns in four C/1913 twin gun turrets. These turrets allowed for depression of the guns to −8 degrees and elevation to 16 degrees. The guns had to be returned to 2.5 degrees to reload them. After the Battle of Dogger Bank in January 1915, where British ships had been able to open fire first, outside the range of the German guns, the gun mountings for modified to allow elevation up to 20 degrees, though the changes reduced depression to −5 degrees. As originally configured, the guns had a maximum range of , but s modified guns could reach . Each turret was fitted with a stereo rangefinder. The main battery was supplied with a total of 720 shells or 90 rounds per gun; these were shells that were light for guns of their caliber. The shell allotment was divided between armor piercing and high explosive versions, with 60 of the former and 30 of the latter. At a range of , the armor-piercing shells could penetrate up to of steel plate. The guns had a rate of fire of around one shell every 38 seconds. Muzzle velocity was .
Post-war tests conducted by the British Royal Navy showed that the guns on could be ready to fire again 23 seconds after firing; this was significantly faster than their British contemporaries, the , which took 36 seconds between salvos. While the German guns were faster to reload, the British inspectors found German anti-flash precautions to be significantly inferior to those that had been adopted by the Royal Navy after 1917, though this was to some degree mitigated by the brass propellant cases, which were far less susceptible to flash detonations than the silk-bagged British cordite. The guns that had been constructed for the battleships and were used as long-range, heavy siege guns on the Western Front, as coastal guns in occupied France and Belgium, and a few as railway guns; these guns were referred to as "Langer Max"".
The ships were also armed with a secondary battery of sixteen SK L/45 quick-firing guns, each mounted in armored casemates in the side of the top deck. These guns were intended for defense against torpedo boats, and were supplied with a total of 2,240 shells. The guns could engage targets out to , and after improvements in 1915, their range was extended to . The guns had a sustained rate of fire of 5 to 7 rounds per minute. The shells were 45.3 kg (99.8 lb), and were loaded with a 13.7 kg (31.2 lb) RPC/12 propellant charge in a brass cartridge. The guns fired at a muzzle velocity of 835 meters per second (2,740 ft/s). The guns were expected to fire around 1,400 shells before they needed to be replaced. and were also equipped with a pair of SK L/45 flak guns, which were supplied with 800 rounds. The guns were emplaced in C/13 pivot mountings, which allowed depression to −10 degrees and elevation to 70 degrees. These guns fired 9 kg (19.8 lb) shells, and had an effective ceiling of at 70 degrees.
As was customary on capital ships of the period, the -class ships were armed with five 60 cm (24 in) submerged torpedo tubes. One tube was mounted in the bow and two on each broadside. A total of 20 torpedoes were carried per ship. When both and struck mines in 1917, the damage incurred revealed structural weaknesses caused by the torpedo tubes and both ships had their lateral tubes removed. The torpedoes were the H8 type, which were long and carried a 210 kg (463 lb) Hexanite warhead. The torpedoes had a range of when set at a speed of ; at a reduced speed of , the range increased significantly to .
Armor