The class was a group of five pre-dreadnought battleships built for the German (Imperial Navy), the last vessels of that type to be built in Germany. The class comprised , the lead ship, , , , and . The ships closely resembled those of the preceding , but with stronger armor and a rearranged secondary battery. Built between 1903 and 1908, they were completed after the launch of the revolutionary British all-big-gun battleship in 1906. As a result, they were obsolescent before entering service. The ships nevertheless saw extensive service in the High Seas Fleet, Germany's primary naval formation, through the late 1900s and early 1910s, when they were used for training, which included overseas cruises.
Following the start of World War I in July 1914, the German fleet adopted a strategy of raids on the British coast, which the five -class ships supported. These operations culminated in the Battle of Jutland on 31 May – 1 June 1916, where all five ships saw action, despite their marked inferiority to British dreadnoughts. Regardless, they intervened to protect the battered German battlecruisers from their British counterparts, allowing them to escape. In the confused night actions, was torpedoed and sunk by a British destroyer. After the battle, the four surviving ships were removed from front-line service and used for coastal defense through mid-1917. Thereafter, alone remained on patrol duty, while the rest were used as barracks or training ships. After Germany's defeat, the Treaty of Versailles permitted the postwar navy to retain several old battleships for coastal defense, including the four -class ships.
was broken up in 1920–1922, but the remainder were modernized and returned to active service in the mid-1920s. Their activities mirrored those of the pre-war period, including overseas training cruises and extensive fleet maneuvers. was decommissioned in 1931 and was to be converted into a target vessel, although this was never done. She was eventually broken up in 1944–1946. and remained in service for training duties through the 1930s into the Nazi-era (War Navy). Both ships saw limited duty during World War II, including bombardment of Polish forces during the invasion of Poland in September 1939 and the occupation of Denmark and invasion of Norway in April 1940. Both ships were sunk near the end of the war.
Design
In 1900, (Vice Admiral) Alfred von Tirpitz, the State Secretary for the (Imperial Naval Office), secured the passage of the Second Naval Law, an amendment to the First Naval Law of 1898. The previous law had called for a total strength of nineteen battleships by 1 April 1904, which was reached with the five s, but the new law increased the projected battle fleet to a total of thirty-eight. The first tranche of vessels—the —introduced the gun, marking a significant increase in firepower over earlier German battleships. The naval command had intended to build ten battleships of the type, starting with the 1901 fiscal year with two ships built per year, but they ultimately only built five. During construction of the s, a series of minor improvements were incorporated into subsequent designs. By the time work began on the second vessel of the 1903 fiscal year, which became , a more significantly altered design had been prepared.
A series of changes were made to the secondary and tertiary batteries for what became , the lead ship of the new class. The designers discarded the wing turrets that the s had used for some of their secondary guns; the turrets had required support structures whose elimination saved weight and allowed the designers to place the secondary battery entirely in casemates in a more efficient arrangement. Removing the turrets freed up deck space that was used to add another pair of guns and place the forward set of four in protective embrasures. and her sister ship were designed for use as flagships for the fleet and a squadron, respectively, which required additional accommodation spaces. After , which mixed sets of fire-tube and water-tube boilers, the remaining four members of the class received a uniform set of water-tube boilers. These were lighter, and the weight savings were passed on to the armor layout in the form of a slightly thicker armor belt and a strengthened upper deck.
The design was criticized in Germany at the time the ships were being built, as the trend in all the major navies pointed to battleships armed with all-big-gun batteries; indeed, work on what would become the design for the of dreadnought battleships had already begun in 1903. Tirpitz insisted on building the s because they were the largest design that could fit in Germany's existing naval infrastructure, most significantly the Kaiser Wilhelm Canal. Widening the canal and improving harbor facilities would be excessively expensive and Tirpitz sought to avoid another budgetary fight with the so soon after the passage of the 1900 law. As a result, the -class battleships were rendered obsolescent almost immediately by the commissioning of the British in December 1906.
General characteristics
The -class ships were long at the waterline and overall. They had a beam of and a draft of forward. The ships were designed to displace normally, and displaced up to at full load. Their hulls were built with transverse and longitudinal steel frames, to which steel hull plates were riveted. The hull was divided into twelve watertight compartments, although had thirteen compartments. Their hulls included a double bottom that ran for 84 percent of the length of the ship.
Because and were completed as flagships, they had an enlarged superstructure aft to house the larger command staffs they typically carried. had a larger forward conning tower that incorporated a central fire-control position; received the same conning tower, but the other three ships had shorter towers without the fire-control room. All five members of the class were fitted with short military masts with lighter poles atop them that were fitted with spotting tops. The ships handled less easily than the preceding -class ships, though they suffered less marked weather helm. Their metacentric height was . Steering was controlled with a single rudder.
The ships' crews numbered 35 officers and 708 enlisted men. When one of them was a flagship, the crew was augmented with an admiral's staff. A squadron commander's staff consisted of 13 officers and 66 enlisted men, while a divisional commander had a staff of 2 officers and 23 enlisted men. After she became a training ship in 1935, s crew consisted of 29 officers and 559 enlisted men, plus up to 214 cadets. differed somewhat; her crew as a training ship numbered 31 officers and 565 men and up to 175 cadets. and her sisters carried several smaller vessels, including two picket boats, one admiral's barge, two launches, one pinnace, two cutters, two yawls, and two dinghies. The boats were handled with a pair of large cranes amidships; had hers located further forward than the other members of the class.
Machinery and her sisters were equipped with three triple-expansion steam engines that each drove a screw propeller; the outer screws were three-bladed and in diameter, while the center shaft used a four-bladed screw that was in diameter. Each engine was placed in its own engine room. was fitted with eight water-tube boilers and six fire-tube boilers, but the rest of the vessels received twelve water-tube models, all of which were coal-fired. These were divided into three boiler rooms, each of which was ducted into a funnel.
s engines were rated at , while the other four ships' engines were rated at . The design speed for all of the ships was , though on trials all five ships exceeded both figures, reaching for and the other members of the class making for . was the fastest member of the class on her trials.
was designed to carry of coal and the other members could carry , though other spaces could be utilized as fuel storage, which increased fuel capacity to for and for the other four vessels. This provided a maximum range of at a cruising speed of . Electrical power was supplied from four turbo generators that provided each at 110 volts.
Armament
The ships carried the same main battery as the preceding class. The primary armament comprised four 28 cm SK L/40 quick-firing guns in hydraulically operated twin turrets. The turrets were placed on the centerline, one forward and one aft. The C/01 turrets allowed the guns to depress to −4 degrees, and elevate to +30 degrees, which enabled a maximum range of . The guns fired shells at a muzzle velocity of . Ammunition storage amounted to 85 shells per gun.
The secondary battery consisted of fourteen 17 cm SK L/40 quick-firing guns, all of which were mounted in casemates. Five were placed on either side in the upper deck and the remaining four were located a deck above in the superstructure, one on each corner. The guns fired shells at a muzzle velocity of . These guns were chosen as they used the largest shell that could be reasonably handled without machinery. The guns could elevate to 22 degrees, which allowed a maximum range of . Their rate of fire was approximately one shot every nine to ten seconds, and each gun was supplied with 130 shells.
For defense against torpedo boats, the ships carried a tertiary battery of twenty 8.8 cm SK L/35 quick-firing guns. These were placed in casemates in hull sponsons, in embrasures in the superstructure, or in open mounts. The guns fired shells at a muzzle velocity of , and could be elevated to 25 degrees for a maximum range of . The ammunition allotment for each gun was 130 shells. The ships were temporarily fitted with four machine cannon, but these were quickly removed.
They were also armed with six torpedo tubes, and 16 torpedoes. The tubes were all placed below the waterline, one in the bow, one in the stern, and two on each broadside. These torpedoes were long and carried a TNT warhead. They could be set at two speeds for different ranges. At , the weapons had a range of . At an increased speed of , the range was reduced to .
Armor The -class ships were equipped with Krupp cemented armor. had a slightly different arrangement in the belt armor and the citadel in the superstructure. s belt was at the waterline and tapered to on the lower edge. Her sister ships' belts were increased in thickness to at the waterline and down to on the bottom edge. In all five ships, this section of armor extended from the forward barbette to the aft one. On either end, the belt was reduced to . In all ships, the belt was backed by a layer of teak that was thick. Above the belt was a strake of armor that protected the casemate guns; in , this was thick, while on the other four ships the armor was 170 mm thick. All members of the class were fitted with cork cofferdams, a common practice at the time intended to prevent uncontrolled flooding in the event of shell hits.
All five ships had an armored deck that was thick. The deck sloped downward at the sides to connect with the lower edge of the belt, which provided a second layer to contain shell fragments from hits that penetrated the belt. The sloped section was in the bow and stern sections where the belt was thinner, and reduced to behind the main section of belt. Their forward conning towers were protected by on the sides and 80 mm on the roofs, while the rear conning towers had worth of armor on the sides. The main battery gun turrets had armored sides that were thick and roofs that were thick. The barbettes that held the turrets were armored with thick steel.
Modifications