The class was a group of four dreadnought battleships built for the German (Imperial Navy) in the early 1900s. The class comprised , the lead ship, , , and . All four ships were laid down in mid-1907, and completed by late 1910. They were Germany's first dreadnought class, and though commonly perceived as having been built in response to the British , their design traces its origin to 1903; they were in fact a response to Dreadnoughts predecessors of the . The s adopted a main battery of twelve guns in six twin-gun turrets in an unusual hexagonal arrangement. Unlike many other dreadnoughts, the -class ships retained triple-expansion steam engines instead of more powerful steam turbines.
After entering service, the -class ships served as II Division, I Battle Squadron of the High Seas Fleet for the duration of their careers. From 1910 to 1914, the ships participated in the normal peacetime routine of the German fleet, including various squadron exercises, training cruises, and fleet maneuvers every August–September. Following the outbreak of World War I in July 1914, the ships took part in numerous fleet operations intended to isolate and destroy individual elements of the numerically superior British Grand Fleet. These frequently consisted of sailing as distant support to the battlecruisers of I Scouting Group as they raided British coastal towns. These operations culminated in the Battle of Jutland on 31 May – 1 June 1916, where the ships helped to sink the armored cruiser .
The ships also saw service in the Baltic Sea against the Russian Empire during the war; and engaged the Russian pre-dreadnought during the inconclusive Battle of the Gulf of Riga in 1915. and were sent to Finland to support White Finnish forces in the Finnish Civil War, though ran aground and was badly damaged. Following Germany's defeat, all four ships were ceded as war prizes to the victorious Allied powers and broken up in the early 1920s.
Design Initial designs
Though the class is commonly cited as a response to the revolutionary , the decision to adopt an all-big-gun main battery predated the construction of the British vessel. Design work on what would eventually become the class began in 1903, with work scheduled to begin in 1906. Kaiser Wilhelm II argued that the navy ought to build large armored cruisers as a single capital ship type. In December 1903, Wilhelm II suggested a new ship, of about displacement, to be armed with four guns and eight guns. Speed was to be . He requested the Construction Office submit proposals based on his ideas; by January 1904, three such designs had been prepared: "5A", "5B", and "6". The first two mounted eight 21 cm guns, in four single-gun turrets and four casemates for "5A" and in four twin-gun turrets in "5B". The "6" design carried ten of the guns in four casemates and the remaining six in a central battery. Though the naval command felt "5B" offered the best firing arcs, they forwarded the "6" design for further consideration. Evaluation of the design led to a conclusion that it offered no significant improvement over the preceding s.
The Kaiser intervened again in February with a request for a ship with secondary batteries of ten 21 cm or guns; the Construction Department and the (Imperial Shipyard) in Kiel submitted proposals. The first, "6B-D", was a variant on the earlier "6" design, while two others, "10A" and "10B" featured the larger guns; the submissions from Kiel have not survived and their details are not known. Wilhelm interrupted this design work by suggesting that speed should be increased significantly at the price of reducing the main battery to 24 cm guns, which resulted in further design studies that were completed by April. All of these were deemed unacceptable and further design work was carried out within the (Imperial Naval Office). The officers there observed that the secondary battery should be limited to 21 cm guns, since the increased weight of the 24 cm weapons limited the number of guns. This resulted in "Project I", armed with twelve of the guns, "Project II", armed with sixteen of the guns, and "Project III", which carried eight 24 cm guns. All three variants kept a 28 cm main battery.
During deliberations in late April, "Project I" emerged as the favored design since it would be cheaper than "II" (which would also require widening of the Kaiser Wilhelm Canal). The design was refined into two versions, "IA" and "IB", with the former using casemates and the latter using single turrets. Wilhelm approved "IA" in May, though the arrangement of the secondary guns proved to be contentious, and in December another variant, "7D", which moved eight of the guns to twin turrets and adopted an improved underwater protection system was submitted, which the Kaiser approved on 7 January 1904. These plans were disrupted immediately when the Germans learned of the characteristics of the British s, which carried a secondary battery of ten guns, and estimates of the next class of battleships, which were to carry an even more powerful armament. This meant that "7D" would be insufficient to counter the next generation of British battleships, and the design staff would have to start over.
All-big-gun proposals
Variants with six 21 cm twin-turrets were submitted, along with the first German all-big-gun battleships; these featured a battery of eight 28 cm guns, four in standard twin turrets and the rest in single-gun turrets. Wilhelm approved the all-big-gun version on 18 March 1905, after which further design refinement was carried out, which included increasing the beam, rearranging the secondary battery of eight guns, and improved turrets for the main battery guns. The Kaiser again attempted to meddle in the design process after he learned of the Italian s, which were capable of ; he pressed the navy to build a similar vessel, along the same lines as the type he had suggested in 1903. Admiral Alfred von Tirpitz pointed out that merging the battleship and armored cruiser categories would not be possible under the Naval Law of 1900, and that the Construction Office was too busy with other projects to take on another one.
During this period, Tirpitz worked to secure the passage of the next Naval Law; he had originally requested six new battleships and six armored cruisers, along with a number of miscellaneous smaller craft. As capital ship designs continued to grow in size and power, their cost spiraled upward. Opposition to budget increases in the (Imperial Diet) forced Tirpitz to reduce his request to six armored cruisers—one of which was to have been placed in reserve—and 48 torpedo boats, dropping his request for new battleships completely; the reduced proposal was voted through on 19 May 1906 as the First Amendment to the Naval Law. A week after the amendment was passed, funds for two 18,000-ton battleships and a 15,000-ton armored cruiser were allocated to the Navy. Funds were also provided to widen the Kaiser Wilhelm Canal and enlarge dock facilities to accommodate the larger ships.
The design staff continued to refine the new ship, and by September 1905, several variants had been proposed, including "F", which replaced the four single-gun turrets with an equal number of twin-gun turrets. The 17 cm guns were also replaced with twelve guns on the basis that they offered a much higher rate of fire. An improved underwater protection system was adopted as well, resulting in the design finalized as "G", which was approved on 4 October. Internal rearrangements to the magazines and boiler rooms resulted in "G2", while an attempt to move all of the gun turrets to the broadside was presented as "G3", but this proved to be unworkable. "G2" was chosen for continued refinement, becoming "G7" and then "G7b", which the Kaiser approved on 3 March 1906. The initial arrangement with three funnels was altered to just two, and a new bow was incorporated, securing approval from the Kaiser on 14 April as "G7d". Construction of the first vessel was authorized on 31 May; another member was added shortly thereafter, with another two authorized for the 1907 construction program.
Specifications
General characteristics The ships were long, wide, and had a draught of . The ships had a length to width ratio of 5.45, which was somewhat "stubby" compared to contemporary designs. To some extent, the greater than normal width was due to the four wing turrets, which necessitated a wider hull. They displaced with a standard load, and fully laden. The ships had nineteen watertight compartments, with the exception of , which only had sixteen. All four ships had a double bottom for eighty-eight percent of the keel. Steering was controlled by a pair of rudders mounted side-by-side. The ships carried a number of boats, including a picket boat, three admiral's barges, two launches, two cutters, and two dinghies. The ships' standard crews numbered 40 officers and 968 enlisted men; while serving as squadron flagships, this was augmented by 13 officers and 66 enlisted men, and as divisional flagships, with 2 officers and 23 enlisted sailors.
As designed, the ships did not handle particularly well, even in calm seas, and their motion was quite stiff. The ships experienced severe rolling due to the weight of the wing turrets. The heavy wing turrets caused the ships to have a large metacentric height, which should have made them very stable gun platforms, but their roll period proved to coincide with that of the average North Sea swell. Bilge keels were later added, which helped to reduce the rolling problem. Despite the tendency to roll, the -class ships were maneuverable and had a small turning radius. They suffered minor speed loss in heavy seas, but up to 70 percent at hard rudder. The roll keels that had been fitted to improve handling caused a portion of the speed loss at hard rudder.
Propulsion
The Imperial German Navy was slow to adopt the advanced Parsons turbine engines used in the British Dreadnought, primarily due to the resistance of both Tirpitz and the Navy's construction department. In 1905, the latter stated that the "use of turbines in heavy warships does not recommend itself." This decision was based solely on cost: at the time, Parsons held a monopoly on steam turbines and required a 1 million mark royalty fee for every turbine engine made. German firms were not ready to begin production of turbines on a large scale until 1910.
The class therefore retained three vertical, three-cylinder triple-expansion steam engines, each in its own engine room, with each driving a 3-bladed screw propeller that was in diameter. Steam for the engines was provided by twelve coal-fired, Schulz-Thornycroft water-tube boilers that were divided into three boiler rooms. The wing turrets and their magazines further divided the machinery into three separated groups, thereby increasing survivability. The boilers were ducted into a pair of funnels. The propulsion system was rated at for a top speed of , though in service, all four ships exceeded these figures by a wide margin. Power output ranged from , with top speeds of . By comparison, Dreadnoughts steam turbines provided a rated speed of . Electrical power was provided by eight turbo-generators, producing at 225 V.
The ships had a normal capacity of of coal, though at full load they could carry up to . At a cruising speed of , the ships could steam for ; increasing speed to reduced their range to , and at their radius of action fell significantly, to . While steaming at , the ships could steam for . In 1915, the boilers were fitted with supplementary oil firing, along with storage for of fuel oil; this allowed oil to be sprayed on the coal to improve combustion rates.
Armament