Braunschweig-class battleship

Line-drawing of the Braunschweig class, showing arrangement of the ships' armament and armor scheme

The Braunschweig-class ships were 126 meters (413 ft 5 in) long at the waterline, and 127.7 m (419 ft) overall. The ships had a beam of 22.2 m (72 ft 10 in), and a draft of 8.1–8.16 m (26 ft 7 in–26 ft 9 in).[7] The beam was constrained by logistical considerations, as it was the widest that could be accommodated by the locks at the entrance to the Kaiserliche Werft (Imperial Shipyard) in Wilhelmshaven.[8] The ships had thirteen watertight compartments and a double bottom that extended for 60 percent of the length of the hull. The ships displaced 13,208 t (12,999 long tons) at their designed weight, and 14,394 t (14,167 long tons) at a full load.[7] The ships were fitted with a pair of heavy military masts that carried searchlights.[9]

Steering was controlled with a single rudder. The ships were described as good sea-boats, but were prone to heavy pitching. The ships were responsive and had a tight turning radius at low speed, but at hard rudder of 12 degrees, the ships lost up to 70 percent speed. The ships had a crew of 35 officers and 708 men normally, and when serving as a squadron flagship, they had an additional 13 officers and 66 men. The ships carried a number of smaller boats aboard, including two picket boats, two launches, a pinnace (later removed), two cutters, two yawls, and two dinghies.[10] The boats were handled by two large goose-necked cranes located on either side of the rear funnel.[9]

The ships of the Braunschweig-class were propelled by three-shaft triple-expansion steam engines that were rated at 16,000 metric horsepower (15,781 ihp; 11,768 kW). The triple expansion engines were powered by eight Marine-type boilers and six cylindrical boilers, all of which burned coal; these were trunked into three funnels amidships.[7] Three funnels were adopted because in earlier vessels, the two-funnel arrangement tended to obstruct views from the bridge, and by splitting the smoke into three funnels instead of two, the funnels could be thinner and thus less obtrusive.[8] At some point after 1915, oil-firing capability was added to supplement the coal-fired boilers.[lower-alpha 1] The two outer propellers were three-bladed, and 4.8 m (15 ft 9 in) in diameter, while the center screw was four-bladed and 4.5 m (14 ft 9 in) in diameter.[7]

The ships' top speed was rated at 18 knots (33 km/h; 21 mph). During trials, however, the engines produced between 16,478 and 16,980 metric horsepower (16,253 and 16,748 ihp; 12,120 and 12,489 kW), and a top speed between 18.2 and 18.7 knots (33.7 and 34.6 km/h; 20.9 and 21.5 mph). The ships of the class could steam 5,200 nautical miles (9,600 km; 6,000 mi) at a cruising speed of 10 knots (19 km/h; 12 mph), with the exception of Hessen. Hessen suffered from unstable steering, which increased fuel consumption and shortened her operational range to 4,530 nmi (8,390 km) at 10 knots (19 km/h; 12 mph). The first two ships—Braunschweig and Elsass—had four generators that produced 230 kW (74 V), while three following ships—Hessen, Preussen, and Lothringen—had four turbo-generators that provided 260 kW (110 V).[7]

Profile drawing of the 28 cm SK L/40 gun in the naval mounting

Their main armament was increased from previous designs, but was still weaker than contemporary foreign battleships; the German Navy had a tendency to emphasize rapidity of fire rather than weight of shell, and smaller guns could generally be fired faster than larger ones.[1] The main armament comprised four 28 cm SK L/40[lower-alpha 2] quick-firing guns in hydraulically-operated twin turrets. The turrets were placed on the centerline, one forward and one aft. The DrL C/01 turrets allowed the guns to depress to −4 degrees, and elevate to +30 degrees, which enabled a maximum range of 18,800 meters (61,700 ft). The guns fired 240-kilogram (530 lb) shells at a muzzle velocity of 820 meters per second (2,700 ft/s).[13][14] The ships carried a total of 340 shells, 85 per gun.[10]

The secondary battery consisted of fourteen 17 cm SK L/40 quick-firing guns, four of which were mounted in single turrets amidships, with the remaining ten in casemates around the superstructure. The guns fired 64-kilogram (141 lb) shells at a muzzle velocity of 850 meters per second (2,800 ft/s). These guns were chosen as they used the largest shell that could be reasonably handled without machinery. The turret-mounted guns could be elevated to 30 degrees, for a maximum range of 16,900 m (18,500 yd), while the casemated guns could only elevate to 22 degrees, and had a correspondingly lower range of 14,500 m (15,900 yd).[13][15] These guns had a total of 1,820 shells, for 130 rounds per gun. To transit the Kiel Canal, the three central 17 cm casemated guns on each side had to be withdrawn into their housings, as they were unable to train fully flush with the sides of the ships. With the guns fully emplaced, the ships would have been too wide to fit in the canal.[10]

The ships also had fourteen 8.8 cm SK L/35 quick-firing guns in casemates along the length of the ship. The guns fired 7 kg (15.4 lb) shells at a muzzle velocity of 770 m/s (2,526 ft/s), and could be elevated to 25 degrees for a maximum range of 9,090 m (9,940 yd).[13] They were also armed with six 45 cm (17.7 in) torpedo tubes, with a total of 16 torpedoes.[10] One tube was in the bow, two were on each broadside, and the final tube was in the stern.[16]

The ships were protected with Krupp armor. The main armored belt was 250 mm (9.8 in) thick in the central portion of the ship where it protected the ammunition magazines and propulsion machinery spaces. The deck armor was 40 mm (1.6 in) thick on the horizontal; its edges sloped down to connect to the lower edge of the belt to protect from shells that passed over the belt. The thickness of the slopes ranged from 140 mm (5.5 in) fore and aft and 75 mm (2.95 in) amidships, where the upper belt armor afforded another layer of protection. Above the main belt, the upper belt of 140 mm steel extended between the fore and aft main-gun turrets. Another strake of armor that was 140 mm thick protected the casemate guns at the main deck level. The casemate guns themselves received 70 mm (2.8 in) gun shields. The main battery turrets had 250 mm sides and 50 mm (1.97 in) thick roofs, while the secondary turrets had 150 mm (5.9 in) thick sides. The sides of the forward conning tower were 300 mm (11.8 in) thick and the roof was 50 mm thick, while the aft conning tower received significantly less protection, with 150 mm thick sides and a 30 mm (1.2 in) roof.[7]

One of the Braunschweig-class battleships

At the start of World War I, Braunschweig and Essen were reactivated and assigned to IV Battle Squadron under the command of Vice Admiral Ehrhard Schmidt, tasked with coastal defense duties.[28] The squadron conducted several sorties into the Baltic Sea to patrol for Russian warships but it saw no action. The ships were also used to guard the mouth of the Elbe in the North Sea in the first year of the war.[29] Braunschweig and Elsass participated in the early portion of the Battle of the Gulf of Riga in August 1915, where they kept the Russian pre-dreadnought Slava at bay while a Russian minefield in the Irben Strait was cleared, but the Russian forces put up a strong defense. Schmidt decided to withdraw his forces when it became apparent that the mine-clearing had taken too long, and there was not sufficient daylight left for the minelayer Deutschland to lay a minefield of its own in Moon Sound to block the northern entrance to the gulf.[30] Following the cancellation of the operation, the squadron saw little activity before being disbanded in December.[31]

In the meantime, the other three ships were still serving in II Battle Squadron, where they participated in the fleet sorties conducted in the first two years of the war. This series of operations culminated in the Battle of Jutland on 31 May–1 June 1916; by that time, only Hessen was still on active service with the squadron. Preussen was on rotation as the guard ship in the Danish straits (and had been replaced as flagship by the battleship Deutschland) and Lothringen was in poor condition and in dire need of repair.[22][26][27] Hessen saw limited action at Jutland, coming into contact with heavy British ships once. This encounter came late on 31 May, when Hessen and the other pre-dreadnoughts of II Battle Squadron briefly engaged Vice Admiral David Beatty's 1st Battlecruiser Squadron, in doing so covering the withdrawal of the battered German battlecruisers under the command of Franz von Hipper.[32] The loss of the pre-dreadnought Pommern during the battle highlighted the vulnerability of the older battleships, and coupled with their slow speed, convinced the German naval command to withdraw them from front-line service. Preussen, Lothringen, and Hessen continued as guard ships in the Baltic in the aftermath of Jutland.[22][26][27]

Starting in 1916, the ships of the Braunschweig class began to be withdrawn from active service, primarily because of manpower shortages.[33] Elsass was reduced to a barracks ship based in Kiel in July, and Hessen was decommissioned and disarmed in December; she thereafter became a depot ship based in Brunsbüttel in 1917. Braunschweig was converted into a training ship, and on 20 August, was reduced to a barracks ship, also in Kiel. Preussen became a depot ship in Wilhelmshaven also in 1917. Lothringen continued her guard ship duties until September 1917, when she too was withdrawn from service, thereafter being used as an engineer training ship in Wilhelmshaven.[10][22] Starting in 1916, guns removed from these ships were used by the Imperial Army as railway guns; one of these guns was captured by the Australian Army and is preserved as the Amiens Gun at the Australian War Memorial in Canberra, Australia.[34][35]

Hessen as a target ship in 1946

After the war, all of Germany's powerful dreadnoughts had either been scuttled in Scapa Flow or ceded to the Allies as war prizes, so the Braunschweig-class battleships were recommissioned into the newly reorganized Reichsmarine. The Treaty of Versailles specifically stated in Article 181 that the Reichsmarine would be permitted to retain eight battleships of the "Lothringen or Deutschland types", six of which could be kept in commission.[33] Three of the ships—Braunschweig, Elsass, and Hessen—saw active duty with the fleet while the other two vessels—Preussen and Lothringen—were instead converted into parent ships for minesweepers, since Germany was required by the Treaty of Versailles to clear the extensive minefields that had been laid in the North Sea during the war. Those two ships were disarmed and modified to carry the minesweepers, but Preussen proved to be top-heavy and saw little actual use. Lothringen remained in service until 1920, by which time the minesweeping work had been completed, and she was laid up in reserve.[10][22][27]

Braunschweig was modernized in 1919–1920 and served in the Reichsmarine from 1921 to 1926, at which point she was withdrawn from active duty. During this period, she served as the flagship of the Marinestation der Nordsee (Naval Station of the North Sea) and later the Linienschiffsdivision (Battleship Division). Elsass was also rebuilt in the early 1920s and thereafter saw active duty in the fleet from 1924 until 25 February 1930, at which point she was removed from active service. Hessen returned to service in 1925. Throughout the 1920s and early 1930s, the fleet conducted a similar training routine to that of the pre-war period, including cruises into the Atlantic in the 1920s. On 31 May 1931, Braunschweig, Elsass, and Lothringen were stricken from the naval register. The first two vessels were converted into hulks at Wilhelmshaven and eventually scrapped, while Lothringen was simply broken up immediately. Hessen remained in service until late 1934, by which time the new Deutschland class of panzerschiffe (armored ships) had begun to enter service.[36][37][38][39]

Hessen was thereafter converted into a target ship. The work involved cutting away most of the superstructure, removing the armament, and replacing the old propulsion machinery with steam turbines. Additionally, equipment to allow the ship to be operated via radio control was installed. Conversion work lasted from 31 March 1935 to 1 April 1937, when she was recommissioned as a target. She served in this capacity through 1945; during World War II, she was also occasionally used as an icebreaker to clear paths in the Baltic. After the war, she was ceded to the Soviet Union and renamed Tsel. The Soviets also used the ship as a target and eventually scrapped the vessel in the 1960s.[10][40] When Preussen was being dismantled in the 1930s, a 63 m (207 ft) length of her hull was retained for use as a target. The hulk was nicknamed "SMS Vierkant ("SMS Rectangle") and remained in use through World War II until Allied bombers attacked and sank it in April 1945.[27]