SMS Tegetthoff (1878)

Tegetthoff was a central battery ship designed by Chief Engineer Josef von Romako.^[1] The ship's namesake, Admiral Wilhelm von Tegetthoff, victor of the Battle of Lissa, had proposed building four new ironclads. These were to be completed by 1878, but poor economic conditions in the early 1870s forced the Austro-Hungarian government to cut back the naval budget. Admiral Friedrich von Pöck, who succeeded Tegetthoff as the head of naval administration, had attempted to secure funding for two new ships, to be named Tegetthoff and Erzherzog Karl from 1871. Pöck finally succeeded in convincing parliament to allocate funds for the first ship in 1875. He continued to try to convince the parliament to build a sister ship for Tegetthoff until 1880, without success. Austro-Hungarian industry was incapable of supporting the construction of the ship, and significant components had to be ordered from foreign manufacturers, including guns from Germany and armor plating from Britain.^[2]

Romako made numerous improvements over earlier central battery ships like Erzherzog Karl and Custoza, including refining the hull shape to reduce the need for curved armor plate. The arrangement of the main battery was altered considerably; whereas the earlier ships had carried guns on two decks, Tegetthoff carried hers on a single deck, and the gun ports were arranged in such a way that the guns could be trained side to side without having to move them to another port. The naval historian R. F. Scheltema de Heere considers Tegetthoff to be "the only sensible casemate ship ever built", which "must be considered a stroke of genius."^[3]

Tegetthoff was 89.39 meters (293.3 ft) long at the waterline and 92.46 m (303.3 ft) long overall, and she had a beam of 21.78 m (71.5 ft). The ship displaced 6,492 long tons (6,596 t) empty, 7,431 long tons (7,550 t) normally, and up to 7,820 long tons (7,950 t) at full load. During stability tests, it was determined that the ship's maximum displacement was 7,939.47 long tons (8,066.87 t). When empty, the ship had a draft of 7.16 m (23.5 ft), at normal loading it increased to 7.573 m (24.85 ft), and at full load, the ship had a draft of 7.88 m (25.9 ft).^[1][4]

As was standard for capital ships of the period, Tegetthoff was fitted with a pronounced ram bow. She had short forecastle and sterncastle decks.^[5] Tegetthoff was the first ship in the Austrian Navy to be built with an all-steel hull, which allowed for a considerable savings in weight.^[6] Steering was controlled with a single rudder, from an unprotected position atop the conning tower or from a battle conning position below decks, behind the ship's heavy side armor. Tegetthoff had a transverse metacentric height of 1.615 m (5 ft 3.6 in).^[7] The ship's crew numbered 525 officers and men.^[1]

As built, the ship was powered by a single 2-cylinder, vertical compound steam engine that drove a single two-bladed screw propeller that was 7.16 m (23.5 ft) in diameter. Steam was provided by nine fire-tube boilers with three fireboxes apiece that were vented through a pair of funnels on the centerline amidships. She was initially fitted with a three-masted sailing rig, though this was removed during the modernization, and two heavy fighting masts were installed in its place.^[1][5]

The propulsion system was rated to produce 1,200 nominal horsepower, but during her initial trials at around normal displacement in 1881, the engines reached 5,231 indicated horsepower (3,901 kW), which gave Tegetthoff a top speed of 14 knots (26 km/h; 16 mph). Two years later, another round of trials were carried out with the ship overloaded to 7,918 long tons (8,045 t), and she nevertheless managed 6,706 ihp (5,001 kW) for 13.97 knots (25.87 km/h; 16.08 mph).^[1][8]

Tegetthoff was initially equipped with a main battery of six 28-centimeter (11 in) L/18 breech-loading guns manufactured by Krupp.^[a] These guns were mounted in a central battery amidships, and were intended to be used during pursuit and ramming attempts. Each gun had a range of elevation from -5° to +8.25°, and the forward guns could fire directly ahead. The aft guns could be fired directly astern, while the center pair had more limited firing arcs. The ammunition magazine was located directly below the main battery. The ship also carried six 9 cm (3.5 in) L/24 breech-loaders, two 7 cm (2.8 in) L/15 breech-loaders, and four 47 mm (1.9 in) quick-firing (QF) guns. All of these guns were carried in individual pivot mounts on the upper deck, and in the case of the 47 mm guns, in fighting tops on the masts.^[1][9]

The main armored belt consisted of 356 mm (14 in) thick armor plate in the central section, and the end bulkheads of the armored citadel were 254 to 305 mm (10 to 12 in) thick. On either end of the citadel, the belt tapered slightly to 330 mm (13 in). The armor plate for the main battery casemate ranged in thickness from 127 to 330 mm (5 to 13 in). The conning tower had sides that were 127 to 178 mm (5 to 7 in) thick. Tegetthoff's armor plate amounted to 2,122.5 long tons (2,156.6 t), more than a quarter of the ship's total displacement.^[1][4]

In the mid-1890s, Tegetthoff was extensively modernized. Her boilers were replaced with eight new Scotch marine boilers.^[10] After her reconstruction in the early 1890s, her propulsion system was replaced with a pair of 3-cylinder triple expansion engines built by the German firm Schichau-Werke. These were rated at 8,160 ihp (6,080 kW), for a top speed of 15.32 kn (28.37 km/h; 17.63 mph) on trials. Her crew was increased to between 568 and 575. Also during the modernization, the main battery was replaced with 24 cm (9.4 in) L/35 C/86 guns from Krupp.^[b] The secondary guns now consisted of five 15 cm (5.9 in) L/35 QF guns, two 66 mm (2.6 in) L/18 guns, nine 47 mm L/44 QF guns, six 47 mm L/33 machine guns, and a pair of 8 mm (0.31 in) machine guns. Tegetthoff was also equipped with two 35 cm (13.8 in) torpedo tubes, one in the bow and one in the stern.^[1]