Battleships are cool an occasional series

The Tegetthoff class (sometimes called Viribus Unitis class) was the sole class of dreadnought battleship built for the Austro-Hungarian navy. Four ships were built, SMS Viribus Unitis, SMS Tegetthoff, SMS Prinz Eugen and SMS Szent Istvan.

The Austrian government ordered the construction of a new fleet in 1908 following the announcement of the start of construction of first dreadnought for the Regia Marina (the Italian navy): the RN Dante Alighieri. The chief designer of the Austro-Hungarian navy, Siegfried Popper, was nearly blind at this stage (he was retired before the ships were launched), and some have blamed this for design deficiencies of the class of ships. The ships of this class were among the first ships to utilize triple gun turrets for its main armament

The Austro-Hungarian navy saw little action during the First World War, spending much of its time in its base at Pola (now Pula, Croatia), but the mere fact of its existence tied up the Italian and French navies in the Mediterranean for the duration of the war. The navy's general inactivity was partly caused by a lack of coal, which as the war progressed became a problem, and partly by a fear of mines in the Adriatic, which also kept the Italian navy in port for most of the war.

In 1918 Admiral Miklós Horthy de Nagybánya became rear admiral of the fleet, and he determined to use the fleet to attack the Otranto Barrage. On 8 June 1918 he took the Viribus Unitis and Prinz Eugen south with a small supporting flotilla; on the evening of 9 June Szent Istvan and Tegetthoff followed. Unfortunately in trying to make maximum speed in order to catch up, Szent Istvan's turbines started to overheat and speed had to be reduced to 12 knots (22 km/h). When an attempt was made to raise more steam in order to increase to 16 knots (30 km/h) Szent Istvan produced a lot of smoke, which at 3.20 a.m. on 10 June attracted the attention of a pair of patrolling Italian torpedo boats. MAS-21 attacked Tegetthoff, but one of her torpedoes failed to leave the launch tube and the other failed to explode. MAS-15 however succeeded in striking Szent Istvan with two torpedoes at 3:31 a.m. The Tegetthof returned to the scene to take the Szent Istvan in tow. An attempt to beach the ship on nearby Molat island (northwest of Zara) was considered, but the ship was taking on too much water. At 6:12 a.m., with the pumps unequal to the task, Szent Istvan capsized, taking 89 of her crew with her. The last half-hour of the sinking was filmed in stages from the Tegetthoff (one of only two battleship sinkings on the high seas to ever be filmed, the other being that of the British battleship HMS Barham in the Second World War). Fearing further attacks by torpedo boats or destroyers from the Italian navy, his element of surprise now destroyed, Admiral Horthy called off the attack and the fleet returned to base for the rest of the war.