SMS Kaiser was a 92-gun wooden ship of the line of the Austrian Navy, the last vessel of the type, and the only screw-driven example, to be built by the Austrians. She was built by the naval shipyard in Pola; she was laid down in March 1855, was launched in October 1858, and was completed the following year. The ship took part in the Second Schleswig War of 1864, but saw no action during her deployment to the North Sea. Kaiser did see action during the Seven Weeks' War two years later, during which she took part in the Battle of Lissa as the flagship of Anton von Petz, commander of the Austrian 2nd Division. Kaiser engaged several Italian ironclads simultaneously, rammed one——and damaged another——with gunfire. In doing so, she became the only wooden ship of the line to engage an ironclad warship in battle.
In 1869, the Austro-Hungarians decided to rebuild Kaiser into an ironclad casemate ship; the work lasted until 1873, and was delayed significantly by budget shortfalls, which slowed the acquisition of armor plate from British firms. By this time, however, casemate ships were being superseded by turret ships, and as a result, Kaiser spent the years 1875–1902 in reserve. She was nevertheless modernized periodically throughout the 1870s and 1880s in attempts to improve her performance. In 1901–1902, she was renamed Bellona and had her armament and engines removed so she could be used as a barracks ship in Pola, a role she filled through World War I. Italy seized the ship as a war prize after the end of the conflict, but her ultimate fate is unknown.
Design
Starting in the early 1850s, the Austrian Empire, faced with a strengthening Kingdom of Sardinia—which unified most of the Italian peninsula in a decade—began to modernize its navy with new steam-driven warships. Archduke Ferdinand Maximilian oversaw the program, which began with the screw frigate laid down in Britain in 1852. Two years later, Ferdinand decided a steam ship of the line should be built next; he originally intended the new ship would be built as a copy of the British 91-gun ship of the line , the plans for which the Royal Navy provided to Austria in exchange for the country remaining neutral during the Crimean War of 1853–1856. The excellent performance of the French ship during the war prompted the Austrians to modify the Agamemnon design to incorporate features of the French vessel, including a greater size and more powerful machinery. A second vessel of a slightly larger design, to have been named Österreich and armed with 101 guns, was cancelled in 1859 before she was laid down.
The Kaiser was designed by Swedish naval engineer Axel Ljungstedt, who was active in Austria between 1850 and 1856. Figures for the ship's original characteristics are unclear. According to the contemporary historian Wilhelm von Rüstow, Kaiser was long, with a displacement of . But the modern naval historian Andrew Lambert states her length was on . He also provides a beam of . Her crew numbered some 900 officers and men, which included a contingent of naval infantry. She was armed with a battery of ninety-two guns, consisting of sixteen 60-pounder guns, seventy-four 30-pounder smoothbores, and two 24-pounder breech loaders. The ship was powered by a two-cylinder horizontal steam engine, which drove a single screw propeller that was in diameter. Steam was provided by six coal-fired boilers with twenty-six fireboxes. The engine, which was manufactured by Maudslay, Sons and Field, was rated at 800 nominal horsepower. A three-masted ship rig supplemented the steam engine.
Service history
The keel of Kaiser was laid down on 25 March 1855 at the naval shipyard in Pola; the ship was launched on 4 October 1858, and commissioned into the Austrian Navy in 1859. She began sea trials on 6 December that year, with the first trip under her own power taking place from Muggia to Pola. In February 1864, the Austrian Empire joined Prussia in the Second Schleswig War against Denmark. Kaiser was sent with the new armored frigate and two smaller vessels under Vice Admiral Bernhard von Wüllerstorf-Urbair to reinforce a smaller force consisting of the screw frigates and Radetzky under then-Captain Wilhelm von Tegetthoff. After the two groups combined in Den Helder, the Netherlands, they proceeded to Cuxhaven on 27 June, arriving three days later. The now outnumbered Danish fleet remained in port for the rest of the war and did not seek battle with the Austro-Prussian squadron. Instead, the Austrian and Prussian naval forces supported operations to capture the islands off the western Danish coast. During the campaign, Kaiser was commanded by Friedrich von Pöck.