SMS Kronprinz Erzherzog Rudolf

SMS Kronprinz Erzherzog Rudolf was a unique ironclad warship built for the Austro-Hungarian Navy in the 1880s. The last ironclad completed for the Austro-Hungarian Navy, Kronprinz Erzherzog Rudolf was laid down in January 1884, launched in July 1887, and completed in September 1889. She was armed with a main battery of three 30.5 cm guns and had compound steel plating of the same thickness on her armored belt. The ship had an uneventful career, in large part due to her rapid obsolescence. She made trips to foreign countries to represent Austria-Hungary, but was reduced to a coastal defense ship by 1906. She continued in this role through World War I, based at Cattaro Bay, where her crew took part in the Cattaro Mutiny in early 1918. After the war, Kronprinz Erzherzog Rudolf was transferred to the Royal Yugoslav Navy and renamed Kumbor, but she remained in the Yugoslav inventory for only three years, being sold for scrap in 1922.

Design
In the decades that followed the Austrian victory at the Battle of Lissa in 1866, naval expenditure in the Austro-Hungarian Empire were drastically reduced, in large part due to the veto power the Hungarian half of the empire held. Surrounded by potentially hostile countries powers on land, the Austro-Hungarian Empire was more concerned with these threats, and so naval development was not prioritized. Admiral Friedrich von Pöck argued for several years to improve the strength of the Austro-Hungarian fleet, finally winning authorization to build the center battery ship SMS Tegetthoff (1878) in 1875. He spent another six years trying in vain to secure a sister ship to Tegetthoff. Finally, in 1881, Pöck succeeded in securing funding for a new ironclad, authorized as "Ersatz SMS Salamander", a replacement for the earlier ironclad frigate. The new ship, to be named Kronprinz Erzherzog Rudolf, cost 5.44 million gulden. The design for the new ship was prepared by Josef Kuchinka, the Director of Naval Construction for the Austro-Hungarian Navy; a second ship, SMS Kronprinzessin Erzherzogin Stephanie, was authorized at the same time. Nearly another decade would pass before the Austro-Hungarian Navy secured funding for new capital ships, the three s begun in 1893.

General characteristics and machinery
Kronprinz Erzherzog Rudolf was 90.26 m long between perpendiculars and 97.6 m long overall. She had a beam of 19.27 m and a draft of 7.39 m, and she displaced 6829 MT. Her hull was constructed with transverse and longitudinal steel frames, over which the outer steel hull plating was riveted; it was also extensively sub-divided into watertight compartments and had a double bottom. She was fitted with electrical pumps that had a capacity of 2000 MT of water per hour. Her crew varied between 447 and 450 officers and enlisted men throughout her career.

Stabilimento Tecnico Triestino manufactured Kronprinz Erzherzog Rudolf's propulsion system. The ship was powered by a pair of two-cylinder vertical triple expansion steam engines, driving two screw propellers. Steam for the engines was provided by ten coal-fired fire-tube boilers that were trunked into two funnels. Her propulsion system was rated to provide 6000 ihp for a top speed of 15.5 kn. With forced draft, the power could be increased to 7500 ihp, though the increase in speed was modest, to 16 kn. The ship was fitted with four electrical generators to power internal lighting and searchlights.

Armament and armor


Kronprinz Erzherzog Rudolf was armed with a main battery of three 30.5 cm 35-caliber guns mounted singly in open barbettes. Two were placed forward in sponsons over the battery deck to maximize end-on fire, with the third placed aft. The guns were manufactured by Krupp, while the carriages that carried them were built by Armstrong Mitchell & Co.. Each of the forward guns had an arc of 180 degrees, while the stern gun could traverse 270 degrees, all hydraulically operated. The guns fired a 450 kg shell using a 140 kg charge of brown powder, which produced a muzzle velocity of 530 m/s. While the open barbettes provided a wide field of fire for the slow-firing guns, they were rapidly rendered obsolete by the successful application of quick-firing (QF) technology to large-caliber artillery pieces.

The main battery was supported by a secondary battery of six 12 cm 35-caliber guns, also built by Krupp. These guns fired a 26 kg shell with a 15 kg propellant charge. She carried seven 47 mm QF guns for close-range defense against torpedo boats; five were 44-caliber guns and the other two were shorter 33-caliber pieces, all built by Hotchkiss. Her gun armament was rounded out by a pair of 37 mm 44-caliber QF guns and a pair of 7 cm 15-caliber landing guns for use by landing parties. As was customary for capital ships of the period, she carried four 40 cm torpedo tubes; one was mounted in the bow, another in the stern, and one on each broadside.

Kronprinz Erzherzog Rudolf was protected with compound armor manufactured by the Dillinger Hütte works in Germany. The ship's armored belt was 305 mm thick amidships, where it protected the ammunition magazines and machinery spaces, and reduced to 62 mm elsewhere. Transverse bulkheads capped the ends of the thickest portion of the belt, with the forward bulkhead 242 mm and the aft bulkhead 203 mm thick. An armored deck 95 mm thick protected the ship's vitals from shells that passed over the side armor. The barbettes for the main battery were 254 mm thick.

Service history
SMS Kronprinz Erzherzog Rudolf was laid down on 25 January 1884 at the Navy Dockyard in Pola. The ship was the first ironclad to be laid down in Austria-Hungary in nearly a decade, since the center battery ship Tegetthoff. She was launched on 6 July 1887 and then began fitting out, which was completed in September 1889. Embarrassingly for the Habsburgs, the ship's namesake had committed suicide earlier that year. In 1890, the German emperor, Kaiser Wilhelm II, invited the Austro-Hungarian fleet to take part in the annual fleet training exercises in August. Kronprinz Erzherzog Rudolf, the ironclad Kronprinzessin Erzherzogin Stephanie, and the protected cruiser SMS Kaiser Franz Joseph I were sent to Germany under the command of Rear Admiral Johann von Hinke. While en route, the squadron made visits in Gibraltar and Britain; during the latter stop, the ships took part in the Cowes Regatta, where they were reviewed by Queen Victoria. The ships also stopped in Copenhagen, Denmark and Karlskrona, Sweden. During the voyage back to Austria-Hungary, the squadron visited Cherbourg, France and Palermo, Italy. Kronprinz Erzherzog Rudolf experienced repeated difficulties with her engines on the trip, but it was nevertheless considered to be a great success in the Austro-Hungarian Navy.

Celebrations to honor the 400th anniversary of Christopher Columbus's first trans-Atlantic voyage were held in several countries; Kronprinz Erzherzog Rudolf, Kronprinzessin Erzherzogin Stephanie, and Kaiser Franz Joseph I represented Austria-Hungary during the ceremonies in Genoa, Italy, Columbus's birthplace. While there, she was inspected by King Umberto I of Italy and his son Victor Emmanuel III. Already by 1898, the ship was regarded by the Austro-Hungarian Navy as a second-rate vessel, after less than 10 years in service. The rapid pace of naval development in the late 19th century had quickly rendered her obsolescent. Kronprinz Erzherzog Rudolf was reclassified as a coastal defense ship in 1906. In 1908, the Austro-Hungarian Navy attempted to sell the ship, Kronprinzessin Erzherzogin Stephanie, and Tegetthoff to Uruguay in an attempt to raise funds for new projects, but the deal fell through.

After Austria-Hungary declared war on Serbia in July 1914, beginning World War I, the ship was stationed in Cattaro Bay under Commander Richard Florio, the leader of Mining Command II. The force also included an old destroyer, four torpedo boats, a minelayer, and two minesweepers, among other minor vessels. She remained there for the duration of the conflict. By early 1918, the long periods of inactivity had begun to wear on the crews of several warships at Cattaro, including Kronprinz Erzherzog Rudolf. On 1 February, the Cattaro Mutiny broke out, starting aboard the armored cruiser SMS Sankt Georg and quickly spreading to other ships. Officers were confined to their quarters while a committee of sailors met to formulate a list of demands, which ranged from longer periods of leave and better rations to an end to the war, based on the United States President Woodrow Wilson's Fourteen Points. The following day, shore batteries loyal to the government fired on Kronprinz Erzherzog Rudolf as she steamed to the Bay of Teodo, the outermost part of Cattaro Bay. The batteries scored a single hit that killed two men, which prompted many of the mutinous ships to abandon the effort. On the morning of 3 February, the s of the III Division arrived in Cattaro, which convinced the last holdouts to surrender. Trials on the ringleaders commenced quickly and four men were executed.

With the end of the war in November 1918 and the dissolution of the Austro-Hungarian Empire, Kronprinz Erzherzog Rudolf was transferred to the fledgling Royal Yugoslav Navy, who renamed her Kumbor. She remained in the Yugoslav inventory only briefly, being broken up for scrap in 1922.