The Tegetthoff class (also called the Viribus Unitis class) was a class of four dreadnought battleships built for the Austro-Hungarian Navy. Named for Austrian Admiral Wilhelm von Tegetthoff, the class was composed of SMS Viribus Unitis, SMS Tegetthoff, SMS Prinz Eugen, and SMS Szent István. Construction started on the ships shortly before World War I; Viribus Unitis and Tegetthoff were both laid down in 1910, Prinz Eugen and Szent István followed in 1912. Three of the four warships were built in the Stabilimento Tecnico Triestino shipyard in Trieste; Szent István was built in the Ganz-Danubius shipyard in Fiume, so that both parts of the Dual Monarchy would participate in the construction of the ships. The Tegetthoff-class ships hold the distinction for being the first and only dreadnought battleships of the Austro-Hungarian Navy. The SMS Szent István had a different more modern propulsion system than her sister ships. Viribus Unitis and Tegetthoff were commissioned into the fleet in December 1912 and July 1913, respectively. Prinz Eugen followed in July 1914. The smaller shipyards in Fiume resulted in a slower construction which was further delayed by the outbreak of the war, with Szent István commissioned into the fleet in December 1915. This was too late for her to take part in the Bombardment of Ancona in which the remaining ships in the class saw action immediately following Italy's declaration of war on Austria-Hungary in May 1915. All of the Tegetthoffs were members of the 1st Battleship Division at the beginning of the war and were stationed out of the naval base at Pola. Following the Bombardment of Ancona and the commissioning of Szent István, the four ships saw little combat due to the Otranto Barrage which prohibited the Austro-Hungarian Navy from leaving the Adriatic Sea. In June 1918, in an attempt to earn safer passage for German and Austro-Hungarian U-boats through the Strait of Otranto, the Austro-Hungarian Navy attempted to break the Barrage with a major attack on the strait, but it was abandoned after Szent István was sunk by the Italian motor torpedo boat MAS-15 on the morning of 10 June. After the sinking of Szent István, the remaining three ships of the class returned to port in Pola where they remained for the rest of the war. When Austria-Hungary was facing defeat in the war in October 1918, the Austrian government decided to transfer Viribus Unitis to the newly formed State of Slovenes, Croats and Serbs in order to avoid having to hand the ship over to the Allied Powers. Renamed Jugoslavija, the ship was destroyed by an Italian mine in the Raid on Pola a day later. Following the Armistice of Villa Giusti in November 1918, Prinz Eugen was ceded to France where she was sunk as a target ship in 1922, while Tegetthoff was handed over to Italy and scrapped between 1924 and 1925. The wreck of Viribus Unitis was salvaged from Pola harbor and broken up between 1920 and 1930.
Background
With the establishment of the Austrian Naval League in September 1904 and the October appointment of Vice-Admiral Rudolf Montecuccoli to the posts of Commander-in-Chief of the Navy (German: Marinekommandant) and Chief of the Naval Section of the War Ministry (German: Chef der Marinesektion), the Austro-Hungarian Navy began an expansion program befitting a Great Power. Montecuccoli immediately pursued the efforts championed by his predecessor, Admiral Hermann von Spaun, and pushed for a greatly expanded and modernized navy. Additional motivations existed which led to the development of the Tegetthoff class beyond Montecuccoli's own plans for the navy. New railroads had been constructed through Austria's Alpine passes between 1906 and 1908, linking Trieste and the Dalmatian coastline to the rest of the Empire. Lower tariffs on the port of Trieste aided the expansion of the city and similar growth in Austria-Hungary's merchant marine. These changes necessitated the development of a new line of battleships capable of more than the defense of Austria-Hungary's coastline. Prior to the turn of the century, sea power had not been a priority in Austrian foreign policy and the navy had little public interest or support. However, the appointment of Archduke Franz Ferdinand – heir to the Austro-Hungarian throne and a prominent and influential supporter of naval expansion – to the position of admiral in September 1902 greatly increased the importance of the navy in the eyes of both the general public and the Austrian and Hungarian Parliaments. Franz Ferdinand's interest in naval affairs stemmed primarily from his belief that a strong navy would be necessary to compete with Italy, which he viewed as Austria-Hungary's greatest regional threat. The Tegetthoff-class battleships were authorized when Austria-Hungary was engaged in a naval arms race with its nominal ally, Italy. Italy's Regia Marina was considered the most important naval power in the region, which Austria-Hungary measured itself against, often unfavorably. The disparity between the Austro-Hungarian and Italian navies had existed for decades; in the late 1880s Italy boasted the third-largest fleet in the world, behind the French Navy and the British Royal Navy. While that disparity had been somewhat equalized with the Imperial Russian Navy and German Imperial Navy surpassing the Italian Navy in 1893 and 1894 respectively, by 1903 the balance began to shift towards Italy's favor with the Italians claiming 18 pre-dreadnoughts in commission or under construction compared to 6 Austro-Hungarian battleships. Following the construction of the final two Regina Elena-class battleships in 1903, the Italian Navy elected to construct a series of large cruisers rather than additional battleships. Furthermore, a major scandal involving the Terni steelworks' armor contracts led to a government investigation that postponed several naval construction programs for three years. These delays meant that the Italian Navy would not initiate construction on another battleship until 1909, and provided the Austro-Hungarian Navy with an opportunity to address the disparity between the two fleets.
Austro-Italian naval arms race
As late as 1903 the Italian advantage in naval arms appeared so large that the difficulty of Austria-Hungary catching up to the Italian Navy, much less surpassing it, appeared insurmountable. Events changed, however, with the revolution in naval technology created by the launch of the British HMS Dreadnought in 1906 and the Anglo-German naval arms race that followed. The value of pre-dreadnought battleships declined rapidly and numerous ships in European navies were rendered obsolete, giving Austria-Hungary an opportunity to make up for past neglect in naval affairs. With an improved financial situation and budget from the Austro-Hungarian Compromise of 1867, and with Archduke Ferdinand and Admiral Montecuccoli both supportive of constructing a new class of modern battleships, the stage was set for the development of Austria-Hungary's first and only class of dreadnought battleships. Shortly after assuming command as Chief of the Navy, Montecuccoli drafted his first proposal for a modern Austrian fleet in the spring of 1905. It was to consist of 12 battleships, 4 armored cruisers, 8 scout cruisers, 18 destroyers, 36 high seas torpedo craft, and 6 submarines. While these plans were ambitious, they lacked any ships the size of the Tegetthoff class. Additional proposals came from outside the Naval Section of the War Ministry. The Slovenian politician and prominent Trialist Ivan Šusteršič presented a proposal to the Reichsrat in 1905 calling for the construction of nine additional battleships. The Austrian Naval League also presented its proposals for the construction of a series of dreadnoughts. Petitioning the Naval Section of the War Ministry in March 1909 to construct three dreadnoughts of 19,000 metric tons (18,700 long tons), the League justified its proposal by arguing that a strong navy would be necessary to protect Austria-Hungary's growing merchant marine, and that Italian naval spending was twice Austria-Hungary's. Following the construction of Austria-Hungary's last class of pre-dreadnought battleships, the Radetzky class, Montecuccoli submitted his first proposal for true dreadnought battleships for the Austro-Hungarian Navy. Taking advantage of political support for naval expansion he had obtained in both Austria and Hungary over the course of several years, and Austrian fears of a war with Italy over the Bosnian Crisis during the previous year, Montecuccoli drafted a new memorandum to Emperor Franz Joseph I in January 1909 proposing an enlarged Austro-Hungarian Navy consisting of 16 battleships, 12 cruisers, 24 destroyers, 72 seagoing torpedo boats, and 12 submarines. While this was a modified version of his 1905 plan, one notable change was the inclusion of four additional dreadnought battleships with a displacement of 20,000 metric tons (19,684 long tons) at load. These ships would become the Tegetthoff class.
Proposals
Following up on Montecuccoli's memorandum, the Naval Section of the War Ministry submitted its specifications for the Tegetthoff-class battleships to Stabilimento Tecnico Triestino in October 1908, who in turn hired naval architect Siegfried Popper to produce a design. In December 1908, the Naval Section of the War Ministry also began a competition for the design of the Tegetthoff class, with the aim of producing alternate designs aside from those Stabilimento Tecnico Triestino would present. Emperor Franz Joseph I approved Montecuccoli's plan in January 1909, who subsequently circulated it among the governments in Vienna and Budapest. In March, Popper presented five pre-project designs for the Tegetthoff class. These initial designs were effectively enlarged versions of the Radetzky class and lacked the triple turrets which would later be found on the Tegetthoffs. In April 1909, Popper returned with a new set of proposals, named "Variant VIII" which included triple turrets. That same month, Montecuccoli's memorandum found its way into Italian newspapers, sparking hysteria among the Italian people and politicians. The Italian Navy used the report as justification for initiating a new dreadnought program. In June 1909 Dante Alighieri was laid down at the naval shipyard in Castellammare di Stabia.
Funding
Budget crisis
The development of Dante Alighieri left the Austro-Hungarian Navy in a precarious position. The Italian battleship was laid down largely due to the leaking of Montecuccoli's memorandum, while the proposal for constructing four new battleships still remained in the planning stages. Complicating the matter further was the collapse of Sándor Wekerle's government in Budapest, which left the Hungarian Diet without a prime minister for nearly a year. With no government in Budapest to pass a budget, efforts to secure funding and begin construction had stalled. The budget crisis likewise affected industries with close ties to the navy, particularly the Witkowitz Ironworks and the Škoda Works. With Radetzky nearing completion and Zrínyi the only remaining Austro-Hungarian battleship still under construction in the shipyards of Trieste, the major shipbuilding enterprises in Austria offered to begin construction on three dreadnoughts at their own financial risk, in exchange for promises from the Austro-Hungarian government that the battleships would be purchased as soon as the budget impasse had been resolved. After negotiations involving the ministries of foreign affairs, war and finance, the navy agreed to the offer but lowered the number of dreadnoughts that would be constructed before a budget was passed from three to two. In his memoirs, former Austrian Field Marshal and Chief of the General Staff Conrad von Hötzendorf wrote that due to his belief in a future war with Italy, construction on the battleships should begin as soon as possible. He also worked to secure agreements to sell the dreadnoughts to, in his words, a "reliable ally" (which only Germany could claim to be) should the budget crisis fail to be resolved in short order. Facing potential backlash over constitutional concerns that the construction of the first two battleships committed Austria-Hungary to spend roughly 120 million Kronen without prior approval by either the Austrian Reichsrat or the Diet of Hungary, the deal remained secret. In the event of the agreement being leaked to the press prior to the passage of a new naval budget, Montecuccoli drafted several explanations to justify the battleships' construction and the necessity to keep their existence a secret. These included the navy's urgent need to counter Italy's naval build up and desire to negotiate a lower price with their builders. By the time the agreement was leaked to the public in April 1910 by the Arbeiter-Zeitung, the newspaper of Austria's Social Democratic Party, the plans had already been finalized and construction on the first two battleships, Viribus Unitis and Tegetthoff, was about to begin.
=== Costs === The costs to construct the Tegetthoff-class battleships were enormous by the standards of the Austro-Hungarian Navy. While the Habsburg-class, Erzherzog Karl-class, and the Radetzky-class battleships cost the navy roughly 18, 26, and 40 million Kronen per ship, each ship of the Tegetthoff class was projected to cost over 60 million Kronen. Under the previous budgets for 1907 and 1908, the navy had been allocated some 63.4 and 73.4 million Kronen, which at the time was considered an inflated budget due to the construction of two Radetzkys. Montecuccoli worried that the general public and the legislatures in Vienna and Budapest would reject the need for the expensive ships, especially so soon after the political crisis in Budapest. The dramatic increase in spending meant that in 1909 the navy spent some 100.4 million Kronen, a huge sum at the time. This was done in order to rush the completion of the Radetzky-class battleships, though the looming construction of four dreadnoughts meant the Austro-Hungarian Navy would likely have to ask the government for a yearly budget much higher than 100 million Kronen. In order to guarantee funding for the ships from the Rothschild family in Austria, who owned the Witkowitz Ironworks, the Creditanstalt Bank, and had significant assets in both the Škoda Works and the Stabilimento Tecnico Triestino, Archduke Franz Ferdinand personally courted Albert Salomon Anselm von Rothschild in order to obtain his family's monetary support until the government could buy the ships.
Budget negotiations and passage
The budgets providing funding for the Tegetthoff class were finally approved after two meetings of the Austrian Reichsrat and the Diet of Hungary in October and November 1910, with opposition being rejected as the Italian Navy had laid down another three battleships during the summer. The retroactive passage of the 1910 budget and the passage of the 1911 budget was secured between December and March with little opposition. István Tisza, who had won Hungary's 1910 parliamentary election but instead chose to allow a government to form under Károly Khuen-Héderváry, secured passage of the budgets with his large parliamentary majority. This was done after it was agreed the contract for the battleship which would eventually become Szent István was to be awarded to the Ganz-Danubius shipyard in Fiume. Tisza's political allies were likewise won over with bribes such as being appointed to the board of directors of the Adria Line. Securing passage of the budgets in the Austrian Reichsrat had been comparatively easy. Karel Kramář, leader of the Young Czech Party, supported the budgets with the justification that he had "a certain weakness for the navy." Šusteršič, leader of the Slovene bloc, rallied support by arguing that the battleships were in the best interests of the navy and the Slovenian people. German politicians supported the battleships' construction on the grounds that their existence made Austria-Hungary a more powerful ally for Germany. The final package included provisions which ensured that while the armor and guns of the Tegetthoff class were to be constructed within Austria, the electrical wiring and equipment aboard each ship was to be assembled in Hungary. Additionally, half of all ammunition for the battleships' guns would be purchased in Austria and half was to be bought in Hungary. Only the Social Democrats opposed the budgets. Their leader, Karl Seitz, decried the worsening relations with Italy and called for negotiations with Rome to end the Austro-Italian naval arms race. In a sign of Austria-Hungary's strained relationship with her nominal ally Italy, the proposal failed with little support outside of Seitz' party. The budgets passed both parliaments with large majorities, ensuring that the financial questions regarding the construction of the ships were resolved.
Design
General characteristics
Designed by naval architect Siegfried Popper, the Tegetthoff-class ships had an overall length of 152 meters (498 ft 8 in), with a beam of 27.90 meters (91 ft 6 in) and a draught of 8.70 meters (28 ft 7 in) at deep load. They were designed to displace 20,000 metric tons (19,684 long tons) at load, but at full combat load they displaced 21,689 metric tons (21,346 long tons). The propellers for the class is where differences in design began to appear between the three ships constructed in Trieste, and Szent István which was constructed in Fiume. The skeg for each propeller shaft on Szent István was a solid, blade-like fitting, unlike the strut-type skegs used in the other three Tegetthoffs. The hull was built with a double bottom, 1.22 meters (4 ft) deep, with a reinforced inner bottom that consisted of two layers of 25-millimeter (1 in) plates. This design was intended by Popper to protect the battleships from naval mines, although it ultimately failed both Szent István and Viribus Unitis, the former being sunk by a torpedo in June 1918 and the latter by a mine in November of that same year. The Tegetthoff class also featured two 2.74-meter (9 ft) Barr and Stroud optical rangefinder posts on both the starboard and port sides for the secondary guns of each ship. These rangefinders were equipped with an armored cupola, which housed an 8-millimeter (0.31 in) Schwarzlose M.07/12 anti-aircraft machine gun. Szent István had a few external variations from the other ships of her class. These differences included a platform built around the fore funnel which extended from the bridge of the ship to the after funnel upon which several searchlights were installed. A further distinguishing feature was the modified ventilator trunk in front of the mainmast. The rangefinders on Szent István had an armored stand which turned 90° to the right of those on the other three ships. This was done in order to present a smaller target for the ship's broadside. Perhaps the most-notable distinguishing characteristic of Szent István was that she was the only ship of her class not to be fitted with torpedo nets. The other three ships of the Tegetthoff class had their torpedo nets removed in June 1917. The Tegetthoff-class ships were manned by a crew of 1,087 officers and men.
Propulsion
Differences between the three battleships constructed in Trieste and the one in Fiume were most apparent when examining each ship's propulsion. Szent István differed from the other ships in that she possessed two propellers and two larger Parsons steam turbines, while the propulsion of Viribus Unitis, Tegetthoff, and Prinz Eugen each had four smaller Siemens turbines and four propellers. These turbines were housed in a separate engine-room and with the exception of SMS Szent István, they were powered by twelve Yarrow boilers. The more modern new type of Babcock & Wilcox boilers of Szent István were 48 tonnes heavier than the older type Yarrow boilers installed on the sister ships; however, they were more efficient than the old boilers. The new Babcock & Wilcox boilers had a huge advantage of being able to maintain top speed for up to eight hours, compared with only two hours on their sister ships. They were designed to produce a total of 26,400 or 27,000 shaft horsepower (19,686 or 20,134 kW), which was theoretically enough to attain a maximum designed speed of 20 knots (37 km/h; 23 mph). While it was reported during the speed trials of Tegetthoff that she attained a top speed of 19.75 knots (36.58 km/h; 22.73 mph), the actual top speed of the Tegetthoff-class ships is unknown as the sea trial data and records for each ship were lost after the war. Each ship also carried 1,844.5 metric tons (1,815.4 long tons) of coal, and an additional 267.2 metric tons (263 long tons) of fuel oil that was to be sprayed on the coal to increase its burn rate. At full capacity, the Tegetthoffs could steam for 4,200 nautical miles (7,800 km; 4,800 mi) at a speed of 10 knots (19 km/h; 12 mph).
Armament
Constructed at the Škoda Works in Plzeň, Bohemia, the Tegetthoffs' main battery consisted of twelve 45-calibre 30.5-centimeter (12 in) Škoda K10 guns mounted in four triple turrets. Two turrets each were mounted forward and aft of the main superstructure in a superfiring pair. The implementation of triple turrets came about for two reasons: the need to ensure the ships had a more compact design and smaller displacement to conform to Austro-Hungarian naval doctrine and budget constraints, and to counter the implementation of triple turrets on the Italian Dante Alighieri. While the Italians had initiated construction on Dante Alighieri before work had begun on the Tegetthoff class, the shipyards in Trieste were able to construct Viribus Unitis faster than their Italian counterparts and she was commissioned in December 1912, just a month before Dante Alighieri. This made the Tegetthoffs the first dreadnoughts in the world with triple turrets, in which the Austro-Hungarian Navy took great pride. Having three guns on each turret rather than two made it possible to deliver a heavier broadside than other dreadnoughts of a similar size and meant a shorter citadel and better weight distribution. The choice of implementing triple turrets also assisted in the construction speed of the first two ships, as the guns were available at short notice because Škoda had already been working on a triple-turret design ordered by the Imperial Russian Navy when their initial order for the Tegetthoff class arrived. The Tegetthoffs carried a secondary armament which consisted of a dozen 50-calibre 15-centimeter (5.9 in) Škoda K10 guns mounted in casemates amidships. Additionally, eighteen 50-calibre 7-centimeter (2.8 in) Škoda K10 guns were mounted on open pivot mounts on the upper deck, above the casemates. Three more 7-centimeter (2.8 in) Škoda K10 guns were mounted on the upper turrets for anti-aircraft duties. Two additional 8-millimeter (0.31 in) Schwarzlose M.07/12 anti-aircraft machine guns were mounted atop the armoured cupolas of each ship's rangefinders. Each ship had two 7-centimeter (2.8 in) Škoda G. L/18 landing guns, and two 47-millimeter (1.9 in) Škoda SFK L/44 S guns for use against small and fast vessels such as torpedo boats and submarines. Each ship was also fitted with four 533-millimeter (21 in) submerged torpedo tubes, one each in the bow, the stern, and each side. Each ship usually carried twelve torpedoes.
=== Armor === The Tegetthoff-class ships were protected at the waterline with an armor belt which measured 280 millimeters (11 in) thick in the central citadel, where the most important parts of the ship were located. This armor belt was located between the midpoints of the fore and aft barbettes, and thinned to 150 millimeters (5.9 in) further towards the bow and stern, but did not reach either. It was continued to the bow by a small patch of 110–130-millimeter (4–5 in) armor. The upper armor belt had a maximum thickness of 180 millimeters (7.1 in), but it thinned to 110 millimeters (4.3 in) from the forward barbette all the way to the bow. The casemate armor was also 180 millimeters (7.1 in) thick. The sides of the main gun turrets, barbettes, and main conning tower were protected by 280 millimeters (11 in) of armor, except for the turret and conning tower roofs which were 60 to 150 millimeters (2 to 6 in) thick. The thickness of the decks ranged from 30 to 48 millimeters (1 to 2 in) in two layers. The underwater protection system consisted of the extension of the double-bottom upwards to the lower edge of the waterline armor belt, with a thin 10-millimeter (0.4 in) plate acting as the outermost bulkhead. It was backed by a torpedo bulkhead that consisted of two 25-millimeter (1 in) plates. The total thickness of this system was only 1.60 meters (5 ft 3 in), which made it incapable of containing a torpedo warhead detonation or mine explosion without rupturing. In the spring of 1909, Montecuccoli sent an officer from the Naval Section of the War Ministry to Berlin in order to obtain input from Alfred von Tirpitz on the design of the Tegetthoff class. The Imperial German Navy had conducted gunnery and torpedo tests and concluded that, "The angle between [the] armored deck and belt armor should be as flat as possible", and that "The armored torpedo bulkhead should be angled inwards, the second longitudinal bulkhead outwards. The distance of the torpedo bulkhead from the outer plating should be raised from 2.5 to 4 meters." While Popper adopted several of Tirpitz's suggestions regarding the external layout of the belt armor for the Tegetthoff class, the internal modifications put forward by the Imperial German Navy were not implemented.
Assessment
Although smaller than the contemporary dreadnought and super-dreadnought battleships of the German Kaiserliche Marine and the British Royal Navy, the Tegetthoff class was the first of its type in the Mediterranean and Adriatic Seas. The Tegetthoffs were described by former Austro-Hungarian naval officer Anthony Sokol in his book The Imperial and Royal Austro-Hungarian Navy as "excellent ships", and were acknowledged as some of the most powerful of their type in the region. Their design signaled a change in Austro-Hungarian naval policy, as the ships were capable of far more than coastal defense or patrolling the Adriatic Sea. The Tegetthoffs were so well received that when the time came to plan for the replacement of Austria-Hungary's old Monarch-class coastal defense ships, the navy elected to simply take the layout of the Tegetthoff class and enlarge them to have a slightly greater tonnage and larger main guns. Despite these praises, criticisms of the Tegetthoff-class design exist. Friedrich Prasky refers to the ships in his article The Viribus Unitis class "The ships were too small and had a very low range of stability." Erwin Sieche writes in his article S.M.S. Szent István: Hungaria's Only and Ill-Fated Dreadnought "There had been much quibbling about the bad design of the Tegetthoff class and the bad workmanship and riveting of the Szent István in particular." Poor riveting has been blamed for the sinking of Szent István, and Karl Mohl, chief non-commissioned officer of Szent István's machinery, reported that the rivets from the ships snapped loose during the battleship's sinking. Furthermore, reports emerged following the ship's gunnery trials of rivets in the double bottom of the hull being blown out of their sockets. The sinking of Szent István revealed several flaws in the design of the ships' armor. The naval commission investigating the loss of the battleship ultimately concluded: "The distance between mine armor and 15-cm-ammunition magazines is too small and a major design failure, which most probably caused the widening of the leak." Following Szent István's sinking, it was also discovered that her propeller shafts had such a high degree of resistance that the ship's rudder could only be laid at a maximum angle of 10° at full speed or else she would suffer from a heavy list.
Ships
Construction
Secrecy
Montecuccoli's plans for the battleships gained approval from Emperor Franz Joseph I in January 1909, and by April plans for the ships' design, construction, and financing in the face of the ongoing budget crisis in Budapest were already being laid out. Upon learning that Austria-Hungary was planning or currently building a class of dreadnoughts, the British Admiralty considered the project "as a concealed addition to the German fleet" and interpreted the ships as Austria-Hungary's way of repaying Germany for her diplomatic support during the former's annexation of Bosnia in 1908. During the spring and summer of 1909, the United Kingdom was locked in a heated naval arms race with Germany which led the Royal Navy to look upon the Austro-Hungarian ships as a ploy by German Grand Admiral Alfred von Tirpitz to outpace British naval construction, rather than the latest development in Austria-Hungary's own naval arms race with Italy. The Admiralty's concerns regarding the true purpose of the ships were so great that a British spy was dispatched to Berlin when Montecuccoli sent the officer to obtain recommendations from Tirpitz regarding the design and layout of the Tegetthoff-class ships. These concerns continued to grow and in April 1909 British Ambassador Fairfax Leighton Cartwright asked Austro-Hungarian Foreign Minister Alois Lexa von Aehrenthal about the rumored battleships. Aehrenthal denied the construction of the Tegetthoff class, but admitted that plans to construct a class of dreadnoughts were being considered. In an attempt to assure Cartwright that Austria-Hungary was not constructing any ships for the German Navy, Aehrenthal justified any naval expansion as being necessary to secure Austria-Hungary's strategic interests in the Mediterranean. At the time, the potential of Austria-Hungary constructing four dreadnought battleships was widely regarded among the British press, public, and politicians as a provocation on the part of Germany. Neither the Admiralty's suspicions, nor those of some politicians, managed to convince the British Parliament that the German government was attempting to use the Tegetthoff class to escalate Germany and Britain's already contentious naval arms race. When Winston Churchill was appointed First Lord of the Admiralty in 1911, he rejected any potential Austro-German collusion regarding the battleships. For a full year, the Austro-Hungarian Navy attempted to keep the project a state secret. This did not prevent rumors about their construction of a series of dreadnought battleships from circulating across Europe. The French Naval Attaché in Vienna complained to Paris in 1910 of extensive secrecy within the Austro-Hungarian Navy, which manifested itself in several ways. Among these were a ban on photography at Pola, future home port of the Tegetthoff class, and near-constant observation by the Austro-Hungarian police. Roughly a year after the project began, the Arbeiter-Zeitung, the Austrian Social Democratic Party newspaper, reported the details of the battleships to the general public. The Christian Social Party, supportive of the construction of the ships and operating on the advice of the navy, published in its own newspaper, Reichspost, that the secret dreadnought project and related financial agreements were true. The Reichspost lobbied in support of the project, citing Austria-Hungary's national security concerns with an Italian dreadnought already under construction. When the story broke Archduke Ferdinand also worked to build public support for the battleships, and the small but growing Austrian Navy League did the same.
Assembly
The first ship of the Tegetthoff class, Viribus Unitis, was formally laid down on 23 July 1910. Originally referred to as "Battleship IV", her keel was laid down after months of fiscal and political uncertainty. Two months later Tegetthoff was laid down on 24 September 1910. The title ship of the class, Tegetthoff, was named after Wilhelm von Tegetthoff, a 19th-century Austrian naval admiral known for his 1866 victory over Italy at the Battle of Lissa. She was laid down once it became clear that Vienna and Budapest would pass the necessary budget funding to pay for the construction of the entire class. By the end of 1910, construction on the Tegetthoff-class ships was well underway. Two ships were being assembled in Trieste's slipways, and more were in preparation. Aside from a brief strike in May 1911, construction on the battleships continued at a fast pace. Less than a year after being laid down in Trieste, Viribus Unitis was launched on 24 June 1911 at a large ceremony featuring Archduke Franz Ferdinand and the Austrian Minister of War, General Moritz von Auffenberg. Viribus Unitis's sponsor at the ceremony was Archduchess Maria Annunziata, sister to Franz Ferdinand. Seven months later, Prinz Eugen was laid down on 16 January 1912. She was followed by Szent István on 29 January. Tegetthoff was launched on 21 March following delays due to poor weather around Trieste. Despite strikes in August 1912 and March 1913 by mechanics working on her engines, Prinz Eugen was launched on 30 November, while construction on Szent István took longer due to the fact that the shipyards in Fiume had to be expanded for a ship of her size. She was launched two years later on 17 January 1914. While the battleships were under construction, discussions began over what to name them. The Naval Section of the War Ministry initially proposed naming the four battleships Tegetthoff, Prinz Eugen, Don Juan, and Hunyadi. Newspapers within Austria reported during construction that one of the ships was to be named Kaiser Franz Joseph I, though it was later revealed the navy had no intentions of renaming the cruiser which already bore the Emperor's name. Archduke Franz Ferdinand proposed Laudon for the fourth ship in honor of the Austrian field marshal. Emperor Franz Joseph I ultimately decided the names of the dreadnoughts, choosing to name the first ship using his own personal motto, Viribus Unitis (Latin: "With United Forces"), while the fourth ship in the class would be named Szent István after the Hungarian king and saint, Stephen I.
Commissioning
When Viribus Unitis was commissioned on 6 October 1912, she was at the time the most expensive warship ever to be constructed. The Italian Dante Alighieri had been laid down before Viribus Unitis but was not commissioned until January 1913. This meant Austria-Hungary became the sixth nation, after the United Kingdom, Germany, the United States, Brazil, and Japan to possess a dreadnought battleship. Montecuccoli addressed the Austrian and Hungarian Parliaments on 15 October 1912 and laid out his vision for the role the Tegetthoff class would play in naval policy. Declaring that Austria-Hungary had become "a Mediterranean power" in light of her new dreadnoughts, Montecuccoli expected that the new class of battleships would help Austria-Hungary "assume our proper place among the Mediterranean powers". Viribus Unitis was soon followed by Tegetthoff, the namesake of the class, on 14 July 1913. During her gunnery trials, a discharge from one of the main guns of Tegetthoff damaged the staterooms of the ship's officers. Prinz Eugen was commissioned on 8 July 1914, ten days after Archduke Franz Ferdinand's assassination in Sarajevo. Expansion of the Graz-Danubius shipyards in Fiume delayed the launching and christening of Szent István until 17 January 1914. Though it was customary for either the Emperor or his heir to be present at the launching of a major warship, Franz Joseph was too feeble and his heir, Franz Ferdinand, refused to be there due to his anti-Hungarian attitudes. Franz Joseph sent a telegram of congratulations to avoid controversy, and the ceremony was presided over by Archduchess Maria Theresa who launched it with the words: "Slip out and may the protection of the Almighty be with you on all your ways!" Also present at the ceremony was Hungarian Prime Minister Tisza, Minister of Finance János Teleszky, and Minister to the Imperial Court Stephan Burián von Rajecz. As the German cruiser Breslau had recently been refitted at Trieste, her officers also attended the ceremony. During the launching itself there was an accident when the starboard anchor had to be dropped to prevent the ship from hitting a ship carrying spectators of the celebrations, but the anchor chain had not been shackled to the ship and it struck two dockworkers, killing one and crushing the left leg of the other. The following day, the navy had to raise the anchor out of 48 meters (157 ft) of water and re-attach it to the ship. Her fitting out was further delayed by the start of World War I six months later, and she was commissioned as the final battleship of the Tegetthoff class on 13 December 1915.
History
Pre-war
Prior to World War I, the Tegetthoff class served as the pride of the Austro-Hungarian Navy, conducting several voyages throughout the Adriatic and Mediterranean Seas as members of the 1st Battle Division under the command of Vice-Admiral Maximilian Njegovan. In the spring of 1914 Viribus Unitis and Tegetthoff, together with Zrínyi and the coastal defense ship Monarch, traveled the eastern Mediterranean, the Sea of Sicily, and the Levant, visiting the ports of Smyrna, Beirut, Alexandria, and Malta. While at port in Alexandria, two of Monarch's crew contracted smallpox and cerebrospinal meningitis which caused the ship to be quarantined for several weeks in Pola. Meanwhile, Viribus Unitis and Tegetthoff arrived at Malta on 22 May, before leaving for Pola on 28 May. Upon their return, Viribus Unitis was tasked with transporting Ferdinand to the Condominium of Bosnia and Herzegovina in order to watch military maneuvers. Following the maneuvers, Ferdinand and his wife Sophie planned to visit Sarajevo to open the state museum in its new premises. On 24 June the battleship brought the Archduke from Trieste to the Narenta River, where he boarded a yacht which took him north towards Sarajevo. After observing the military maneuvers for three days, the Archduke met his wife in Sarajevo. On 28 June 1914, they were shot to death by Gavrilo Princip. Upon hearing of the assassination, Commander-in-Chief of the Navy Anton Haus sailed south from Pola with an escort fleet comprising Tegetthoff, the scout cruiser Admiral Spaun, and several torpedo boats. Two days after their murders, Ferdinand and Sophia's bodies were transferred aboard Viribus Unitis, which had been anchored waiting to receive the Archduke for his return, and were transported back to Trieste. Viribus Unitis was shadowed by Haus' escort fleet for the journey, with the fleet moving slowly along the Dalmatian coast, usually within sight of land. Coastal towns and villages rang church bells when the ships passed while spectators watched the fleet from the shoreline. The Archduke's death triggered the July Crisis, culminating in Austria-Hungary's declaration of war on the Kingdom of Serbia on 28 July 1914.
World War I
Outbreak of war
Events unfolded rapidly in the ensuing days. On 30 July 1914 Russia declared full mobilization in response to Austria-Hungary's declaration of war on Serbia. Austria-Hungary declared full mobilization the next day. On 1 August both Germany and France ordered full mobilization and Germany declared war on Russia in support of Austria-Hungary. While relations between Austria-Hungary and Italy had improved greatly in the two years following the 1912 renewal of the Triple Alliance, increased Austro-Hungarian naval spending, political disputes over influence in Albania, and Italian concerns over the potential annexation of land in the Kingdom of Montenegro caused the relationship between the two allies to falter in the months leading up to the war. Italy's 1 August declaration of neutrality in the war dashed Austro-Hungarian hopes to use the ships of the Tegetthoff class in major combat operations in the Mediterranean, as the navy had been relying upon coal stored in Italian ports to operate in conjunction with the Regia Marina. By 4 August Germany had already occupied Luxembourg and invaded Belgium after declaring war on France, and the United Kingdom had declared war on Germany in support of Belgian neutrality. The assistance of the Austro-Hungarian fleet was called upon by the German Mediterranean Division, which consisted of the battlecruiser Goeben and Breslau. The German ships were attempting to break out of Messina, where they had been taking on coal prior to the outbreak of war. By the first week of August, British ships had begun to assemble off Messina in an attempt to trap the Germans. While Austria-Hungary had not yet fully mobilized its fleet, a force was assembled to assist the German ships. This consisted of the three Radetzkys and the three Tegetthoffs, along with the armored cruiser Sankt Georg, Admiral Spaun, six destroyers, and 13 torpedo boats. The Austro-Hungarian high command, wary of instigating war with Great Britain, ordered the fleet to avoid the British ships and to only support the Germans openly while they were in Austro-Hungarian waters. On 7 August, when the Germans broke out of Messina, the Austro-Hungarian fleet had begun to sail for Brindisi to link up with the Germans and escort their ships to a friendly port in Austria-Hungary. However, the German movement toward the mouth of the Adriatic had been a diversion to throw the British and French off their pursuit, and the German ships instead rounded the southern tip of Greece and made their way to the Dardanelles, where they would eventually be sold to the Ottoman Empire. Rather than follow the German ships towards the Black Sea, the Austrian fleet returned to Pola.
1914–1915
Following France and Britain's declarations of war on Austria-Hungary on 11 and 12 August respectively, the French Admiral Augustin Boué de Lapeyrère was issued orders to close off Austro-Hungarian shipping at the entrance to the Adriatic Sea and to engage any Austro-Hungarian ships his Anglo-French fleet came across. Lapeyrère chose to attack the Austro-Hungarian ships blockading Montenegro. The ensuing Battle of Antivari ended Austria-Hungary's blockade, and effectively placed the entrance of the Adriatic Sea firmly in the hands of Britain and France. After the breakout of Goeben and Breslau, the ships of the Tegetthoff class saw very little action, spending much of their time in their base at Pola. The navy's general inactivity was partly caused by a fear of mines in the Adriatic. Other factors contributed to the lack of naval activity among the ships of the Tegetthoff class in the first year of the war. Haus was fearful that direct confrontation with the French Navy, even if it should be successful, would weaken the Austro-Hungarian Navy to the point that Italy would have a free hand in the Adriatic. This concern was so great to Haus that he wrote in September 1914, "So long as the possibility exists that Italy will declare war against us, I consider it my first duty to keep our fleet intact." Haus' decision to use the Austro-Hungarian Navy as a fleet in being earned sharp criticism from the Austro-Hungarian Army, the German Navy, and the Austro-Hungarian Foreign Ministry, but it also led to a far greater number of Entente naval forces being devoted to the Mediterranean and the Strait of Otranto. These could have been used elsewhere, such as against the Ottoman Empire during the Gallipoli Campaign. The most important factor contributing to the Tegetthoffs spending most of their time at port may have been the lack of coal. Prior to the war, the United Kingdom had served as Austria-Hungary's primary source for coal. In the years before the war an increasing percentage of coal had come from mines in Germany, Virginia in the United States, and from domestic sources, but 75% of the coal purchased for the Austro-Hungarian Navy came from Britain. The outbreak of war meant that these sources, as well as those from Virginia, would no longer be available. Significant quantities of coal had been stockpiled before the war however, ensuring the navy was capable of sailing out of port if need be. Even so, the necessity of ensuring the navy's most important ships such as the Tegetthoffs had the coal they needed in the event of an Italian or French attack or a major offensive operation resulted in the dreadnoughts remaining at port unless circumstances necessitated their deployment at sea. In early 1915 Germany suggested that the Austro-Hungarian Navy conduct an attack on the Otranto Barrage in order to relieve pressure on the Ottoman Empire at the height of the Gallipoli Campaign. Haus rejected the proposal, countering that the French had pulled back their blockade to the southernmost end of the Adriatic Sea, and that none of the Anglo-French ships assigned to blockading the strait had been diverted to the Dardanelles. Haus also advocated strongly in favor of keeping his battleships, in particular the ships of the Tegetthoff class, in reserve in the event of Italy's entry into the war on the side of the Entente. Haus believed that Italy would inevitably break her alliance with Austria-Hungary and Germany, and that by keeping Austria-Hungary's battleships safe, they could rapidly be employed against Italy. This strategy enabled Austria-Hungary's battleships to engage the Italians shortly after Italy's declaration of war in May 1915.