Viribus Unitis, Austria-Hungary's prototype dreadnought, was laid down in 1909 and commissioned late in 1912. Named for Franz Josef I's motto, meaning "With united forces" in Latin, she took to the waves in 1911 as the first instalment of Austria's reply to Italy's initial dreadnought, the Dante Alighieri.
Like the German Nassaus, these ships were first contemplated as large semi-dreadnoughts and were already on the drawing boards of Ing. Siegfried Popper when he retired part way through the construction of his previous project, the Radetzky class semi-dreadnoughts, in 1907. However, despite his failing eyesight, he continued on as a consultant at STT, the Trieste shipyard that produced the bulk of the Habsburg Empire's fighting ships. When news came in 1908 of the laying down of Italy's first dreadnought, the pressure to outdo Vienna's hereditary enemy proved irresistible.
Hence Popper could not produce a ship with armament weaker than twelve 12". In fact he considerably improved on the Italian plan. Whereas the Dante Alighieri -- and the seven Russian dreadnoughts which copied the plan -- had four triple turrets all mounted on a flush deck, giving a broadside of 12 but only three bow or stern guns, the Tegetthoffs adopted superfiring turrets bow and stern, giving them an equal broadside but six barrels bow or stern.
The gun turrets, too, were of a new triple design being produced at Skoda Works in Plzen (right) for the Imperial Russian navy, licensing technology developed by Armstrongs in Britain for the Italian Dante. The ships thus started off with a major advantage, in the excellence of their artillery and mountings, matching the armament of Austria-Hungary's hated rival.
When Popper showed preliminary sketches of ships 580 feet long (as dictated by the laws of weight distribution with such a heavy armament), Adm. Montecuccoli angrily threw them back at him and told him to redesign smaller ships, ships that the parsimonious Austro-Hungarian treasury might find it possible to fund. The redesigned ships were cut down by one deck forward, shortened to under 500 feet, but carrying an undiluted armament. Vienna's Reichstag approved partial funding of the four ships and green-lighted the project late in 1908.
But the reduced size of the hulls was only the beginning of the shortcuts taken. The reduced length impaired the ships' stability and seaworthiness in anything heavier than a flat calm. And the vessels' watertight subdivision was very sketchy. The main feature was a longitudinal bulkhead -- a watertight wall running down the centerline from bow to stern. In practice this proved to be a dangerous expedient when not combined with a fine network of side-to-side compartments. And -- again for reasons of cost -- the lateral watertight bulkheads were restricted to the ends of the main boiler rooms and engine rooms, making for very large and long watertight compartments. As seen in numerous incidents during World War I, ships so divided showed a distressing tendency to capsize, as all the water flooding in from an injury to one side was trapped on one side by the longitudinal bulkhead. The cases of HMS Victoria, the Lusitania, and the Live Bait cruisers all come to mind; though there were many more since the longitudinal bulkhead was a standard feature of British and French warship design in the pre-dreadnought era.
Plan of the Tegetthoff Class as drawn by ing. Siegfried Popper in 1909. The design featured great metacentric height and top-heaviness due to the enormous weight of the turrets in proportion to the mass of the hull.
Specifications for the Tegetthoffs: Dimensions: 499'3" x 89'8" x 29' Displacement: 20,014 std., 21,595 deep laden. Armament: All Skoda guns. (12) 12"/45, (12) 5.9"/40, and (12) 3" 12-pdr guns; (4) 2¾" 12-pdr AA guns, (2) 66 mm fieldpieces, and (2) 8 mm machine guns; (4) 21" torpedo tubes and 20 mines. Armor: 11"/4" belt; 11" turrets; 11" barbettes: 11" conning tower; 8" upper belt; 7" secondary battery; 1.75"/1.4" deck. Fuel capacity: 900 tons of coal std; 2,000 maximum. Propulsion: 12 coal-fired Yarrow boilers; (4) Parsons steam turbines developing 27,000 hp, shafted to quad screw. Speed: 20.3 kts. Tactic radius: 4,200 nm @ 10 kts. Crew: 1,087. Except:Szent István, propulsion: (12) Babcock & Wilcox boilers, (4) AEG Curtis steam turbines, quad screw; maximum speed 16 kts. No torpedo tube carried on Szent István.
Ships in class: Viribus Unitis · Prinz Eugen · Tegetthoff · Szent István.
Metric Specifications: Dimensions: 152.17m x 27.33m x 8.84m Displacement: 20,014 std, 21,595 deep laden. Armament: All Skoda guns. (12) 305 mm/45, (12) 150 mm/40, (12) 70 mm 12-pdr, and (4) 70mm 12-pdr AA guns; (2) 66 mm fieldpieces; and (2) 8 mm machine guns; (4) 533-mm torpedo tubes; 20 mines. Armor: Krupp type. 280/102 mm belt; 280 mm turrets, barbettes, and conning tower; 203 mm upper belt; 178 mm secondary battery; 45/36 mm deck. Fuel capacity: 900 tons of coal std; 2,000 maximum. Propulsion: 12 coal-fired Yarrow boilers; (4) Parsons steam turbines developing 20,134 kW, shafted to quad screw. Maximum speed: 37.6 km/hr. Tactical radius: 7,800 km @ 18.5 km/hr. Crew: 1,087. Except:Szent István, propulsion: (12) coal-fired Babcock & Wilcox boilers; 4 AEG Curtis steam turbines; quad screw; maximum speed 29.6 km/hr. No torpedo tube carried on Szent István.
Dreadnought cognoscenti will deduce some of the disadvantages of the class from a close look at the specs above. The ships were smallish, under-engined, and over-gunned. These problems derived from the creaky finances of empire and the need to keep up appearances in the final days of the Habsburg domain -- in particular the need to browbeat Serbia. There was the need for more advanced ships than the Italians,' and more of them. Four dreadnoughts was a very ambitious program for a country with only two shipyards capable of producing such behemoths. Moreover, the government had to resort to raising a popular subscription for each ship beyond the lead ship, the Viribus Unitis (top of page). Hungary insisted that it be awarded the contract to build one of the four, even though it had no suitable facility in its port at Rijeka (Fiume). In order to get political agreement to the programme, the government thus had to build first a shipyard, then a state-of-the-art battleship! The ship so constructed, the Szent István (pronounced "Saint Shtefan"), was never satisfactory: alone of the four ships, she had a one-off arrangement of the shafts. This simply would not work properly at speed. Finally the incomplete ship had to be towed to Pola Naval Arsenal for completion. She only entered service on November 17, 1915, 17 months after her contracted date. Because of her propulsion issues, this ship never was a fully satisfactory unit.
Another disadvantage of the design: these were wet ships, with a low, flush weather deck. They were originally designed with a raised forecastle deck, but this option was torpedoed for the sake of economy. The lower freeboard also made the secondary battery liable to washing out in a seaway, reducing the ships' defensive capabilities against torpedo attack. Being large and heavy, the 3 ships that worked properly were on the slow side, 20.49 kts. being achieved by the Viribus Unitis on trials, 21.8 f.d. In addition, the class had relatively inadequate watertight subdivision, a flaw with fatal consequences for two out of the four. The internal torpedo bulkhead was affixed only 2.45m behind the ship's shell plating, where best practices in the German fleet -- later proven in battle -- allowed 4.5m space betwen the two. Despite their many drawbacks, these were remarkably handsome ships, with a clean, symmetrical sweep and minimal superstructure. They followed Popper's previous designs, kicking them up a notch in size without losing the graceful proportions that characterized his best work.
Popper's near blindness has been blamed for many defects in the construction of the ships. Perhaps lack of enthusiasm for the failing rule of Kaiser Franz Josef played a role in the less than stellar quality of Austria-Hungary's dreadnoughts. The four-ship class also boasted a less than stellar service record. After a few bombardments in 1915, when Italy joined the War on the Allied side, the great ships remained moored at their base, Pola. Before the War, the Kriegsmarine had imported much of its steam coal from Britain; now there was a severe coal shortage, and these ships simply could not move without fuel. Meantime the Allies filled the lower Adriatic with mines and torpedo craft; the Germans and Austrians countered with U-boats. Most of the Italian and Austrian surface vessels thus stayed safe in port and let the submarines and torpedo boats do the fighting except for specific missions undertaken with hoarded coal. The Allies constructed a great barrage across the Strait of Otranto, largely bottling up the Habsburg fleet in the Adriatic. Rather than great engines of war, the battleships only proved trophies in the squabbles over the breakup of the Habsburg Empire in 1918.
During the only coordinated fleet maneuver the Hungarian C-in-C, Nicholas Hórthy, devised during the War, they lost the Szent István. On June 9, 1918, the Austro-Hungarian armada sailed to destroy the great obstruction at Otranto by a surprise attack. St. István and Teggetthoff sailed from Pola, and were to rendezvous with the other two dreadnoughts near Dubrovnik. So confident of success was Hórthy that a movie crew was embarked to record the anticipated victory. However, Szent István's temperamental engines overheated on her first night out and her division dropped back to 12 knots, smoking copiously and thus revealing their position far over the horizon. Just before dawn they were ambushed by two Italian motor torpedo boats commanded by Italy's leading torpedo boat ace, Cmdr. Luigi Rizzo. Szent István took two torpedoes in the boiler room -- the largest interior spaces in the ship -- and immediately took a 10° list. Efforts to beach the ship or tow her failed; the rapid flooding shut down all but two boilers -- enough to keep the lights on but not to run the pumps. The turrets were trained to port and remaining crew lined up along the port rail to counterbalance the list, but in vain. The pride of Hungary sank spectacularly three hours after the torpedoing as the cine-cameras rolled, not to record a great victory but a humiliating defeat. Tegetthoff was hit also by MAS-21, but her torpedoes proved to be duds. 89 men were killed in the incident, nearly all of them stokers and engineers who had been ordered to remain below and keep the pumps working even when the ship's doom was evident to all. The "abandon ship!" came so late that nearly all the ship's crew took a dunking as their vessel turned bottom-up and sank; but they were soon picked up by the Tegetthoff or destroyers with the force.
Hórthy assumed that his plans were betrayed to the Italians, and quickly called off the operation. In reality, the Italian MTBs did not have radio sets and the Italian command did not know they had encountered dreadnoughts for another day; Hórthy could have carried out his raid with a good chance of success. This was truly one of history's ironies, for Hórthy later became virtual dictator of Hungary based on his record as a war hero.
Viribus Unitis also became a casualty of Italian sappers. At the very end of the War, when the newly crowned Emperor Karl was presiding over the dissolution of the Empire's assets, he negotiated away the battleships to the Croats about to formally take power at Zagreb and Pola. Croat-born admiral Janko Vukovich received the great ship on October 31, 1918 and raised his flag above her as Croats in the city raised their new banner and sang patriotic hymns, amid fireworks and much celebration. Some days before this, diplomatic notifications had been sent out to the belligerent countries (including Italy) informing them that the successor states no longer considered themselves at war.
But someone had neglected to tell the two volunteer saboteurs, Rosetti and Paolucci, piloting their tiny craft, the Mignatta (or Leech), into Pola harbor around the abundant obstructions. In their diving gear, they fastened two 400-lb. limpet mines to the bottom of Viribus Unitis' hull. Spotted and pulled from the water about 0500 on Nov. 1, 1918, they confessed the plot and were confined on board the Tegetthoff. Amid scenes of chaos and confused evacuation, the mines under Viribus' hull exploded with catastrophic effect. The great ship capsized and sank at 6:10 that morning. Rosetti and Paolucci escaped in the confusion and became national heroes on their return to Italy. A grateful state awarded them gold medals and pensions of 1.3 million lire each.
And what of the remaining two sisters in the class? Prinz Eugen was awarded to France as reparations. Her guns were removed and reused, and the ship used as a target for aerial bombing. She was finally sunk off Toulon on June 28, 1922 by three of the Courbet class battleships. Tegetthoff spent some months on display as a war trophy in Venice during 1919. She was further used to feed Italian triumphalism in a silent propaganda film, Eroi di nostri mari, in which she represented the Szent István. In 1920 the ship was awarded to Italy outright as a prize of war. Eventually she was sold for scrap and went to the shipbreakers in 1924.
While steaming off the Dalmatian coast near dawn on June 10, 1918, the Austrian second division (including the Tegetthoff and Szent István) was attacked by two Italian motor torpedo boats under the command of Cmdr. Luigi Rizzo, who became Italy's foremost war hero for his exploits. It was a classic case of speed and mobility overcoming ponderous armored ships. Thanks to the inexperience of the Austrian secondary gunners, both MTBs escaped unscathed. Rizzo's boat, the MAS-15, has been preserved to this day at the Vittoriano, the grandiose memorial to Victor Emmanuel II in Rome.
Thrilling but misleading illustration of the MTB attack on Szent István. The two boats involved were MAS-15 and MAS-21.
In Adm. Hórthy's ill-starred 1918 sortie, St. István was torpedoed twice during the night. She was filmed by a cine-camera crew on the Tegetthoff as she capsized and sank the following day. In this still from the movie, her guns are all trained to port -- away from the wounded side -- and her men are adding their weight to the port-side deck.
The footage shown was cut into a Red Cross fund-raising film used for European relief after the War. It has been seen by so many millions worldwide that it has entered the vernacular, even being "quoted" in grunge rock posters in the 1990s.
Here is the Tegetthoff at Pola at war's end, just before being paraded around as an Italian war trophy.
The Prinz Eugen disarmed at Toulon, 1920. She was used as aerial bomb target.
An excellent 1:100 scale model of Szent István shows the form of the ship's ram bow.