Viribus Unitis
The Flagship of the Austro-Hungarian Fleet

Specifications

• Builder: Stabilmento Tecnico Tristino,Trieste
• LD: July 24, 1910
• LCH: June 20, 1911
• COM: October (or December?) 6, 1912
• Displacement: 19,698 tons (standard) and 21,254 tons (maximum) 
• Dimensions: length O.A. - 524.9', 528.2' max.; length P.P. - 496.7'; beam - 89.6', draft - 26.9'-28.2'
• Propulsion
  • Boilers: 12 Yarrow coal burners, Babcock in Szent Istvan
  • Turbines: 4 Parson geared steam, 2 AEG geared turbines (Szent Istvan)
  • Shafts: 4, 2 in Szent Isvtan
  • Max. Speed: 20 knots, 20.8 knots trials
  • Range: 4,200 nautical miles @ 10 knots
  • Coal/Oil Bunkerage: 900/2000 tons coal
• Armament
  • Main Battery: 12 x 12"/L45 cal (Skoda built) in four triple turrets
  • Heavy Secondary Battery: 12 x 5.9"/L50 cal in 12 single mountings in hull casemates
  • Light Secondary Battery: 18 x 2.76" AA single mounted on turrets and deck, 6 removed later
  • Torpedo Tubes: 4 x 21" below waterline, 2 x 21" (Tegetthoff and Viribus Unitis)
• Armor
  • Side Belt: 11"
  • Waterline Belt: 3.9"
  • Torpedo Bulkhead: 1.4"
  • Deck: 1.9" + 1.9"
  • Turrets: 7.9" front, increased to 12"
  • Barbettes: 11"
  • Conning Tower: forward: 9.84"-11", increased to 14"
• Complement - Usual: 982-1050

The 21,000-ton battleship SMS Viribus Unitis was the flagship of the Austro-Hungarian fleet. Launched in 1911 at Trieste, she was the name ship of her class, the other members being the Tegethoff, Prinz Eugen, and Sant Istvan. Based at Pola, these were thoroughly modern and satisfactory warships, mounting a dozen 12" guns in four triple turrets superimposed fore and aft. None of the ships saw significant action in World War I. However their existence upset the balance of power in the Mediterranean, so they comprised a formidable "fleet-in-being" that tied down portions of the French and Italian fleets from 1914 and 1918.

A Feldpost letter showing the ships postal marking (courtesy of Jim Simon).

Archduke Franz Ferdinand and his wife Sophie were assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb, together with Nedeljko Cabrinovic and other accomplices. They were members of the Black Hand and had obtained their weapons in Belgrade.  Dalmat brought the bodies of Franz Ferdinand and his wife from Metkovic out into estuary of river Narenta, where on Jun 28, 1914 they were transferred to the Viribus Unitis for voyage to Trieste.

On May 24, 1915, the Viribus Unitis took part in the bombardment of the town of Ancona, then returned to Pola. On Apr 12, 1918 it was on exercises with Szent István. It left Pola with Prinz Eugen on June 8, 1918, arriving at Tajer on June 9; at Slano on June 10, then returned to Pola.

With the fall of the Austro-Hungarian Empire, the state of Yugoslavia was formed by the southern Slavs and declared on the side of the Allies. Viribus Unitis (Capt. Janko Vukovic de Podkapelski, also provisional Yugoslav Fleet commander) was taken over on the 31st October by the Yugoslav National Council as the flagship of the new navy. In fact, it was slated to be the first and largest ship in the Croatian/SHS Navy. 

Raffaele Rossetti	Raffaele Paolucci

Presumably unaware of the changed circumstances, the Italians went ahead with a planned attack on Pola. Early in the morning of the 1st of November and with few defensive precautions now being taken, two Italian frogmen, Maj. of Naval Engineers Raffaele Rossetti and Doctor Lt. Raffaele Paolucci, slipped into the naval base and attached "Mignatta" (or leech) self-propelled mines to the dreadnought and the liner Wien. Both ships sank, Viribus Unitis capsizing and going down around dawn. 

Mignatta mines	Map of the planned attack (click image for larger view)

One report said that several hundred men died including the new Captain, another said 400 lost their lives. Either way, the Austrian Captain had command of his ship only a day or two before losing his ship, his command, and his life. Thus, the pride of the Austrian navy met her untimely death at the Pola naval base (c 44-45'N, 13-45'E). In 1920-30, the ship was scrapped in 200 feet of water.

Click image to see enlargement

The sinking of the Viribus Unitis as viewed from the Tegetthoff