SMS Szent István

The Vessel

SMS Szent István (Hungarian: "Saint Stephen") was an Austro-Hungarian dreadnought battleship of the Tegetthoff class, built at the Hungarian Danube Shipbuilding Company yard at Fiume (now Rijeka, Croatia) between 1912 and 1915 and commissioned on 13 December 1915. She was 152 metres long, 20,000 tons displacement, and armed with twelve 30.5-centimetre primary guns in four triple-gun turrets (two forward, two aft), twelve 15-centimetre secondary guns in casemate positions, and four 53-centimetre torpedo tubes. Her armour protection included a 280-millimetre main belt of Krupp cemented armour, 280-millimetre turret face armour, and 76-millimetre deck armour.

She was the last of the four Tegetthoff-class dreadnoughts completed by the Austro-Hungarian Navy and, at her commissioning in December 1915, among the most powerful capital ships in the Mediterranean. Her specific distinction, beyond her sister ships, was her Hungarian construction: she was the only major Austro-Hungarian capital ship built at a Hungarian shipyard (Fiume) rather than at the Austrian naval arsenal at Pola. Her construction had been the specific political commitment of the Hungarian government in the Austro-Hungarian Compromise of 1867; the Hungarian political class had insisted that the Hungarian shipbuilding industry be represented in the Austro-Hungarian dreadnought programme.

By June 1918, Szent István had been the Austro-Hungarian fleet's flagship at various points of the First World War. Her operational deployment had been substantially constrained by the Italian naval blockade of the Adriatic, which effectively kept the Austro-Hungarian fleet bottled up at Pola through the majority of the war.

Her master on her final voyage was Captain Heinrich Seitz, 42. Her complement was approximately 1,094 officers and ratings.

The Voyage

In June 1918, Admiral Miklós Horthy (the future Hungarian regent, then commander of the Austro-Hungarian Navy) planned Operation Istria: a major surface-fleet operation intended to break the Italian naval blockade of the Strait of Otranto. The planned operation involved the full Austro-Hungarian battle-fleet (four Tegetthoff-class dreadnoughts: Viribus Unitis, Tegetthoff, Prinz Eugen, Szent István), supporting pre-dreadnought battleships, and extensive destroyer and torpedo-boat screens.

The operational objective was the destruction of the Italian-French-British Otranto Barrage, a combined Allied naval force that had been blockading the southern exit of the Adriatic since 1915. The destruction of the barrage would have permitted Austro-Hungarian submarines to operate freely into the Mediterranean and would have substantially improved the German-Austrian strategic position in the eastern Mediterranean.

Szent István and her sister-ship Tegetthoff departed Pola in the evening of 9 June 1918, in the first wave of the operation, bound for the rendezvous point off the Dalmatian island of Premuda. The ships were sailing at approximately 14 knots on an easterly course; the weather was fair; the sea state was moderate.

At approximately 03:15 on 10 June 1918, the Italian Motoscafo Armato Silurante (MAS) torpedo boat MAS 15, commanded by Capitano di Corvetta Luigi Rizzo, detected the two Austrian battleships at approximately 800 metres range. The MAS boats were a specific Italian naval innovation: small (approximately 16 metres long), fast (30 knots), torpedo-armed motor boats designed for rapid hit-and-run attacks on larger surface vessels. MAS 15 and her consort MAS 21 had been patrolling the Dalmatian coast on anti-shipping patrol; their encounter with the Austrian battleships was substantially accidental.

The Disaster

Capitano Rizzo's tactical response was immediate and aggressive. MAS 15 closed to approximately 300 metres of Szent István and launched her two 45-centimetre torpedoes; MAS 21 similarly engaged Tegetthoff, but Tegetthoff's torpedo strike failed to detonate. The torpedo launches occurred at approximately 03:25 on 10 June 1918.

Both of MAS 15's torpedoes struck Szent István on her starboard side. The first torpedo struck at approximately frame 32 (forward of the amidships), below the waterline, and exploded against the ship's starboard side. The second torpedo struck at approximately frame 48 (amidships), also below the waterline, and exploded against the ship's starboard side. The two torpedo impacts produced a single catastrophic breach of approximately 25 metres along the ship's starboard side.

The immediate damage control response was systematic but ultimately insufficient. Szent István began to list substantially to starboard within seconds of the impact; her pumps were activated but could not keep pace with the flooding rate; her adjacent watertight compartments were progressively compromised by the continuing structural failure. Captain Seitz's standard counter-flooding response (flooding port-side compartments to compensate for the starboard flooding) was implemented but was substantially inadequate for the specific damage pattern.

Over the subsequent two hours, Szent István's list progressively increased from 5 degrees to 10 degrees to 15 degrees to 25 degrees. At approximately 06:05 on 10 June 1918, the list exceeded approximately 35 degrees and the ship passed the point of recoverable stability. SMS Szent István capsized at approximately 06:12 on 10 June 1918 in approximately 60 metres of water off the Dalmatian coast.

The capsize was remarkable in naval history for being comprehensively filmed: the Austro-Hungarian Navy film unit, which had been embarked aboard the accompanying destroyer for Operation Istria documentation purposes, filmed the entire capsize sequence. The resulting footage is the only extant film record of a dreadnought battleship sinking from catastrophic damage, and has subsequently been widely distributed in naval historical documentation.

Of her 1,094 complement, 89 died: primarily killed in the initial torpedo explosions or drowned in the capsize. Approximately 1,005 survived, rescued from the water by the accompanying destroyers and by Tegetthoff's boats. Captain Seitz survived.

The Legacy

The sinking of SMS Szent István by an Italian MAS torpedo boat on 10 June 1918 was one of the most specific and consequential naval engagements of the First World War. The engagement demonstrated the tactical viability of the small, fast, torpedo-armed motor boat against the largest capital ships: a 16-metre, 22-tonne MAS boat had sunk a 152-metre, 20,000-tonne dreadnought battleship. The tactical principle - that small fast torpedo craft could produce disproportionate results against larger vessels - became a foundational principle of subsequent twentieth-century naval doctrine.

The specific operational consequence of the Szent István sinking was the cancellation of Operation Istria. Admiral Horthy, upon learning of the loss of Szent István, ordered the remainder of the Austro-Hungarian fleet to return to Pola; the major surface-fleet operation against the Otranto Barrage was abandoned. The cancellation represented the effective end of Austro-Hungarian surface-fleet operations for the remainder of the First World War.

The subsequent Austro-Hungarian naval policy reflected the specific lesson of Szent István: major surface-fleet operations in restricted coastal waters were substantially vulnerable to small-craft torpedo attack. The remaining three Tegetthoff-class dreadnoughts were retained at Pola for the remainder of the war; Austro-Hungarian naval operations emphasised submarine warfare and coastal defence rather than surface-fleet engagement.

The specific cultural memory of Szent István has been substantial in Italian, Hungarian, Austrian, and international naval history communities. The filmed sinking sequence has been widely distributed and analysed; Luigi Rizzo's torpedo attack has been studied as a foundational case in fast-torpedo-craft doctrine. The Italian Navy established Rizzo as a national hero; he was awarded the Military Order of Savoy and the Gold Medal of Military Valour; he commanded Italian naval forces in the Second World War and retired as a senior admiral.

The wreck of SMS Szent István lies in approximately 60 metres of water off Premuda, in the Croatian Adriatic. The wreck was located in 1918 by Italian post-war naval surveys and has been systematically surveyed since the 1970s. The wreck is protected under Croatian cultural heritage legislation as a designated Protected Maritime Monument. Substantial portions of her superstructure remain intact on the seabed; the ship's bell was recovered in 2007 and is displayed at the Croatian Naval Museum, Split.

The 89 dead are commemorated by memorials at the Croatian Naval Memorial, Pula; at the Hungarian National War Memorial, Budapest; and at the Austrian Naval Memorial, Vienna. The ship's capsize is annually commemorated on 10 June at Croatian, Italian, and Austrian naval ceremonies.