Otranto Barrage - Raids and Battles

Raids and Battles

The Austrians mounted a number of nighttime raids against the barrage, five in 1915, nine in 1916 and ten in 1917. The largest raid was on the night of 14/15 May 1917 when the cruisers Novara, Helgoland, and Saida supported by the destroyers Csepel, Balaton and Austro-Hungarian U-boats SMS U-4 and SM U-27, along with German U-boat SM UC-25 (operating as Austro-Hungarian U-boat U-89). The fleet, commanded by Admiral Miklós Horthy, sank 14 drifters out of 47 on duty, and damaged a further three seriously.

Skipper Joseph Watt was later awarded the Victoria Cross for defending his drifter Gowanlea under heavy attack from the SMS Novara. The British cruisers HMS Dartmouth and Bristol—together with Italian and French destroyers, under command of Italian Rear Admiral Alfredo Acton—steamed from Brindisi to engage the Austrians, resulting in the Battle of the Otranto Straits. The British damaged Saida and disabled Novara, severely injuring Horthy. However, the British cruisers broke off the engagement when the Italian flag officer had notice of heavy Austrian forces coming out of Cattaro and Saida towed Novara back to port. Dartmouth was damaged by UC-25 as it returned to Brindisi. The night before, the same U-boat had laid a minefield at the mouth of Brindisi harbour; the French destroyer Boutefeu struck one of these mines exiting the harbour the very same day and exploded, sinking with all hands.

In June 1918, Horthy—by now commander-in-chief of the Austro-Hungarian Navy—determined to launch an attack on the barrage employing the four Tegetthoff-class battleships based at Pola, the most modern in the fleet. While en route down the Adriatic, the dreadnought SMS Szent István was torpedoed and sunk by an Italian torpedo boat at dawn on 10 June, resulting in the attack being cancelled.