At various times between 1909 and 1912, each of the Nembo-class destroyers underwent a radical modernization; Espero′s took place in 1912. Her coal-fired boilers were converted into oil-fired ones, and her original two short, squat funnels were replaced with three smaller, more streamlined ones, profoundly altering her appearance. Her armament also changed, with her original five QF 6 pounder Nordenfelt 57 mm/43 guns replaced by four Cannon 76/40 (3 in) Model 1916 guns, and her original four 356-millimetre (14in)torpedo tubes replaced by two 450-millimetre (17.7in) tubes.[2][3][4] Sometime between 1914 and 1918, Espero underwent additional modifications in which minelaying equipment was installed aboard her.[3][4]
At 19:00 on 8June1916 Espero departed Vlorë (known to the Italians as Valona) in the Principality of Albania with the protected cruiserLibia and the destroyers Impavido, Insidioso, and Pontiere to escort the armed merchant cruiserPrincipe Umberto and the troopshipRomagna, which together had embarked the 2,605 men of the Italian Royal Army′s (Regio Esercito′s) 55th Infantry Regiment for transportation to Italy. The convoy had traveled only a short distance when the Austro-Hungarian submarine U-5 hit Principe Umberto in the stern with two torpedoes. Principe Umberto sank in a few minutes about 15 nautical miles (28km; 17mi) southwest of Cape Linguetta with the loss of 1,926 of the 2,821 men on board, the worst naval disaster of World War I in terms of lives lost. The escorting warships rescued the survivors but could not locate and counterattack U-5.[5]
Espero continued her World War I service without taking part in any other significant actions. By late October1918, Austria-Hungary had effectively disintegrated, and the Armistice of Villa Giusti, signed on 3November1918, went into effect on 4November1918 and brought hostilities between Austria-Hungary and the Allies to an end. World War I ended a week later with an armistice between the Allies and the German Empire on 11November1918.
Fiume
Espero at Fiume in December1920. Note damage to her bridge.
Before Italy entered World War I, it had made a pact with the Allies, the Treaty of London of 1915, in which it was promised all of the Austrian Littoral, but not the city of Fiume (known in Croatian as Rijeka). After the war, at the Paris Peace Conference in 1919, this delineation of territory was confirmed, with Fiume remaining outside of Italy's borders and amalgamated into the Kingdom of the Serbs, Croats and Slovenes (which in 1929 would be renamed the Kingdom of Yugoslavia). Opposing this outcome, the poet and Italian nationalistGabriele D'Annunzio led a force of about 2,600 so-called "legionaries" to Fiume and seized the city in September 1919 in what became known as the Impresa di Fiume ("Fiume endeavor" or "Fiume enterprise"). The Italian government opposed D'Annunzio's move, and in response D'Annunzio declared Fiume to be the Italian Regency of Carnaro in September 1920. Relations between Italy and D'Annunzio's government continued to deteriorate, and after Italy signed the Treaty of Rapallo with the Kingdom of the Serbs, Croats, and Slovenes in November 1920, making Fiume an independent state as the Free State of Fiume rather than incorporating it into Italy, D'Annunzio declared war on Italy.
At the time, Espero was serving in the Adriatic Sea on escort duty on the shipping route between Šibenik (known to the Italians as Sebenico) and Trieste. She switched to D'Annunzio's side and arrived at Fiume on 8December1920 to support him.[6] Italy launched a full-scale invasion of Fiume on 24December1920, beginning what became known as the Bloody Christmas. The Italian battleshipAndrea Doria fired on Espero on 26December, inflicting serious damage on her and setting her on fire, and one of the men killed during the Bloody Christmas was a member of her crew.[6][7][8][9]
The Bloody Christmas fighting ended on 29December1920 in D'Annunzio's defeat and the establishment of the Free State of Fiume. In January 1921, Espero arrived at Pula for repairs and modifications. Like other Italian ships which had supported D'Annunzio, she was disarmed and briefly stricken from the naval register.[6]
Later service
The ship as the torpedo boatTurbine sometime between 1921and1923.
Espero was reinstated on 16January1921 with the name Turbine, the name previously held by her sister ship Turbine, which Austro-Hungarian ships had sunk on 24May1915. After completion of her repairs and modifications — which included the removal of one 76-millimetre gun and the installation of a Colt Browning 65-millimeter/80-caliberantiaircraftmachine gun[4] — Turbine returned to operations in June 1921. Reclassified as a torpedo boat in July 1921, she again was stricken from the naval register in 1923[3] and subsequently scrapped.