On 3December1915 Impetuoso , Indomito, Insidioso, Intrepido, and Irrequieto got underway from Brindisi to escort one of the first supply convoys for Italian troops in Albania. As the convoy — composed of the troop transports Re Umberto and Valparaiso, carrying a total of 1,800 men and 150 draft animals — approached Shëngjin (known to the Italians as San Giovanni di Medua) on the coast of Albania, Re Umberto, with 765 men on board, hit a mine laid by the Imperial German NavysubmarineUC-14, broke in two, and sank in 15 minutes. Rescuers saved 712 men.[3][4][5]
On 8 December 1915, Impetuoso and Insidioso escorted the steamshipPalermo, carrying over 700 men and 43 draft animals, from Taranto to Vlorë (known to the Italians as Valona) in Albania. On the night of 11–12 December 1915Impetuoso, still under Sirianni's command, and Insidioso escorted Valparaiso, loaded with troops, from Taranto to Vlorë.[5]
1916
On 23February1916 Impetuoso and Insidioso bombarded Austro-Hungarian artillery positions on the mountain Sasso Bianco in the Dolomites during the evacuation of Durrës (known to the Italians as Durazzo) in Albania.[4] The same day, Impetuoso, Indomito, the protected cruisers Libia and Puglia, and the destroyer Ardito positioned themselves in the harbor at Durrës to protect the withdrawal of the "Savona" Brigade.[4] Some sources claim that Impetuoso sank a Central Powers submarine sometime in the next few days,[4] although there was no confirmation of the sinking.
On 9July1916 Impetuoso (now under the command of an officer named Ponza di San Martino) and Irrequieto set out in pursuit of the Austro-Hungarian scout cruiserNovara, which had attacked the Otranto Barrage in the Strait of Otranto and sunk the naval drifters — armed fishing boats that patrolled anti-submarine barriers — Astrum, Claivis, and Spei, but Novara reached the Austro-Hungarian naval base at Cattaro before they could intercept her.[4]
At 15:30 on 10July1916 Impetuoso and Insidioso were patrolling the barrage when the Austro-Hungarian submarine U-17 attacked them. Impetuoso′s crew sighted the wake of U-17′s torpedo at a range of only 150 metres (160yd), too late for her to take evasive action. The torpedo hit Impetuoso and she sank suddenly[4] in position 40°10′N018°50′E / 40.167°N 18.833°E / 40.167; 18.833 (Impetuoso)[6] with the loss of 37 lives.[4] Fifty-one men were rescued.[4]
Favre, Franco. La Marina nella Grande Guerra. Le operazioni navali, aeree, subacquee e terrestri in Adriatico (in Italian).{{cite book}}: CS1 maint: ref duplicates default (link)
Fraccaroli, Aldo (1985). "Italy". In Gray, Randal (ed.). Conway's All the World's Fighting Ships 1906–1921. Annapolis: Naval Institute Press. pp.252–290. ISBN978-0-87021-907-8.