Alagi was built in the
CRDA shipyard, in
Monfalcone. She was laid down on 19 March 1936, launched on 15 November that year and commissioned on 6 March 1937. On 11 May 1937
Alagi was assigned to the 23rd Squadron based in
Naples, from where she conducted training in the
Dodecanese. During the
Spanish Civil War, between 27 August and 4 September 1937, she carried out a special mission. In 1939 she was reassigned for some time to the base in
Cagliari and then to
Messina. In 1940
Alagi was assigned to 71st Squadron (V Submarine Group) based at
Cagliari. On 10 June 1940, at the outbreak of hostilities,
Alagi was on patrol in the waters off
Bizerta. She remained on station until 20 June without sighting any enemy ships. From 5 to 11 June 1941,
Alagi, under command of captain Giulio Contreas, patrolled 20 miles northeast of Ras Azzaz. She sighted a small enemy ship and tried to launch an attack, but it was interrupted by a second ship which detected
Alagi and headed in her direction, forcing her to disengage. (141 killed and 165 survivors). On 12 July 1942 at 20:04, at , northwest of Tripoli, Syria,
Alagi fired two torpedoes and scored one hit in the engine room of the Turkish tanker
Antares (3723 GRT, 1893) on a trip from
Iskanderun to
Haifa, causing him to be beached on
Ruad Island. The tanker was later re-floated, towed to Turkey and scrapped in late 1943. In August 1942
Alagi operated along the
Regia Marina and
Luftwaffe to intercept and block an Allied
convoy to Malta (
Operation Pedestal). On 12 August 1942 at 21:05, at ,
Alagi fired a spread of 4 torpedoes against a merchant and a cruiser, and immediately dove. 3 explosions were heard. At 21:12 cruiser was hit forward by one of four torpedoes and sustained damage to bow structure. was able to make 25 knots and remained with the convoy to continue operating in defense of merchants. The other 2 torpedoes hit and sunk M/V
Clan Ferguson which was previously damaged by a bomb from
Ju 88. On 8 November 1942, while sailing submerged to her area of operation near
Bizerta, she collided underwater with another Italian submarine and suffered serious damage to her tower and had to turn back and return to
Naples. In December she first patrolled between Cape Bougaroun, island of
La Galite and Cape Fer and then from 29 December near
Bona, Algeria. In January 1943
Alagi patrolled northeast of Bona. From February to June 1943 she conducted several patrols south and southwest of
Sardinia. In July 1943
Alagi first patrolled south of
Sardinia, and later provided defensive screen in the waters of
Sicily. On 16 July at 6:13, at , she intercepted a column of three destroyers.
Alagi launched three torpedoes while on surface. After a minute and 45 seconds a violent explosion was heard, but no information about this action was ever reported in British official documentation. On 3 September 1943
Alagi was deployed to the
Gulf of Salerno, and on 7 September under the Zeta Plan, she was sent along with ten other submarines to the
Tyrrhenian Sea, between the
Gulf of Gaeta and the Gulf of Paola to intercept an anticipated Anglo-American landing in southern Italy. On 9 September 1943, following the announcement of the
Armistice,
Alagi which at that time was about sixty miles from
Augusta headed for
Malta, where she arrived on 16 September 1943 along with five other submarines escorted by destroyer . Upon arrival she surrender to the Allies. On 13 October 1943
Alagi together with fifteen other submarines left
Malta for mainland Italy. In October 1943,
Alagi was transferred to
Haifa where she was employed as a training unit for British troops and as a shipping vessel for supplies to the
Aegean Islands. She returned to
Taranto in December 1944, where she remained inactive until the end of the war. She was sold for scrap on 1 February 1948. == Notes ==