Italian submarine Adua

Italian submarine Adua was an built in the 1930s, serving in the Regia Marina during World War II. She was named after a town Adwa in northern Ethiopia.

Design and description
The Adua-class submarines were essentially repeats of the preceding. They displaced 680 t surfaced and 844 t submerged. The submarines were 60.18 m long, had a beam of 6.45 m and a draft of 4.7 m.

For surface running, the boats were powered by two 600 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 400 hp electric motor. They could reach 14 kn on the surface and 7.5 kn underwater. On the surface, the Adua class had a range of 3180 nmi at 10.5 kn, submerged, they had a range of 74 nmi at 4 kn.

The boats were armed with six internal 53.3 cm torpedo tubes, four in the bow and two in the stern. They were also armed with one 100 mm deck gun for combat on the surface. The light anti-aircraft armament consisted of one or two pairs of 13.2 mm machine guns.

Construction and career
Adua was built at the CRDA shipyard, in Monfalcone. She was laid down on 1 February 1936, launched on 13 September of the same year, and commissioned on 14 November 1936. After intense 1937 spring training in the waters of the Dodecanese, Greece and Libya, Adua was assigned to the 23rd Squadron based at Naples. In 1939 she was transferred to Cagliari and became part of the 71st Squadron (VII Submarine Group).

On June 10, 1940 at the time of Italy's entrance into World War II, Adua was already at sea, south of Sardinia (between Cape Teulada and the island of La Galite) under command of Giuseppe Roselli Lorenzini. On June 13, she moved to an area between Ibiza and Mallorca and later to the Gulf of Lion fifteen miles east of Cape Creus. During night of June 17, 1940 Adua sighted a destroyer, but could not launch an attack. The following morning, she sighted a French convoy (five merchants and two escorts) on the Marseille - Toulon route. Not being able to approach because of the escort, she launched a single torpedo from 1,800 meters at a larger transport. However, there are no confirmations of any ships being damaged or sunk on this day at this time and this location.

Shortly thereafter, captain Luigi Riccardi assumed command of the submarine.

From October 22, 1940 to March 12, 1941 Adua served as the training vessel at the Pola Submarine School. During this span she carried out 46 training missions. Carlo Todaro and Mario Resio served as her commanders during this time. In mid-March 1941 Adua was transferred back to Taranto, and she was again put under command of captain Luigi Riccardi.

From March to May 1941 Adua was deployed in the Gulf of Taranto, and also off the coast of Greece, carrying out three unsuccessful missions:


 * In March, forty miles west of Lefkada, then in the Gulf of Taranto;
 * In April, south of Cape Krio and in Kythira Strait;
 * In May, between Alexandria and Kasos Strait at first, then south of Crete.

On May 10, 1941 she was transferred to Leros.

At 01:30 on June 3, 1941 she intercepted a small motor barge carrying gasoline and 72 British troops on board, including 8 officers, attempting to reach Egyptian coast. Adua took officers prisoner, and escorted the vessel to Crete, where other soldiers were taken prisoners.

On June 4, 1941, she headed back to Taranto where the submarine underwent a three-month long maintenance at the Arsenal of Taranto.

In the middle of September Adua operated near Menorca returning to Cagliari on September 16.

On September 23, 1941 the submarine left Cagliari to set an ambush on the route of the British convoy to Malta (Operation Halberd) together with three other submarines. On September 26 Adua was near Cape Palos, north of Spanish city of Cartagena. The British convoy went undetected and reached Malta. The submarines, including  Adua spotted and attacked British ships on their return. On September 30, 1941 at 3:50 Adua detected a group of eleven English destroyers, and attacked them with a four-torpedo salvo, but missed them and then moved north. Shortly after at 5:25, Adua sent a radio transmission to the Headquarters informing them of British convoy position. She was never heard from again.

After the war, it was discovered that the submarine had been traced by two destroyers, HMS Gurkha (G63) and HMS Legion (G74) (perhaps it was the radio communication with the base that allowed British ships to locate her). After having detected Adua with ASDIC, they started depth charge attacks, and at 10:30 hit and sunk Adua with all hands in the position 37.16667°N, 0.93333°W or 36.83333°N, 0.93333°W.