The ''Adua''-class submarine was the fourth sub-class of the 600 Series of

coastal submarine A coastal submarine or littoral submarine is a small, maneuverable submarine with shallow draft well suited to navigation of coastal channels and harbors. Although size is not precisely defined, coastal submarines are larger than midget submarin ...

s built for the (Royal Italian Navy) during the 1930s. There were 17 submarines in this class, almost all named after places in

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the Er ...

which had been an Italian colony since 1936, but only one, , survived World War II. Three submarines of this class (''Gondar'', ''Ascianghi'', and ''Neghelli'') were sold to Brazil before the war and replaced with submarines of the same names.

Design and description

The ''Adua''-class submarines were essentially repeats of the preceding design. They displaced surfaced and submerged. The submarines were long, had a

beam Beam may refer to: Streams of particles or energy * Light beam, or beam of light, a directional projection of light energy ** Laser beam * Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized g ...

of and a

draft Draft, The Draft, or Draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a ves ...

of .Chesneau, pp. 309–10 For surface running, the boats were powered by two

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-ca ...

s, each driving one

propeller shaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...

. When submerged each propeller was driven by a

electric motor An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate forc ...

. They could reach on the surface and underwater. On the surface, the ''Adua'' class had a range of at , submerged, they had a range of at .Bagnasco, p. 154 The boats were armed with six internal

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed abo ...

s, four in the bow and two in the stern. One reload torpedo was carried for each tube, for a total of twelve. They were also armed with one

deck gun A deck gun is a type of naval artillery mounted on the deck of a submarine. Most submarine deck guns were open, with or without a shield; however, a few larger submarines placed these guns in a turret. The main deck gun was a dual-purpose ...

for combat on the surface. The light anti-aircraft armament consisted of one or two pairs of machine guns.

Ships

Service

The boats, once commissioned, were assigned to complete the squadrons of "600" submarines strengthening the 11th and 14th Squadrons at

La Spezia La Spezia (, or , ; in the local Spezzino dialect) is the capital city of the province of La Spezia and is located at the head of the Gulf of La Spezia in the southern part of the Liguria region of Italy. La Spezia is the second largest ci ...

and 43rd at

Taranto Taranto (, also ; ; nap, label=Tarantino dialect, Tarantino, Tarde; Latin: Tarentum; Old Italian: ''Tarento''; Ancient Greek: Τάρᾱς) is a coastal city in Apulia, Southern Italy. It is the capital of the Province of Taranto, serving as an ...

. After initial training, many of these boats carried out training cruises in the

Dodecanese The Dodecanese (, ; el, Δωδεκάνησα, ''Dodekánisa'' , ) are a group of 15 larger plus 150 smaller Greek islands in the southeastern Aegean Sea and Eastern Mediterranean, off the coast of Turkey's Anatolia, of which 26 are inhabited ...

and along the coast of North Africa. During the

Spanish Civil War The Spanish Civil War ( es, Guerra Civil Española)) or The Revolution ( es, La Revolución, link=no) among Nationalists, the Fourth Carlist War ( es, Cuarta Guerra Carlista, link=no) among Carlism, Carlists, and The Rebellion ( es, La Rebeli ...

(1937–1938) five of the submarines already in service made seven special missions on behalf the Franco's regime without much success. During 1938–39 the boats largely changed their assignment locations: there was at first a single squadron on four submarines at

four other submarines formed the 23rd Squadron at

Naples Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adminis ...

, and five more were assigned to

Leros Leros ( el, Λέρος) is a Greek island and municipality in the Dodecanese in the southern Aegean Sea. It lies (171 nautical miles) from Athens's port of Piraeus, from which it can be reached by an 9-hour ferry ride or by a 45-minute flight f ...

. In 1939 there was not a single boat of the series at

, while the squadron at

was strengthened. In 1939 four boats from

and

bases were sent to

Tobruk Tobruk or Tobruck (; grc, Ἀντίπυργος, ''Antipyrgos''; la, Antipyrgus; it, Tobruch; ar, طبرق, Tubruq ''Ṭubruq''; also transliterated as ''Tobruch'' and ''Tubruk'') is a port city on Libya's eastern Mediterranean coast, near t ...

. At the outbreak of the

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, there were four submarines assigned to each of the bases of

Cagliari Cagliari (, also , , ; sc, Casteddu ; lat, Caralis) is an Italian municipality and the capital of the island of Sardinia, an autonomous region of Italy. Cagliari's Sardinian name ''Casteddu'' means ''castle''. It has about 155,000 inhabitan ...

Messina Messina (, also , ) is a harbour city and the capital city, capital of the Italian Metropolitan City of Messina. It is the third largest city on the island of Sicily, and the 13th largest city in Italy, with a population of more than 219,000 in ...

and

, and one submarine, was located at the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...

base of

Massawa Massawa ( ; ti, ምጽዋዕ, məṣṣəwaʿ; gez, ምጽዋ; ar, مصوع; it, Massaua; pt, Maçuá) is a port city in the Northern Red Sea region of Eritrea, located on the Red Sea at the northern end of the Gulf of Zula beside the Dahl ...

Notes

References

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External links