Italian submarine Ondina

History
Kingdom of Italy
Name	Ondina
Namesake	Undine
Builder	Cantieri Riuniti dell'Adriatico, Monfalcone
Laid down	1931
Launched	2 December 1933
Fate	Sunk, 11 July 1942
General characteristics
Class and type	Sirena-class submarine
Displacement	691 t (680 long tons) (surfaced); 850 t (837 long tons) (submerged);
Length	60.18 m (197 ft 5 in)
Beam	6.45 m (21 ft 2 in)
Draft	4.7 m (15 ft 5 in)
Installed power	1,350 kW) (diesels); 800 hp (600 kW) (electric motors);
Propulsion	2 shafts; diesel-electric; 2 × diesel engines; 2 × electric motors;
Speed	14 knots (26 km/h; 16 mph) (surfaced); 7.5 knots (13.9 km/h; 8.6 mph) (submerged);
Range	5,000 nmi (9,300 km; 5,800 mi) at 8 knots (15 km/h; 9.2 mph) (surfaced); 72 nmi (133 km; 83 mi) at 4 knots (7.4 km/h; 4.6 mph) (submerged);
Armament	1 × single 100 mm (3.9 in) deck gun; 2–4 × single 13.2 mm (0.52 in) machine guns; 6 × 533 mm (21 in) torpedo tubes (4 bow, 2 stern);

Ondina was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina (Royal Italian Navy) during the early 1930s.

Design and description

The Sirena class was an improved and enlarged version of the preceding Argonauta-class submarines. They displaced 691 metric tons (680 long tons) surfaced and 850 metric tons (837 long tons) submerged. The submarines were 61.5 meters (201 ft 9 in) long, had a beam of 5.7 meters (18 ft 8 in) and a draft of 4.7 meters (15 ft 5 in). Their crew numbered 45 officers and enlisted men.^[1]

For surface running, the boats were powered by two 675-

propeller shaft. When submerged each propeller was driven by a 400-horsepower (298 kW) electric motor. They could reach 14 knots (26 km/h; 16 mph) on the surface and 7.5 knots (13.9 km/h; 8.6 mph) underwater.^[2] On the surface, the Sirena class had a range of 5,000 nautical miles (9,300 km; 5,800 mi) at 8 knots (15 km/h; 9.2 mph);^[1] submerged, they had a range of 72 nmi (133 km; 83 mi) at 4 knots (7.4 km/h; 4.6 mph).^[2]

The boats were armed with six 53.3-centimeter (21 in)

13.2-millimeter (0.52 in) machine guns.^[1]

Construction and career

Ondina was

laid down by Cantieri Riuniti dell'Adriatico at their Monfalcone shipyard in 1931, launched on 2 December 1933 and completed the following year.^[1]

On 23 June 1941 Ondina under the command of Corrado Dal Pozzo at location indicated as (36.08N-34.44E) in Italian naval records. Ondina and Italian Naval records show the submarine fired a torpedo and sank the Turkish Transport vessel Refah of whom only 32 survived out of 200 on board.

Ondina was also sunk a year later by the warships HMSAS Protea, HMSAS Southern Maid (both Southern-class whalers) and Supermarine Walrus warplanes near Cyprus At (34-35 N, 34-56 E) on 11 July 1942. However, the command of Ondina was under Lieutenant Gabriele Adolfi at that time. The Italian sailors from Ondina were recovered by the warships. (5 killed/41 survived).^[3]