HNLMS O 12
Class overview
Name	O 12
Builders	Koninklijke Maatschappij De Schelde (3) Fijenoord (1)
Operators	Royal Netherlands Navy
Preceded by	O 9 class
Succeeded by	O 16
Built	1928–1932
In commission	1931–1945
Completed	4
General characteristics
Type	Submarine
Displacement	610 tons surfaced 754 tons submerged
Length	60.42 m (198 ft 3 in)
Beam	6.83 m (22 ft 5 in)
Draught	3.6 m (11 ft 10 in)
Propulsion	2 × 900 bhp (671 kW) diesel engines 2 × 310 bhp (231 kW) electric motors
Speed	16 kn (30 km/h; 18 mph) surfaced 8 kn (15 km/h; 9.2 mph) submerged
Range	3,500 nmi (6,500 km; 4,000 mi) at 8 kn (15 km/h; 9.2 mph) or 10 kn (19 km/h; 12 mph) on the surface 26 nmi (48 km; 30 mi) at 8 kn (15 km/h; 9.2 mph) submerged
Complement	29–31
Armament	4 × 21 inch bow torpedo tubes 1 × 21 inch stern torpedo tube 2 × 44 mm guns 1 × 12.7 mm machine gun

The O 12-class submarine consisted of four submarines built for the Royal Netherlands Navy. The ships, with a diving depth of 60 metres (200 ft), were used for patrols in the Dutch home waters. The class comprised O 12, O 13, O 14 and O 15. O 12 entered German service in 1943 as UD-2.

The ships were built by two shipyards. O 12, O 13 and O 14 were built by Koninklijke Maatschappij De Schelde in Vlissingen and O 15 in Rotterdam at Fijenoord shipyard.

• Jalhay, P.C.; Wijn, J.J.A. (1997). Ik nader ongezien! De onderzeeboten van de Koninklijke Marine [I'm Approaching Unseen! The submarines of the Royal Netherlands Navy] (in Dutch). Amsterdam: De Bataafsche Leeuw. ISBN 978-90-6707-462-9.

• Description of class