German submarine UD-4

History
Netherlands
Name	O 26
Ordered	24 June 1938
Builder	Rotterdamsche Droogdok Maatschappij, Rotterdam
Yard number	RDM-209
Laid down	20 April 1939
Captured	By Germany, 14 May 1940
Nazi Germany
Name	UD-4
Launched	23 November 1940
Acquired	14 May 1940
Commissioned	28 January 1941
Decommissioned	19 March 1945
Fate	Scuttled, 3 May 1945
General characteristics
Class & type	O 21-class submarine
Displacement	987 long tons (1,003 t) (surfaced); 1,488 long tons (1,512 t) (submerged);
Length	255 ft (77.7 m)
Beam	21 ft 6 in (6.6 m)
Draught	13 ft (4.0 m)}
Propulsion	2 × 2,500 bhp (1,864 kW) diesel engines; 2 × 500 bhp (373 kW) electric motors;
Speed	19.5 knots (36.1 km/h; 22.4 mph) (surfaced); 9 kn (17 km/h; 10 mph) (submerged);
Range	10,000 nmi (19,000 km; 12,000 mi) at 11 knots (20 km/h; 13 mph) (surfaced); 28 nmi (52 km; 32 mi) at 9 kn (17 km/h; 10 mph) (submerged);
Test depth	330 ft (100 m)
Complement	60
Armament	4 × 21 in (533 mm) bow torpedo tubes; 2 × 21 in (533 mm) stern torpedo tubes; 2 × 21 in (533 mm) external traversing torpedo tubes; 2 × 2 cm (0.8 in) AA guns;

UD-4 was an O 21-class submarine built for the Royal Netherlands Navy during the 1930s for European service. The boat was captured incomplete during the German invasion of the Netherlands in May 1940 during World War II and was later commissioned into the Kriegsmarine as UD-4. The submarine served as a training boat during the war. She was decommissioned in early 1945 and scuttled in May 1945.