HNLMS O 21

	O 21
History
Netherlands
Name	O 21
Builder	Koninklijke Maatschappij De Schelde, Vlissingen
Laid down	20 November 1937
Launched	21 October 1939
Commissioned	10 May 1940
Decommissioned	2 November 1957
Fate	Sold for scrap, 24 January 1958
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)
Draft	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 × single 40 mm (1.6 in) AA guns;

O 21 was the lead ship of her class of submarines built for the Royal Netherlands Navy during the 1930s for European service. Completed in 1940, she sank several ships during World War II, among them the German submarine U-95.