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 scrapping, 24 January 1958
General characteristics [1]
Class and type	O 21-class submarine
Displacement	990 tons surfaced 1205 tons submerged
Length	77.7 m (254 ft 11 in)
Beam	6.8 m (22 ft 4 in)
Draught	3.95 m (13 ft 0 in)
Propulsion	2 × 2,500 bhp (1,864 kW) diesel engines 2 × 500 bhp (373 kW) electric motors
Speed	19.5 kn (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 12 kn (22 km/h; 14 mph) surfaced 28 nmi (52 km; 32 mi) at 8.5 kn (15.7 km/h; 9.8 mph) submerged
Complement	39
Armament	4 × 21 in (533 mm) bow torpedo tubes 2 × 21 in stern torpedo tubes 2 × 21 in (1×2) external-traversing TT amidships

O 21, laid down K XXI was an O 21-class submarine of the Royal Netherlands Navy that saw service during World War II. During the war she sank several ships, among them the German submarine U-95.

Ship history

The submarine was laid down on 20 November 1937 as K XXI at the Koninklijke Maatschappij De Schelde, Vlissingen During construction she was renamed O 21, and was finally launched on 21 October 1939. Following the German invasion of 10 May 1940, the O 21 was hastily commissioned, still incomplete, and sailed for England on 12 May together with her sister O 22 and the tugboat B.V. 37, to be finally completed at the Navy yard in Rosyth.^[2]

During the war she operated around England, the Mediterranean Sea, Colombo in the Indian Ocean and Fremantle off the west coast of Australia. She survived the war and was decommissioned on 2 November 1957 and sold for scrap the following year.^[2]

Summary of raiding history

Ships sunk and damaged by O 21.^[3]