O 21-class submarine
 HNLMS O 21 | |
| Class overview | |
|---|---|
| Name: | O 21 class |
| Builders: |
R.D.M, Rotterdam (4) Koninklijke Maatschappij De Schelde, Flushing (2) Fijenoord, Rotterdam (1) |
| Operators: |
 Royal Netherlands Navy Kriegsmarine |
| Preceded by: | O 19 class |
| Succeeded by: | HNLMS Dolfijn |
| Built: | 1937–1940 |
| Completed: | 7 |
| General characteristics | |
| Type: | 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) on the surface 28 nmi (52 km; 32 mi) at 8.5 kn (15.7 km/h; 9.8 mph) submerged |
| Complement: | 39 |
| Armament: | 4 × 21 inch bow torpedo tubes 2 × 21 inch stern torpedo tubes 2 x 21 inch (1x2) external-traversing amidships |
The O 21 class was a class of seven submarines, built for the Royal Netherlands Navy. The ships were still incomplete at the start of the German invasion of the Netherlands O 21, O 22, O 23 and O 24 were hastily launched and escaped to the United Kingdom. O 25, O 26 and O 27 were not able to escape and were captured by the German forces. The Kriegsmarine ordered the completion of the ships and they entered German service as U-D3, U-D4 and U-D5. The submarines diving depth was 100 metres (330 ft).
Construction
The ships were built by three different shipyards. O 21 and O 22 were built by the Koninklijke Maatschappij. O 23, O 24, O 26 and O 27 by R.D.M, Rotterdam and O 25 also in Rotterdam at Fijenoord shipyard.
| Name | Laid down | Launched | Commissioned | Decommissioned |
|---|---|---|---|---|
| O 21 | 20 November 1937 | 21 October 1939 | 10 May 1940 (uncompleted) | 2 November 1957 |
| O 22 | 20 November 1937 | 20 January 1940 | 10 May 1940 (uncompleted) | 8 November 1940 |
| O 23 | 12 October 1937 | 5 December 1939 | 13 May 1940 (uncompleted) | 1 December 1948 |
| O 24 | 12 November 1937 | 18 March 1940 | 13 May 1940 (uncompleted) | 22 February 1954 |
| O 25 Commissioned as: U-D3 |
10 April 1939 | 1 May 1940 | 8 June 1941 | 13 October 1944 3 May 1945 (scuttled) |
| O 26 Commissioned as: U-D4 |
20 April 1939 | 23 November 1940 | 28 January 1941 | 3 May 1945 (scuttled) |
| O 27 Commissioned as: U-D5 |
3 August 1939 | 1941 | 30 January 1942 13 July 1945 (Dutch navy) |
14 November 1959 |
External links
| ||||||||||
| ||||||||||||||||||||||||||||||||||||||||||