Recognition Guide Warships of the Second World War
Royal Netherlands Navy — Submarine

German submarine UD-4

O 21-class submarine

Displacement
987 long tons (1,003 t)
Length
77.72 m (255 ft)
Beam
6.4 m (21 ft)
Speed
19.5 knots (36.1 km/h, 22.4 mph)
Complement
60
Main gun
20 mm (0.8 in)

Service

  1. Royal Netherlands Navy as O 262,193 days of the war
  2. Kriegsmarine as UD-428 January 1941 — 19 March 19451,511 days of the war
O 21-class submarine Particulars
Name
UD-4
Builder
Rotterdamsche Droogdok Maatschappij, Rotterdam
Ordered
24 June 1938
Laid down
20 April 1939
Launched
23 November 1940
Commissioned
28 January 1941
Decommissioned
19 March 1945
Fate
Scuttled, 3 May 1945 (1945)
Status
Wreck

Specifications

Displacement, surfaced
987 long tons (1,003 t)
Displacement, submerged
1,488 long tons (1,512 t)
Length
77.72 m (255 ft)
Beam
6.4 m (21 ft)
Draught
3.96 m (13 ft)
Speed
19.5 knots (36.1 km/h, 22.4 mph)
Range
10,000 nmi (18,520 km)
Complement
60
Main gun
20 mm (0.8 in)

UD-4 was a O 21-class submarine, operated by the Royal Netherlands Navy. Rotterdamsche Droogdok Maatschappij, Rotterdam laid her keel on 20 April 1939. She entered service on 28 January 1941, having been launched on 23 November 1940.

She was one of seven ships of her class. The class followed the O 19-class submarine and was succeeded by the Dolfijn-class submarine.

The boat displaced 987 long tons surfaced and 1,488 long tons submerged. She measured 77.7 m (255 ft) long with a beam of 6.4 m (21 ft). Her designed speed was 19.5 knots, and she carried a complement of 60.

Her main battery was two 20 mm (0.8 in) guns.

She served with the Royal Netherlands Navy as O 26. She then passed to the Kriegsmarine, serving as UD-4 from 28 January 1941. She was in commission for 3,704 days of the Second World War. She was decommissioned on 19 March 1945.

She was scuttled on 3 May 1945. The wreck survives.

Written from the harvested record. Every figure above is sourced; the wording is this site's own.

Armament and machinery

Armament and machinery
Propulsion
  • 2 × 2500 bhp diesel engines
  • 2 × 500 bhp electric motors
Armament
  • 4 × 21 in bow torpedo tubes
  • 2 × 21 in stern torpedo tubes
  • 2 × 21 in external traversing torpedo tubes
  • 2 × 2 cm AA guns

Sister ships

Sources