Type IXD U-Boats

The Type IXD U-boat was designed as an extension to the already tried and tested long-distance ocean going cruiser submarines, IXC. These new models had increased size, the Type IXD2 considrably enlarged fuel bunkerage. However, the initial Type IXD1 proved unsatisfactory and the power increased by coupling a pair of slow running diesels to each propeller shaft, rather than single fast running engines.

The development of the Type IXD was also largely influenced by a desire to develop a transport submarine that could traverse the Atlantic and Indian Oceans to the Far East, the Type IXD1 ultimately being the unarmed result, its torpedo tubes removed after a brief combat career to allow for greater storage capacity aboard. The Type IXD2 essentially became the fighting version of the IXD1, with upgraded machinery layout.

Dimensions:
IXD1 - 87.6 metres x 7.5metres x 5.4 metres (draught).
IXD2 - 87.6 metres x 7.5 metres x 5.4 metres (draught).

Displacement:
IXD1 - 1, 610 tons (1,799 tons submerged).
IXD2 - 1,610 tons (1,799 tons submerged).

Complement: 4 officers, 53crew.

Armament:
IXD1: 1 x 3.7cm AA cannon
4 x 2cm (2 x 2) AA cannon

252 tons of fuel oil carried as cargo

IXD2: 4 x 53.3cm (21") torpedo tubes at bow below the designed waterline.
2 x 53.3cm (21") torpedo tubes at stern below the designed waterline.

22 x torpedoes or 44 TMA (66 TMB)

1 x Utof 10.5cm/45 deck cannon (110 rounds).

1 x 3.7cm AA (2,625 rounds).

1 x 2cm AA cannon (4,250 rounds).

From 1943 the 10.5cm cannon removed and two twin 2cm AA mounted in place of the single.

Propulsion:
IXD1: 2-shaft diesel/electric motors, BHP/SHP 2,800/1,100. Originally powered by six fast running diesel engines (three per shaft), but soon proven unsatisfactory.

IXD2: 2-shaft diesel (two engines per shaft) / electric motors, BHP/SHP 5,400/1,100.

Speed:
IXD1: 16 knots surfaced / 7 knots submerged.
IXD2: 19.25 knots/ 7 knots submerged.

Endurance:
IXD1 - 9,900 miles (diesel electric surfaced) @ 12 knots.
115 miles (submerged) @ 4 knots.

IXD2 - 23,700 miles (diesel electric surfaced) @ 12 knots.
57 miles (submerged) @ 4 knots.

Rated Depth: 108 metres