Type IX U-Boats

The Type IX U-boat was designed as a long-distance ocean going cruiser submarine. During 1935 German naval command stupulated the need for a U-boat that had:

"A range sufficient for a lengthy stay in the Western Mediterraneran.
"A sufficiently high cruising speed to keep as short as possible the time spent getting to and from the zone of operation and to facilitate quick and speedy results when in action.
"The ability to carry a sufficient number of torpedoes or mines, whichever has to be carried to bring about the maximum effect on all operations undertaken"

While the Type VII was the design favoured by Dönitz as the prefect compromise between weight and weaponload, it was considered too small to match the above requirements by those who controlled the building programme. Correspondingly, the larger Type I had not met expectations and was proving a relative failure. Thus, by the end of 1935 the Type IX design was approved.

Improvements over the Type I included supercharged 9-cylinder diesel engines (replacing the 8-cylinder ones used in the Type Is), the conning tower moved to the centre of the boat for improved stability, greater hull streamlining, thicker pressure hull, two rudders (one behind each prop) and a restructured and more finely balanced interior.

U37, laid down in Bremen's A.G.Weser shipyard on 15 May 1937, was the first to be launched on 14 May 1938, commissioned into the Kriegsmarine (Hundius Flotilla) less than three months later.

During the years that followed the Type IX underwent several modifications, leading to the IXB, IXC andIXC/40 (the IXD-1 and IXD-2, capable of traversing the routes between France and Japan, will be dealt with elsewhere).

Dimensions: IXA - 76.5 metres x 6.51 metres x 4.7 metres (draught).
IXB - 76.5 metres x 6.76 metres x 4.7 metres (draught).
IXC - 76.7 metres x 6.76 metres x 4.7 metres (draught).
IXC40 - 76.7 metres x 6.86 metres x 4.67 metres (draught).

Displacement: IXA - 1,032 tons (1,153 tons submerged).
IXB - 1,051 tons (1,178 tons submerged).
IXC - 1,120 tons (1,232 tons submerged).
IXC40 - 1,144 tons (1,257 tons submerged).

Complement: 4 officers, 44 crew.

Armament: 4 x 53.3cm 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)

U162 - 170, 505 - 550 not fitted for mines.

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.

U66 - 68, U103, U104, U124 - 131, U153 - 158 fitted as communications boats.

Propulsion: 2 x MAN 9-cylinder, 4-stroke, M 9 V 40/46 supercharged diesels in compartment two. 2 x Siemens - Schuckert 2 GU 345/34 double electric motors in compartment two. 1 + 1 62-cell AFA 36 MAK 740 battery in battery boxes with rubber shock absorbers (9260 amps/hour) stored below flooring in compartments four. (U38 had 1 x 62-cell AFA 36 MAK 740 W battery - 4630 amp/hours - plus 1 x 62-cell AFA 44 MAL 740 W battery. U37 and U43 had 1 + 1 62-cell AFA 44 MAL 740 W batteries - 11,300 amp/hours).

Speed: IXA & IXB: 18.2 knots surfaced / 7.7 knots submerged.
IXC & IXC40: 18.3 knots/ 7.3 knots submerged.

Endurance:
IXA - 11,350 miles (diesel electric surfaced) @ 10 knots.
10,500 miles (surfaced, cruising) @ 10 knots.
MAK battery: 128 miles (submerged) @ 2 knots.
MAK battery: 65 miles (submerged) @ 4 knots.
MAL battery: 152 miles (submerged) @ 2 knots.
MAL battery: 82 miles (submerged) @ 4 knots.

IXB - 12,400 miles (diesel electric surfaced) @ 10 knots.
12,000 miles (surfaced, cruising) @ 10 knots.
134 miles (submerged) @ 2 knots.
64 miles (submerged) @ 4 knots.

IXC - 16,300 miles (diesel electric surfaced) @ 10 knots.
13,450 miles (surfaced, cruising) @ 10 knots.
128 miles (submerged) @ 2 knots.
63 miles (submerged) @ 4 knots.

IXC40 - 16,800 miles (diesel electric surfaced) @ 10 knots.
13,850 miles (surfaced, cruising) @ 10 knots.
128 miles (submerged) @ 2 knots.
63 miles (submerged) @ 4 knots.