Type XB U-boat

Length: 89.8 metres
Beam: 9.2 metres
2117 tonnes (submerged)
Surface Speed: 17 knots
Submerged Speed: 7 knots
Max. Depth: 722 ft
Range: 18,450 miles @ 10 knots
Complement: 5 officers, 47 crew.


Designed in 1938, the Type XB U-boat was built as a submerged minelayer. Originally, it was intended to carry 66 SMA mines (Schachtmine = Shaft Mine) and 15 torpedoes. Each mine was 2.15 metres long and 1.33 metres diameter and 2 x 12 mines were to be stored in vertical shafts on each side of the hull with a further 6 mineshafts in forward outer hull . Unfortunately, due to a design fault, these mines suffered from premature detonation when they were deployed and it was not until March 1943 that the problem was rectified. Consequently, the XB was used as a U-tanker or Milchkuhs (Milk Cow) since it could carry 240-tons of fuel to supply attack U-boats to extend their endurance. Unlike the other U-boats, the XB had only stern torpedo tubes (2 x 21”).

2 x 9-cylinder 4-stroke 2100 horsepower supercharged diesel engines.
2 x 287 horsepower electric motors.
800 batteries with a total capacity of 1960 ampere hours.

15 torpedoes for the two stern torpedo tubes.
1 x 10.5cm cannon (200 rounds).
1 x 3.7cm AA cannon (2 500 rounds).
1 x 2cm AA cannon (4 000 rounds).