This illustration shows the interior of a U-Boat bunker. An operational boat is undergoing repair and maintenance in one of the dry dock capable pens. These were generally intended to only accommodate one boat at a time, unlike the wet pens that could normally take at least two boats. The pen has been fully drained, but water would continue to leak in and so pumps were used to keep the pen as dry as possible. The U-Boat has been lowered onto the stocks, and engineers are examining a damaged propeller. This view gives a good impression of the depth of a typical pen. Note also the corrugated steel shuttering on the ceiling, the purpose of which was to prevent any masonry dislodged by a heavy-bomb direct hit from becoming dislodged and crashing down onto any boat within the pen. In most cases the quays between the pens would be around 6.3m wide, with a dividing wall running down the centre, thus allowing only a fairly narrow walkway around 2.5m wide each side. Looking up towards the ceiling, we can see the mobile gantry crane. The crane was used for tasks such as removing a damaged periscope from a U-Boat. Such operations explain why the pens had what might otherwise be seen as unnecessarily high ceilings.



The interior of the Bruno bunker in Bergen. The U-Boats of the Kriegsmarine have been replaced by the submarines of the Royal Norwegian Navy.


(Photo Hans Lauritzen)