Construction

Forward Torpedo tubeForward Torpedo tubeThe wreck shows the twin hull construction typical of U-boats: a pressure resistant inner hull and free flooding outer casing.
 
The cylindrical pressure hull is built from riveted 12mm nickel-steel plates with external steel frames. The inside of the pressure hull is separated into compartments by a number of bulkheads made from 16-21mm thick steel. The forward and aft collision bulkheads are visible where bow and stern are damaged.
 
Conning tower hatchConning tower hatchOn the outside, the pressure hull is completely surrounded by outer casing made from 3.5-4mm thick galvanised torpedo-boat steel. The outer casing protected the pressure hull. The rigid connection of outer casing and pressure hull enhanced the strength of the pressure hull. On the wreck the outer casing is only partially preserved and the pressure hull is clearly visible in the upper deck area.
 
Forward Escape hatchForward Escape hatchmade from 30mm galvanised steel is riveted onto the pressure hull. It is fully preserved with only the protective casing and armour missing. Recesses for the navigation lights and maintenance access hatches are visible either side of the tower. The main conning tower hatch is situated aft of the periscopes and was found slightly ajar.
 
Aft torpedo tubeAft torpedo tubeTwo torpedo loading hatches were observed at bow and stern, aft and forward of the torpedo rooms. At the stern of the vessel, the engine room escape hatch is wide open. The forward escape hatch is sealed.
 
At the bow of the u-boat, the two bow torpedo tubes are split at the forward collision bulkhead. The tubes have an internal diameter of ca. 58cm. The tube construction with outer reinforcement rings and bolted segments is clearly visible.

The two stern tubes are heavily damaged and lie at a 90° angle to the hull within the stern wreckage. The outer torpedo tube door is visible on one of the aft tubes.