O 12-class submarine

The O 12 class was a class of four submarines, built for the Royal Netherlands Navy. The ships, with a diving depth of 60 m, were used for patrols in the Dutch home waters. The class comprised O 12, O 13, O 14 and O 15. O 12 entered German service in 1943 as U-D2.

Construction
The ships were built by two different shipyards. O 12, O 13 and O 14 were built by Koninklijke Maatschappij De Schelde in Vlissingen and O 15 in Rotterdam at Fijenoord shipyard.