Dora 1

Dora 1 is a former German submarine base and bunker built during World War II in Trondheim, Norway. Trondheim was traditionally referred to as Drontheim in German, and the name DORA is the letter "D" in the German phonetic alphabet.

History

Background

Following the occupation of Norway in 1940, it was soon realised that the country only had limited facilities for minor naval repairs. More extensive work usually meant a return to Germany. The capitulation of France two months later overshadowed the strategic importance of Norway to some extent, but it was still regarded as a better location for access to the Atlantic and Arctic Oceans than Germany. Nevertheless, better protection for U-boats from aerial attack was required so a bunker-building programme was instigated.

Construction

Construction of the bunker which would become part of the largest German naval base in Northern Europe, started in the autumn of 1941, one year after the invasion of Norway. The concrete roof was 3.5 m (11 ft 6 in) thick and reinforced with steel. The walls were also concrete but these were 3 m (9 ft 10 in) thick. The whole bunker was 153 m × 105 m (167 yd × 115 yd). The work was undertaken by the Todt Organisation's (OT) Einsatzgruppe 'Wiking' and the Sager & Wörner construction company from Munich.