Training budgets affected whether Norway's listed weapons could become effective fighting forces. Fortifications formed the core defence of critical places, with Oscarsborg guarding the sea approach to Oslo. Its German 280-mm (11-inch) guns dated from 1890 and had barrels 35 times their bore diameter; the torpedo battery followed between 1898 and 1901. Surplus artillery after the First World War offered a cheaper opportunity to replace old weapons. Gun barrels ordered early for warships later cancelled under the Washington Naval Treaty provided another possible source. Limited improvements, including some anti-aircraft guns, left much of the old system intact. The commander's long familiarity with the installation helped at Drøbak Sound, but that familiarity also reflected how little the main weapons had changed.
Chapter · 25:01-30:56
Oscarsborg's old guns concealed decades of neglected modernization
Norway treated the existence of heavy guns and torpedoes at Oscarsborg as proof of readiness while training and repeated opportunities to modernize the fortress were neglected.