 Köln joined Gneisenau and nine destroyers for a sortie into the North Sea on 7 – 9 October. The goal was to draw units of the Royal Navy over a U-boat line and into range of the Luftwaffe, though it failed on both counts. The British launched an air attack consisting of 12 Wellington bombers, though it too failed to hit any of the German warships. On 20 – 22 November, Köln and the cruiser Leipzig escorted the battleships Gneisenau and Scharnhorst on the first leg of their sortie into the North Atlantic. On the 22nd, Köln and Leipzig were detached to join an unsuccessful patrol for Allied merchant ships in the Skagerrak along with Deutschland and three torpedo boats. The patrol lasted until 25 November, and failed to locate any Allied freighters. On 13 December, Köln, Leipzig, and Nürnberg covered the return of several destroyers that had laid an offensive minefield off Newcastle.
