Scharnhorst and Gneisenau needed torpedo boats to escort them through the minefields between Denmark and Norway. Those boats were absent at Skagen on 23 January and did not arrive until the 25th, costing Lütjens nearly 40 hours. Both navies were reading changes in the volume of enemy radio traffic, so Britain did not need to decrypt a detailed naval message to suspect a sortie. Reports from agents in Denmark, passed through the British naval attaché in Sweden, then confirmed the ships' passage through the Great Belt. Tovey reinforced the Iceland-Faroes patrol line before the raiders had cleared the breakout route.
Chapter · 1:27:27-1:32:09
A 40-hour escort delay gave British intelligence time to react
Late German torpedo boats delayed the Great Belt passage while radio traffic and agents in Denmark warned Tovey that a sortie was developing.