Britain launches Operation Claymore - Mar 04, 1941 - HISTORY.com

The British navy raids a German position off the coast of Norway and inside the Arctic Circle—the Lofoten Islands. The raid, code name Operation Claymore, proved highly destructive of its target—an armed German trawler—but ultimately a failure in achieving its objective, the capture of an Enigma decoding machine.

The Brits severely damaged the trawler, called the Krebs, and killed 14 German sailors, took another 25 prisoner, and destroyed the Germans’ local stockpile of oil. While the attack boosted British public morale temporarily, the Enigma machine still eluded the British military. The commander of the Krebs, Lieutenant Hans Kupfinger, threw it overboard before he was killed in the raid, but the Brits were able to recover documents that gave clues to the Enigma’s workings. British intelligence was able to piece together enough of the German coding system to track German naval activity for about five weeks.