On 7 April 1940, "Scharnhorst" and "Gneisenau" formed the primary covering force for the invasions of Narvik and Trondheim in Norway during Operation Weserübung. At 04:30 on 9 April, the "Seetakt" radar on "Gneisenau" picked up a contact, beginning the action off Lofoten; both ships went to battle stations. Half an hour later, muzzle flashes were observed, from what turned out to be the old battlecruiser which had been part of the cover for a British minelaying operation. The British battlecruiser initially targeted "Gneisenau", at a range of . In the span of five minutes, "Gneisenau" hit "Renown" twice, but sustained one 15" and two 4.5" hits in return. One of the two 4.5" hits disabled "Gneisenau"s A turret, The 15" hit destroyed the main armament fire control station, and knocked out her "Seetakt" radar. "Scharnhorst"s gunnery radar suffered technical problems, which prevented her from effectively engaging "Renown". The British ship engaged "Scharnhorst" for a brief period starting at 05:18, but effective maneuvering by "Scharnhorst" allowed her to escape unscathed. Fears that the destroyers escorting "Renown" might make a torpedo attack prompted the German commander to break off the engagement. By 07:15, the German ships had escaped from the slower "Renown". In the course of their escape "Scharnhorst" suffered from damage to her A turret caused by the heavy seas coming over her bows. "Scharnhorst" and "Gneisenau" rendezvoused with the heavy cruiser before proceeding to Wilhelmshaven.