Rösselsprung was a plan by the German "Kriegsmarine" to intercept an arctic convoy in mid-1942. It was the German navy's largest operation of its type, and arguably the most successful, resulting as it did in the near destruction of Convoy PQ 17. Ironically, this success was entirely indirect, as no "Rösselsprung" ship caught sight of the convoy or fired a shot at it. PQ 17's losses were instead due to U-boat and aircraft attacks. Despite not making contact with the convoy a number of the "Rösselsprung" ships were damaged in the course of the operation, notably the heavy cruiser "Lützow", which ran aground in thick fog, necessitating three months of repairs.