Convoy PQ 17

PQ 17 was the code name for an Allied Arctic convoy during the Second World War. On 27 June 1942, the ships sailed from Hvalfjörður, Iceland, for the port of Arkhangelsk in the Soviet Union. The convoy was located by German forces on 1 July, after which it was shadowed continuously and attacked. The First Sea Lord Admiral Dudley Pound, acting on information that German surface units, including the German battleship Tirpitz, were moving to intercept, ordered the covering force built around the Allied battleships HMS Duke of York and the USS Washington away from the convoy and told the convoy to scatter. Because of vacillation by Oberkommando der Wehrmacht (OKW, German armed forces high command), the Tirpitz raid never materialised. The convoy was the first large joint Anglo-American naval operation under British command; in Churchill's view this encouraged a more careful approach to fleet movements.

As the close escort and the covering cruiser forces withdrew westwards to intercept the German raiders, the merchant ships were left without escorts. The merchant ships were attacked by Luftwaffe aircraft and U-boats and of the 35 ships, only eleven reached their destination, delivering 70,000 short tons (64,000 metric tons) of cargo. The convoy disaster demonstrated the difficulty of passing adequate supplies through the Arctic, especially during the summer midnight sun. The German success was possible through German signals intelligence and cryptological analysis.