text: The second series of convoys, JW (outbound) and RA (homebound) ran from December 1942 until the end of the war, though with interruptions in the summer of 1943 and again in the summer of 1944.
  The convoys ran from Iceland (usually off Hvalfjörður) and traveled north of Jan Mayen Island to Arkhangelsk when the ice permitted in the summer months, shifting south as the pack ice increased and terminating at Murmansk. From February 1942 they assembled and sailed from Loch Ewe in Scotland.
  Outbound and homebound convoys were planned to run simultaneously; a close escort accompanied the merchant ships to port, remaining to make the subsequent return trip, whilst a covering force of heavy surface units was also provided to guard against sorties by ships such as  Tirpitz. Escorts would  accompany the outbound convoy to a cross-over point, meeting and then conducting the homebound convoy back,  while the close escort finished the voyage with its charges.
  The route skirted  occupied Norway en route to the Soviet ports. Particular dangers included:
  the proximity of German  air, submarine and  surface forces
  the likelihood of severe weather
  the frequency of fog
  the strong currents and the mixing of cold and warm waters, which made ASDIC use difficult