Convoy PQ 18 was an Arctic convoy of forty Allied freighters from Scotland and Iceland to Arkhangelsk in the Soviet Union in the war against Nazi Germany. The convoy departed Loch Ewe, Scotland on 2 September 1942, rendezvoused with more ships and escorts at Iceland and arrived at Arkhangelsk on 21 September. An exceptionally large number of escorts was provided by the Royal Navy in Operation EV, including the first escort carrier to accompany an Arctic convoy. Detailed information on German intentions was provided by the code breakers at Bletchley Park and elsewhere, through Ultra signals decrypts and eavesdropping on Luftwaffe wireless communications.