 Complete the following phrase:  After further brief exercises in the Clyde in early May, Trident was ordered to Iceland to meet and escort convoy PQ16 to northern Russia. She was one of two submarines assigned to this duty, the other being HMS Seawolf. This eventful patrol saw Trident pick up nine survivors from the American merchantman Alamar which had been abandoned due to air attack and carry out orders to torpedo its remains as well as try to fend off other air attacks using her anti-aircraft guns. The convoy underwent five days of air attacks from Luftwaffe aircraft as well a submarine attacks. Of the 35 ships which left Iceland, 8 were lost. After a short anti-U-boat patrol from Polyarnoe, in June 1942 Trident was tasked with providing cover to convoys QP 13 and 