At 16.38 hours on 6 July 1942 the John Witherspoon (Master John Stewart Clark) was torpedoed by U-255 about 20 miles from the shore of Novaya Zemlya. The ship had been in convoy PQ-17 which was dispersed on Admiralty orders in the Barents Sea on 4 July 1942. One torpedo struck on the starboard side between the #4 and #5 holds, followed by a second torpedo about one minute later underneath the bridge. At 16.55 hours, two coups de grâce were fired, which struck on the port side amidships and broke the ship in two, causing her to sink within minutes. At this time, the eight officers, 31 crewmen and 11 armed guards (the ship was armed with one 4in, four .50cal and two .30cal guns) already abandoned ship in three lifeboats and one raft. One seaman fell overboard and drowned. The U-boat approached the boat of the master and asked for the master and about the cargo, offered food and water, promised to send a message for the survivors, gave directions to the nearest land and then left.

On 9 July, the most survivors were picked up by HMS La Malouine (K 46) (Lt V.D.H. Bidwell, RNR), but 16 crew members and three armed guards in another boat had been trapped in the ice for 53 hours and had been unable to get free. They were picked up in a heavy fog by the El Capitan, after the chief mate spotted the boat after hearing the tone of a bosun pipe. On 9 July, this ship was bombed by a German aircraft and later sunk by U-251 (Timm). The survivors from the John Witherspoon had to abandon ship again and were picked up by HMS Lord Austin (FY 220) and taken to Archangel.