At 23.56 hours on 29 December 1942 the Ingerfem (Master Johan Johnsen) was hit by one torpedo from U-631 amidships. The ship had been in convoy ONS-156, but had engine problems and lost convoy after three days. The most crew members abandoned ship in two lifeboats, while the master, third mate and a gunner were seen struggling with a third lifeboat midships, but before it was launched the ship broke in two and sank ten minutes after the hit. One of the lifeboats, carrying 33 men, was later lost.

The other with eight men in it, also had problems in the bad weather, it was taking water and finally capsized three days later. All men get into it again, but the first mate and two crewmen died, standing upright in the boat, that same day. After one week, the boat had taken too much water and turned over again. The remaining men managed to straighten it out, but that night four of them died, leaving the gunner Ole Næss (age 22) alone in the boat. He "buried" the dead in the sea, but it had all been too much for him and he jumped overboard, but a wave immediately washed him on board again. Then he drank large amounts of seawater in an attempt to end his life, but that did not succeed either. On 11 January, the lifeboat was spotted about 500 miles west of Scotland by the American steam merchant Staghound. The sole survivor was then unconscious and could not be straightened out so he was lifted in sitting position onto the vessel, where the doctor on board gave him the best care possible, until he could be taken to the hospital in Ards District near Belfast two days later, suffering from severe shock and salt water sores. He was nursed back to health again, though his legs for a long time were threatened by gangrene, but he was spared from amputation.