At 22.39 hours on 7 Dec, 1940, U-99 fired a torpedo at the Farmsum (Master B. Jansma), a straggler from the convoy OB-252, in heavy seas. The torpedo was a surface-runner and struck the ship above the waterline at the stern, blowing the stern gun overboard. A second torpedo was fired on the bow of the ship but also struck the stern. The next torpedo hit amidships and caused the ship to sink within three minutes. 19 survivors abandoned ship in lifeboats and were eventually picked up by HMS Ambuscade (D 38) (LtCdr R.A. Fell, RN) with severe signs of frostbite, four of them died.