45044 Oxford (Walton Well Road) 23 August 1985

Strange goings on at Oxford on 23 August 1985. 45044 had worked the 6V19 06:32 Bescot to Didcot Speedlink freight and then just over an hour after it passed Oxford it returned with this freightliner, heading back from whence it came. Presumably it was deputising for a failed locomotive on the freightliner, which it must have picked up at either Oxford or Didcot. Any more information would be gratefully received.