A number of locomotives of Classes 31, 33, 37 & 47 received the plain dark grey livery in the early 1990s, prior to the adoption of the 'Dutch' colour scheme for departmental locos. One such loco was 37162, seen here passing Llanwern West Junction in the rain on 19 November 1994 with a westbound engineer's train. Note the small Railfreight Petroleum logo midway along the bodyside.