Mainline Freight was created in 1994, along with Transrail and Loadhaul, when British Rails Trainload Freight operations were split with Mainline centring around South East England, East Anglia and the East Midlands. Several locomotives were soon decorated in Mainlines Aircraft Blue livery including Class 37/0 No. 37055. In association with EMAP/Bauer Media magazine RAIL, No. 37055 received the name Rail Celebrity during a naming ceremony at Toton in 1995.
Mainline, Transrail and Loadhaul were later subject to a takeover bid by a US led consortium and, together with Rail Express Systems, were formed into a new company English, Welsh & Scottish (EWS). Despite now being a EWS loco, No. 37055 remained in Mainline blue livery into the 2000s, appearing on a variety of workings including London Underground train deliveries and railtours alongside its usual freight turns.