 Three former Class 25 locomotives were converted for use as mobile generators to provide electric heating on trains where the hauling locomotive could not supply this.They were referred to as ETHEL units (Electric Train Heating Ex-Locomotives), and unofficially named Ethel 1, Ethel 2 and Ethel 3.They were painted in a blue/grey livery in an effort to match the coaching stock livery of the day, but this was not too successful.