This locomotive was from the batch of twenty (D325 to D344) built with 'split-box' type headcode. Train identification roller blinds were housed in illuminated units on either side of the nose ends. This enabled interconnecting gangway doors to be fitted. These were a little-used facility for crew changing purposes on 'double-headed' locomotive workings. This same locomotive batch included the notorious D326, involved in the 'Great Train Robbery' of 1963 and various other incidents.

40135 was built by English Electric at Vulcan Foundry, Newton-le-Willows, entering service on 11th March 1961 allocated to 5A Crewe North. She was later reallocated in April 1966 to Western Lines, June 1968 to D05 Stoke Division, May 1969 to D09 Manchester Division, Jan. 1972 to D08 Liverpool Division, May 1973 to Springs Branch, August 1973 to Carlisle Kingmoor, and May 1975 to Longsight, where she remained until withdrawal on 22nd Jan. 1985.

From this point, the locomotive led something of a charmed life. Thanks to behind-the-scenes intervention, the loco avoided a very close call with the cutter's torch at Doncaster Works. Having survived scrapping, she was one of four Class 40's miraculously returned to departmental traffic in May 1985, for use in the remodelling of Crewe Station approaches. Based at Crewe Diesel TMD and renumbered to 97406, she and the other three 97's worked around Crewe and on various other freight duties in the London Midland Region.

Final withdrawal from British Rail service came on 16th December 1986. Thankfully, further intervention prevented the loco from reaching Swindon Works for scrapping. After painstaking negotiations and discussions, 40135 was put onto the BR tender list, along with 40012. The CFPS successfully tendered for the loco in May 1988, and she was delivered to Bury later that year.

The CFPS carried out their first locomotive repaint on 40135 during the summer of 1991 to a very high standard. Steam heating was restored in December 1991, which included the re-manufacture, virtually from scratch, of the boiler water tanks. The loco then went on to become a reliable ELR winter passenger loco for a considerable period. The Clayton steam heat generator was subsequently transferred to 40145. A light overhaul of the power unit was completed in 1997.

The loco unfortunately suffered engine damage in April 1998. After lengthy repairs, D335 was successfully restarted in September 2000, in time for the ELR Diesel Gala. Following this, bodywork restoration and a repaint into rail blue were completed for the ELR July 2001 Diesel Event. Steam heating was again restored to the locomotive in January 2002.