|Power Unit:||National Diesel 6-Cyl|
|Power Output:||400 HP|
|Max Speed:||15 MPH|
|Train Brakes:||Air (Vacuum piped)|
The pair were numbered 4001/2 at the MSC. Sister loco 4001 also survived for many years as a static non-operational exhibit at the Winfields Store site at Acre Village (between Haslingden and Accrington) however the loco was cut up in 2018 as it was in a poor state. 4001 has donated many parts to allow 4002 to live on as a working example.
'Billy' has worked on passenger services very rarely at the ELR, during the July 2003 Diesel Event and May 2011 Small Engines Weekend. In September 2010, 4002 was a special guest at the Middleton Railway (Leeds) Manchester Ship Canal Gala event featuring both Steam and Diesel locomotives from the company. The loco is through piped for vacuum operation with a destroyer valve fitted, although without an exhauster it relies on another loco to create vacuum.
4002 featured at the Small Engines Event in April 2016 but had to be stood down due to running a hot axlebox. Since then the loco has had a good deal of attention and is currently the Works Pilot at Baron Street.
Some video footage of 4002 at the ELR and the MSC Gala event can be found on YouTube.