This locomotive was one of 20 locomotives ordered by the Ministry of Defence in 1941. This small diesel locomotive was designed and built by Andrew Barclay, Sons & Co.Ltd. at their Kilmarnock Works. WD42 was part of the second batch to be built [WD39-44/AB354-359]. No.'s WD39-44, were concentrated at Longmoor for use in the invasion of Europe, and were shipped from Southampton to Cherburg during September 1944. WD42-44, went into 102 Transportation Stores Depot at Bayeux. In August 1945, it was renumbered WD70042 and allocated to Merelbeck[Ghent].
The locomotive returning to the U.K. in June 1946. In January 1951, WD70042 became WD823, and in February that year, it was one of six locomotives sent to the Middle East, returning to the U.K. in 1955 and allocated to Bicester Central Ordnance Depot. In May 1961, it was renumbered WD859. Between May 1961 and October 1992, WD859 was allocated to the following locations;
In October 1992, ARMY 202 was restored to its original number WD42 and named "OVERLORD" as part of the 50th Anniversary celebrations of the D-Day Landings, for which it was again shipped over to France for the event. The loco was intended for the Army Transport Museum at Beverley, but was still at Burton Dassett W.D. Depot, now known as CAD Kineton in 1993.
The loco eventually arriving at the Royal Engineers' Museum at Chatham, where it was displayed on a section of track outside the museum. After a period of time on display,the locomotive was moved to Chatham`s Historic Dockyard and placed on display in The Big Store [No.3 Slip].