The locomotive was built by Andrew Barclay in 1937 for United Collieries Ltd, and worked at Foulshiels Colliery, near Addiewell, West Lothian, and at Quarter Colliery, near Hamilton. It was given the number 4.
After nationalisation in 1948, No.4 moved to Canderigg Colliery in 1951, Blantyre Colliery in 1954, then to Twechar in 1957. There it was renumbered as No.6 and worked at Bedlay and Wester Auchengeich Collieries before moving to Dollar Colliery in 1968, and later to Kinneil.
It moved to Bo’ness for an engineering assessment of the boiler, with possible repair, and has now been restored to operational condition. It is likely to remain in Bo’ness for the foreseeable future.
The locomotive is owned by East Lothian Council.