The locomotive was built originally (as their No.4) for United Collieries Ltd, and worked at Foulshiels Colliery, near Addiewell, West Lothian, and at Quarter Colliery, near Hamilton. 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 is at Bo'ness for an engineering assessment of the boiler, with possible repair to follow.
