This is the oldest remaining substantially original Scottish-built railway wagon. It was built to carry coal tar, a by-product of making gas and coke, from gas works to the tar distillery where it would be refined into other products from pitch to naphtha. It is a typical 19th century tank wagon, with a rectangular iron tank on a wooden frame, with sprung buffers. It was owned by Scottish Tar Distillers Ltd at Lime Road, Falkirk, and used around their works until the mid 1960s.