This digital working model of a beam engine and house was developed from the Neath Abbey Ironworks’ plans which are held at West Glamorgan Archives. The engine was constructed by Neath Abbey Ironworks in 1818 for Vivian's Hafod Copper Works in Swansea to power the rolling mill, and remained working until at least 1857 as plans for upgrades dated that year exist for it. The beam engine was of the condensing type, with a 40 inch diameter cylinder. The valve gear was of the type designed by William Murdoch, the steam-valves had hollow spindles, like tubes, in order to admit the spindles of the exhausting-valves to pass through them. This enabled either valve to be lifted from above independently of the other, by levers situated on the outside of the boxes. Reliability was essential to avoid halting production, and the engines 40 years in service is a testament to Neath Abbey Iron Works' quality of workmanship.