This is the last remaining of four stone and brick built blast furnaces* that once occupied the site at the height of iron production at the Brymbo Ironworks before changing to steel production at the end of the 19th century. The blast furnace is believed to occupy the site of an original Wilkinson blast furnace, having been constructed in c. 1820 by John Thompson, it is now considered one of the earliest intact furnaces of the Industrial Revolution (SAM No: DE202). The furnace, nicknamed `Old Number One?, remained working until 1894 when it was `damped down? to make way for greater steel production using the open hearth process (Brymbo Steelworks Ltd). The furnace is constructed of large, dressed sandstone blocks with an interior lining of fireclay brick; the fireclay brick lining would have been replaced c. every five years and was produced locally. It has a number of lower arches to allow for air to be blasted into the furnace and for the molten iron to be tapped. The iron was tapped into the cast house, which attaches to the southern elevation of the furnace. The eastern elevation is the only clearly visible, with the remaining being adjoined to cast house, blast wall and later stores. The furnace has some later brick patching and iron ties that run up each corner. Internally the brick lining is covered in slag and an iron lintel remains in place, which was likely to have been water-cooled. In later years the blast furnace was used as a sand hopper, which may be the reason it has remained intact. Behind the furnace the original blast wall remains in place, which would have been used to charge the furnace, ready for firing.

*number three blast furnace was demolished and rebuilt as number four in 1892.

Ross Cook, RCAHMW. 11th December 2012