Octagonal Building at Bersham Ironworks Site

Cadw's description

Location

In the centre of Bersham Village, towards the E end of the Ironworks site.

History

History: The buildings form a significant component of the ironworks site: A blast furnace was recorded in Esclusham by c1670, though not necessarily on the present site. The first furnace recorded on this site was operated from c1717 by Charles Lloyd of Dolobran, and in 1721, became the first Welsh furnace to use coke rather than charcoal as its fuel. The ironworks was leased by Isaac Wilkinson from c1753. From c1763, it was operated as the New Bersham Company by his sons John and William. In 1774, John patented a machine for the precision-boring of cannon, and in 1775, for boring out steam-engine cylinders for Boulton and Watt: there followed a major expansion of the works which became a highly successful venture playing a leading role in the development of iron manufacture in Britain. However, following an argument between John Wilkinson and his brother William, the works were partially destroyed c1795, but continued to operate until their sale in 1812. The site was later used as part of a farm.

The octagonal building was built c1775, almost certainly as a cannon foundry connected with the increased demand for cannon following the outbreak of the American War of Independence in 1775. A drawing of c1780 shows the building with 4 chimneys and an open-top roof, suggesting its use as a foundry, and a description of the site in 1775 refers to a cannon foundry with 4 furnaces casting simultaneously: the octagonal or near-circular form of the building would have permitted this. By 1829, it was in use as a stack house on the farm. The single storeyed building adjoining it, now known as the 'fettling shop', is probably contemporary with the octagonal building, although its precise original purpose is unknown. This building was extended at some time to the E.

Exterior

Roughly 8-sided or near-circular brick and rubble structure, with pyramidal roof (the slates removed at time of inspection, July 1995). The roof is supported by pentagonal brick piers at each angle. Between the piers, the NW, E, and S walls appear to be contemporary brickwork. The S wall has relieving arch with later rubble infil below; the upper part of the elevation is open. There is a similar blocked arched opening in the E wall, which provided access to the adjacent 'fettling shop'. The NW wall is bowed out in its central section. The W side is open, while the SW elevation, which is brick above a rubble base, was probably infilled at a later date, and has a small ventilation slit. The N elevation has brick infil on a rubble plinth, with stone sill to open upper section. Blind brick infilled NE elevation. Single storeyed attached range has been extensively rebuilt (probably in the late C19-early C20), but incorporates earlier work between and below the windows in its N elevation. 5-light windows have concrete sills and lintels. In the E bay (probably a later extension), the roof is supported on cast-iron Wilkinson pipes. A-frame timber truss exposed in E gable. Lean-to extensions to S.

Interior

Although the building is now a single space internally, excavation in 1987 revealed traces of internal walls parallel to the external walls. These were probably removed to enable the building's reuse. Braced king-post roof, the king-post at the intersection of massive cross tie-beams. In the centre of the underside of the post, a cast-iron bracket has a central hole, probably associated with C19 agricultural machinery.

Reason for designation

Listed at grade II* as one of the few extant buildings associated with Wilkinson's Bersham Ironworks, and for its exceptional interest as a purpose-designed cannon foundry of highly unusual form.