The Glamorgan-Gwent Archaeological Trust
Historic Environment Record

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Primary Reference Number (PRN) : 01083m
Trust : Glamorgan Gwent
Community : Rhymney
Unitary authority : Caerphilly
NGR : SO1086709168
Site Type (preferred type first) : Post-Medieval Iron works / Post-Medieval Furnace
Status : Scheduled Monument

Summary :
Remains of blast furnace at Upper Rhymney (formerly the Union Iron works). The furnace consists of a circular hearth and bowl standing 2.3m high on the west side. Later operated with the Rhymney (Bute) Ironworks.

Description :
Remains of blast furnace at Upper Rhymney, partially intact with the hearth visible. The furnace operated from 1801 to c1862 (1987).

The Upper Furnace site of what was the Union Iron works at Rhymney is important as a potentially unique survivor of the first generation of single coke fired and presumably water blown blast furnaces in South Wales. The scheduled area lies in field at the foot of a steep west-facing slope. The furnace consists of a circular hearth and bowl standing 2.3m high on the west side, and sloping down to the ground-level on the east side. The furnace, 3.5m in diameter, is constructed of black vitrified bricks with a massive “bear” or lump of slag from the first firing occupying the interior.

The Rhymney Ironworks has an interesting but complicated early history. The first ironworks to
be built in the Rhymney Valley was the Union Ironworks, which dates from 1800. The works received its name because the furnace was constructed at a point where the counties of
Brecon, Monmouth and Glamorgan met. In 1803 Richard Crawshay, Watkin George, Benjamin Hall, Richard Cunningham and Thomas Williams owned the works. At that time new furnaces were being constructed at a second site further down the valley. It was intended that the output of these furnaces would supply the forges and mills of the Crawshays works at Cyfarthfa. In 1804 the Rhymney Ironworks, as it came to be known, was being operated by Crawshay, George and Hall, with Hall becoming the sole owner in 1810.

The site of the blast furnaces from the former Bute ironworks is now under the A469 embankment. The only standing structure appears to be a locomotive shed. The site has been heavily developed. (Anthony 2006)

Sources :
Anthony M. , 2006 , Archaeological Desk Based Assessment: Pellet processing Plant, Capitol Valley Industrial Estate, Rhymney, Caerphilly
03/MM Record Card/OS//1980/SO 10 SW 4/;
02/PM Mention////HMS Newsletter/Blast Furnaces in UK;
01/MM Letter/Welsh Office/Ford GM/1980//;
04/MM Desc Text/CADW/Whittle E/1985/AM 107/

Events :
E000043 : Field visit, Rhymney Ironworks (year : 2004)
E005748 : Pellet Processing Plant, Capitol Valley Industrial Estate, Rhymney, Caerphilly (year : 2006)
E005797 : Pellet Processing Plant, Capitol Valley Industrial Estate, Rhymney, Caerphilly (year : 2006)

Related PRNs : E005797

Compiled date : 01-04-1980

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