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Sirhowy Ironworks

A Grade II* Listed Building in Tredegar, Blaenau Gwent

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Latitude: 51.7833 / 51°47'0"N

Longitude: -3.2441 / 3°14'38"W

OS Eastings: 314278

OS Northings: 210141

OS Grid: SO142101

Mapcode National: GBR YW.YV84

Mapcode Global: VH6CT.QFCR

Entry Name: Sirhowy Ironworks

Listing Date: 14 October 1999

Last Amended: 14 October 1999

Grade: II*

Source: Cadw

Source ID: 22496

Building Class: Industrial

Location: Graham’s Yard is located off Dukestown Road. Ironworks is set into hillside to E.

County: Blaenau Gwent

Community: Tredegar

Community: Tredegar

Locality: Sirhowy

Built-Up Area: Tredegar

Traditional County: Monmouthshire

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Opened 1778, the first ironworks in Monmouthshire to be fired by coke rather than charcoal. Much reconstructed in the later C19, before closure in 1882. The lease of the site was taken in 1778 by Thomas Atkinson, William Barrow, Bolton Hudson and John Sealy, London speculators. A square furnace was built of river stone, the bellows at first driven by hand, until a water wheel was set up in the Sirhowy river: this doubled the 4-6 tons (4.06-6.1 tonnes) weekly output. The early 1790s saw a slump in the industry, and the works were sold in 1794 to Matthew Monkhouse and Richard Fothergill, the latter eventually constructing tramways, and initiating the building of the Sirhowy-Newport tramroad from 1802. A second furnace was built in 1799, complete with a Boulton and Watt beam blowing engine, which provided the extra blast required when another furnace was built 1801-02. In 1818, the partnership’s lease ended, and the site was acquired much to the consternation of Richard Fothergill, by John Harford, a partner in the Ebbw Vale Ironworks. Fothergill immediately stripped the site of all moveables, but eventually was fined £6000 for his action. By 1826, two of the three furnaces were in blast, producing 7800 tons (7925.22 tonnes) of pig iron during that year, for processing at Ebbw Vale. By 1839, four furnaces were working, powered by a blowing engine from the Neath Abbey Iron Company. In 1844, the assets of the Ebbw Vale Company were put up for sale. The Sirhowy Works then consisted of five blast furnaces, four using hot blast. Each furnace could produce 90-100 tons (91.44-101.6 tonnes) of iron per week. In addition were cast-houses, bridge houses, four mine kilns, coke-yards, two limekilns, and a clay-mill. A tunnel ran through to Ebbw Vale, conveying the pig iron, and a second tunnel was under construction. The new purchasers was a partnership, including Abraham Darby and Thomas Brown. They invested heavily at the Ebbw Vale works, and probably carried out major improvements at Sirhowy. Five furnaces were in blast in the 1850s, but only three in the 1870s. The growing slump saw all three closed in 1879, with 300 people made unemployed. The works finally closed in 1882.


The remains largely consist of a massive rubble-built furnace bank, built against the valley-side. This contains three high narrow arches with yellow brick heads, puncturing the retaining walls as brick barrel vaults. Parallel barrel-vaulted passage to rear of furnace bank, accessed by round-arched doorways. The left-hand and centre arches are similar, both with rubble rear walls. Passage to left of left arch, off which branch two lower cross-passages. Communicating arch between tunnels. Middle tunnel has circular oculus: in front of arch is low circular brick furnace base, with large lump of slag on top. In front of left arch are brick footings. The right-hand arch is much taller, and shallower, with a semi-elliptical arch to the rear, with filled-in rear shaft and arched side openings (much obscured by debris). Much masonry has been lost above the arch-rings, but set above are two small rubble-vaulted culverts, one containing a large cast-iron pipe.

To the S, in the hillside, are the remains of another furnace, consisting of the base of a slag-lined crucible, with footings of brick rectangular structure. To the NW are the remains of a stone building, with the mouth of a stone-lined barrel vaulted tunnel facing S, over C20 garages. In the NE corner of the site, the foundations of a small rubble-built structure, including the mouth of a stone-lined conduit.

Reasons for Listing

Listed as a significant survival of the early iron industry in the Monmouthshire Valleys.

Scheduled Ancient Monument: MM185(BLG).

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