The Glamorgan-Gwent Archaeological Trust Ltd.

Character Areas


005 Forgeside and Big Pit

Big Pit with associated buildings: view to the south.

HLCA 005 Forgeside and Big Pit

Relict industrial landscape characterised by nineteenth century industrial processing, associated extraction and waste tips; Big Pit colliery workings and former site of the later Blaenavon ironworks. Possible buried remains of features relating to Blaenavon ironworks. Important transport links: railway and tramroad. Water management features. Historic events and persons associated with the area.Back to map

Historic Background

The historic landscape area of Forgeside and Big Pit covers the extent of surviving industrial landscape including Big Pit, its associated tips and the site of the former ironworks at Forgeside.

The Blaenavon Iron and Coal Company started construction of its new ironworks at Forgeside in 1838. The plan was to construct three furnaces and develop new forges and mills once production was underway. Two furnaces were under construction in the following year and in 1840 a 52 1/2 in beam blowing engine had been purchased from Neath Abbey Ironworks. However, a lack of resources delayed completion of the new works and the furnaces remained idle as late as 1861. The first part of the new works to be finished was the forge, opened in 1859. In 1860, the mill was completed; this contained a pair of horizontal 36ft x 6ft engines built by James Watt and Co. suitable for working a rail mill or heavy bar and plate mill. In 1860, a 30in x 4ft6in high-pressure horizontal engine began work powering a pair of rough down rolls and a three high train of blooming rolls. Development accelerated at the new works with a railway tyre mill, commencing work in 1861, driven by a 34in engine (James Watt and CO.). This plant overtook the old site in production as it was linked by steam railway to Pontypool and Newport and offered more room for expansion. While the old works closed in 1900, the new works were kept in operation until 1938, (Ince, 1993:122-123). Above ground remains were later cleared and the area subsequently landscaped.

The production of coal and iron increased with demand and improvements in transportation. In 1854 Blaenavon was linked by rail to Newport by the Monmouthshire Railway Eastern Valley Branch, later supplemented by the LNWR Blaenavon-Brynmawr Branch in 1868, prior to this date transport to the coast had been via road and canal, to the north.

Coal working to supply the Blaenavon Ironworks dates from around 1800. Initially coal would have been worked by means of levels or drifts following the outcropping seams dug into the hillsides. Examples of these earlier drift mine workings include Forge Level (driven in 1812), Mine Slope (sunk c.1840) and Dodd's Slope.

Big Pit, with an elliptical haulage shaft of 39m, was developed on the site of an earlier mine; Kearsley Pit from 1860. The shaft at Big Pit, extended to 89m in 1880, was the first shaft in the area wide enough to wind two trams of coal side by side. Other workings were later incorporated such as Mine Slope and Forge Level, and the shafts of the neighbouring Coity Pit; the latter, subsequently used for ventilation. Colliery output at Big Pit soon exceeded 100,000 tonnes of coal from an area of about 12 square miles.

Over its lifetime, the workings at Big Pit exploited nine different coal seams and produced first-class 'steam coal' for which South Wales became famous around the world. The final seam to be worked was the Garw, producing excellent coking coal, the seam at 366ft with a maximum thickness of 71cm, proved difficult to work.

Mechanisation came to Big Pit in 1908 with the installation of a mechanical conveyor and the pit was among the first in South Wales to be electrified; by 1910 the ventilating fan, pumps and underground haulage system were all worked by electricity. The winding gear, however, continued to be powered by steam until 1953. A major addition to the mining landscape was the construction in 1939 of the pithead baths.

Output of coal peaked in South Wales in 1913 and in its heyday Big Pit employed 1300 men and produced more than 250, 000 tons of coal a year. Slow decline followed with the worst period being the slump of the 20s and 30s when there was 57% unemployment in Blaenavon. Apart from a brief interlude during the Second World War, the decline continued and by 1966, Big Pit was the only surviving deep mine remaining in the Blaenavon area. In 1980 the mine finally closed and in 1983 reopened as a colliery museum.

Historic Landscape Characteristics

Forgeside and Big Pit is predominantly characterised today by the important surviving features and standing buildings now part of the Big Pit Mining Museum, but also has considerable potential for the survival of buried archaeological remains associated with the mid-nineteenth century ironworks and colliery workings at Forgeside.

The Big Pit site includes an assemblage of listed pit head buildings and structures dating from the latter part of the nineteenth century through to the mid-twentieth century: the Pit Head Building, Headframe and Tram Circuit; Miners' Baths and Canteen, (both Listed Grade II*); Winding Engine house; U-Shaped Group Including Welding and Fitting Shop, Blacksmiths Shop and Tea Shop; Saw Mill; Deputies Lodge; Office, Electrical Workshop; Haulage Engine House and Pitman's Cabin; Reception (Fitting Shops); Fan and Compressor House; and Powder House (all Listed Grade II). This group of buildings presents a strong industrial character against a background of partially reclaimed tips.

Landscaped former industrial land, a relatively recent addition, is also characteristic of the area and is considered likely to mask buried remains of interest. The landscaped site of the former Blaenavon Ironworks' Forgeside plant is the main example. This plant stood immediately to the north east of Big Pit and included hot-blast furnaces, puddling furnaces, rolling mills for bar iron and rails and extensive coke ovens all interconnected by a tramroad/rail network. While some of this area (site of Forge/Tyre Mill) now lies under modern industrial units, much of the former works lie under open ground and there is a strong possibility that buried remains may survive.

The north-eastern boundary of the area follows and includes the lines of the LNWR Blaenavon-Brynmawr Branch (now the line of the Pontypool and Blaenavon Railway), which remains a visible feature in the landscape. This was part of a far more extensive network including tramroads, which served the collieries and ironworks of the area.

Water management features are also characteristic of the area; reservoirs supplied water-balance systems and steam engines in the mines and the Forgeside works. The water management system comprised three main elements; Coity Pond (HLCA004), Forge Pond and a reservoir to the east of Coity Pit. Associated with these were a number of smaller ponds, aqueducts and leats (1st edition OS map). Of the main water management features in the area (HLCA005), Forge Pond remains intact while the reservoir east of Coity Pit has been infilled and is now a car park.

Another characteristic of the area is the extensive tipping of colliery waste to the north of Coity Pit/Big Pit, which was largely in place by the survey of the 1st edition OS map in (1879-80). An additional area of more recent (latter half of the twentieth century?) and now landscaped tipping lies in the area to the south east of Big Pit. This was one of three large conical tips previously known as little Egypt.

Like the ironworks site to the northeast, this area is associated with the advances made in steel production under the direction of Percy Carlyle Gilchrist and Sydney Gilchrist Thomas. In December 1877 the site at Forgeside was used for larger scale experiments, which succeeded in using a basic lining to convert iron made from phosphoric ores into steel, previously unachievable using the Bessemer process.