Historic Landscape Characterisation
Merthyr Tydfil

019 Penydarren Tramroad Corridor

HLCA 019 Penydarren Tramroad Corridor Corridor of nationally important Penydarren Tramroad and other mineral lines, Plymouth Iron Works site; historic associations; site of industrial housing; mining features.

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(Photo: GGAT Merthyr 019)

Penydarren Tramroad Corridor character area: tramroad associated with the first recorded steam locomotive journey to be undertaken on rails.


A transport corridor based on the route of the Penydarren Tramroad, which is famous for its historic association with Richard Trevethick and the first recorded steam locomotive journey to be undertaken on rails in 1804. The Trevethick Tunnel is still extant, and the course of the tramroad is still partly fossilised in the modern street system (Cobden Place). The site of the Plymouth Iron Works, which lie within the area, may contain important buried remains.

Historical background

The historic landscape area of the Penydarren Tramroad Corridor essentially reflects the course of the Penydarren or Merthyr Tramroad, both the north-south route from the Penydarren Iron Works and Abercynon, well beyond the southern boundary of the historic landscape, and the east-west route from the ironworks to the canal head at George Town. Also within the area is the site of the earliest of the three Plymouth Iron Works furnace sites.

The Penydarren Tramroad from Penydarren to Abercynon was constructed in 1802 because of disagreements over tariffs charged on the Glamorganshire Canal between Richard Crawshay of Cyfarthfa, who held the largest share in the Canal Company, and the owners of the other iron works of the area, Penydarren, Dowlais and Plymouth.

The Tramroad is associated with Richard Trevithick, employed by Samuel Homfray at Penydarren to develop high-pressure steam engines. On 21 February 1804, one of Trevithick's steam engines became the first ever-recorded steam locomotive to run on rails when it completed a ten-mile journey from Merthyr to Abercynon along the Penydarren Tramroad. An important feature associated with the Penydarren Tramroad is the Plymouth Work's Tunnel (or Trevithick's Tunnel), which was the first recorded railway tunnel used by a locomotive. This survives under the site of the charging bank of the Plymouth Iron Works Furnaces, also included within HLCA 019.

The Plymouth Iron Works, ie the northernmost of the three Plymouth Iron Works sites, was the earliest, founded in 1763 by Isaac Wilkinson and John Guest on land leased from the Earl Plymouth, and two years later sold to Anthony Bacon following an initial lack of progress. Control of the works fell to Richard Hill (d. 1806) following Bacon's retirement in 1783. The works remained in the Hill family until the death of Anthony Hill in 1862. when bought by Messers Fothergill, Hankey and Bateman. The Plymouth Works relied on water power, long after it had become obsolescent elsewhere and in order to re-use the water supply the works was forced to expand into three separate plants, the Pentrebach Forge and Dyffryn furnaces (see HLCA 015) being added. Steam power was finally introduced leading to a dramatic increase in output following the dry summers of 1843 and 1844. During the second half of the 19th century, obsolete technology and economics combined to the disadvantage of the Plymouth Iron Works. The lack of capital to convert to steel production finally leads to closure in 1880; though the company continued to mine its vast reserves of coal. The area of the ironworks was the subject of two major reclamation schemes in 1974, which resulted in a major transformation of landscape, obliterating most of the surviving remains.

Cartographic evidence of 1836 shows the route of the Merthyr Tramroad in some detail. The route followed the streets of Tramroad Side North and South, continuing south to run between Plymouth House and the Ironworks Office, and skirting around the eastside of the Plymouth Iron Works. The route west to the canal head was also shown. The Penydarren or Merthyr Tramroad was associated with a complex network of interconnecting tramlines by 1850; this was particularly evident near the Pentrebach Iron Works. The 1878 OS map identified features associated with adjacent workings, Graig, Tai-bach and Wern-las Pits situated along the route, and features associated with the Dyffryn Furnaces, ie the Coke Ovens. While isolated Rows industrial housing with associated yards and allotments, such as Pen-Yard Row, Pencae-bach Cottage, and Winches Row were also a characteristic features of the landscape. By 1905 the northern and western stretch of the route from Penydarren was disused and the tracks lifted. A remaining area of possible use indicated in the area around the site of the former Plymouth Iron Works, south of the Dowlais Railway, while the route south from Wern-las, Graig Pit and South Dyffryn Pits remained in use as a Mineral Railway.


For further information please contact the Glamorgan-Gwent Archaeological Trust at this address. Link to the Countryside Council for Wales website at www.ccw.gov.uk or Cadw at www.cadw.wales.gov.uk