Former Lewis Merthyr Colliery now operating as Rhondda Heritage Park, preserving the oldest surviving headframes in Wales and offering underground guided tours.
Lewis Merthyr Colliery at Trehafod in the lower Rhondda Valley was one of the largest and longest-lived collieries in South Wales. The site's origins go back to 1850 when two pits, Hafod and Coedcae, were sunk by separate parties but both abandoned early due to difficult working conditions. In the mid-1870s William Thomas Lewis, later Lord Merthyr, purchased and reopened the two pits and then sank the Bertie shaft around 1878–80 and the Trefor shaft around 1890, both named after his sons.
By 1900 Lewis Merthyr Consolidated Collieries Ltd employed around 5,000 men and produced close to a million tons of coal annually. The colliery passed to the Powell Duffryn Steam Coal Company in 1929 and was nationalised in 1947. In 1958 Lewis Merthyr merged with the neighbouring Ty Mawr Colliery, and all coal winding at Lewis Merthyr ceased.
Coal production at the combined Ty Mawr/Lewis Merthyr Colliery ended in June 1983. The pithead buildings and headframes were preserved and opened as the Rhondda Heritage Park, now operating as a visitor attraction offering underground guided tours led by former miners. The Bertie and Trefor headframes and associated colliery buildings are listed Grade II*.
The history of the Lewis Merthyr site begins in 1850 when two pits were opened on land in the lower Rhondda Valley at Trehafod. The Hafod pit was sunk by brothers David and John Thomas and the Coedcae pit was started by Edward Mills. Both ventures were abandoned early on due to difficult working conditions; the Coedcae sinking was abandoned by Mills because of excessive water in the shafts, and David and John Thomas then purchased and completed the Coedcae sinking to the No. 3 Rhondda seam, with the Old Pit as the upcast ventilation shaft and the New Pit as the downcast, both 115 yards deep.
The original Hafod pit was also sunk to the No. 3 Rhondda seam in 1850 but was abandoned because of geological problems before any coal was produced. In the mid-1870s William Thomas Lewis, later Lord Merthyr, purchased and reopened the two pits, working the upper bituminous household coal seams. By 1880 Lewis had sunk the Bertie shaft, constructed around 1878; the Bertie pithead and headframe, built in lattice girder style and covered by a stone and brick pitbank building, are the oldest surviving headframes in Wales.
By 1890 the Trefor shaft had been sunk; the associated winding house, dated to 1878, and the Trefor winding engine house, positioned to the east, are constructed of rusticated pennant sandstone. Both shafts were sunk to the steam coal seams, initially to a depth of 359 yards to the Six Feet seam, and later deepened to 453 yards to the Five Feet seam in 1898. The Bertie shaft, 17 feet in diameter, served as the downcast ventilation shaft; the Trefor shaft, 14 feet in diameter, served as the upcast.
In 1881 the Lewis Merthyr Navigation Collieries Limited was formed. By 1896 the colliery was working eight seams: the Two-Feet-Nine, Four Feet, Six Feet, Red Vein, Nine Feet, Upper Five Feet, Lower Five Feet, and No. 3 Rhondda. At this time the ventilation was provided by Schiele type fans generating 430,000 cubic feet of air per minute.
In 1900 W. T. Lewis formed the Lewis Merthyr Consolidated Collieries Limited, uniting the Coedcae Coal Company and Lewis Merthyr Navigation Colliery Company. A coking plant at the colliery, one of the first in the Rhondda, had by 1910 developed into a battery of fifty ovens with a gas and by-product plant. By 1900 the Coedcae pit was using compressed air coal cutters of bar, disc, and chain types.
Lewis Merthyr was among the first collieries in South Wales to adopt electric power turbine pumps to deal with large volumes of water. Annual output reached 1,500,000 tons per year in the early 1900s. By 1908 Bertie pit employed 1,053 men and Trefor pit 1,066.
In 1918 Bertie and Trefor pits employed 1,792 men combined, Coedcae 556 men, and Hafod Nos. 1 and 2 a total of 1,496 men. In 1929 Lewis Merthyr Consolidated Collieries Limited was purchased by the Powell Duffryn Steam Coal Company Limited. In the same year Coedcae ceased winding coal.
Hafod No. 2 ceased in 1930, and Hafod No. 1 in 1933. During 1945 Bertie and Trefor pits together employed 1,433 men. A pocket of gas was ignited by a rock fall on 22 November 1956; two men were killed instantly and seven others including the manager died later from their injuries.
Output at this time was around 1,250 tons per day with a workforce of 1,160 men. On nationalisation in 1947 the colliery was placed in the National Coal Board's South Western Division. In 1958 Lewis Merthyr Colliery merged with the neighbouring Ty Mawr Colliery.
All coal winding ceased at Lewis Merthyr, with coaling continuing via Ty Mawr and men and supplies only transported via Lewis Merthyr. By 1969 the combined concern was known as the Ty Mawr/Lewis Merthyr Colliery. The colliery worked up to thirteen seams in total using the longwall method.
Production at Lewis Merthyr came to an end on 14 March 1983. Coal production continued in the Four Feet seam until July 1983, when coaling ceased forever at the Ty Mawr/Lewis Merthyr site. The pithead gear and buildings were preserved.
The site was subsequently developed as the Rhondda Heritage Park. The two headframes and associated colliery buildings are listed Grade II*. The Bertie pithead and headframe are listed as a rare surviving pitbank complete with cover building and for having the oldest headframe remaining in Wales.
The Trefor pithead and headframe, Bertie winding engine house, Trefor winding engine house, and lamproom and fan house are also listed Grade II*. The chimney, a tall yellow-brick stack approximately 50 metres high built in 1892 on a pennant sandstone base, and the fanhouse are listed Grade II. In May 2000 a six-foot replica Miner's Lamp monument was unveiled at the entrance of Rhondda Heritage Park as a memorial to those who lost their lives or suffered as a result of the mining industry of the South Wales coalfield.
