Triangle Business Park, former Pentrebach Ironworks
South of the Plymouth Furnaces, Trevithick’s locomotive would have continued
along the Penydarren tram road, which had been built on land over which
Richard Hill had acquired extensive mineral rights. In 1804 however, the
ironworks and collieries that were to make the Hill family very wealthy, had
yet to be developed. Two new blast furnaces were to be built at Plymouth in
1807 and1815, and by this time construction of works at Pentrebach had
Whilst the blast furnaces at Plymouth turned the raw materials of ironstone,
coke and limestone into pig iron, the Pentrebach works was constructed to
refine that metal. At the site, puddling furnaces and rolling mills were
built to turn the useless pig iron into a more malleable material that could
be cast or rolled into different shapes. The Hill’s still relied heavily on
water to power machinery in the works so the water feeder that served the
Plymouth site was continued south to serve Pentrebach. This works became a
very important part of the Plymouth concern and in 1841 modern rolling mills
At the same time as the Pentrebach works were being built the owners decided
to erect new cottages for their workers. A number of separate rows were
built to the south, but immediately to the north, confined by the bend of
the Plymouth water feeder, four rows were constructed, three of these making
the shape of a Triangle. Toilets were located in the centre of the enclosed
space. These were good quality houses for the skilled ironworkers of
Pentrebach. After the death of Richard Hill in 1806 his three sons were
involved in the running of the works.
It was however the youngest son, called Anthony after his uncle Anthony
Bacon, who became the most notable of the family. He had studied geology,
chemistry and metallurgy and became a Fellow of the Geological Society.
Although the Hills tried to sell the works in 1834 no buyer came along and
the concern remained in their ownership for almost another thirty years.
Despite becoming a very wealthy family, the Hills continued to live at
Plymouth House overlooking the site of the original works.
They seemed to shun the extravagant lifestyles of the other Merthyr
ironmasters, preferring to provide for the education and spiritual welfare
of their workers. It was not until 1850 that Anthony built the mansion that
still stands at Pentrebach and where he lived until his death in 1862. (The
second large building on the site used as a motel is a modern construction).
Anthony Hill in particular was a man of great generosity, establishing
schools at Plymouth and Troedyrhiw, paying the teachers and leaving money in
his will for the maintenance of the buildings.
Travelling south of the Pentrebach Ironworks, a site now occupied by
business offices and chain stores, the tramroad continued towards where
Anthony Hill was to develop a third location for iron manufacture. At
Duffryn he was to build five more blast furnaces with other associated
structures, and here too deeper pits were to be sunk which would reach the
richer steam coal seams of the Taff Valley. Graig and Duffryn Collieries,
sunk alongside the Penydarren Tramroad would continue to produce best
quality coal for world shipping for well over a half a century after Anthony