At one time this name embraced all those pits and levels worked by the Plymouth Iron Company to supply their works. They were situated approximately 2 – 3 miles south of Merthyr in an area which extended from a point north of Pentrebach to Troedyrhiw.

A Time – Line

1763 – John Guest and Isaac Williams commence a 99 year lease on lands belonging to the Earl of Plymouth at a rent of 60 per annum.

1765 – The land is sub-leased to Anthony Bacon who constructed the Plymouth Iron Works.

1786 – On the death of Anthony Bacon a 15 year lease was passed to Richard Hill at an annual cost of rent plus 268.

1818 – Richard Hill died and ownership of the works passed to his sons Richard and Anthony.

1837 – North Duffryn Pit No. 1 was sunk to the Nine–Feet seam at 162 yards.

1842 – The Plymouth Collieries featured prominently in the Royal Commission Enquiry into the employment of children underground. At this time these pits and levels employed 90 boys and 25 girls under the age of 13 years and also 80 women. Susan Reece aged 6 years had been employed underground for six or eight months. Philip Phillips aged 9 years had a face scarred by being badly burned in an underground accident a year previously. Mary Davies aged 6 years said  I sometimes fall asleep and I think the rats stole my bread and cheese. These are but three of the numerous similar stories heard by the Commissioners which directly led to the Mines Act 1842 which banned women and children under ten from working in the mines.

1844 – Richard junior and died sole ownership passed to Anthony Hill.

1856 – North Duffryn Pit No. 2 was sunk to the Lower-Five-Feet seam at a depth of 213 yards.

1862 – Anthony Hill died and the Plymouth Iron Works was sold to Fothergill, Hankey and Bateman. The Hills Plymouth Company continued to work their mining interests and in this year they opened the South Duffryn Colliery with two shafts 270 yards deep.

1880 – A 40 feet diameter Waddle type ventilator was installed using the North Duffryn Pit No. 2 as the upcast shaft.

1882 – The closure of the Plymouth Iron Works.

1907 – At this time 3000 miners were employed by the Hills Plymouth Company.

1927 – D. R. Llewellyn bought out the company which then became Llewellyn (Plymouth) Limited.

1935 – The company employed 1780 men producing 500,000 tons of coal annually from seven collieries.

1940 – The last of the Plymouth collieries to work, South Duffryn, ceased production in November although pumping operations to protect Merthyr Vale Colliery continued until 1968.

The Levels – Some examples around Troedyrhiw

Brazil Level – A relatively small part of the Hills Plymouth operation. This level employed between 11 and 57 men in the period 1903 to 1920.

Saron Levels – These levels numbered 1, 2, 3, and 4, originating from before 1878, were by 1898 producing, together with Brazil level, approximately 46,000 tons of coal annually for the mortgagees of the Plymouth Iron Works. From 1895 in the ownership of the Hills Plymouth Company 80 men were employed and production was approximately 35,000 tons annually. They were abandoned in 1913.

Taldwyn Level – This was listed in 1923/25 as belonging to the Hills Plymouth Company and employing 85 men. By 1935, in the ownership of Llewellyn (Plymouth) Limited it employed 120 men.

Nantrodyn Level – Another small Hills Plymouth level listed as having a workforce of 21 to 36 men in the period 1910 to 1913. By 1937 it was abandoned.

Green Meadow – A very small level working the No 1 Rhondda (Danyderi) seam. It was owned by Richard Price in 1908 and employed four men. By 1912 the workforce had risen to six men and by December 1915 the level was closed.


A coal seam

Many different coal seams were exploited in this area but of particular note is that known here as the Saron seam (elsewhere called No 2 Rhondda) which was extensively worked locally at a section of 20 – 30 inches.