This next post relates in passing to the Penydarren Tramroad. It focuses primarily on the Plymouth Ironworks an Collieries which grew as a result of the existence of the Tramroad and the later railways in the Taff Valley. ...http://rogerfarnworth.com/2019/11/13/the-plymouth-or-south-duffryn-colliery-in-the-taff-valley
South Duffryn or Plymouth Colliery, situated to the south of Pentrebach and just north of Troedyrhiw, was opened by the Hills Plymouth Company in 1862. It was served by the Taff Valley Railway and the Penydarren Tramroad. I have been prompted to write this short post by reading an article written by Clive Thomas in the Archive Journal of September 2014.
The featured image above shows the colliery sidings in a postcard image from the early 20th century.