The merger of these two pits created the largest colliery in the south Wales coalfield.

There were several large collieries dating back to the 18th century, also malt kilns and a cotton mill.

Originally Waratah had as its industrial base a large colliery bearing its name.

Small mining operations founded by local residents gave way to large, highly capitalized collieries, capable of reaching coal veins deep underground.

By 1848, Padiham had many coal pits around the town, including two large collieries and a number of smaller workings.

By the early 20th century Greenside had the largest colliery in the district.

The first large colliery, the Hub Shaft, opened in 1861.

Nearby was Royston engine shed built in the early 1930s, code 20C, to provide motive power for trains from the large collieries of the area.

Cwmdare had four large collieries in operation during its history, all of which had closed by 1977.

This led to the rapid development of more and larger collieries.