Llantrisant and Taff Vale Junction Railway
In time the Canal became overwhelmed by the volume of traffic, and encouraged by the successful opening of railways with more advanced technology than the horse tramways of previous years, the Taff Vale Railway was promoted. It was authorised by Parliament in 1836 and it opened between Merthyr and Cardiff docks in 1841. The line passed close to the Maesmawr workings but did not make a connection.
Taff Vale Railway
Following World War I the government decided to restructure most of the railways of Great Britain into one or other of four large companies. The process was called the "grouping" and was legislated in the Railways Act 1921. The old Great Western and six of the South Wales railway companies were constituents of the new Great Western Railway. The other smaller railways in the GWR area were "subsidiaries". The Taff Vale Railway was the second largest constituent of the new Great Western Railway; the old GWR was the largest. The Taff Vale Railway was amalgamated into the putative new GWR on 1 January 1922.