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.
Vale of Neath Railway
The West Midland Railway had been formed in 1860 from the amalgamation of the NA&HR with other lines. It still harboured a desire to reach Aberdare, but in frustration it now considered joining the Taff Vale Railway at Mountain Ash to do so, although this would have deprived it of the possibility of reaching above Aberdare.