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.
Rhymney Railway
The first line was dependent on the co-operation of the Taff Vale Railway (TVR) for part of the transit, and this relationship was uneasy; the Rhymney Railway built an independent line to Cardiff in 1871. Better relations were created with the London and North Western Railway, and later the Great Western Railway (GWR), and two important joint lines with the GWR were built: the Taff Bargoed line (1876) and the Quakers Yard and Merthyr Joint line (1882).