From 1839 the Trustees of the Marquis of Bute, operated a large dock operation in Cardiff, the "Bute Docks". This was very successful, but was overwhelmed by the huge volume of coal exported through Cardiff. At the same time it was seen that railway companies, especially the Taff Vale Railway (TVR), were making money conveying the coal to the docks.

The Taff Vale Railway (TVR) was a standard gauge railway in South Wales, built by the Taff Vale Railway Company to serve the iron and coal industries around Merthyr Tydfil and to connect them with docks in Cardiff. It was opened in stages in 1840 and 1841.