 In conjunction with the sinking of the first colliery at the head of the Rhondda , the second issue of transportation was being tackled at the same time with the extension of the Taff Vale Railway ( TVR ) line . After Royal Assent was given to construct the railway in 1836 , the original line was laid from Cardiff to Abercynon , and by 1841 a branch was opened to link Cardiff with Dinas via Pontypridd . This would allow easier and faster transportation for Walter Coffin 's Dinas mine , an unsurprising addition considering Coffin was a director of the TVR . In 1849 the TVR had extended into the Rhondda Fach and by 1856 the railway had reached the furthest areas of both the Fach and Fawr valleys at Maerdy and Treherbert . For the first time the Rhondda Valley was connected by a major transportation route to the rest of Wales and the exploitation of its coalfields could begin . 
