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. A low-key passenger service was operated, and a colliery at Nantgarw was served until 1952. The passenger service was cut back to Coryton in 1931 and continues to operate today.