The Brecon and Merthyr Railway
During the mid-1800's competition for railway access to, and in, the south Wales valleys was fiercely contested by the various railway companies and Acts of Parliament were sought with great vigour. This was also the case in the Bargoed Rhymney (Darran) Valley.
The Brecon and Merthyr Tydfil Junction Railway (the B&M or BMR) obtained an Act of Parliament on 1 August 1859 to construct a line between Talybont and Pant. It was intended that the section between Brecon and Talybont would be built on the route of the 1816 Hay Tramroad, but the Hay, Hereford and Brecon Railway (HHBR) planned to take over most of it. The B&M secured the section west of Talyllyn however, but had to enlarge the tunnel to allow other trains to use it, together with the line into Brecon. Train services between Brecon and Pant officially began on 23 April 1863 but two trains per day ran from 19 March 1863. The company went into receivership from 1866 until 1870.
Talyllyn became a junction on 19 September 1864, when the HHBR opened. Trains to Hereford were the responsibility of the B&M until the Midland Railway took over in 1869.
Following fierce competition with the Rhymney Railway, regarding access through the Bargoed Rhymney (Darran) valley, from Pant to Bargoed, an agreement was reached whereby the Brecon & Merthyr (B&M) would be afforded a new and better junction at Bargoed, with the Rhymney Railway constructing the line between Bargoed and Deri Junction and the B&M the section between Pant and Deri Junction.
The B&M was to have running powers for through traffic, whilst the RR could work over the four miles of the B&M north of Deri Junction for access to the Fochriw Collieries and Pant-y-Waun Junction. The ravine at Groesfaen was too narrow for the laying of two separate railways although both B&M and RR surveyed the section at the same time with both company's surveying pegs being in evidence over the same route.
In 1865 the B&M applied for powers for a 7 mile line connecting Merthyr to Quaker's Yard to join with the Newport, Abergavenny & Hereford Railway, down the west bank of the River Taff. This was strongly contested by RR, TVR and GWR, and even the Glamorganshire Canal Company, since it would give the B&M a through route to Newport independent of the RR.
RR also protested that this new route was being sought despite the B&M refusing to complete its junction with the RR at Deri Junction, although the B&M line from Pant to Deri was ready for opening and Savin's (B&M's contractor) locomotives were working over it. The RR from Bargoed to Deri Junction had been completed in 1864 but RR knew that the B&M could not open its line between Pant and Deri Junction for public traffic until it had honoured its legal obligations to complete a Merthyr connection.
The Merthyr branch was opened for public service on 1 August 1868 and subsequently the Pant to Dowlais Top section was opened on 1 August 1867. The Dowlais Top to Fochriw section opened on