Fochriw was on the Brecon and Merthyr Railway line from Bargoed to Dowlais Top.
The Bargoed branch of the Rhymney Railway ran north from Bargoed to Deri Junction, then the B&M constructed the line from Deri northwards, through Fochriw.
Each company had running rights, with the Rhymney running as far north as Fochriw Colliery, past a number of other collieries in the Darran valley.
The Rhymney section to Deri was opened in 1864, but the B&M did not open through Fochriw to Dowlais Top until 1 September 1867, as they had been legally obliged to complete their connection from Dowlais to Merthyr first.
The line through Fochriw may have been completed some years before this, and coal shipped northwards from the colliery, but the line was not yet officially opened for passenger service.
Increasing coal traffic southwards from Cilhaul and Ogilvie collieries after 1900 led to the Rhymney section being relaid as double track.
The Ogilvie Colliery at Deri was sunk between 1918 and 1923.

The climb from Deri Junction to Fochriw was steep, three miles of 1:40, a shallow gradient through the station, and then a further climb for a mile of 1:38.
The highest point of the line, and the highest railway in South Wales, was in the cutting before Pant-y-waun, adjacent to the still-extant reservoir of Rhaslas Pond.
At 1314 feet, this was a single foot higher than Torpantau summit in the Brecon Beacons.

By 1919, there was also a connection from Fochriw Colliery through to Cwm Bargoed, west of the village.

Fochriw station was built to the north of Brook Row, on top of the embankment which can still be seen on the east of Railway Terrace.
Southwards its path can still be seen as a footpath between Aelbryn and Plantation Terrace.
As well as the platform, there was also a small goods shed.
The siding and goods shed were removed in 1959 and the railway closed to passengers on the 29 December 1962.
Fochriw was on the Brecon and Merthyr Railway line from Bargoed to Dowlais Top. The Bargoed branch of the Rhymney Railway ran north from Bargoed to Deri Junction, then the B&M constructed the line from Deri northwards, through Fochriw. Each company had running rights, with the Rhymney running as far north as Fochriw Colliery, past a number of other collieries in the Darran valley. The Rhymney section to Deri was opened in 1864, but the B&M did not open through Fochriw to Dowlais Top until 1 September 1867, as they had been legally obliged to complete their connection from Dowlais to Merthyr first. The line through Fochriw may have been completed some years before this, and coal shipped northwards from the colliery, but the line was not yet officially opened for passenger service. Increasing coal traffic southwards from Cilhaul and Ogilvie collieries after 1900 led to the Rhymney section being relaid as double track. The Ogilvie Colliery at Deri was sunk between 1918 and 1923.
The climb from Deri Junction to Fochriw was steep, three miles of 1:40, a shallow gradient through the station, and then a further climb for a mile of 1:38. The highest point of the line, and the highest railway in South Wales, was in the cutting before Pant-y-waun, adjacent to the still-extant reservoir of Rhaslas Pond. At 1314 feet, this was a single foot higher than Torpantau summit in the Brecon Beacons.
By 1919, there was also a connection from Fochriw Colliery through to Cwm Bargoed, west of the village.
Fochriw station was built to the north of Brook Row, on top of the embankment which can still be seen on the east of Railway Terrace. Southwards its path can still be seen as a footpath between Aelbryn and Plantation Terrace. As well as the platform, there was also a small goods shed. The siding and goods shed were removed in 1959 and the railway closed to passengers on the 29 December 1962.
Fochriw