In 1916 a train passed a signal at danger near the station causing a collision that killed two people.

The tunnel is 666 yards (609m) long, and the south-west portal (railway mileage 14miles-2¾ chains from Brecon station) was reached after a three-mile (5 km) ascent from the Merthyr side.

At an elevation of 1,313 feet (400 m), it was the highest standard gauge rail tunnel above sea level in regular use anywhere in Great Britain.

For operational and access reasons, Torpantau station was rebuilt slightly south of the original site, on the opposite side of the road.

The nearby original station site is a popular start point for walks in the Brecon Beacons.