Ystrad Mynach South Signal Box

Cadw's description

Location

To the south of Ystrad Mynach station on the west side of the tracks off a rough lane from Twyn Road. Private property.

History

Built c1890 for the Rhymney railway by McKenzie and Holland and shown on the 1901 2nd Edition Ordnance Survey Map. Constructed as a Type 3 McKenzie and Holland Box but with a stone base, as specified by the Rhymney Railway, over the normal McKenzie and Holland practice of using brick and timber for a base. Its siting - high on an embankment overlooking the rail line - is a rare survivor of a once-common south Wales practice giving signalmen a clear view in this case of the sweeping line south of Ystrad Mynach station and the junction with the Merthyr branch line. This siting requires the use of an external platform to take the signal wires to ground level. Originally it would have been equipped with a McKenzie and Holland mechanical lever frame but this was removed shortly after inspection in 2013, along with the quadrants and block shelf indicators and instruments, but (disconnected) locking levers still in situ.

Exterior

Signal Box. Two storey of rock faced stone and timber with hipped corrugated sheet roof with ventilators. East trackside elevation with 2 tall round headed windows with small paned framed glazing to lower floor and timber gallery to the upper floor with continuous glazing of four horizontally sliding slash window. Built against the tackside elevation at low level is a platform supportng two changes in direction of the point rodding and signal wires, diverting them to ground level. Gallery on upper floor returns to north and south, later first floor extension with part galzed door to lever room and access steps to the south, presumably replacing originals. Plain stone rear (west) elevation.

Interior

Upper floor retains block shelf, locking levers and track layout plan.

Reason for designation

Included for its special architectual interest as a well preserved signal box, a rare surviving example of a McKenzie and Holland type 3 signal box, its design adapted to fit local requirements.