Machine Bridge (also known as Pont y Doctor)

Cadw's description

Location

Spanning the River Taff at the SE end of Broadway and E of St Dyfrig's Church.

History

Built in 1809 by Dr Richard Griffiths to carry coal mined at Hafod Uchaf to the Glamorganshire Canal.
Griffiths pioneered the export of Rhondda coal. Machine Bridge was part of a 5-mile tramroad from the
collieries down which coal was carried and transferred to a short canal, one mile long, that was joined to the
Glamorganshire Canal at Treforest in 1813. Over 200,000 tons of coal were carried over the bridge in 1839.
The opening of the Taff Vale Railway in 1840 saw a decline in traffic on the tramroad, although it remained
in use until the early C20 to carry coal from Pwllgwaun Colliery. It subsequently became a road bridge.
A weighing machine once stood at one end of the bridge hence the name "Machine Bridge".
The bridge was reconstructed and widened around 1910, an early use of reinforced concrete. The parapets
and masonary of the sides of the bridge were removed, leaving the piers and arches intact. The piers were
widened by the addition of concrete piers on the downstream side; these piers bear concrete posts supporting the new widened deck. The deck also projects on the northern side.
The surviving C19 fabric is believed to be the earliest surviving multi-arched railway bridge in the world,
predating the Laigh Milton Mill viaduct in Scotland by 3 years.

Exterior

Three segmental arches on piers of coursed hammer-dressed stone with concrete spandrels. On the N
(upstream) side are V-shaped stone cutwaters which rise to the height of the imposts, above which they
continue in concrete and form brackets supporting the added footway and parapet projecting out from the
original bridge.
The footway has a parapet comprising a dwarf concrete wall with vertical ribs, and cast iron railings with
intermediate and terminal concrete piers. The S side has a similar parapet but has been widened by means
of bases extended out from the original piers, from which uprights support the deck. The parapets have
terminal piers of rock-faced stone that are integral with added rock-faced abutments.

Reason for designation

Graded II* for the industrial archaeological interest of its origins as an extremely early multi-arched tramway bridge, and for its association with the early Rhondda coal trade.