Cwm Prysor Viaduct

Cwm Prysor Viaduct, which is occasionally referred to as Blaen-y-Cwm Viaduct, is a railway viaduct which crosses the Afon Prysor in thinly populated uplands east of Trawsfynydd, Gwynedd, Wales. It was built by the Bala and Festiniog Railway. It carried a single track on a line that ran between Bala Junction and Blaenau Ffestiniog. The line it was built for went out of service in 1961.^[6][7]

v t e Bala & Festiniog Railway
Legend
Conwy Valley line to Llandudno Ffestiniog Railway to Porthmadog Harbour Blaenau Festiniog Junction Blaenau Ffestiniog North Blaenau Ffestiniog Ffestiniog Railway to Duffws (FR) Diphwys (F&BR) Glynllifon Street (F&BR) Former wooden viaduct Tan-y-Manod (F&BR) Graig Ddu Quarry Pengwern Quarry Tyddyngwyn (F&BR) Manod Teigl Halt Festiniog Maentwrog Road Line to south dismantled Trawsfynydd power station loading point Trawsfynydd Lake Halt Trawsfynydd Camp Trawsfynydd Llafar Halt Bryn-Celynog Halt Cwm Prysor Viaduct Cwm Prysor Halt Arenig Capel Celyn Halt Section flooded by Llyn Celyn Tyddyn Bridge Halt (under dam wall) Frongoch Bala (New) Bala Junction Ruabon–Barmouth line to Llandderfel Bala (Penybont) (original Bala Lake Halt) Bala Lake Railway to Llanuwchllyn Ruabon–Barmouth line to Barmouth

Cwm Prysor Viaduct
Cwm Prysor Viaduct in 2014
Coordinates	52.9323°N 3.8235°W / 52.9323; -3.8235
Carries	Ex-Bala and Festiniog Railway
Crosses	Afon Prysor
Locale	Cwm Prysor, east of Trawsfynydd, Gwynedd, Wales
Official name	Cwm Prysor Viaduct
Characteristics
Design	9 36 feet (11 m) brick arches on stone piers[1][2]
Total length	490 feet (150 m)
Width	Single Standard Gauge Rail
Height	105 feet (32 m)[3]
History
Opened	1 November 1882[4]
Closed	28 January 1961[5]
Statistics
Daily traffic	Footpath
Location

History

The structure consists of nine stone arches carrying a single bi-directional track over which passenger trains ran from 1882 to 1960, with freight trains lasting until 1961. The viaduct was the most substantial single structure on the line. It is sharply curved, necessitating the provision of a check rail in its active railway days.^[8][9]

In 1953 extensive repair work was undertaken in which the opportunity was taken to raise the parapet and add metal railings on top.^[10][11]

A "Last Train" special crossed the viaduct a week before final closure.^[12][13] The track was lifted in the 1960s.

The prospect of rail traffic returning over the viaduct is very remote, not least because part of the route has been flooded by the construction of a dam at Llyn Celyn.

Modern access

The structure is Grade II Listed.^[14] The landowner allows public access but there is no public right of way.^[15]