Pont Briwet

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Pont Briwet (1)
Pont Briwet (1).jpg
The previous Victorian Pont Briwet; looking south towards Llandecwyn
Carries Cambrian Coast railway and A4085 A4085 road (toll)
Crosses River Dwyryd
Locale Penrhyndeudraeth, Gwynedd North Wales
Owner Private
Maintained by Network Rail
Heritage status Grade II listed (formerly)
Pier construction Wood, iron bracing
Total length 140 m (460 ft)
Width Standard gauge (4 foot 8½ inch) railway track
10 feet (3.0 m) roadway
Height 4 m (13 ft)
Piers in water 21
Load limit 2 t (2.2 tons) (vehicles)
Design life rebuild GWR (1932)
Constructed by Aberystwyth and Welsh Coast Railway
Opened 1867
Closed 2013

Pont Briwet refers to the road and railway bridges that cross the River Dwyryd, near Penrhyndeudraeth, Gwynedd in North Wales. The first bridge was a Victorian road and railway viaduct that was constructed entirely from timber.[1] Although it was Grade II listed - as a rare example of a surviving 19th-century wooden road and railway viaduct, the structure was demolished in 2014 during a joint project between the Welsh government and Network Rail to upgrade the route.

The new Pont Briwet crosses the Dwyryd on the same alignment as the original structure but it is both stronger and wider to accommodate larger vehicles and traffic volume.


Victorian bridge[edit]

The Aberystwyth and Welsh Coast Railway was authorised in 1861 to build a line along Cardigan Bay between Aberystwyth and Porthdinllaen on the Lleyn Peninsula. Pont Briwet would carry the Cambrian Coast railway to Porthmadog. In 1865 the company merged with Cambrian Railways. However boardroom struggles within the newly created company led to a delay in the work. In February 1866 the bridge's contractor was declared bankrupt. Pont Briwet was not completed until the following year.

Pont Briwet stood on 21 piers; each pier comprised four or five timber piles that were braced with iron X-framed supports. These created a series of frames on which longitudinal beams carried the road and railway; beams under the rail tracks were substantially larger than those under the roadway. Although the bridge was decked with timber planks, the road carriageway was waterproofed with a metalled surface. Iron was used for bolts and bracing bars.

In 1932, the bridge was extensively rebuilt by GWR. Half the wooden piles were replaced with new creosoted pitch pine. Additional work also included changing the cross members and bracings. The work increased the overall width of the viaduct to 8.5 m (28 ft). Despite the nationalisation of the "Big Four" British railway companies in 1947, the viaduct remained a privately owned toll road for traffic between Penrhyndeudraeth and Harlech.

By 2010, a speed limit of 20 mph (32 km/h) had been imposed on trains crossing the bridge. Single-file traffic, which was controlled by signals at each end of the bridge, was restricted to vehicles under 2 t (2.2 tons). The weight restriction meant that the route was only passable by cars. This resulted in 8 miles (13 km) detours for heavier vehicles such as lorries or ambulances.[2] Pedestrians were also unable to use the bridge because of the narrow width of the carriageway.


Pont Briwet (2)
Completed IMG 3988 -1.jpg
Completed Pont Briwet rail crossing
Carries Cambrian Coast railway
A4085 A4085 road
Crosses River Dwyryd
Locale Penrhyndeudraeth, Gwynedd North Wales
Pier construction concrete, steel
Width 18 m (59 ft) (completed)
Piers in water 6
Opened 2014 (rail)
2015 (road)
Replaces Victorian wooden viaduct

In July 2010, the Welsh Assembly Government announced a £20 million joint project with Network Rail to replace the existing bridge with a new structure by 2013. The old bridge was to have been retained due to its listed structure and transformed into a pedestrian walkway.[2] However once work began approval was granted for the viaduct's demolition in February 2012.[3]

The new Pont Briwet would carry the single-track railway plus a two-lane carriageway and a 2.5 m (8 ft 2 in) cycle/walkway. The road's speed limit would be raised to 40 mph (64 km/h) and toll charges abolished.[4] Although the road and rail bridges share the same pillars, like the original viaduct, the superstructures of the new crossings would be separate.

Planners also said that, apart from a four-week period when power cables had to be moved, the old viaduct would remain open throughout the works.[5]


Work began in March 2013. However, in November 2013 the existing wooden bridge was found to have been affected by the piling work for the new bridge. It was declared structurally unsafe and closed in December 2013. This necessitated an 8-mile diversion via Maentwrog for road users and rail services were terminated at Harlech, closing the 22 miles (35 km) line to Pwllheli via Porthmadog.[6] A new temporary road bridge was due to be in place by Spring 2014, but this plan was shelved by Gwynedd County Council in favour of a controlled traffic management system on the A496 between Maentwrog and Llandecwyn because of safety fears due to increased traffic on the A496.[7][8]


The new rail viaduct opened for services between Harlech and Pwllheli on 1 September 2014.[9] But work on the accompanying roadway was delayed by problems relocating the electricity cables and a water main that used the old bridge. After two years of work that incorporated significant delays, the road crossing opened to traffic in the summer of 2015.[10]

See also[edit]


  1. ^ Baugham, P E (1980). A Regional History of the Railways of Great Britain. Vol. XI. London. 
  2. ^ a b "New £20m road and rail bridge plan for Penrhyndeudraeth". BBC Wales News. 12 July 2010. Retrieved 13 July 2010. 
  3. ^ "Pont Briwet demolition plans approved by Snowdonia National Park". BBC News. 22 February 2012. 
  4. ^ "Penrhyndeudraeth-Harlech bridge replacement under way". BBC News. British Broadcasting Corporation. 15 March 2013. Retrieved 20 January 2014. 
  5. ^ "Penrhyndeudraeth-Harlech bridge closes for cable work". BBC News. British Broadcasting Corporation. 15 April 2013. Retrieved 20 January 2014. 
  6. ^ "Railway line closed after work destabilises rail and road crossing in North Wales". Daily Post. 6 November 2013. 
  7. ^ "Pont Briwet bridge closed over safety as £20m crossing built". BBC News. British Broadcasting Corporation. 13 January 2014. Retrieved 20 January 2014. 
  8. ^ Milner, Chris (1 January 2014). "Bridge fiasco could close Porthmadog line until 2015". The Railway Magazine. Mortons Media Group. Retrieved 20 January 2014. 
  9. ^ "Pont Briwet Road Maintenance and Improvement Scheme". Gwynedd County Council. Retrieved 8 September 2014. 
  10. ^ "Long-awaited Pont Briwet opens after more than two years of building work". North Wales Daily Post. 13 July 2015. Retrieved 19 July 2015. 

External links[edit]

Coordinates: 52°55′27″N 4°03′20″W / 52.924169°N 4.055672°W / 52.924169; -4.055672