Loughor railway viaduct

Railway viaduct of 2013, left, alongside the road bridge across the Loughor Estuary

The Loughor railway viaduct is a railway viaduct carrying the West Wales Line across the River Loughor. The structure is adjacent to the Loughor road bridge. The recently replaced 1880 structure was Grade II listed.[1]

History

The Loughor viaduct was built for the broad gauge South Wales Railway west of Swansea to Carmarthen. The line across it opened in 1852.[2] The viaduct has since been rebuilt several times.

Original construction

The original viaduct was designed by Brunel, with Fletcher as resident engineer. It was of typical design for one of Brunel's many viaducts, especially those on the coastal parts of the SWR, with timber construction and a small opening span to permit river traffic. It was 750 ft long with a 40 ft opening swing bridge at the Swansea (east) end.[2][3] The seventeen fixed spans were of similar size.

When first constructed, it was supported on timber piles driven 14 feet into the sand and clay bed of the river. These piles were arranged in groups of three, across the width of the viaduct. Above this was a timber deck and a double track railway, laid on timber baulks. These tracks were both laid as mixed-gauge track, both broad gauge for the SWR and standard gauge for the Llanelly Railway.

1880 rebuilding

Loughor railway viaduct, the pre-2013 bridge

In 1880 the viaduct was rebuilt for the first time. The original piles were retained but a new deck was provided. Three longitudinal wrought iron H-girders were laid along the bridge with an iron deck above this. This deck was made of surplus Barlow rail, laid widthways. As the SWR had converted to standard gauge in 1872, the two tracks were laid as a baulk road, but now only to standard gauge.

Barlow rail was widely used for civil engineering tasks at this time, including the building of Clevedon Pier. Although it had enjoyed a vogue for railway use, it was soon discovered that this lightweight form of bridge rail was too light for prolonged use and tended to spread, leading to inaccurate gauge and risk of derailments. As a result, large quantities of it were available cheaply. The SWR offered 400 tons of it for sale in 1857, with free delivery anywhere along the line.[4]

1909 rebuilding

A major rebuilding was carried out between 1908 and 1909. The piers were replaced and were changed from a three pile design to four piles across the width.[2]

The swing bridge had last been used in 1887. With this rebuilding, it was removed altogether.[2]

1979–1981 refurbishment

A further extensive refurbishment was carried out between 1979 and 1981.[5] This was described as 'sympathetic' to the original bridge, retaining a large proportion of the original timber.[2] The 1880 construction remained as the only Brunel viaduct still using timber as a substantial proportion of its structure until it was replaced.[6]

2013 replacement

The viaduct sat on a five-mile section of track between Cockett and Duffryn which was reduced to single track operation in 1986 to save on maintenance costs. This section of track was re-doubled during 2012/2013 to allow for an increase in the number of trains using this stretch of line.[7]

With the re-doubling of railway tracks between Cockett West Junction and Duffryn West Junction, Network Rail replaced the viaduct with a new modern railway bridge. The old grade two listed structure was unable to take the weight of two trains at once. Elements of the old structure were relocated on railway land just to the west.[8] Work started on the new bridge on 24 March 2013 and was completed by 8 April 2013.[9][10]

See also

External links

References

  1. ↑ "Loughor Railway Viaduct (partly in Llwchwr community), Llwchwr". British Listed Buildings.
  2. 1 2 3 4 5 Jones, Stephen K. (2006). Brunel in South Wales. II: Communications and Coal. Tempus. pp. 154–159. ISBN 0-7524-3918-9.
  3. ↑ Isambard Brunel (2006) [1870]. The Life of Isambard Kingdom Brunel, Civil Engineer. STEAM / Nonsuch Publishing. pp. 148–149. ISBN 1-84588-031-5.
  4. ↑ Jones & II, p. 159
  5. ↑ "Loughor Viaduct". Railwest (7): 7. March 1981.
  6. ↑ Jones & II, pp. plate 31, pp. 128–129
  7. ↑ NAW – Inquiry into the Future Rail Infrastructure in Wales
  8. ↑ Rail Loughor viaduct plans given go ahead
  9. ↑ Network Rail – Work to replace the Loughor Viaduct near Swansea is complete
  10. ↑ This Is South Wales

Coordinates: 51°39′45″N 4°04′57″W / 51.662374°N 4.082397°W / 51.662374; -4.082397

This article is issued from Wikipedia - version of the 11/6/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.