This viaduct carries the former GWR main line across the River Usk in Newport city centre in south Wales.
The original wooden structure was designed by Isambard Kingdom Brunel for the South Wales Railway in 1848. On 31 May, as the final arch was nearing completion, a heated bolt being inserted in a hole ignited the wood, which had been chemically preserved, and a catastophic fire destroyed most of the structure. No water supply was on hand, despite the obvious hazard.
To rebuild the central span, Brunel adopted a wrought iron bow-string girder construction, similar to that he'd used at Windsor. This had three girders in parallel, the central one being of heavier construction to accommodate trains being on both tracks at the same time. The remainder of the viaduct was rebuilt in timber, preserved by the Kyanising process.
Deterioration of the eleven timber spans led to them being gradually replaced by wrought iron plate girders, still on timber supports. The five western spans had been dealt with by 1867, and the remaining five were replaced in 1871. The timber piers were replaced by masonry by 1886.
In 1924 the bridge was extensively rebuilt and widened by the GWR to accommodate four tracks.
Sources of Information
- 'Brunel's Timber Bridges and Viaducts' by Brian Lewis, Ian Allan Publishing, 2007