Wharncliffe Viaduct

Wharncliffe Viaduct
Looking north, July 2006
Carries	trains, telecommunications via cables
Crosses	River Brent and Brent Valley
Locale	London (Hanwell/Southall)
Characteristics
Design	arch bridge, viaduct
Total length	886 feet (270 m)
Width	55 feet (17 m)
Longest span	70 feet (21 m)
History
Construction begin	1836
Construction end	1837

The Wharncliffe Viaduct is a brick-built viaduct that carries the Great Western Main Line railway across the Brent Valley, between Hanwell and Southall, Ealing, UK, at an elevation of 66 feet (20 m). The viaduct, built in 1836–7, was constructed for the opening of the Great Western Railway (GWR). It is situated between Southall and Hanwell stations, the latter station being only a very short distance away to the east.

The viaduct was the first major structural design by Isambard Kingdom Brunel, the first building contract to be let on the GWR project, and the first major engineering work to be completed. It was also the first railway viaduct to be built with hollow piers, a feature much appreciated by a colony of bats which has since taken up residence within.

Constructed of engineering brick, the 886-foot-long (270 m) viaduct has eight semi-elliptical arches, each spanning 70 feet (21 m) and rising 17.5 feet (5.3 m). It is 55 feet (17 m) wide. The supporting piers are hollow and tapered, rising to projecting stone cornices that held up the arch centring during construction.

When built, the viaduct was designed to carry two broad gauge tracks: the piers were 30 feet (9.1 m) wide at ground level and 33 feet (10 m) at deck level.

The contractor was the partnership of Thomas Grissell and Samuel Morton Peto. The cost was £40,000. The foundation works were carried out by William Brotherhood and his son Rowland. The young Charles Richardson also worked here under Brunel, as one of his first works for the Great Western.

As travel by rail became more popular and rail traffic grew, pressure mounted to have an additional local line. Also, the Gauge Act of 1846 decreed that George Stephenson's (narrower) standard gauge should be the standard used for all railways across the country. Therefore, in 1877 the viaduct was widened by the addition of an extra row of piers and arches on the north side. Then in 1892 the broad gauge track was converted to standard gauge, and this allowed enough width for four standard gauge tracks.