The most important single contribution towards the development of Southall as an industrial town was the construction of the railway: village life gradually declined as industrial and commercial enterprises were introduced. The canal had already had some effect, particularly by encouraging new industries by its banks: a vitriol factory, a small gas works, an ordnance depot at North Hyde and a large mill at Norwood, for instance. Most of the traffic on the canal, however, passed straight through, and about the only exports from Southall were local market produce and bricks.
In 1835 the Great Western Railway Company obtained permission to build a line from Paddington to the West of England. Work started almost immediately. The first contract to be let was for the viaduct across the Brent between Hanwell and Southall, and construction began in February 1836. It was much the most important work between London and Maidenhead, and when finished eighteen months later, it was 300 yards long and 65 feet high with eight arches of 70 feet span, each pier consisting of two slightly tapering pillars to which a third was added in 1877 when the line was widened. The Directors’ report tells us:
‘In acknowledgement of the zealous and indefatigable attention of Lord Wharncliffe , as Chairman of the Committee on the Act of Incorporation in the House of Lords, it was, by his Lordship’s permission, named Wharncliffe Viaduct’.
and his coat of arms still decorates the southern side. By repeated slipping the steep embankments at both ends of the viaduct caused a great deal of trouble for some years.
A little further west the line had to cross the Uxbridge Road just at the point where it was already cut by Windmill Lane, the road from Greenford to Brentford. This was very awkward and caused Brunel, the engineer of the line, considerable inconvenience. The cast-iron girders were supported by two rows of pillars, eight in each row, separating the main carriageway from the footpaths. The two central ones on each side flanked the two junctions with Windmill Lane and were of cast-iron, whereas all the rest were of brick. The spaces between the girders at the top were initially filled with brick, but this proved too heavy and one of the main girders gave way in March 1839. Planks replaced the bricks, but they too had their hazards for in May 1847 they caught fire and burnt so fiercely that the heat cracked nearly all the girders. A new bridge was made from wrought-iron. Brunel wrote:
‘Cast-iron bridges are always giving trouble…
our Great Western road bridge at Hanwell [sic], since 1838 has always been under repair and has cost its first cost three times over…’27