Railway Bridge

Railway Bridge, St Mary's Road, Langley St Mary

This railway bridge was built between 1836 and 1838 by Isambard Kingdom Brunel as part of the original Great Western Railway construction from London to Bristol. The bridge is 18 feet wide and was designed to carry two broad-gauge tracks. It comprises a 30-foot-span semi-elliptical arch constructed in London stock brick with white hydraulic mortar on limestone imposts. The arch is finished with brick string courses and dressed gritstone copings. The original span and southern abutment retain their original parapets, approaches, gritstone copings and terminal pilasters. The gently-splayed abutments at each end originally flanked the arch. Some limited cementitious repointing has been carried out in places.

The bridge has been extended twice since its original construction. In 1878, during the Southall-Slough quadrupling project, the northern abutment was largely demolished and the bridge was extended northward with a matching, slightly skewed 25-foot arched extension, also in London stock brick with similar finishes. Raking buttresses stand either side of the pier between the original arch and the 1878 addition; these buttresses retain fabric from Brunel's original northern abutment and reflect its angle. In 1914, during the creation of the Langley-Dolphin (Slough) loop, the bridge was extended north again with a skewed 19-foot-9-inch-span single-line steel girder span. The accompanying new northern abutment has steeply-angled wing walls.

The bridge originally carried two broad-gauge tracks; from 1861 it accommodated two mixed broad- and standard-gauge tracks until the abolition of broad gauge in 1892.

This bridge is a good example of a Brunel overbridge from the first phase of Great Western Railway construction. Despite later extensions and the loss of its north buttress, over two-thirds of the original Brunel fabric survives, including the parapets, making it of considerable historic significance.