Durley Lane Bridge (MLN111439), Keynsham, Bath and North East Somerset

Summary

An accommodation underbridge in the Tudor-Gothic style with a four-centred arch, built into an embankment c.1839-40.

Description

MATERIALS: pennant stone throughout, squared and coursed on the faces and soffit, ashlar dressings for voussoirs, quoins, string course and copings.

DESCRIPTION: depressed, four-centred arch with a span of 16ft (5m) and chamfered voussoirs terminating at the footings in chamfer stops. Low continuous chamfered plinth around the external faces and the carriageway faces. Arch soffit and carriageway faces unaltered throughout. On both faces, archway flanked by stepped buttresses, the offsets with drip-mould and arris. Beyond the buttresses the faces continue unbroken and parallel to the trackbed as straight wing walls, and running across the full width of each is a string course moulded with arris, which merges with the top of the upper offsets of the buttresses. A cast-iron pipe is fixed to the south (Down) face, passing through the buttresses. Continuous parapets terminating in projecting piers. The piers and parapet unified by coping with external face cut sharply to an arris. Post-war, galvanised steel, round section railings mounted above the coping to both faces. Beyond the east (low mileage) piers are C20 parapet extensions in stone and on the south (Down) side also in pre-cast concrete sections. Here also a small post-war red-brick extension and access steps from the roadway up to the tracks, with steel handrail. These C20 modifications are not of special interest.

History

The Great Western Railway was authorised by an Act of Parliament in 1835 to construct a line from London to Bristol. At 118 miles this was slightly longer than the other major trunk railway of its time, the London and Birmingham (112 miles) and considerably longer than other pioneering lines. Construction of the line began in 1836, using a variety of contractors and some direct labour. The first section to be completed, from London to Maidenhead Riverside (Taplow), opened in 1838, and thereafter openings followed in eight phases culminating in the completion of the whole route in 1841. Work at the Bristol end of the line had started in 1835, and the section from Bristol to Bath had opened in August 1840.

The engineering of the railway was entrusted in 1833 to Isambard Kingdom Brunel (1806-59), who was already known for his engineering projects in Bristol. More than any other railway engineer of his time he took sole responsibility for every aspect of the engineering design, from surveying the line to the detailing of buildings and structures. He sought to achieve as level a route as possible and, working from first principles, he persuaded the Directors of the GWR to adopt a broad gauge of 7ft 0¼ in rather then the standard (4ft 8½in) gauge in use on other lines. A two track broad gauge line was 30ft wide, and this determined the span of the overbridges and other structures. Except for larger bridges such as Maidenhead Bridge, the majority of Brunel’s masonry bridges did not need to be as innovative as his works in timber and iron, and his structures followed the typical architectural idioms of his time, but they were all beautifully detailed and built and together they formed integral parts of a consistently-designed pioneering railway.

Although he left no written statement concerning his design concept for the line, it can be inferred from its design and from the way it was described when opened that part of his vision was a line engineered according to picturesque principles. This influenced his selection of the route and the design of structures along it. For reasons of cost, but also because it helped blend the railway to the landscape, he used local materials for bridges and other structures, ranging from stock brick at the London end of the line, to red brick, Bath stone east of Bath and Pennant stone west of Bath. This intentional variety was remarked on by contemporaries, for instance in J.C.Bourne, 'The History and Description of the Great Western Railway' (1846). On the line from Bristol to Bath, where the track runs along the Avon valley, Brunel chose to use Tudor four-centred arches for both the over- and underbridges, and castellation for tunnel portals and viaducts. This makes it the most distinctive part of the whole route from London to Bristol, and it is also the section on which the structures have generally survived in their original form because this part of the route was not quadrupled and the Pennant stone used for most structures has lasted well.

Durley Lane Bridge

Existing contract drawings for bridges and other structures on this section of the line carry the signature of I.K.Brunel, reflecting his involvement with every aspect of the project. The Resident Engineer was G.E. Frere (1807-87), assisted by G.T. Clark (1809-98) and Michael Lane (1802-68), but their individual contributions have not been identified.

Durley Lane Bridge was one of the structures built c.1839-40 in time for the opening of this stretch of the line in August 1840. Contract drawings survive together with a sketch in one of Brunel's sketch books show him trying five different variations for Gothic underbridges and selecting the design which was executed with minor changes at Durley Lane and in a number of other locations. The bridge is unaltered except for the C20 addition of a service pipe, parapet extensions and access steps.

Reasons for Listing

Durley Lane Bridge, constructed c.1839-40 is designated at Grade II for the following principal reasons:
* Date: an early example of a railway structure dating from the pioneering phase in national railway development;
* Architectural interest: it is characteristically well designed, by the hand of Brunel, with a chamfered, four-centred arch and stepped buttresses;
* Group value: it forms a group with other listed structures on the section between Bristol and Bath, and this is enhanced by their shared architectural style;
* Historic association: it is constructed to a design by Isambard Kingdom Brunel who is widely perceived as one of the most important transport engineers and architects of the C19.

External Links

External links are from the relevant listing authority and, where applicable, Wikidata. Wikidata IDs may be related buildings as well as this specific building. If you want to add or update a link, you will need to do so by editing the Wikidata entry.