Summary
A triple-span accommodation bridge with semi-elliptical arches, erected over a cutting c. 1839-41.
Reasons for Designation
Green Bridge near Chippenham, constructed c.1839-41, 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;
* Design: for its elegant triple-arched form, constructed in Bath stone, probably intended to create a dignified entrance to Chippenham;
* Group value: it forms a group with other architecturally-similar overbridges on the section of line between Wootton Bassett and Chippenham;
* Historic association: it is constructed to a design by Isambard Kingdom Brunel, widely perceived as one of the most important transport engineers and architects of the C19.
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.
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).
Surviving 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.
Green Bridge was built c. 1839-41 under Contract 3C on the Wootton Bassett to Chippenham section of the route, which opened May 1841. The contract drawing was signed by the contractor Edward Price in June 1839. This stretch of the line was never quadrupled and so the bridge has not been extended. The bridge was built in Bath stone ashlar, but in the late C19 or early C20 the east (low mileage) elevation was refaced below the cornice in engineering brick.
Details
MATERIALS: west (low mileage) elevation: Bath stone ashlar throughout, apart from small patches of engineering brick repair (e.g. arch rings). East (low mileage) elevation: similar, except the entire face below the cornice has been refaced in red and purple contrasting GWR engineering brick. Soffits have largely been refaced in similar engineering brick, as well.
DESCRIPTION: level parapet and a vertical face continuing unbroken as wing walls, which curve slightly at the outer ends. Into this face of ashlar are set the central 30ft [9m] span and much lower side arches with spans of 15ft 6in [4.6m]. The transverse arches in the piers are blocked. Bold, stepped cornice. Parapet terminates in square piers. Coping is bold and square.
The bridge is located on the edge of Chippenham in gentle countryside. Although it is in a cutting, it is visible from certain vantage points in the wider landscape.
