Summary
Skew viaduct across the River Thames built in two phases, sharing cutwaters. The west (or fast) viaduct was built 1838-40 to the design of Isambard Kingdom Brunel, and the east (or relief) viaduct is of 1890-3. West elevation partly refaced, probably 1890-3.
Reasons for Designation
Gatehampton Viaduct is designated at Grade II for the following principal reasons
* Date: it belongs to the pioneering phase of the GWR under Brunel, and of railway construction nationally;
* Design, engineering and material interest: it is notable for its elegant elliptical-arched design and high quality brickwork, and the west (1838-40) elevation has undergone relatively little alteration. The extension, while of less intrinsic merit, is nonetheless impressive, designed with great respect for the existing structure;
* Historic interest: it was designed by Brunel himself, and is illustrated in his sketchbook of the GWR (1835).
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 8½ in) 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.
By the 1870s the growth of traffic, especially at the London end of the route, necessitated the widening of the line from two to four tracks. This was carried out in two stages, from London to Taplow in 1875-84 and from Taplow to Didcot in 1890-3. By the time of these widenings the broad gauge was being phased out (the final conversion to standard gauge took place in 1892), and the design of the extended or new structures took this into account. However the designs were exceptionally sympathetic to Brunel’s original designs, in form and detail; also in the choice of materials, although engineering brick, seldom or never used by Brunel, began to make an appearance in 1890s. The engineers chiefly responsible for the widened lines, whose names appear on the surviving archive drawings, were William George Owen (1810-85), Lancaster Owen (1843-1911) and Edmund Olander (1834-1900).
Brunel’s chosen route, designed to be direct and level, required the line to cross the River Thames twice in the narrow Goring Gap, west of Reading. This was achieved by two similar skew viaducts at Gatehampton (MLN14402) and Moulsford (MLN14370), built less than 3½ miles apart in c.1838-40. John Hammond was Brunel’s assistant engineer on this section of the line. These are brick structures with four flat semi-elliptical arches. As with other large bridges on the route, Brunel reduced the forces acting through the structure by using a system of internal longitudinal walls and voids to lighten the superstructure above the arches. This reduced the mass of the bridge and its foundations, saving material, time and cost.
Though all these characteristics are shared with the Maidenhead Railway Bridge, the local conditions in the Goring Gap did not require the engineering daring of that celebrated structure, and Moulsford and Gatehampton viaducts have shorter spans than Maidenhead. Nevertheless they are handsome and substantial, with a presence in an admired Thames landscape, and were illustrated by Bourne in his History.
When the line was widened for four tracks west of Maidenhead in 1890-3 drawings were produced to widen both viaducts on the east (Up) side to carry the new Relief Lines. These new structures were executed with great sympathy and with little variation from the Brunel elevations. In contrast to Maidenhead, because the widening was undertaken on one side only, the west (Down) elevations of Moulsford and Gatehampton Viaducts are still those of Brunel. Contract and construction drawings survive for both phases. Since the 1890s, there have been no major alterations.
Details
MATERIALS: red brick, laid in English bond, with Bramley Fall gritstone dressings. Some patching in similar red engineering brick.
DESCRIPTION: the viaduct is slightly skewed, c.120 m long and 18m wide. The west elevation (1838-40) has four low semi-elliptical arches springing from water level, with a square span of 62ft (19m). Round cutwaters boldly moulded in ashlar. Plain, shallow stepped string-course. Several tie plates across the elevation. Parapets have stone coping with rounded edge, broken for open steel refuges over every pier that were inserted in the C20 along with steel railings along the top of the parapet. The arch voussoirs, originally stone, replaced in brick. On each bank, a step-out to raked and slightly splayed abutments. These retain the bold, stepped roll mouldings which originally continued across the central spans. The east elevation (1890-3) is similar, but with stone roll moulding around the arch rings and no refuges or railings.
The viaduct is prominent in the landscape of the River Thames as it flows through the Goring Gap, in an Area of Outstanding Natural Beauty.
