Summary
Tunnel portal in a classical style with a horseshoe arch, at the end of a long, deep, steep-sided cutting. Erected c.1897-1903.
Reasons for Designation
The East Portal of Chipping Sodbury Tunnel is designated at Grade II for the following principal reasons:
* Architectural interest: the survival of a group of two tunnel portals and their six, related tunnel vents and their shared aesthetic;
* Design, engineering and material interest: the quality and strength of the design, its sympathy to the surrounding landscape and the fact that the visible parts of the tunnel symbolise the considerable engineering achievement of a tunnel of 2.5 miles in length;
* Group Value: there is clear interest in the inter-related grouping of the tunnel mouths and the six ventilation towers, and their relationship to the wider context of their historic architectural and landscape setting.
History
The Great Western Railway (GWR) line from London to Bristol was built in 1835-41. It was always envisaged that it would connect with a line to South Wales, providing a link to Fishguard and Ireland. However the route to Wales was at first an awkward one, either (from 1852) circuitously via Gloucester or by train and ferry from New Passage, north of Bristol. The construction of the Severn Tunnel in 1876-83 transformed the rail connection to Wales for both passenger and freight (especially coal) traffic. However to reach the tunnel trains still had to go via Bath and Bristol, making the distance from London to Cardiff 155 miles. The decision was taken in 1896 to shorten that route by creating a direct 30 mile link from Wootton Bassett to Patchway. This reduced the distance to Wales by 10 miles and avoided the congestion and slow running in and around Bristol. The line was built 1897- 1903, and was one of the most important of a number of improvements to long distance routes made by the GWR at that time.
The bridges and other structures along this line were built to more standardised designs than characterised the engineering of earlier parts of the GWR network, especially in the use of brick segmental arched bridges, of single- or triple-span. The tunnel portals, and even more the tunnel vent shafts, were more distinctive, perhaps in recognition of their role in the landscape. It is not known who was directly responsible for their design, but Sir J.C. Inglis (1851-1911), later General Manager of the GWR, was the principal engineer of the new route.
The Cotswold Edge escarpment was the largest topographical impediment to a direct, fast route. It was overcome by boring the Chipping Sodbury Tunnel. At 2.5 miles, it is the longest tunnel on the line, and passes under the Badminton Estate. It was one of the last major mainline railway tunnels to be built in the UK until the Channel Tunnel Rail Link opened in 2003.
Details
MATERIALS: engineering brick with stone dressings.
DESCRIPTION: circular horseshoe tunnel mouth with brick architrave surround, and roll moulding and gigantic keystone in stone. Piers flanking the arch and projecting above the panelled parapet, and outside these very small wing walls meeting the rubble-lined cutting sides. Stone bands and coping with quarry-faced moulding.
The portal is deep in a lined cutting in pastoral countryside 1 mile south-west of Badminton House.
