Summary
Former railway accommodation bridge built to allow farm traffic to pass beneath the 1825 mainline of the Stockton & Darlington Railway (S&DR).
Reasons for Designation
The former Throstle Nest Bridge, now (2021) known as the Arnold Road Subway Darlington, built in 1824 for the Stockton & Darlington Railway, is listed at Grade II for the following principal reasons:
Architectural interest:
* as a very early example of a railway accommodation bridge, built under the direction of George Stephenson prior to the opening of the S&DR in 1825;
* archaeological investigation, by revealing details of the bridge’s construction and alterations in the C19, adds to the architectural interest.
Historic interest:
* built for the pioneering and internationally influential Stockton & Darlington Railway, the early widening of the bridge marking company's rapid success after opening following the financial constraints of its original construction, surviving documentary references to the bridge contributing to its interest.
Group value:
* one of a group of very early railway structures in Darlington, a surviving marker of a closed section of the line.
History
An Act of Parliament passed in 1821 granted the Stockton & Darlington Railway (S&DR) powers to compulsorily purchase the land required to build its railway, but also placed several obligations on the company. One of these obligations was the requirement to provide bridges, not only for public roads, but also for landowners whose land was divided by embankments or cuttings for the line. The number and cost of providing these additional bridges, known as accommodation bridges, was underestimated and placed a considerable strain on company finances before the railway opened for business in 1825. What is now known as Arnold Road subway was built as one of these accommodation bridges. It was originally known as Throstle Nest Bridge and was built for George Coate whose land had been divided by the mainline that was set on an embankment at this point. Construction of the bridge was ordered by the S&DR in September 1824. The £31 contract for labour was awarded to Francis Peacock (1782-1864), a building contractor who was also engaged in the construction of Skerne Bridge about 1km further along the line to the west. As originally built, Throstle Nest Bridge only supported a single line, the track bed across the structure being no more than 3.2m wide. Although embankments and cuttings for the main line are thought to have been constructed wide enough for dual track, initial financial constraints on the S&DR led them to lay a single line with passing loops, with bridges also generally built for single line working.
The S&DR proved to be highly successful, with traffic carried by the railway considerably exceeding expectations leading to the upgrade of the entire mainline between Stockton and Brusselton Bank Foot to double track in 1830-1832, the bridge being widened on its southern side to just over 6m. Sometime between 1855 and 1896 (the dates of the first and second edition Ordnance Survey maps), the railway embankment was considerably widened on both sides and slightly heightened, requiring the further extension of the bridge, both north and southwards, to 21.3m wide. This was to accommodate new sidings serving a coal depot immediately to the west of the bridge and a brickworks to the east, both on the northern side of the line, as well as new running lines associated with the junction with the North Eastern Railway’s (NER) main line a short distance to the west. This alteration may have been made after the S&DR was absorbed into the NER in 1863. The heightening of the embankment resulted in parts of the earlier parapet walls being buried, these being recorded via archaeological excavation prior to strengthening works associated with the construction of the Darlington Eastern Transport Corridor, a new road that opened in 2008 reusing the route of a section of the line that was closed in the 1970s.
Through its willingness to share information with visiting engineers and railway promoters, the S&DR was highly influential in the establishment of other railways both in England and abroad. The engineer responsible for the construction of the S&DR was George Stephenson (1781-1848), who went on to engineer the Liverpool & Manchester Railway (opened 1830) and several subsequent lines, being popularly regarded as ‘the Father of the Railways’. It is presumed that Stephenson was responsible for the design of the original bridge. Although both north and south elevations of the bridge date to the later C19 widening, their design (with the exception of the brickwork vaulting) is thought to have been taken from the original bridge, the wing walls of which at least partly survive within the embankment. The S&DR also had a fundamental impact on the development of the local economy, partly in the way that the company placed contracts with local businesses, making the fortunes of men like Peacock who started out as a carpenter but was listed alongside the gentry at his death.
Details
Former railway accommodation underbridge by George Stephenson for the Stockton & Darlington Railway in 1824, widened in 1830 and the late C19. Since 2008, this has been used as a pedestrian subway beneath the B6279 road.
MATERIALS: ashlar sandstone with cream-coloured machine-made brick.
DESCRIPTION: the bridge’s north and south sides are effectively matching having plain ashlar spandrels and curving wing-walls capped by flat coping slabs. The arch is semi-circular, formed with four rings of brickwork, this brickwork forming the barrel vault of the late C19 widening of the bridge. The original bridge and the 1830 widening have stone ashlar barrel vaults of the same dimensions as the later extensions. The butt-joints between the widenings can be clearly seen.
