Summary
Railway accommodation overbridge, 1842 by John Storey of Darlington, for Bishop Auckland and Weardale Railway Company; the contractor was The Shildon Works Company.
Reasons for Designation
This railway overbridge DAE2/12 of 1842 by John Storey of Darlington, for Bishop Auckland and Weardale Railway Company, is listed at Grade II* for the following principal reasons:
Architectural interest:
* a mid-C19 railway bridge associated with one of the major railway companies, constructed during the period when most buildings are listed;
* a lenticular truss bridge by John Storey which is considered the earliest wrought-iron, lenticular truss, occupation bridge in situ, after the removal of the earlier, pioneering example by George Stephenson.
Historic interest:
* it carried a farm track across the Bishop Auckland and Weardale Railway, a subsidiary venture of the Stockton & Darlington Railway, aimed at extending that company’s reach north and west of Shildon.
Group value:
* it benefits from an historic and functional group value with DAE2/11, another railway bridge on the same line.
History
This railway overbridge (railway Engineer’s Line Reference (ELR) bridge no DAE2/12) carried a farm track, now public footpath, wide enough for a single vehicle, across the Bishop Auckland and Weardale Railway. The latter was a subsidiary venture of the Stockton and Darlington Railway (S and DR), aimed at extending the company’s reach north and west of Shildon. The stretch of line on which the bridge lies opened in 1843. Following company mergers, the line came to be managed as a sub-section of the much longer North Eastern Railway route between Darlington and Eastgate in Weardale. Since the closure of the line west of Bishop Auckland in 1993, the Weardale section has operated as an independent heritage trust known as Weardale Railway. Original drawings dated 14 April 1842 are signed ‘John Storey | Darlington’, and bear the signature of Oswald Gilkes, for the contractor, The Shildon Works Company. The drawings show piers rising from the abutment faces, supporting parapets, and there are also short wing walls terminating in piers. The piers have been removed, and the wing walls and original parapets replaced by modern fencing. A drawing dated 10 June 1862 shows details of the lower bottom member which was added at this time to strengthen the superstructure.
This bridge is considered to be the earliest wrought-iron, lenticular truss, occupation bridge in situ. The earlier and pioneering example designed by George Stephenson in 1823 to take the western section of the S and DR main line across the River Gaunless between West Auckland and Shildon is now (2022) housed in the collection of the National Railway Museum at York. John Storey was the brother of Thomas Storey (1789-1859) who succeeded Stephenson as the S and DR’s Chief Engineer. The contractors, The Shildon Works Company, are thought to be the same as the later Shildon Wagon Works which after about 1840 was owned and operated directly by the S and DR. As such, both John and Thomas would have been extremely familiar with Stephenson's pioneering lenticular truss over the River Gaunless.
Details
Railway accommodation overbridge, 1842 by John Storey of Darlington, for Bishop Auckland and Weardale Railway Company; the contractor was The Shildon Works Company.
MATERIALS: Cast- and wrought-iron with timber deck and stone abutments.
PLAN: lenticular beam bridge between stone abutments, crossing the railway cutting at a skew angle.
DESCRIPTION: this beam bridge comprises iron, lattice, side girders carried on stone abutments which rise from the tops of the railway cutting. The girders are tied together to form a single lenticular truss, which crosses the cutting at a skew angle. The timber deck is attached directly to the upper chords, giving the bridge a humpback profile. The bridge has span of 86ft 3in (26.29m) and has a timber deck on timber and iron cross joists. The main top member is H-section cast iron and the bottom member is wrought iron flat link chain. There are twelve panels to the trusses incorporating 11 verticals of round bar with diagonal flats alternately rising and falling. An additional lower bottom member is of square bar and is coupled to the chain of the truss by cast clamps which carry the cross tie-rods. There are horizontal and vertical cross bracings of wrought iron flats. The abutments are built from squared, tooled blocks and have faces that break forward slightly beneath each girder. The hinges of the truss rest on stone or concrete blocks, with angled tops, that are set back from the abutment faces. The timber parapets are renewed, and the timber deck was replaced in 2009.
