DEMOLISHED in 1971.
Located to the west of Barnard Castle Station, it was 244 yards long and 132 feet high. Designed by Thomas Bouch for the South Durham and Lancashire Union Railway over Stainmore. Opened in 1861. It had lattice girders supported by masonry piers, all of slender proportions. Remained in use until April 1965. Demolition started in 1971, but the stone abutments survive.
1914 Contract for reconstruction placed with the Motherwell Bridge Co. There were two approach spans of 21ft. long, and five spans at 110ft. centres, each made up of three girders. The height of the viaduct from the river was 132ft. The central girder of each span was strengthened and retained, while the rest of the metal structure was completely renewed. 
1860 'Opening of the Tees Viaduct, Barnard Castle.—
On Thursday last the greater portion of the line was traversed by the directors. An engine belonging to Mr. Boulton, the contractor, conveyed a party from Barras, near Brough, over the Mousegill Viaduct, and thence over Stainmore, passing down the Valley of the Greta, until arriving at Bowes Gate, where, owing to the incompleteness of a bridge, which prevented the engine passing, a change of engine had to be effected. A fresh engine, with carriage attached, was kept in readiness at this point, and the party, consisting of some of the directors, and Mr. Anderson, the contractor for the line from Bowes to the Tees Viaduct, passed through the deep cutting, extending for near two miles, and over the Deepdale Viaduct. few minutes brought the party to the village of Lattington, where another engine and carriage, belonging to the Stockton and Darlington Railway Company, and some of the directors from the east end of the line, met the party from the west, and both trains proceeded in company over a gentle run of a mile and a half, through the estate of the Rev. T. Witham, to the Tees-Viaduct, which bore for the first time a locomotive engine. The foundation-stone this viaduct was laid by John Wakefield, Esq., of Kendal on the 7th of October, 1857, so that its construction has occupied nearly three years. This erection, which has the most massive and substantial appearance of any bridge on the line, consists of two abutments and four piers of massive masonry, executed by Mr. D. P. Appleby, of Barnard Castle.
The beautiful iron superstructure and girders have been manufactured and erected by the eminent firm of Kinnaird Bro's., of Crumlin and Westminster. Each span consists of two wrought-iron lattice girders 120ft. long, 15ft. 10 inches deep, and 16ft. apart from centre to centre. The girders rest upon expansion rollers, fixed to the top of the piers and abutments. The permanent way is laid upon longitudinal beams of timber, firmly spiked and bolted down. Check rails are fixed to prevent the possibility a train getting off the rails. An elegant hand-rail runs across the Viaduct, and adds much to the appearance of the structure.
The height of the bridge is 134 feet, and its length 800 feet.
The prospect from the bridge is grand and imposing - the beautiful vale of the Tees exhibiting here one of its most attractive aspects. Towards the south, the town of Barnard Castle, with its ancient Castle, meets the eye, with a panoramic view of the country near Rokeby and Brignal, bounded by the Yorkshire hills. The northern or upland prospect is scarcely less inviting, whilst the profusion of woodland on tho banks of the river, and the winding Tees "rushing o'er its pebbly bed" add another charm to the landscape. The two trains stood on the centre of the bridge in the midst of this scene, and the party gave three hearty cheers, which reverberated down the valley, and were distinctly heard in the town of Barnard Castle. The steam was again applied, and the trains, crossing the Percy Beck Viaduct, a structure 70 feet high, over the ravine traversed by Percy Beck, passed forward to the Barnard Castle Station. The directors then proceeded to hold their monthly meeting at Barnard Castle, and dined together at the King's Head inn, at that place.— Teesdale Mercury.'