Improved Viaducts.

In recent years there has been registered a steady replacement of the old timber bridges and viaducts that at one time abounded on the Home railways, by modern structures of steel and ferro-concrete. Only rarely is timber now employed for railway bridgework in Britain, and page 21 with the recent replacement of the old timber viaduct at North Seaton, Northumberland, on the L. & N.E. system, by a new steel structure, there has disappeared one of the most interesting of ancient landmarks. Timber viaducts were especially common in the north of England at one time. The old timber structure at North Seaton carried the historic Blyth and Tyne railway over the River Wansbeck, and dated from 1859. Its length was 357 yards, and the height from river bed to rail level was 86 feet.

The new North Seaton viaduct is composed of plate girders supported by trestles built up from rolled sections resting upon concrete foundations on the shore, and concrete foundations on ferroconcrete piles in the river. The total length between abutments is 1,042 feet, made up of eleven spans. Work was begun on the site in 1925, and the contract has involved the provision of 6,500 cubic yards of earthwork in cuttings and embankments; 5,900 cubic yards of excavation in foundations; 9,750 cubic feet of reinforced concrete piles; 6,000 cubic feet of masonry, and 1,650 tons of steelwork. The approximate cost of the work is £90,000.