The Cefn Bychan viaduct carries the Shrewsbury to Chester Railway over the River Dee between Newbridge and Cefn-Bychan. It was built to the design of Henry Robinson of Llantysilio, the chief engineer to the Shrewsbury to Chester Railway, in 1846. Thomas Brassey was the general contractor, and it was completed in August 1848 at a cost of £72,346. The Shrewsbury to Chester line was initiated by Robinson, who had received his training under George Stephenson, and he recognised the need, not met by the canals, to transport materials to Wrexham and Chester. The line became part of the Great Western Railway system in 1854.

The viaduct is a fine example of early railway design and is constructed of coursed and squared rock-faced sandstone, the upper arched stage of brick faced with stone. It is 460m (1,508ft) long, comprising 19 arches of 18.2m (60ft) span, rising 46m (147ft) above the river. The main piers are tapered upwards to the springing line, above which the arch voussoirs are recessed behind the face. Above, the low parapet is carried on a corbel table.

RCAHMW, 4th September 2008

Sources:
RCAHMW AP94-CS 0170
RCAHMW AP945022/49; 965133/56
Edward Hubbard, Clwyd, Buildings of Wales series, 1986, p.116.