The bridge has a single span of approximately 46 metres (151 ft) and was revolutionary for its time, in that it used an extremely slender arch which was not possible using traditional masonry construction. The ironwork was cast at the Plas Kynaston iron foundry at Cefn Mawr, near Ruabon in Denbighshire by William Hazledine, who cast a number of Telford bridges. The ironwork was transported from the foundry through the Ellesmere Canal and Pontcysyllte Aqueduct then by sea to Speymouth, where it was loaded onto wagons and taken to the site. Testing in the 1960s revealed that the cast-iron had an unusually high tensile strength. This was probably specified by Telford because, unlike in traditional masonry arch bridges, some sections of the arch are not in compression under loading.
At each end of the structure there are two 15 m (49 ft) high masonry mock-medieval towers, featuring arrow slits and miniature crenellated battlements.
History
The bridge was in regular use until 1963, when it was closed for a major refurbishment. A plaque records the completion of this work in 1964.
The side railings and spandrel members were replaced with new ironwork fabricated to match the originals. A 14 ton restriction was placed on the bridge at this point. This, along with the fact that the road to the north of the bridge takes a sharp right-angled turn to avoid a rock face, made it unsuitable for modern vehicles. Despite this, it carried foot and vehicle traffic across the River Spey until 1972, when its function was replaced by a reinforced concretebeam bridge built by Sir William Arrol & Co. which opened in 1970 and carries the A941 road today. Telford's bridge remains in good condition, and is still open to pedestrians and cyclists. The bridge has been given Category A listed status by Historic Scotland and has been designated a civil engineering landmark by the Institution of Civil Engineers and American Society of Civil Engineers.[2]
Moray Council maintain the bridge, but it is not known who owns it. In November 2017 efforts were started to discover the owner.[3]
Usage in media
Scottish composer William Marshall saw the bridge completed in 1814, and included a strathspey named for it, Craigellachie Brig, in his 1822 collection of tunes.[4]