Constructed in 1824, it gave access to the Clydach Ironworks, the most significant industrial enterprise in the gorge.

The Clydach Ironworks were established in 1793 by Edward Frere and Thomas Cooke, on land sublet from the Duke of Beaufort.

[1] By the early 19th century, the works were the major industrial enterprise in the gorge and Smart's Bridge was built in 1824[2] to give a tramway link from the works to the Clydach Railroad.

[1] In 1987, Blaenau Gwent County Borough Council took responsibility for the site, stabilised the remains, and opened it to the public.

[1] The bridge is a single span, of cast iron, with "lancet tracery in the arch spandrels.