Southdown Road Skew Bridge

Southdown Road Skew Bridge is a ribbed skew arch railway bridge, which carries the Midland Main Line across Southdown Road in Harpenden, Hertfordshire. Built of brick by the Midland Railway and opening in 1868, it is notable for its extreme skew angle of approximately 65°.
Located approximately 0.8 miles south of Harpenden station, the bridge was built to carry a double-track standard gauge railway line across Southdown Road, which borders Harpenden Common in Hertfordshire, as part of the Midland Railway's southern extension towards its London terminus at St Pancras, and opened to traffic in 1868. Owing to the highly acute angle at which the railway crosses the road the bridge was built as a ribbed arch, a variation of the "false" skew arch and a design championed by French civil engineer A. Boucher.
The bridge was widened in 1893 when the line was converted to quadruple track.
On 1 January 1923 ownership of the bridge, along with the rest of the line, passed to the London, Midland and Scottish Railway and thence to the London Midland region of British Railways on nationalisation in 1948. It became a Grade II Listed structure in 1984.
Following privatisation the bridge passed into the custodianship of Railtrack and it is currently the responsibility of Network Rail.

Wikipedia