Carlisle Bridge

The Carlisle Bridge is the main railway bridge crossing the River Lune at Lancaster, Lancashire, England, carrying the West Coast Main Line over three 120-foot spans. This section of the railway, including the original version of the bridge, was the work of Thomas Brassey, William Mackenzie, and John Stephenson; it was built between 1844 and 1846 and opened in 1847. There is a walkway for public use attached to the east side of the bridge.

Source: Wikipedia