Birmingham Corporation Tramways operated a network of tramways in Birmingham from 1904 until 1953. It was the largest narrow-gauge tramway network in the UK, and was built to a gauge of 3 ft 6 in (1,067 mm). It was the fourth largest tramway network in the UK behind London, Glasgow and Manchester. There were a total of 843 trams (with a maximum of 825 in service at any one time), 20 depots, 45 main routes and a total route length of 80+1⁄2 miles (129.6 km). Birmingham Corporation built all the tramways and leased the track to various companies.