Interior of Box Tunnel, Great Western Railway, 1846.
© NRM / Pictorial Collection / Science & Society Picture Library
Lithograph by J C Bourne showing a steam train travelling into the darknes of Box Tunnel, which at the time of its construction between Chippenham and Bath, was the largest railway tunnel in existence. The tunnel was one of Isambard Kingdom Brunel's major engineering achievements on the Paddington to Bristol line. Construction began in 1838 and it was opened to traffic on 30 June 1841. It is on a continuous gradient of 1 in 100 falling towards Bristol and its total length is 1 mile and 1452 yards.