English: Express train locomotive designed by James Cudworth for the South Eastern Railway (SER). Cudworth was chief engineer for locomotives at SER from 1845 to 1876 and built up the Ashford Locomotive Works, one of the first locomotive factories designed for series production. SER procured 16 so-called single locomotives for express service in the 1860s, which had only one single driving axle with large driving wheels. The locomotives were equipped with a double firebox with two fire holes. The locomotives were fired by coal, in contrast to the coke firing that was still common at the time. The locomotives were used for almost 24 years on the Dover Mail express trains between London and the Channel coast. They had a weight of 30 metric tons and pulled trains with a weight of about 125 metric tons on the route, which was not easy in terms of gradients. Source: Ernest Leopold Ahrons: 'The British steam railway locomotive, 1825-1925' p. 147. The picture shows the locomotive in the condition of the 1880s shortly before it was discarded. The side walls of the cab and the sandbox arranged around the dome were added after delivery.