The Metropolitan Railway A Class and B Class were condensing steam locomotives built for the Metropolitan Railway by Beyer Peacock, first used in 1864. A total of 40 A Class and 26 of the slightly different B Class were delivered by 1885. Used underground, the locomotives condensed their steam, and coke or smokeless coal was burnt to reduce the smoke. Most locomotives were withdrawn after electrification in the early 20th century, forty having been sold by 1907. The last one was withdrawn in 1948, and is now preserved at the London Transport Museum. History Construction When the Metropolitan Railway (Met) opened in 1863, the Great Western Railway (GWR) provided the services with their Metropolitan Class locomotives. However, the GWR withdrew their services in August 1863, and the Met bought their own locomotives, which needed to condense as the line from Paddingdon to Farringdon was underground. A tender was received from Beyer, Peacock and Company of Manchester for building eighteen locomotives at £2,600 each that would be available in six months. The design of the locomotives is frequently attributed to the Metropolitan Engineer John Fowler, but the design was a development of a locomotive Beyers had built for the Spanish Tudela-Bilbao railway, Fowler only specifying the driving wheel diameter, axle weight and the ability to navigate sharp curves. The locomotives delivered in 1864 had cylinders, diameter driving wheels and weighed 42 ton 3 cwt in working order. The boiler pressure was , the front wheels were on a Bissel truck and fitted with bunker. As they were intended for an underground railway, the locomotives did not have cabs, just a simple spectacle plate. To reduce smoke underground, at first coke was burnt, changed in 1869 to smokeless Welsh coal. The first 18 locomotives originally carried names, although the nameplates were withdrawn during overhaul. These were followed by five more each year from 1866 to 1868, and six in 1869. These were supplied with a tender capacity of ; after 1868 the boiler pressure had been increased to . From 1879 more locomotives were needed, and these were a modified design, with Adams bogies, and the wheelbase was , shorter than the previous locomotives at . A total of 24 of these later locomotives were delivered between 1879 and 1885. The locomotives were numbered in sequence as they arrived, and in 1925 the examples built before 1870 were classified as A Class