Metropolitan railway class A and B

The Metropolitan Railway opened in 1863 with trains provided by the Great Western Railway (GWR) with their Great West Railway Metropolitan Class, this arrangement ended in August 1863 when the Great Western Railway (GWR) withdrew its services. Consequently the Metropolitan Railway purchased their own locomotives, which needed to be able to condense because the line was underground between Paddington and Farringdon, Beyer Peacock of Manchester tendered for the construction of eighteen locomotive that would be available in six months at the cost of £2,600 each.

The design of the locomotives where based on the development of a locomotive called Beyers which had been constructed for use on the Spanish Tudela and Bilbao Railway. However, John Fowler a Metropolitan Railway engineer is frequently attributed to the design of the locomotives, however he only specified the driving wheel diameter, axle weight and the ability to navigate sharp curves along the line.

The locomotives were delivered in 1864, coming equip with 406 mm x 508 mm (16in x 20in) cylinders, 1.537m (5ft ½in) diameter driving wheels and weighed approximately 42 tons. The front wheels were based on a Bissel truck, with a boiler pressure of 120PSI and fitted with a 1.1m3 (40ft3) bunker. The locomotives did not come with a driving cabin just a spectacle plate, to reduce the smoke initially coke was burned, although this was changes to smokeless Welsh coal in 1869.

The first eighteen locomotives carried names, initially, with the nameplates being removed during their refurbishment. The locomotives were called:

• Jupiter
• Mars
• Juno
• Mercury
• Apollo
• Medusa
• Orion
• Pluto
• Minerva
• Cerberus
• Latona
• Cyclops
• Daphne
• Dido
• Aurora
• Achilles
• Ixion
• Hercules

These were followed by an additional five units in 1866 and 1868 followed by six in 1869, these were supplied with 1.9m3 (67ft3) boilers with these being changes in 1868 to allow a boiler pressure of 130PSI. Additional rolling stock was needed by 1879, these where a modified design with Adams bogies, and a 2.46m (8ft 1in) wheelbase and shorter than the previous locomotives at 2.69m (8ft 10in); twenty-four locomotives where constructed and delivered between 1879 and 1885.

The numbering of the units was in succession of delivery, with the units built before 1870 being classed as Class A and those constructed after 1879 classified as Class B from 1925. The St Johns Wood Railway received five Burnett locomotives in 1868, these took locomotive numbers 34 - 38 therefore the Class A locomotives consisted of numbers 1 - 33 and 39 - 44 whereas the Class B reused the 34 - 38 numberings further to numbers 50 - 66.

The locomotives where initially a bright olive green with black and yellow accenting, brass was used for the domes and locomotive numbers, with the chimneys capped in copper. Midcared, a shade of the colour dark red, became the colour for the locomotives in 1885, with the domes also painted and this was the standard colour that was continued by the London Transport Passenger Board (LTPB) in 1933.

Seventeen locomotives where re-boilered at Edgware Road between 1880 and 1885 with the works continuing at Neasden depot from 1886, where the boiler pressure was increased to 150PSI, after 1894 the wheel diameter was also increased to 1.78m (5ft 10in) and cylinders to 440mm (17 ½in). Cabins for the drivers and crew were introduced in 1895 because it became too hot working inside the tunnels.

There were accidents in 1873 and 1884 which were caused by coupling rods breaking, the cross section was increased in 1885, however the problem was not resolved until 1893 when the Allan Motion was replaced by a Gibson and Lilley link Motion, with all the locomotives modified by 1896.

Experimentally locomotive number 62 was converted in 1898 to operate burning oil rather than coal or coke, however this proved expensive because of the quality that would be needed to burn underground although further experiments with burning oil were carried out later in 1921.

The Metropolitan Railway Class A and B operated across the entire Metropolitan Railway, which included the Hammersmith & City line today and the East London Line which is a part of the London Overground network today. In 1884 the locomotives where stabled at:

The electrification of the lines within central London between 1905 and 1906, the locomotives where redundant. The first locomotive to be withdrawn was in 1897 when locomotive number 1 was evolved in an accident at Baker Street and forty had been either sold or scrapped by 1907. Thirteen locomotive where still in use for shunting, departmental work and working trains on the Brill Tramway in 1914 but the remainder had been sent to R Fraser for scrapping. The closure of the Brill Tramway in 1935, the purchase of other locomotives and the changes to London and North Eastern Railway (LNER) freight the fleet except one locomotive, number 22 which was sold to the Metropolitan District Railway (MDR), where scrapped by 1936. Locomotive number 22 survived until 1931 having been sold to the Metropolitan District Railway (MDR) in 1925. Other locomotives also survived, outside the fleet on the Brill Tramway, locomotive number 7 survived on the Mersey Railway until 1939 and locomotive number 44 which survived until 1948 on the Pelaw Main colliery.

There is one locomotive, which has been preserved at the London Transport Museum, the Metropolitan Railway Class A locomotive number 23 also known as London Transport number 45.