Since the beginning of railways in 1804, when Richard Trevithick ran the first steam locomotive in South Wales, steam was the preferred traction for the British railways. Steam locomotives facilitated any duty from shunting jobs to the nation’s most prominent express trains. Beginning in the forties, London, Midland, Scottish (LMS) began implementing diesel shunters into their fleet, which were perceived to be reliable and cost effective to maintain. Thus, the birth of diesel traction in Britain began, and the LMS experimented further with mainline power.
Beginning in 1947, the London, Midland, Scottish (LMS) began experimenting with the D16/1 locomotives built in a joint effort with English Electric at the LMS Derby Works. These locomotives were powered by an English Electric prime mover, similar to the ones found in their early shunter locomotives. These locomotives quickly entered service on LMS services between London and Derby. Since then, diesel traction has been the traction of choice for many services. Diesel traction became a staple on the British railways through the modernisation effort that began in the fifties. The diesel locomotives could out perform a steam engine on many fronts, particularly on ease and cost of maintenance. Diesel locomotives could be easily maintained and have a greater availability for the railways, as they were in the shop for a substantially shorter time.
Diesels soon became the staple of the British Rail network, replacing many steam engines. On the East Coast Main Line (ECML), the “Deltic” locomotives could shave an hour off the time between London and Edinburgh, whilst operating more efficiently. The diesel locomotives were increasingly versatile as well, as they could be used as a long haul freight carrier, and be just as much at home pulling express passenger services.
Although diesel locomotives were not as powerful as steam, diesels are capable of multiple unit operation. This allowed multiple to be controlled by a single driver in the cab of the lead unit. This is done through various electrical and pneumatic connections between the units. In the days of steam if a train had to be double headed, two crews would be needed to drive both locomotives. Multiple unit operation improved efficiency, and provided railways with various cost savings.
British Railways experimented with various types of diesel locomotives, from the diesel-mechanical small shunters, to the present day diesel-electric locomotive. Diesel-mechanical locomotives were mainly used for various shunting duties, and rarely traversed the mainline. These were some of the simplest diesel locomotives, as the diesel prime mover powered a mechanical transmission, in which powered the wheels.
Seeing the success of the diesel-hydraulic in Germany, British Rail experimented with these, ordering this type to be built for the western region, such as the Class 42 “Warship”, Class 52 “Western”, and the Class 35 “Hymek”. These types of locomotives operated by the diesel prime mover These locomotives were built in Britain and went to work hauling various trains throughout the western region. However,these locomotives were not reliable due to the complicity of the hydraulic transmission systems, which would fail often. Additionally, due to the absence of traction motors, the locomotives were much lighter than their diesel-electric counterparts, therefore had inferior tractive effort.The diesel-electric locomotive was deemed more efficient and increasingly reliable, and became the diesel locomotive of choice on British Railways.
With the incorporation of diesel locomotives into the British Railways fleet, they were distinguished by type. Type 1s being between 800-1000 hp, type 2s 1001-1499 hp, type 3s from 1500-1999hp, type 4s 2000-2999hp, and type 5s rated as any locomotive over 3,000 horsepower.
Today, many of the early BR diesels remain in active mainline service and continue to serve the nation. Many new and more modern locomotives have been introduced post-privitisation, and are true workhorses, boasting reliability and sustainability.
This page is designed to be an encyclopedia for every diesel locomotive on British railways. Included will be background and technical data on each.
British Diesel Encyclopedia
Small Shunters: BR Class 01, BR Class 02, BR Class 03, BR Class 04, BR Class 05, BR Class 06, BR Class 07.
Large Shunters: BR Class 08, BR Class 09, BR Class 10, BR Class 11, BR Class 12, BR Class 13.
Type 1: BR Class 14, BR Class 15, BR Class 16, BR Class 17, BR Class 20.
Type 2:BR Class 21, BR Class 22, BR Class 23,BR Class 24, BR Class 25, BR Class 26, BR Class 27, BR Class 28, BR Class 29, BR Class 31.
Type 3: BR Class 33, BR Class 35, BR Class 37.