The British Rail

British Rail

British Railways , which from 1965 traded as British Rail, was the operator of most of the rail transport in Great Britain between 1948 and 1997. It was formed from the nationalisation of the "Big Four" British railway companies and lasted until the gradual privatisation of British Rail, in stages...

 Class 40 is a type of British railway diesel locomotive

Diesel locomotive

A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...

. Built by English Electric

English Electric

English Electric was a British industrial manufacturer. Founded in 1918, it initially specialised in industrial electric motors and transformers...

 between 1958 and 1962, and eventually numbering 200, they were for a time the pride of the British Rail

British Rail

British Railways , which from 1965 traded as British Rail, was the operator of most of the rail transport in Great Britain between 1948 and 1997. It was formed from the nationalisation of the "Big Four" British railway companies and lasted until the gradual privatisation of British Rail, in stages...

 early diesel fleet. Despite their initial success, by the time the last examples were entering service they were already being replaced on some top-link duties by more powerful locomotives. As they were slowly relegated from express passenger uses, the type found work on secondary passenger and freight services where they worked for many years, the final locomotives being retired from regular service in 1985.
The origins of the Class 40 fleet lay in the prototype diesel locomotives (Types D16/1

British Rail Class D16/1

British Railways Class D16/1 or 10000 and 10001 were the first mainline diesel locomotives in Great Britain. They were built by the London, Midland and Scottish Railway at its Derby Works, using the EE16SVT 1600 hp diesel engine with electric transmission, in association with English Electric and...

 ordered by the London, Midland and Scottish Railway

London, Midland and Scottish Railway

The London Midland and Scottish Railway was a British railway company. It was formed on 1 January 1923 under the Railways Act of 1921, which required the grouping of over 120 separate railway companies into just four...

 and British Railways and D16/2

British Rail Class D16/2

British Railways Class D16/2 was a class of prototype diesel locomotive built by BR at Ashford Works and introduced in 1950-1951, with a third example being introduced in 1954. They had been designed by Oliver Bulleid for the Southern Railway before the 1948 nationalisation but did not appear until...

 ordered by British Railways between 1947 and 1954) and most notably with the Southern Region

Southern Region of British Railways

The Southern Region was a region of British Railways from 1948. The region ceased to be an operating unit in its own right in the 1980s and was wound up at the end of 1992. The region covered south London, southern England and the south coast, including the busy commuter belt areas of Kent, Sussex...

 locomotive No.