Two separate types of
diesel locomotive operating in
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It i ...
have been given the
TOPS
Total Operations Processing System (TOPS) is a computer system for managing railway locomotives and rolling stock, known for many years of use in the United Kingdom.
TOPS was originally developed between the Southern Pacific Railroad (SP), S ...
classification Class 21.
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British Rail Class 21 (NBL)
The British Rail Class 21 was a type of Type 2 diesel-electric locomotive built by the North British Locomotive Company in Glasgow for British Rail in 1958–1960. They were numbered D6100-D6157. Thirty-eight of the locomotives were withdrawn b ...
- a class of 58 diesel-electric locomotives produced by the
North British Locomotive Company from 1958-1960.
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British Rail Class 21 (MaK)
The second use of the TOPS classification Class 21 for locomotives used on the British railway network came through the use of a number of related diesel-hydraulic and diesel-electric locomotives procured following the opening of the Channel ...
- a group of diesel-hydraulic locomotives produced by
MaK/
Vossloh
Vossloh AG is a rail technology company based in Werdohl in the state of North Rhine-Westphalia, Germany. The SDAX-listed group has achieved sales of around €930 million in 2016 with more than 4,000 employees (as of 2017).
Vossloh is a global ...
and used on the
Channel Tunnel Rail Link.
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