The vast majority of photography is by myself, some photos have been purchased and scanned for classes of locomotive and unit i did not manage to see in the past (and probably wouldn't be able to ever unless they invent a time machine). See the footer of this blog for copyright information.
Total Operations Processing System (TOPS)
TOPS which is a computer system adopted by British Railways in the 1960s to help keep tabs on, organise and control its fleet of rolling stock. Under TOPS every class of locomotive and multiple unit was given a unique class number and running number derived from it. More on TOPS can be seen here.
For example the BR DJ15 class of shunter was renamed the Class 03 and individual locomotives numbered 03 001, 03 002 and so on.
|From the Class 03 shunter 03 073|