The locomotives have been broken down into their regional classes of:
- GWR - Great Western Railway
- SR - Southern Region
- LMS - London Midland & Scottish Railway
- LNER - London & North Eastern Railway
- BR - British Railways
- HR - Heritage Railways
There is an unavoidable overlap of locomotives where these are operated by Heritage Railways and also operate as main line locomotives such as 60007 Sir Nigel Gresley owned and operated by The North Yorkshire Moors Railway but used to haul charter trains over the main line network.
