Pre grouping (up to 1923)

NBR North British Railway (LNER)
GER Great Eastern Railway (LNER)
GNR Great Northern Railway (LNER)
LNWR London and North Western Railway (LMS)
FR Furness railway (LMS)
LYR Lancashire and Yorkshire Railway (LMS)
CR Caledonian Railway (LMS)
Midland Railway (LMS)
LBSCR London, Brighton and South Coast Railway (SR)
LSWR London and South Western Railway (SR)
SECR South Eastern and Chatham Railway (SR)
GWR Great Western Railway

Post grouping (1923-48): the "Big Four"

LNER London and North Eastern Railway
LMS London, Midland and Scottish Railway
GWR Great Western Railway
SR Southern Railway

Nationalisation (1948-1995)

BR British Railways, British Rail (from 1968)
Regions corresponded to the old Big Four:
Eastern Region
London Midland Region
Western Region
Southern Region
Scottish Region

Engine Workshops

Doncaster (GNR – LNER)
St Rollox Glasgow (CR – LMS)
Crewe (LNWR – LMS)
Derby (Midland – LMS)
Horwich (LYR – LMS)
Swindon (GWR)
Brighton (LBSCR - SR)
Eastleigh (LSWR -SR)

London Termini

King’s Cross (GNR - LNER)
St Pancras (Midland Railway - LMS)
Euston (LNWR - LMS)
Paddington (GWR)
Victoria (LBSCR - SR)
Waterloo (LSWR - SR)


Wheel arrangements

Steam engines and diesel shunters ("Whyte")

ooOO

4-4-0

ooOOOo

4-6-2 - "Pacific"

ooOOO

4-6-0 - "Ten Wheeler"

OOO

0-6-0

oOOO

2-6-0 - "Mogul"

OO

0-4-0

OOo

0-4-2

Tank engines - add "T" eg. 0-6-0T
ST = "saddle tank" eg. 0-4-0ST
PT = "pannier tank"eg. 0-6-0PT

Diesels

(Bold = unpowered axle)


oo---oo = Bo-Bo (one traction motor per axle) or B-B (hydraulic unit powers both bogie axles so the "o" is dropped)
ooo---ooo = Co-Co or C-C
ooo---ooo = A1A-A1A
oooo---oooo = 1Co-Co1
ooo---oo = Co-Bo

Note on loco classes

The LMS and subsequently BR classed steam engines by power type and the work they had to do.

Hence

0F = power 0, freight – a light shunter.
5MT = power 5, mixed traffic – the Black Five
8P = power 8, passenger – Coronation class express pacific

The LNER had letter code for wheel arrangements with a designating number.


J = 0-6-0
Y = 0-4-0
D = 4-4-0
A = 4-6-2
V = 2-6-2
N = 0-6-2
Etc.
Hence class numbers Y6, D30, A3 etc.

The GWR classified their engines by number series, eg. 57xx, 14xx. However, main-line engines were nearly all named and were classed by the name series, eg. "City", "Star", "County", "Manor", "Hall", "King", "Castle" etc.

Early BR diesels were classed by power type. Hence the Co-Bo was "Type 2", the Hymek was "Type 3", while the EE 1Co-Co1 and the Peak were both "Type 4". This was reflected in the standard 1968 numbering system still in use which designated each loco a two-digit class number, eg. 08, 28, 35, 40, 44, followed by a three-digit running number.