ROUTE AVAILABILITY

'Route Availability' is a system by which railway lines in the United Kingdom are graded. The system works on the principle of axle loads (and occasionally other factors), and is designed to stop locomotives with too high an axle load travelling over track which may be damaged by them.
In this system, each class of locomotive is allocated a route availability between one and ten, based primarily on the weight per axle. Each route is similarly allocated an RA number between 1 and 10. The rule is that a locomotive may not work over a route that has a route availability (RA) group lower than its own RA group.

Contents

Network Rail

Historical notes

Great Western Railway

See Also

References

Network Rail

Network Rail currently gives the allowed axle loadings as follows:^[1]

'Axle loading by Route Availability'

Route Availability	Axle Load
RA1–RA6	≤20.3 tonne
RA7-RA9	≤24.1 tonne
RA10	≤25.4 tonne
''EU average''	≈22.5 tonne

The information regarding route availability (RA) on this page comes from the British Rail (London Midland Region) Route Availability Guide, and the Freight Train Loads Book, both issued in 1969. It should be noted that several routes will have had their RA numbers changed since that time.

'Route Availability by Locomotive Class'

Group Number	Mainline Classes	Shunters
1	Y14	01, 03, 04 ★ , 11104, 15097
2	158	02$, 04 ★ , 05
3
4	15, 16, 17, 22, 10800
5	20, 23, 25, 27, 29, 31 ★ , 37, 43, 55, 185	06, 08 ★ , 09, 10, 11, 12
6	8K, D16/2, 24, 26, 31 ★ , 33, 35, 40, 42, 47 ★ , 48, 50, 52 ★ , 53, 57, 71, 73, 81, 82, 83, 84, 85, 86, 87, 89	07, 08 ★
7	44, 45, 46, 47 ★ , 52 ★ , 57, 58, 59, 66, 74, 91
8	67, 76	13
9
10

★ ''Depending on sub-class, see individual article for details.''
$ ''Discrepancy with original data.''

Historical notes

Before nationalisation the Big Four railway companies had their own classification systems:

Great Western Railway

Each locomotive had a coloured disc painted on the cab side to indicate its route availability:

★ uncoloured, lightest locomotives

★ yellow disc

★ blue disc

★ red disc

★ two red discs, heaviest locomotives

See Also

★ 2D53 Introduction to Route Availability and tables].

References

1. Network Rail Loading Gauge documentation