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[[File:7812_Cab_20130806.jpg|thumb|300px|right|Erlestoke Manor was rated axle load class ‘Blue’ and power class D]]
The cab side of GWR locomotives from the 1920s onwards carried a coloured disc bearing a letter. The colour of the disc showed the locomotive’s axle weight classification, which determined which routes the locomotive could work on. The letter showed the locomotive’s power classification, which was used to determine the maximum load it could haul on each route.
GWR locomotives currently resident on the SVR were classed as follows:
{| class="wikitable"
! Locomotive !! Type!! GWR Power class !! BR Power class!!GWR Axle load class
|-
|[[GWR 813 Saddle Tank|813]]||Ex-PTR||Unclassified||n/a||Unclassified
|-
|[[GWR 1450|1450]]||1400 class||Unclassified||1P||Unclassified
|-
|[[GWR Pannier 1501|1501]]||1500 class||C||4F||Red
|-
|[[GWR 2857 Heavy Goods Loco|2857]]||2800 class||E||8F||Blue
|-
|[[GWR Large Prairie 4150|4150]]||5101 class large prairie||D||4MT||Blue
|-
|[[GWR Small Prairie 4566|4566]]||4500 class small prairie||C||4MT||Yellow
|-
|[[GWR 4930 Hagley Hall |4930]]||4900 Hall class||D||5MT||Red
|-
|[[GWR Large Prairie 5164|5164]]||5101 class large prairie||D||4MT||Blue
|-
|[[GWR Pannier 5764|5764]]||5700 class||C||4F by BR(W)||Blue (Yellow from 1950)
|-
|[[GWR 5600 class 6634|6634]]||5600 class||D||5MT||Red
|-
|[[GWR Mogul 7325|7325]]||4300 class||D||4MT||Blue
|-
|[[GWR Pannier 7714|7714]]||5700 class||C||4F by BR(W)||Blue (Yellow from 1950)
|-
|[[GWR 7802 Bradley Manor|7802]]||7800 Manor class||D||5MT||Blue
|-
|[[GWR 7812 Erlestoke Manor|7812]]||7800 Manor class||D||5MT||Blue
|-
|[[GWR 7819 Hinton Manor|7819]]||7800 Manor class||D||5MT||Blue
|-
|}
== GWR route classification colours==
Routes on the GWR were normally classified as "Red", "Blue", "Yellow" or "Uncoloured", according to the maximum axle load permitted by the Civil Engineer, as follows:
{| class="wikitable"
! Colour !! Maximum axle load
|-
|Red || 20 Tons
|-
|Blue || 17 tons 12 cwt
|-
|Yellow || 16 tons
|-
|Uncoloured || 14 tons
|}
Certain routes could be modified as “dotted”, for example "Dotted Blue" meant a route could be worked by "Blue" locomotives but subject to a 25mph speed restriction. Locomotives in the lower "Yellow" and "Uncoloured" classes could work the route without this additional speed restriction.
The axle weight was the main factor used in determining route colour, but this could be varied where it was considered appropriate. An example of this was the 5700 class pannier tanks, which were reclassified from "Blue" to "Yellow" by BR(W) in 1950. The reason given was the low 'hammer blow' that the class produced, which reduced the wear on the track.
===Severn Valley Railway Route Classification===
The classification and rules for working the Severn Valley Railway were set out in Section 15 of the 1948 Working Timetable as follows:
:''' ''Dotted "Red" route – Hartlebury and Bewdley'' '''<br>
:''Engines in the “Red” group (with the exception of the ‘King’ and the 2-8-0 47xx Class) may work between Hartlebury and Bewdley, subject to the maximum speed not exceeding twenty miles per hour at any point, also to strict adherence to the following prohibitions and restrictions.''
:''' ''"Dotted "Blue" route – Bewdley and Iron Bridge and Broseley'' '''<br>
:''Engines in the “Blue” group (with the exception of the 2-8-0 types) may work between Bewdley and Iron Bridge and Broseley, inclusive, at a maximum overall speed not exceeding 25 miles per hour at any point, subject to the following prohibitions and restrictions. ''
:''' ''"Blue" Route – Buildwas and Shrewsbury'' '''<br>
:''Engines in the “Red” group (with the exception of the ‘King’ and the 2-8-0 47xx Class) may work over the running lines only between Buildwas and Shrewsbury, provided the speed does not exceed 20 miles per hour at any point and subject to service restrictions.''
John Marshall’s history of the Severn Valley Railway also states that special rules applied to 51xx and 81xx ‘large prairies’, which were subject to a 25mph restriction between [[Victoria Bridge]] and [[Linley]].<ref>[[Bibliography#Bools | Marshall (1989)]] p. 137.</ref>
The maximum permitted line speed between Hartlebury and Shrewsbury was 50mph. The additional prohibitions and restrictions referred to mainly related to sidings and weighbridges, although there were details restrictions on the working of locomotives over [[Victoria Bridge]].
===Kidderminster to Woofferton Route Classification===
Information on the Kidderminster to Bewdley Loop line and the Tenbury Branch was included in Section 12 of the 1948 Working Timetable, as follows:
:''' ''Kidderminster and Bewdley'' '''<br>
:''Any engine in the “Red” group (excluding the ‘King’ class and the 2-8-0, 47xx Class) may work between Kidderminster and Bewdley subject to the maximum overall speed not exceeding 20 miles per hour.''
:''' ''Bewdley and Woofferton. (Dotted Blue)'' '''<br>
:''Engines in the “Yellow” group may work between Bewdley and Woofferton subject to service and special speed restrictions.''
:''Engines in the “Blue” group are authorised to work between Bewdley and Woofferton at a maximum speed of 25 miles per hour subject to the following prohibitions and service speed restrictions.''
As with the Severn Valley Branch, the overall line speed was limited to 50 mph, while the prohibitions and restrictions mainly related to sidings and weighbridges.
==GWR locomotive power classification==
The GWR allocated locomotives into power classes ranging from Ungrouped (lowest), A to E (highest), and Special (King class) as follows:
{| class="wikitable"
! Power class !! Tractive effort (lb)
|-
|Special || Over 38,000
|-
|E || 33,001 – 38,000
|-
|D || 25,001 – 33,000
|-
|C || 20,501 – 25,000
|-
|B || 18,501 – 20,500
|-
|A || 16,500 – 18,500
|-
|Ungrouped || Below 16,500
|}
For each route, the working timetable included a table of locomotive classes and the maximum permitted load. For example the 1948 working timetable specified that a ‘small prairie’ such as 4566 was limited to a load of 310 tons between Hartlebury and Shrewsbury, although a load of 335 tons was permitted for “trains liberally timed”. The power classes and loads did not differentiate between Passenger, Freight and Mixed traffic working.
==After nationalisation==
After nationalisation, BR adopted a more refined system. Route Availability was based on classes RA 1 to RA 10, while locomotive power was based on classes 0 to 9 with distinctions made for Passenger, Freight and Mixed Traffic. However the old system continued to be used on ex-GWR locomotives on the BR Western Region.<ref>Wikipedia</ref>
==Preservation==
When the SVR began operations in 1970, the line was still subject to the 17 tons 12 cwt axle weight restriction. This meant that large locomotives such as [[61994 The Great Marquess]] could not be used until a program of upgrading the line had been undertaken. The successful completion of this means that the SVR has since hosted a GWR 'King' class locomotive, as well as similar classes of locomotives from other companies. However [[Victoria Bridge]] remains subject to operating procedures which restrict the double-heading of locomotives.
The Light Railway Order under which the SVR operates specifies a maximum speed of 25mph for normal services. Operation up to 50mph may be carried out between Kidderminster and Bewdley when the railway is closed to the public; a recent example being the testing of Metropolitan Railway 0-4-4T No 1 in 2012 prior to its participating in the London Underground events in 2013.
==References==
<references />
==Links==
[http://en.wikipedia.org/wiki/Great_Western_Railway_Power_and_Weight_Classification GWR Power and Weight Classifiation on Wikipedia]<br>
[http://en.wikipedia.org/wiki/Route_availability Route availability on Wikipedia]<br>
[http://www.michaelclemensrailways.co.uk/?atk=592 1948 BR(W) Working Timetables on Michael Clemens' website] (Section 15 includes the Severn Valley Branch, Section 12 includes Kidderminster to Woofferton)
The cab side of GWR locomotives from the 1920s onwards carried a coloured disc bearing a letter. The colour of the disc showed the locomotive’s axle weight classification, which determined which routes the locomotive could work on. The letter showed the locomotive’s power classification, which was used to determine the maximum load it could haul on each route.
GWR locomotives currently resident on the SVR were classed as follows:
{| class="wikitable"
! Locomotive !! Type!! GWR Power class !! BR Power class!!GWR Axle load class
|-
|[[GWR 813 Saddle Tank|813]]||Ex-PTR||Unclassified||n/a||Unclassified
|-
|[[GWR 1450|1450]]||1400 class||Unclassified||1P||Unclassified
|-
|[[GWR Pannier 1501|1501]]||1500 class||C||4F||Red
|-
|[[GWR 2857 Heavy Goods Loco|2857]]||2800 class||E||8F||Blue
|-
|[[GWR Large Prairie 4150|4150]]||5101 class large prairie||D||4MT||Blue
|-
|[[GWR Small Prairie 4566|4566]]||4500 class small prairie||C||4MT||Yellow
|-
|[[GWR 4930 Hagley Hall |4930]]||4900 Hall class||D||5MT||Red
|-
|[[GWR Large Prairie 5164|5164]]||5101 class large prairie||D||4MT||Blue
|-
|[[GWR Pannier 5764|5764]]||5700 class||C||4F by BR(W)||Blue (Yellow from 1950)
|-
|[[GWR 5600 class 6634|6634]]||5600 class||D||5MT||Red
|-
|[[GWR Mogul 7325|7325]]||4300 class||D||4MT||Blue
|-
|[[GWR Pannier 7714|7714]]||5700 class||C||4F by BR(W)||Blue (Yellow from 1950)
|-
|[[GWR 7802 Bradley Manor|7802]]||7800 Manor class||D||5MT||Blue
|-
|[[GWR 7812 Erlestoke Manor|7812]]||7800 Manor class||D||5MT||Blue
|-
|[[GWR 7819 Hinton Manor|7819]]||7800 Manor class||D||5MT||Blue
|-
|}
== GWR route classification colours==
Routes on the GWR were normally classified as "Red", "Blue", "Yellow" or "Uncoloured", according to the maximum axle load permitted by the Civil Engineer, as follows:
{| class="wikitable"
! Colour !! Maximum axle load
|-
|Red || 20 Tons
|-
|Blue || 17 tons 12 cwt
|-
|Yellow || 16 tons
|-
|Uncoloured || 14 tons
|}
Certain routes could be modified as “dotted”, for example "Dotted Blue" meant a route could be worked by "Blue" locomotives but subject to a 25mph speed restriction. Locomotives in the lower "Yellow" and "Uncoloured" classes could work the route without this additional speed restriction.
The axle weight was the main factor used in determining route colour, but this could be varied where it was considered appropriate. An example of this was the 5700 class pannier tanks, which were reclassified from "Blue" to "Yellow" by BR(W) in 1950. The reason given was the low 'hammer blow' that the class produced, which reduced the wear on the track.
===Severn Valley Railway Route Classification===
The classification and rules for working the Severn Valley Railway were set out in Section 15 of the 1948 Working Timetable as follows:
:''' ''Dotted "Red" route – Hartlebury and Bewdley'' '''<br>
:''Engines in the “Red” group (with the exception of the ‘King’ and the 2-8-0 47xx Class) may work between Hartlebury and Bewdley, subject to the maximum speed not exceeding twenty miles per hour at any point, also to strict adherence to the following prohibitions and restrictions.''
:''' ''"Dotted "Blue" route – Bewdley and Iron Bridge and Broseley'' '''<br>
:''Engines in the “Blue” group (with the exception of the 2-8-0 types) may work between Bewdley and Iron Bridge and Broseley, inclusive, at a maximum overall speed not exceeding 25 miles per hour at any point, subject to the following prohibitions and restrictions. ''
:''' ''"Blue" Route – Buildwas and Shrewsbury'' '''<br>
:''Engines in the “Red” group (with the exception of the ‘King’ and the 2-8-0 47xx Class) may work over the running lines only between Buildwas and Shrewsbury, provided the speed does not exceed 20 miles per hour at any point and subject to service restrictions.''
John Marshall’s history of the Severn Valley Railway also states that special rules applied to 51xx and 81xx ‘large prairies’, which were subject to a 25mph restriction between [[Victoria Bridge]] and [[Linley]].<ref>[[Bibliography#Bools | Marshall (1989)]] p. 137.</ref>
The maximum permitted line speed between Hartlebury and Shrewsbury was 50mph. The additional prohibitions and restrictions referred to mainly related to sidings and weighbridges, although there were details restrictions on the working of locomotives over [[Victoria Bridge]].
===Kidderminster to Woofferton Route Classification===
Information on the Kidderminster to Bewdley Loop line and the Tenbury Branch was included in Section 12 of the 1948 Working Timetable, as follows:
:''' ''Kidderminster and Bewdley'' '''<br>
:''Any engine in the “Red” group (excluding the ‘King’ class and the 2-8-0, 47xx Class) may work between Kidderminster and Bewdley subject to the maximum overall speed not exceeding 20 miles per hour.''
:''' ''Bewdley and Woofferton. (Dotted Blue)'' '''<br>
:''Engines in the “Yellow” group may work between Bewdley and Woofferton subject to service and special speed restrictions.''
:''Engines in the “Blue” group are authorised to work between Bewdley and Woofferton at a maximum speed of 25 miles per hour subject to the following prohibitions and service speed restrictions.''
As with the Severn Valley Branch, the overall line speed was limited to 50 mph, while the prohibitions and restrictions mainly related to sidings and weighbridges.
==GWR locomotive power classification==
The GWR allocated locomotives into power classes ranging from Ungrouped (lowest), A to E (highest), and Special (King class) as follows:
{| class="wikitable"
! Power class !! Tractive effort (lb)
|-
|Special || Over 38,000
|-
|E || 33,001 – 38,000
|-
|D || 25,001 – 33,000
|-
|C || 20,501 – 25,000
|-
|B || 18,501 – 20,500
|-
|A || 16,500 – 18,500
|-
|Ungrouped || Below 16,500
|}
For each route, the working timetable included a table of locomotive classes and the maximum permitted load. For example the 1948 working timetable specified that a ‘small prairie’ such as 4566 was limited to a load of 310 tons between Hartlebury and Shrewsbury, although a load of 335 tons was permitted for “trains liberally timed”. The power classes and loads did not differentiate between Passenger, Freight and Mixed traffic working.
==After nationalisation==
After nationalisation, BR adopted a more refined system. Route Availability was based on classes RA 1 to RA 10, while locomotive power was based on classes 0 to 9 with distinctions made for Passenger, Freight and Mixed Traffic. However the old system continued to be used on ex-GWR locomotives on the BR Western Region.<ref>Wikipedia</ref>
==Preservation==
When the SVR began operations in 1970, the line was still subject to the 17 tons 12 cwt axle weight restriction. This meant that large locomotives such as [[61994 The Great Marquess]] could not be used until a program of upgrading the line had been undertaken. The successful completion of this means that the SVR has since hosted a GWR 'King' class locomotive, as well as similar classes of locomotives from other companies. However [[Victoria Bridge]] remains subject to operating procedures which restrict the double-heading of locomotives.
The Light Railway Order under which the SVR operates specifies a maximum speed of 25mph for normal services. Operation up to 50mph may be carried out between Kidderminster and Bewdley when the railway is closed to the public; a recent example being the testing of Metropolitan Railway 0-4-4T No 1 in 2012 prior to its participating in the London Underground events in 2013.
==References==
<references />
==Links==
[http://en.wikipedia.org/wiki/Great_Western_Railway_Power_and_Weight_Classification GWR Power and Weight Classifiation on Wikipedia]<br>
[http://en.wikipedia.org/wiki/Route_availability Route availability on Wikipedia]<br>
[http://www.michaelclemensrailways.co.uk/?atk=592 1948 BR(W) Working Timetables on Michael Clemens' website] (Section 15 includes the Severn Valley Branch, Section 12 includes Kidderminster to Woofferton)
