BR Standard Class 8

The BR Standard Class 8 is a one-off "Pacific" type steam locomotive designed by Robert Riddles for use by British Railways. Only a single locomotive, the prototype, was constructed, which was named Duke of Gloucester. Constructed at Crewe Works in 1954, the Duke, as it is popularly known, was a replacement for the destroyed LMS Princess Royal Class locomotive 46202 Princess Anne, which was involved in the Harrow and Wealdstone rail crash of 1952. The locomotive returned to main line use in 2025 following an extensive overhaul.

Background

Riddles had frequently argued the case for the inclusion of a Standard Class 8 Pacific in the standard range of locomotives being introduced by British Railways. However, those proposals were rejected by the Railway Executive on the grounds that attempting to develop a new form of steam motive power was unnecessary because there were enough Standard Class 7 Britannia locomotives already available for use.

However, opportunity came out of adversity when the short-lived rebuild of the former LMS Turbomotive, 46202 Princess Anne was destroyed in the Harrow and Wealdstone rail disaster of 1952. That gave Riddles the perfect opportunity to press the case for his new design, a prototype of which was duly authorised for construction. However, the size of the cylinders needed to achieve the 8P power classification would mean that the locomotive was outside the British loading gauge, so a reluctant reversion to the three-cylinder layout ensued. It was based on Italian locomotive practice and allowed precise control of steam admission to the cylinders, as well as improving exhaust flow and boiler draughting when compared to the more conventional Walschaerts and Stephenson valve gear.

The main problem was known even when the locomotive was under construction, because L.T. Daniels, the representative of the British Caprotti company, recommended the use of the Kylchap blastpipe, which could have coped with the fierce exhaust blasts experienced with the Caprotti system. Further problems relating to the firebox of the locomotive were only discovered during its restoration, including a poorly dimensioned ashpan, and dampers that were too small, starving the fire of air when operating at speed.

Following the occasional appearance of cracks near the spring brackets of the Britannias and Clans, a substantial re-arrangement took place in that area, which resulted in the locomotive riding on three cast steel "sub-frames" carrying the ten front-most spring brackets, and lengthened spring brackets behind the rear driven axle.

Construction history

The opportunity to create an entire batch of locomotives within the 8P category was declined by the Railway Executive because the design process had been very expensive and complex, so that when the locomotive emerged from Crewe Works in 1954, the construction of similar locomotives was seen as inappropriate, especially given the 1955 Modernisation Plan. As a result, 71000 remained the solitary member of the proposed class of Standard 8P locomotives.

Naming the locomotive

After emerging from Crewe Works in 1954, the locomotive was named Duke of Gloucester prior to entering revenue-earning service. Had further locomotives been constructed, they would have belonged to the Duke Class, standing alongside the sister locomotives of the Britannia and Clan Classes. Since then, the locomotive has colloquially been referred to by enthusiasts and crews as the Duke.

Operational details

The Duke was highly unpopular with crews in British Railways service, who regarded it as something of a liability due to its poor steam production. The fact that no effort was made to rectify the problems indicates the change in policy regarding steam locomotives, with the Modernisation Plan coming into operation just as the "Duke" entered service. Following on from the 'Britannias', the Duke was numbered under the British Railways standard numbering system in the 71xxx series. The "Duke" was given the number 71000, and featured brass nameplates with a black background, located on the smoke deflectors.

Preservation

thumb|No 71000 Duke of Gloucester on the [[East Lancashire Railway, 2007]]

After withdrawal, the Duke was selected for inclusion in the National Railway Museum, but it was later decided that only the cylinder arrangement was of interest.

The firebed (grate) air inlet dampers had not been built to the drawings and were too small, resulting in poor air supply and inefficient combustion.

In preservation, the "Duke" had an impeccably reliable operational record. However, on 9 June 2007, the engine operated a railtour from to Carlisle returning via , where, for operational reasons, the locomotive's start position was changed to . A little over into the journey, the locomotive was stopped at with leaking tubes in the firebox and removed from the train. After undergoing a heavy overhaul, the locomotive returned to main line operation in 2025. built to coarse scale standards, which apply mainly to the wheels rather than the model more generally. Uniquely, the model has a representation of working Caprotti valve gear.

The only well-documented construction of working live-steam scale model of Duke of Gloucester in Model Engineer magazine was by Denis Evans, of Blackpool, England. Beginning in the 1966, and using original drawings from British Railways and Associated Locomotive Equipment (a subsidiary of Heenan & Froude), Evans built three Dukes, with fully working Caprotti valve gear, first in 7¼ inch gauge, and then 5 inch and 3½ inch gauges. The 7¼ inch gauge Duke won awards at the 48th Model Engineer Exhibition in 1979, as did his 3½ inch gauge locomotive at the 61st Model Engineer Exhibition in 1992.

References

Citations

External links

The BR Class 8 Steam Locomotive Trust website - latest news and photos of 71000 Duke of Gloucester
The Duke of Gloucester website - more detail and pictures
Steam Special along the West Cumbria Coast 24 February and 10 March 2007