LMS Princess Royal Class explained

Princess Royal Class
Powertype:Steam
Designer:William Stanier
Builder:LMS Crewe Works
Builddate:1933 (2), 1935 (10)
Totalproduction:12
Whytetype:4-6-2
Uicclass:2′C1′ h4s
Leadingdiameter:3feet
Driverdiameter:6feet
Trailingdiameter:3feet
Wheelbase:63feet
Engine Total:37feet
Drivers:15feet
Tender Total:15feet
Length:74feet
Width:9feet
Height:13feet
Tenderweight:54.65LT
Fueltype:Coal
Watercap:4000impgal
Fireboxtype: 
Firearea:45square feet
Boiler:LMS type 1
Lengthinside:19feet
Smalltubediameter:NaN0NaN0, 32 off
Largetubediameter:NaN0NaN0, 123 off
Boilerpressure:250abbr=onNaNabbr=on
Totalsurface: 
Tubesandflues:2299square feet
Fireboxarea:190square feet217square feet
Superheaterarea:584square feet
Cylindercount:4
Cylindersize:Production Models:
NaNx
Valvegear:Walschaerts
6205 had outside Walschaerts with rocking shafts operating inside valves.
Valvetype:Piston valves
Tractiveeffort:402862NaN2 (production engines)
Powerclass:7P reclassified 8P in 1951
Fleetnumbers:(4)6200/1/3–12
Nicknames:Lizzies
Locale:London Midland Region
Withdrawndate:1961 (6), 1962 (6)
Preservedunits:6201, 6203
Disposition:Two preserved, remainder scrapped

The London, Midland and Scottish Railway (LMS) Princess Royal Class is a class of express passenger 4-6-2 steam locomotive designed by William Stanier. Twelve examples were built at Crewe Works, between 1933 and 1935, for use on the West Coast Main Line. Two are preserved.

Overview

The designer of the class, William Stanier, had previously been Works Manager of the Great Western Railway's depot at Swindon Works, and had been recruited with a brief to replace the LMS's miscellany of locomotives inherited from its constituent companies. He made extensive use of Great Western features in his designs.

To match the power and speed and especially the prestige of the London and North Eastern Railway's express Pacific locomotives, Stanier designed the Princess Royal class almost as soon as he was appointed to the LMS. When originally built, they were used to haul the famous Royal Scot train between London Euston and Glasgow Central.

Design

The class was based on GWR 111 The Great Bear, a design produced in 1907 for the Great Western by George Jackson Churchward. The smokebox and cylinders were closely based on those of the GWR 6000 Class (also known as the King Class). The inside cylinders were abreast the leading bogied wheels and drove cranks on the leading coupled axle, the outside cylinders were abreast the rear bogie wheels (which made substantial cross bracing necessary to brace the cylinders and the locomotive frame together) and drove crank pins on the centre coupled axle. Each of the four cylinders had its own set of Walschaerts valve gear.

Other minor details, such as corks to close oil boxes, closely followed Great Western practice.

Construction

A prototype batch of three locomotives was to be constructed in 1933. Two were constructed as drawn but the third set of frames was retained as the basis for an experimental turbine locomotive.[1]

Turbomotive

See main article: LMS Turbomotive. The third prototype was constructed with the aid of the Swedish Ljungstrom turbine company and known as the Turbomotive, although not named. It was numbered 6202, in sequence with the Princess Royals. Although 'generally similar' to the rest of the Princess Royals, and 'not all that much different', it used a larger 40 element superheater to give a higher steam temperature, more suitable for turbine use.[2] [3] This boiler was also domeless as would later be used for the second batch of the Princess Royals. The continuous exhaust of the turbine, rather than the sharper intermittent blast of the piston engine, also required changes to the draughting and the use of a double chimney.[4] [5] It entered service in June 1935 on the London–Liverpool service.

This Turbomotive was rebuilt in 1952 with conventional 'Coronation' cylinders and named Princess Anne, but was soon destroyed in the Harrow and Wealdstone rail crash.[5]

Later production

A second batch of eleven locomotives was constructed later.[6] The first two locomotives of the class to be produced had a firebox combustion volume too small for the grate area, and the subsequent locomotives had enlarged fireboxes.

Accidents and incidents

On 21 September 1951, locomotive No. 46207 Princess Arthur of Connaught was hauling an express passenger train that was derailed at Weedon, Northamptonshire due to a defective front bogie on the locomotive. Fifteen people were killed and 35 were injured.

See main article: Harrow and Wealdstone rail crash. On 8 October 1952, locomotive No. 46202 Princess Anne was one of the locomotives on the 8:00 a.m express from Euston to Liverpool and Manchester, along with LMS Jubilee Class No. 45637 Windward Islands. Princess Anne took serious damage in the crash, having the leading bogie torn off and main frames buckled, and was scrapped after being deemed uneconomic to repair it.

Naming

Each locomotive was named after a princess, the official name for the class was chosen because Mary, Princess Royal was the Colonel-in-Chief of the Royal Scots. However, the locomotives were known to railwaymen as "Lizzies", after the second example of the class, named for Princess Elizabeth, who later became Queen Elizabeth II. Later examples of 4-6-2 express passenger locomotive built by the LMS were of the related but larger, Coronation Class.

Withdrawal

The class was withdrawn in the early 1960s in line with British Railways' modernisation plan.

Details

LMS
No.
BR
No.
Name(s)Date
Built
Date
Withdrawn
PhotographNotes
620046200The Princess RoyalLast to be withdrawn.
620146201Princess ElizabethPreserved.
620346203Princess Margaret RosePreserved. Owned by the Princess Royal Class Locomotive Trust.
620446204Princess Louise
620546205Princess VictoriaFitted with modified valve gear in 1947. Converted back to normal in 1955.
620646206Princess Marie Louise
620746207Princess Arthur of ConnaughtAppeared in the 1930s classic documentary film No. 6207; A Study in Steel which showed the production of the locomotive from molten steel to the finished product.
620846208Princess Helena Victoria
620946209Princess Beatrice
621046210Lady Patricia
621146211Queen Maud
621246212Duchess of Kent

Preservation

Two examples, 6201 Princess Elizabeth and 6203 Princess Margaret Rose are preserved and both have operated on the mainline in preservation. They were named after the two children of Prince Albert, Duke of York (later King George VI), and his wife, Elizabeth, Duchess of York (later Queen Elizabeth, and after the king's death, Queen Elizabeth the Queen Mother). Princess Elizabeth Alexandra Mary (later Queen Elizabeth II) was seven years old in 1933 when her namesake was built, and Princess Margaret Rose was nearly five in July 1935 when her namesake was completed. At the time, they were third and fourth in line to the throne. 'Princess Margaret Rose' is owned by The Princess Royal Class Locomotive Trust and is on static display at the West Shed Museum, Midland Railway-Butterley, Ripley, Derbyshire.

Note: Loco numbers in bold mean their current number.

NumberNameBuiltWithdrawnService LifeLiveryLocationOwnersStatusMainline CertifiedPhotographNotes
LMSBR
620146201Princess ElizabethNov 1933Oct 196228 Years, 11 MonthsLMS Crimson Lake (on completion)Carnforth MPD6201 Princess Elizabeth SocietyUnder Overhaul [7] No, to be certifiedWithdrawn July/August 2021 due to cracked firebox.Mainline Standard overhaul commenced in September 2023.[8]
620346203Princess Margaret RoseJul 1935Oct 196227 Years, 3 MonthsBR Crimson Lake, Late CrestButterleyPrincess Royal Class Locomotive TrustStatic DisplayNoLast ran in 1996.

Media

References

Further reading

External links

Notes and References

  1. Book: Rowledge, J.W.P. . The LMS Pacifics . 1987 . . 0-7153-8776-6 . 3: The Princess Royal Class – The First Two . 24–35.
  2. Book: Cook, A.F. . Raising Steam on the LMS . 1999 . . 0-901115-85-1 . 126–127.
  3. Book: Rowledge, J.W.P. . The LMS Pacifics . 1987 . . 0-7153-8776-6 . 4: The 'Turbomotive' . 47.
  4. Book: The British Steam Railway Locomotive . II: from 1925 to 1965 . 9: Unconventional Locomotives 1929–1935 . . 1966 . 0-7110-0125-1 . . 112–117.
  5. Book: Experiments With Steam . 18: Stanier's 'Turbomotive' . Patrick Stephens Limited . 1990 . 1-85260-269-4 . . 163–171.
  6. Book: Rowledge, J.W.P. . The LMS Pacifics . 1987 . . 0-7153-8776-6 . 5: The Princess Royal Class – Modifications, and the 1935 Batch . 44–51.
  7. Work Start's on Lizzie's Overhaul Trackside issue 27 October 2023 page 6
  8. Work Start's on Lizzie's Overhaul Trackside issue 27 October 2023 page 6