Home RAILWAY OPERATING DEPARTMENT UNIVERSAL WORKS

GWR LARGE PRAIRIE TANKS
 
  INTRODUCTION  
 

 

    

Having completed and painted Ron Brook's Rosebud Kitmaster inspired Swiss Crocodile, my next challenge was a slightly later Airfix kit of the Great Western Railway Large Prairie Tank Engine. First issued in 1963, this represented 5100 Class 2-6-2T 4167 which had been built at Swindon Works as part of Lot 369 in October 1948 after the GWR had become the Western Region of British Railways.

 
Having completed and painted Ron Brook's Rosebud Kitmaster inspired Swiss Crocodile, my next challenge was a slightly later Airfix kit of the Great Western Railway Large Prairie Tank Engine.  First issued in 1963, this represented 5100 Class 2-6-2T 4167 which had been built at Swindon Works as part of Lot 369 in October 1948 after the GWR had become the Western Region of British Railways. 

Its number had previously been used by a Great Western 4100 Class 4-4-0 built at Swindon in July 1908, allocated to Cardiff and withdrawn from there in July 1929.  However, even this engine had a longer life than the subject of the kit which was allocated new to Newton Abbot and spent its final years at 84E Tyseley, being withdrawn from there in May 1964.
 
  FROM AMERICA TO AIRFIX  
 

 

    

The 2-6-2T wheel arrangement originated in the USA although the first six examples - built by the Baldwin Locomotive Works in Philadelphia - were exported to the then British colony of New Zealand in 1885. Just like the first Double Fairlie locomotives exported to New Zealand in 1872, the addition of leading and trailing axles to a six coupled fixed powered wheelbase enabled the Prairies to cope with tight curves and lightly laid track.

 
  The 2-6-2T wheel arrangement originated in the USA although the first six examples - built by the Baldwin Locomotive Works in Philadelphia - were exported to the then British colony of New Zealand in 1885.  Just like the first Double Fairlie locomotives exported to New Zealand in 1872, the addition of leading and trailing axles to a six coupled fixed powered wheelbase enabled the Prairies to cope with tight curves and lightly laid track.

In 1898 Baldwin built a 2-6-2 for the McCloud River Railroad while in 1900 Brooks of Dunkirk, New York, erected further examples for the mid western prairie lines of the Chicago, Burlington & Quincy Railroad.

Prairie tender locomotives in Britain were limited to Sir Nigel Gresley's V2 and V4 classes introduced from 1936 while the first British Prairie tank locomotives were six outside cylindered machines built by Beyer Peacock of Gorton, Manchester for the Mersey Railway - linking Liverpool and Birkenhead - in 1887. 

A seventh Mersey Railway 2-6-2T was constructed by Kitson & Company of Leeds in 1892 while the first British railway company to design and build its own Prairie tank engines was the Lancashire and Yorkshire with twenty strong class appearing in 1903 under the supervision of Henry Albert Hoy. 

These locomotives survived to become LMS numbers 11700 to 11716 but, like all the preceding 2-6-2Ts, had rigid chassis.  Looking both across the Atlantic and to the curving branch and secondary lines of the Great Western Railway however, George Jackson Churchward saw the potential of carrying wheels mounted on swinging pony trucks.  This allowed increased coal bunkerage and boiler capacity without losing the wide route availability of an 0-6- tank engine.

The first Great Western 2-6-2T was also built in 1903, numbered 99 and featured a short-cone taper Swindon Number 2 boiler evaporating saturated steam at 195 psi from short, straight side tanks containing 1 380 gallons of water.  18" x 30" outside cylinders were supplied through piston valves actuated through rocking shafts by Stephenson link motion located between the frames and combined with 5' 8" diameter wheels the Prairie produced 23 690 lb of tractive effort. Locomotive 99 was built to Lot Number 140 and carried Swindon Works number 1992.

  
 

 

    
 

Experience with GWR 99 led to Churchward increasing the capacity of the side tanks to 2 000 gallons and tapering their front ends to improve the driver's forward vision before two distinct types of Great Western 2-6-2T emerged.

 
 

 

    
  Experience with GWR 99 led to Churchward increasing the capacity of the side tanks to 2 000 gallons and tapering their front ends to improve the driver's forward vision before two distinct types of Great Western 2-6-2T emerged. 

For rural branch line work there was the Small Prairie, starting with the 4400 Class in 1904, while for inner suburban work Large Prairies were needed to make the most of the acceleration and  ease of use that the wheel arrangement offered when faced with heavy trains.

Large Prairies of the 3100 Class - with prototype 2-6-2T 99 being renumbered as 3100 - were fitted with long-cone boilers with a barrel length of 11' 2" and were outshopped from Swindon from 1905. 

Locomotives 3111 - 20 of that year were built to Lot 150 and carried Works numbers 2066-75 while the running numbers 3121 - 30 were built to Lot 152 with Works numbers 2086 - 2095. Locomotives 3131 -3149 were built in 1906 to Lot 159 and Works numbers 159.

In 1906 Churchward experimented further.  Locomotive 3150 was fitted with a Swindon Number 4 boiler and cylinders increased in diameter to 18.5" allowing its tractive effort - and  that of engines  3151 to 3190 - to be rated at 25 670lb. 

As such the 3150 Class were mainly allocated to banking duties and became a familiar sight around the Severn Tunnel and on Sapperton Incline between Stroud and Kemble in Gloucestershire.  However, the strain of this work often lead to buckling or fracturing of their frames and Churchward's solution was the support struts that became a fixture on all pony truck fitted Great Western locomotives - and are accurately reproduced on the Airfix model. 

Locomotive 3150 was also built to Lot 159 in 1906 with works number 2157 with classmates 3151 - 3170 following in 1907 to Lot 169 and carrying Works numbers 2239 - 2258.  Running numbers 3171 - 3184 followed in 1907 to Lot 172 and Works numbers 2280-93.

Although the last new 3150 Class locomotives - 3185 to 3190  (Lot 172 and Works numbers 2294-2299)  - left Swindon Works in 1908 the GWR Large Prairie engines were progressively upgraded  with larger diameter chimneys, superheating (1909), and top boiler feeds (1911) so that by 1919 they could turn a 200 psi boiler pressure into 24 300 lb of tractive effort.  Churchward then extended their bunker capacities by 18 hundredweight to increase range.

Renumbering in 1927 caused the original 40 production Large Prairies - originally identified as 3100 and 3111 to 3149 - to become 5100 and 5111 to 5149.  The newly created 5100 Class was further extended between 1935 and 1949 by the use of redundant numbers 4100 to 4179 and these 2-6-2Ts - with GWR Blue route availability and Class D power, later 4MT under British Railways - were seen over most of the Great Western main and secondary lines. One important recognition feature of the Large Prairies was the footplate raised from the front of the cylinders to the cab door and the back of the bunker curving out over the rear buffer beam.

Locomotives 4100 - 4109 were built at Swindon to Lot 292 in 1935 with 4110 - 4119 being built in 1936 to the same Lot number.  Lot 313 covered running numbers 4121-4122 in 1937 and 4122-4129 in 1938.  Locomotives 4130-4139 were built to Lot 323 in 1939 while post War production commenced with 4140-4149 to Lot 335 in 1946 followed by 4150-4159 (Lot 361 in 1947) 4160-4169 ( Lot 369 in 1948 ) and finally 4170 - 4179 ( Lot 369 in 1949 )

Ron's model came to me without decals and as a replacement sheet would be hard to source I decided to merely add the post 1956 BR "ferret and dartboard" crest ( found in my decal box and originally destined for a Battle of Britain Pacific ) to a Brunswick Green livery. 

As there was no black and orange lining to add to the side tanks and cylinders I also decided to simply paint the raised ridge on the tanks ( shades of the early Hornby Class 47 with a moulded ridge between tones of green!) black and try out some weathering techniques to represent an unloved locomotive near the end of its service life or possibly one just acquired by preservationists who had yet to apply paraffin soaked rags to clean up the paintwork or indeed to affix a stored cabside number plate.  A longer term objective would be to acquire some etched brass plates as a number of locomotives from Swindon Lot 369 have been preserved, including 4110, 4115, 4121, 4141, 4144, 4150 and 4160, seen below awaiting repairs at Minehead on the West Somerset Railway.

More specifically, the weathering phenomenon included rust on the lower curve of the smokebox door due to ash not being removed during maintenance.  The ash would then heat up during operation and burn the paint off the outside of the door, thus leading to corrosion.  Also featured was water spilling down the front side of the tanks from the filler caps and causing rust and limescale,  Similarly, limescale also formed from leaking valves as water dribbled down the side of the boiler and evaporated.  Finally, cylinders not properly lubricated would overheat due to friction leading in turn to steam leaks and corrosion and an overall coat of "filth" was applied to the green paintwork..

  
 

 

    
 

As there was no black and orange lining to add to the side tanks and cylinders I also decided to simply paint the raised ridge on the tanks ( shades of the early Hornby Class 47 with a moulded ridge between tones of green!) black and try out some weathering techniques to represent an unloved locomotive near the end of its service life or possibly one just acquired by preservationists who had yet to apply paraffin soaked rags to clean up the paintwork or indeed to affix a stored cabside number plate. A longer term objective would be to acquire some etched brass plates as a number of locomotives from Swindon Lot 369 have been preserved, including 4110, 4115, 4121, 4141, 4144, 4150 and 4160, seen below awaiting repairs at Minehead on the West Somerset Railway.

  
 

 

    
  OTHER GREAT WESTERN LARGE PRAIRIES  
 

 

    
  With the 31xx series available after the 1927 renumbering, Class 3150 2-6-2Ts 3155, 3156, 3173, 3179 and 3181 were rebuilt as specialist banking engines and numbered 3100- 3104 to Swindon Lot 319 during 1938 and 1939.  These locomotives allied new 18 1/2" x 30" cylinders to 225 psi boilers and 5' 3" diameter driving wheels, giving a tractive effort of 31 170 lb.  3100 was first allocated to Gloucester Horton Road in December 1938 and was finally withdrawn from Tondu in May 1957 although 3103 was not withdrawn from Ebbw Junction until January 1960.

Also after the 1927 renumbering, the numbers 5101 to 5110 and 5150 to 5199 were allocated to what became known as the 5101 Class, built to Swindon Lot Numbers 257 and 284 between 1929 and 1934.  These engines used the Standard Swindon Number 2 boiler but, as in other locomotives in the 51xx series, had an axle loading of 17 tons 12 hundredweight. 5101 Class bunkers were also enlarged to increase their coal capacity and
outside steam pipes and a curved front frame was fitted as standard to number 5101 onwards, previous engines being modified when new cylinders were required.

  
 

 

    
 

6100 itself - built as part of Lot 269 - was the first to be withdrawn from Reading in September 1958 although nine classmates saw out the last months of Western Region steam in 1965 and of these 6106 is now preserved by the Didcot based Great Western Society and worked on the Nene Valley Railway in 1988, Gloucestershire and Warwickshire Railway in 1990 and West Somerset Railway in 1991, as seen above and below.

  
 

 

    
 

By 1931 Churchward's 4-4-2T "County Tanks", which shared many components with prototype Prairie 99, were proving not powerful enough for the increasing amount of London outer suburban traffic and the solution of Chief Mechanical Engineer Charles Baker Collett ( who had taken over from Churchward in 1921) was to increase the boiler pressure of the 5101 Class to 225 psi and create 70 new members of the 6100 Class, outshopped from Swindon between 1931 and 1935 and yielding a tractive effort of 27 340 lb.

Class 6100 stayed in charge of local trains to Slough, Reading and High Wycombe until displaced by diesel multiple units at the end of the 1950s.  After this time a number of 6100s worked around Gloucester on freight and passenger turns as well as being based at Brimscombe to bank trains up Sapperton Incline towards Kemble.

6100 itself - built as part of Lot 269 - was the first to be withdrawn from Reading in September 1958 although nine classmates saw out the last months of Western Region steam in 1965 and of these 6106 is now preserved by the Didcot based Great Western Society and worked on the Nene Valley Railway in 1988,  Gloucestershire and Warwickshire Railway in 1990 and West Somerset Railway in 1991, as seen above and below.

In 1938 Collett also produced the ten strong 8100 Class by rebuilding members of the post 1927 5100 Class - including 5100 ( formerly 3100 and 99 ) - with 225 psi boilers, 18" x 30" cylinders and driving wheels of only 5' 6" yielding a tractive effort of 28 165 lb.  The 8100 Class were also, at 76 tons 11 cwt, lighter than the 78 tons 9 cwt of the 5101 and 6100 Classes.

Total 8100 Class production would have been 40 locomotives had World War II not intervened but the ten machines ( formerly 5100, 5123, 5118, 5145, 5124, 5126, 5120, 5116, 5133 and 5115 )found useful employment in the West Midlands and South Wales with Carmarthen based 8100s hauling the Pembroke Coast Express for part of its journey.

  
 

 

    
 

By 1931 Churchward's 4-4-2T "County Tanks", which shared many components with prototype Prairie 99, were proving not powerful enough for the increasing amount of London outer suburban traffic and the solution of Chief Mechanical Engineer Charles Baker Collett ( who had taken over from Churchward in 1921) was to increase the boiler pressure of the 5101 Class to 225 psi and create 70 new members of the 6100 Class, outshopped from Swindon between 1931 and 1935 and yielding a tractive effort of 27 340 lb.