GWR 4100 Class

The GWR 4100 Class was a class of steam locomotives in the Great Western Railway (GWR) of the United Kingdom.

Atbara class engine No. 3373 Atbara

The Badminton class express passenger 4-4-0 steam locomotives were introduced in 1897 as a development from the earlier Duke class. The name Badminton was chosen after the Duke of Beaufort's Badminton estate, through which the GWR was building a new line to South Wales at the time.[1]

Further modifications to the design resulted in the Atbara Class entering service in 1900, the names for these locomotives generally being taken from contemporary military engagements or senior army commanders. Later engines were named after cities of the British Empire.

The final batch of locomotives were named after varieties of garden plant and in consequence were known as the Flower Class.

These three types were later standardised and treated as a single class, so are listed together here. Four other prototype 4-4-0s, originally built in 1894 as the Armstrong Class, were also later rebuilt as Badmintons (see below).

This class were subject to the 1912 renumbering of GWR 4-4-0 locomotives, which saw the Bulldog Class gathered together in the series 3300-3455, and other types renumbered out of that series. This class took numbers 4100-4172 (of which numbers 4101-4120 had previously been used by Flower Class locomotives).

Badminton class

The first member of the class, no. 3292, was completed in December 1897 with a domed parallel boiler, a raised Belpaire firebox and an extended, built-up smokebox similar to that used on the Duke Class.[2] The outside frames were curved over each driving wheel axle.[3] It was named Badminton in April 1898.[4] A batch of eleven locomotives, nos. 3293 to 3303, were completed between April and July 1898, with a further batch of eight, nos. 3304 to 3311, between September 1898 and January 1899.[5] The class were the first locomotives on the GWR to be fitted with copper Belpaire fireboxes.[6] The penultimate example, no. 3310 Waterford, was fitted with a domeless parallel boiler, a steel Belpaire firebox, and an enlarged cab.[5][6]

The class were fitted with a steam chest and slide valves located beneath the cylinders. The valves were driven by Stephenson valve gear.[7] This inverted arrangement of slide valves and steam chest, originally introduced by William Stroudley of the LB&SCR, allowed the valves to drop away from the cylinder's steam port faces when the regulator was closed, thus reducing wear.[8] Because the steam chest was below the cylinders, and not between them, the latter could have an increased diameter. The centre line of the cylinders was inclined at an angle of 6° to the centre line of the valves, each centre line being aligned with the driving centre. This arrangement allowed the valve rods to be driven directly from the expansion link.[8][9][10] First used on the Armstrong and 3031 Classes, this arrangement of cylinders, valves and valve gear was subsequently used on all GWR outside framed 4-4-0s, with the slide valves being eventually replaced by piston valves.[11]

The crankpins for the coupling rods were placed in line with the corresponding inside crankpins for the connecting rods.[5][6] This arrangement was also developed by Stroudley, who claimed that the motion of the inside cranks was smoothly transferred to the coupling rods, as happens in an outside-cylindered engine, where the connecting rod acts directly on a crankpin shared with the coupling rod. According to Stroudley, the axleboxes, bearing surfaces, hornblocks and coupling rods of locomotives with outside cylinders had a service life twice as long as those on inside-cylindered examples.[12] However, by aligning the two cranks together, heavy balancing weights were required on the driving wheels, at 180° to the outside crank, to counteract the combined mass of the cranks and rods.[5] The Badmintons had massive crescent-shaped balancing weights, which made the unmounted pairs of wheels difficult to handle in the workshop.[6]

Numbers Names
First Second (1912) First Second
3292 4100 Badminton
3293 4101 Barrington
3294 4102 Blenheim
3295 4103 Bessborough
3296 4104 Cambria
3297 4105 Earl Cawdor
3298 4106 Grosvenor
3299 4107 Hubbard Alexander Hubbard
3300 4108 Hotspur
3301 4109 Monarch
3302 4110 Mortimer Charles Mortimer
3303 4111 Marlborough
3304 4112 Oxford Name removed in 1927
3305 4113 Samson
3306 4114 Shelburne
3307 4115 Shrewsbury Name removed in 1927
3308 4116 Savernake
3309 4117 Shakespeare
3310 4118 Waterford
3311 4119 Wynnstay

One locomotive of the Badminton Class was rebuilt with an experimental boiler. With the impending opening of the direct Reading-Taunton route which was of more undulating nature than the route via Bristol, there was a need to ensure that the most appropriate locomotives were provided. Churchward's Chief Assistant, F.G. Wright, designed a large boiler with a very deep firebox, which was fitted to no. 3297 Earl Cawdor in July 1903.[13] The boiler was designed to hold a large volume of hot water, forming a reservoir to assist the locomotive running along an undulating line.[14] It also provided a steam space of 85.13 cu ft (2.411 m3) as against the 76.2 cu ft (2.16 m3) of the Standard No. 4 boiler, the larger of the two types of standard boiler fitted to the 4-4-0s.[15][16] This increase in volume was intended to provide a reservoir of steam.[16] The firebox was set deep between the coupled axles, with a horizontal grate.[14] The intention with this was to allow a thick fire to be built up, increasing the area of the firebox in contact with the fire, and decreasing the temperature gradient along the firebox plates, thus reducing the risk of broken firebox stays.[13] The boiler was pressed to 210 lbf/in2 (1.4 MPa).[16] No. 3297 was also fitted with a large cab with two side windows, reminiscent of North Eastern practice.[16][17] The locomotive was regularly rostered on the most demanding trains, but it soon became apparent that it was not up to the work demanded and it was relegated to secondary duties. In October 1906 the boiler was removed and replaced by a Standard No.4 boiler, the North Eastern style side-window cab having been replaced by a Churchward type in November 1904.[17]

Atbara class

No. 3373 Atbara was built in April 1900, the first of a class of forty locomotives.[18] Instead of the curved outside frames of the Badmintons, this class had straight-topped frames, which became the standard pattern for all subsequent outside-framed 4-4-0s.[19] These straight frames were less prone to fracturing, because of the greater depth of plate between the coupled wheels.[6] The Atbaras retained the Stroudley crank layout, cylinders, valves and valve gear of the Badmintons, but differed in the boiler, which was a parallel domeless Standard No. 2 type.[20][21] No. 3405 Mauritius was reboilered in September 1902 with a tapered boiler, a prototype for the Standard No. 4 type.[22] It was the first GWR 4-4-0 to be fitted with a tapered (or coned) boiler.[23] Following this, another nine Atbaras, nos. 3400 to 3404 and 3406 to 3409, were rebuilt with No. 4 boilers between February 1907 and February 1909. The ten were added to the City Class.[18][24] No. 3382 Mafeking was heavily damaged in an accident on 24 June 1911. Adjudged unrepairable, it was withdrawn in September 1911, so was not included in the 1912 renumbering.[25] The remaining Atbaras were withdrawn between April 1927 and May 1931.[18]

Atbara Class locomotive no. 3373, in Royal Sovereign livery, on February 2, 1901.
Numbers Names
First Second (1912) First Second Third
3373 4120 Atbara
3374 4121 Baden Powell
3375 4122 Conqueror Edgcumbe Colonel Edgcumbe
3376 4123 Herschell Name removed in 1914
3377 4124 Kitchener
3378 4125 Khartoum
3379 4126 Kimberley
3380 4127 Ladysmith
3381 4128 Maine
3382 Withdrawn Mafeking
3383 4129 Kekewich
3384 4130 Omdurman
3385 4131 Powerful
3386 4132 Pembroke Name removed in 1930
3387 4133 Roberts
3388 4134 Sir Redvers
3389 4135 Sir Daniel Pretoria
3390 4136 Terrible
3391 4137 Wolseley
3392 4138 White
3393 4139 Auckland
3394 4140 Adelaide Name removed in 1910
3395 4141 Aden
3396 4142 Brisbane
3397 4143 Cape Town
3398 4144 Colombo
3399 4145 Dunedin
3400 City 3700 Durban
3401 City 3701 Gibraltar
3402 City 3702 Halifax
3403 City 3703 Hobart
3404 City 3704 Lyttelton
3405 City 3705 Mauritius
3406 City 3706 Melbourne
3407 City 3707 Malta
3408 City 3708 Killarney
3409 City 3709 Quebec
3410 4146 Sydney
3411 4147 St. Johns
3412 4148 Singapore

Flower class

The Flower Class were fitted with deeper outside frames than the Atbaras, and a new design of bogie developed from the type fitted to the French de Glehn Atlantics.[26] Twenty of the class were built between April 1910 and January 1913. Three were withdrawn in July 1927, with the last withdrawal, no. 4150 Begonia, going in April 1931.[27]

Numbers Name
First Second (1912)
4101 4149 Auricula
4102 4150 Begonia
4103 4151 Calceolaria
4104 4152 Calendula
4105 4153 Camellia
4106 4154 Campanula
4107 4155 Cineraria
4108 4156 Gardenia
4109 4157 Lobelia
4110 4158 Petunia
4111 4159 Anemone
4112 4160 Carnation
4113 4161 Hyacinth
4114 4162 Marguerite
4115 4163 Marigold
4116 4164 Mignonette
4117 4165 Narcissus
4118 4166 Polyanthus
4119 4167 Primrose
4120 4168 Stephanotis

Prototype 4-4-0 locomotives

The Armstrong Class were a group of four locomotives designed by William Dean and built in 1894 with 7 ft 1.5 in (2.172 m) driving wheels.[28] In April 1915 no. 16 Brunel was rebuilt with 6 ft 8.5 in (2.045 m) wheels and piston valves, having already been fitted with a Standard No.2 boiler. It was renumbered 4169 as a member of the Flower Class.[29] No. 14 Charles Saunders was converted in May 1917, and the remaining two were dealt with in February 1923.[30]

Numbers Date
Renumbered		 Names Date
Withdrawn
First Second First Second
16 4169 April 1915 Brunel July 1930
14 4170 May 1917 Charles Saunders August 1928
7 4171 February 1923 Charles Saunders Armstrong September 1928
8 4172 February 1923 Gooch April 1929

References
  1. Davies 1993, p. 107
  2. Holcroft 1971, p. 74
  3. Nock 1977, p. 32
  4. Nock 1977, p. 33
  5. Nock 1977, p. 34
  6. Holcroft 1971, p. 68
  7. Holcroft 1971, p. 67
  8. Holcroft 1971, p. 62
  9. Nock 1977, p. 10
  10. Nock 1977, p. 46
  11. Nock 1977, p. 27
  12. Nock 1977, p. 13
  13. Nock 1977, pp. 62–63
  14. Nock 1977, p. 62
  15. Holcroft 1971, p. 82
  16. Nock 1977, p. 63
  17. le Fleming 1954, p. G30
  18. Nock 1978, p. 88
  19. Nock 1977, p. 43
  20. Nock 1977, p. 45
  21. Nock 1977, p. 94
  22. Nock 1977, p. 58
  23. Nock 1977, p. 57
  24. Nock 1978, p. 39
  25. Ferris, Robert. "Henley in Arden accident". Warwickshire Railways. Retrieved 12 October 2012.
  26. Nock 1977, p. 81
  27. Nock 1978, p. 89
  28. Nock 1977, p. 12
  29. Nock 1978, p. 60
  30. le Fleming 1954, p. G27-G29

Bibliography
  • Davies, Ken (April 1993). The Locomotives of the Great Western Railway, part fourteen: Names and their Origins - Railmotor Services - War Service - The Complete Preservation Story. Lincoln: RCTS. ISBN 0-901115-75-4.
  • le Fleming, H.M. (October 1954). White, D.E. (ed.). The Locomotives of the Great Western Railway, part seven: Dean's Larger Tender Engines. Kenilworth: Railway Correspondence and Travel Society. ISBN 0-901115-18-5.
  • Holcroft, Harold (1971). An Outline Of Great Western Locomotive Practice 1837-1947. Shepperton, Middlesex: Ian Allan. ISBN 0-7110-0228-2.
  • Nock, O.S. (1977). Standard Gauge Great Western 4-4-0s Part 1 Inside Cylinder Classes 1894-1910. Newton Abbot: David & Charles. ISBN 0-7153-7411-7.
  • Nock, O.S. (1978). Standard Gauge Great Western 4-4-0s Part 2 Counties to the Close 1904-1961. Newton Abbot: David & Charles. ISBN 0-7153-7684-5.
  • GWR Engines Names, Numbers Types & Classes. Originally published by the Great Western Railway and Great Western Railway Magazine 1911 and 1928. Reprinted: David & Charles, Newton Abbot, Devon. 1971. ISBN 0-7153-5367-5
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