GWR 4200 Class
4270 atArley on theSevern Valley Railway in 2016
Type and origin Power type Steam Designer G. J. Churchward Builder GWR Order number Lots 182, 187, 196, 200, 203, 213, 220 Build date 1910–1923 Total produced 105
Specifications Configuration: ​  • Whyte 2-8-0T Gauge 4 ft 8+1⁄2 in (1,435 mm)standard gauge Leading dia. 3 ft 2 in (965 mm) Driver dia. 4 ft7+1⁄2 in (1,410 mm) Minimum curve 2 chains (130 ft; 40 m) Length 40 ft 9 in (12.421 m) Width 8 ft 11 in (2.718 m) Height 12 ft10+1⁄16 in (3.913 m) Loco weight 81 long tons 12 cwt (182,800 lb or 82.9 t) (82.9 t; 91.4 short tons) Fuel type Coal Fuel capacity 4 long tons (4.1 t; 4.5 short tons) Water cap. 1,800 imp gal (8,200 L; 2,200 US gal) Boiler GWR Standard No. 4 Boiler pressure 200 psi (1.38 MPa) Cylinders two outside Cylinder size 18+1⁄2 in × 30 in (470 mm × 762 mm)
Performance figures Tractive effort 31,450 lbf (139,900 N)
Career Power class GWR: D BR: 7F Numbers 4200–4299, 5200–5204 Axle load class GWR: Red Locale Great Western Railway, British Railways Withdrawn 1937–1939, 1959–1965 Disposition 14 rebuilt as7200 Class; 5 preserved; remainderscrapped

TheGreat Western Railway (GWR)4200 Class is a class of2-8-0Tsteam locomotives.

After the GWR took over operations and then absorbed the variousSouth Wales based railways from the late 1800s, operational practice on most was defined by moving heavy coal trains on sharp, steep and undulating tracks. Thus many of these railways - especially the dominantTaff Vale Railway - specified and used an0-6-2T, which gave maximum tractive effort whilst riding well on the undulating track.^[1]

With coal trains increasing in size and scale, the GWR needed to develop a more powerful locomotive to meet these requirements, on what were relatively short haul routes. Thus in 1906, Chief EngineerGeorge Jackson Churchward took the basic design of hisGWR 2800 Class, and adapted it. After proposing a 2-8-2T design, Churchward developed the UK's first 2-8-0tank engine, through concerns that the longer frames required for a 2-8-2T would restrict operation in theSouth Wales Valleys.^[1][2]

Churchward upgraded the power of the design, modifying the frames to hold a GWR standard No.4 boiler over the 2800 Class standard No. 1. The flanges of the second and third driving wheels were made thinner, and the coupling rods between the third and fourth sets of driving wheels used spherical joints, all to create side play and hence flexibility in operations. The prototype No. 4201 was out shipped fromSwindon Works in 1910 under Lot No. 142, with a straight back bunker capable of containing three tonnes of coal. In 14 months of testing, it easily proved itself capable of negotiating curves down to 2 chains (130 ft; 40 m) in radius.^[1][2]

Put into production in 1912 under Lot No. 187, the first locomotives were Nos. 4202 to 4221, which had both top feed boilers and curved upper bodies to their coal bunkers to provide 3.5 tonnes of coal carrying capacity.^[2] Working heavy coal trains of over 1,000 tons through the South Wales Valleys, fromcoal mines toports, the large boilers and restrictedloading gauge resulted in narrow side tanks. Although passing numerouswater stops along their routes, because of the class's heavy water consumption and limited tank capacity, they were nicknamed "Water Carts". 105 4200s were built between 1910 and 1923.^[1][2]

In 1919, from Lot No. 213 (4262 to 4285) onwards, the coal bunker was built six inches taller, increasing coal capacity to 4 tons.^[1][2] In 1921, having also run out of allocation numbers, the class received its first major upgrade. Increasing cylinder diameter from 18.5 inches (470 mm) to 19 inches (480 mm) increasedtractive effort to 33,170 pounds, thus creating the distinctive laterGWR 5205 Class.^[1][2]

The last batch of the 5205 Class produced pre-World War II were lot No. 266 of 1930, producing numbers 5275 to 5294. However, due to theStock Market Crash of 1929, and a resultant down turn in coal exports toEurope, a number of the 4200 Class having been returned to Swindon for overhaul, had in fact been stored there. To increase their operational ability across the wider GWR network, Chief EngineerCharles Collett took the board-agreed decision to alter this batch in production to 2-8-2T by adding a bolt-on 4 feet (1.22 m) extension to the frames to accommodate a pair of rear trailing wheels, which took the coal capacity up to 6 tons and water tanks to 2500 gallons. This created theGWR 7200 Class 2-8-2T.^[4] Due to demands from the Operational Department for more of the 7200 Class, from the stored 4200 Class locomotives at Swindon, fourteen were rebuilt between 1937 and 1939 as 7200 Class locomotives.^[1][2][4] Although operationally banned from certain goods yards, most 7200's found work across the GWR system, mostly deployed oniron ore and stone trains fromBanbury.^[5]

In later years many of the remaining 4200s were upgraded to 5205 specification with outside steam pipes, larger cylinders and in some cases curved frames at the front end.^[1][2]

All but one, No. 4224, passed in the ownership ofBritish Railways on Nationalisation.^[1][2] The first engine withdrawn was number 4224 in February 1959 and by the end of steam on the former GWR system, 18 were still working at the start of 1965, the last withdrawn being No. 4268 in August 1965.^[6]

Five have been preserved, with all rescued fromWoodham Brothersscrapyard inBarry, Vale of Glamorgan,South Wales. Three of the five surviving members of the 4200 have run in preservation.

Number	Year Built	Withdrawn	Location	Status	Photograph	Notes
4247	Mar 1916	Apr 1964	East Somerset Railway	Awaiting Overhaul		In 5205 specification, outside steampipes but straight footplate. Left Barry in April 1985. It is the oldest survivor of its class in preservation marking its centenary in Mar 2016. Overhaul to commence at East Somerset Railway before moving to the Dartmouth Steam Railway.
4248	Apr 1916	May 1963	Swindon Steam Railway Museum	Static museum exhibit		In 5205 specification. Left Barry in May 1986. Conserved rather than restored, on show dismantled as if it were "in theSwindon Works."
4253	Mar 1917	Apr 1963	Kent and East Sussex Railway	Under restoration		Has 5275 style footplate with a raised section over the cylinders. Left Barry in August 1987, stored atPontypool and Blaenavon Railway until 2011, then sold to group from K&ESR.[7]
4270	Dec 1919	Sept 1962	Gloucestershire Warwickshire Railway	Stored awaiting overhaul		Retains original inside steam pipes. Left Barry in July 1985, owned byJeremy Hosking.[8]
4277Hercules	Apr 1920	Jun 1964	Dartmouth Steam Railway	Operational		Retains original inside steam pipes. Left Barry in June 1986.[9]

In the case of 4277 its name is historically inaccurate, i.e. it being applied in preservation.

In 2012,Hornby released models of the 4200 class in both original GWR green and BR black.^[10] The GWR green version was aDCC-ready model of locomotive No. 4283, as it appeared between 1934 and 1942.^[11]

• List of GWR standard classes with two outside cylinders

Wikimedia Commons has media related toGWR 4200 Class.

• Allcock, N. J.; Davies, F. K.; le Fleming, H. M.; Maskelyne, J. N.; Reed, P. J. T.; Tabor, F. J. (1968) [1951]. White, D. E. (ed.).The Locomotives of the Great Western Railway, part one: Preliminary Survey. Kenilworth:RCTS.

• Railway locomotives introduced in 1910
• Great Western Railway locomotives
• 2-8-0T locomotives
• Freight locomotives
• Standard-gauge steam locomotives of Great Britain
• 1′D h2t locomotives

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