GWR 6800 Class

The Great Western Railway (GWR) 6800 Class or Grange Class was a mixed traffic class of 4-6-0 steam locomotive, built to replace the GWR 4300 Class 2-6-0. There were 80 in the class, all built at the Swindon works, using some reconditioned parts from withdrawn 4300 Class locomotives .

Great Western Railway 6800 Class
6877 Llanfair Grange at Exeter St David's
Type and origin
Power typeSteam
BuilderGreat Western Railway Swindon Works
Build date1936–1939
Total produced80
Specifications
Configuration:
​
 • Whyte4-6-0
 • UIC2'Ch2
Gauge4 ft 8 1⁄2 in (1,435 mm) standard gauge
Leading dia.3 ft 0 in (0.914 m)
Driver dia.5 ft 8 in (1.727 m)
Minimum curve8 chains (530 ft; 160 m) normal,
7 chains (460 ft; 140 m) slow
Length63 ft 0 1⁄4 in (19.21 m)
Width8 ft 11 1⁄4 in (2.724 m)
Height13 ft 0 in (3.962 m)
Axle load18 long tons 8 cwt (41,200 lb or 18.7 t)
(20.6 short tons)
Adhesive weight55 long tons 2 cwt (123,400 lb or 56 t)
(61.7 short tons)
Loco weight74 long tons 0 cwt (165,800 lb or 75.2 t)
(82.9 short tons) full
Fuel typeCoal
Fuel capacity7 long tons 0 cwt (15,700 lb or 7.1 t)
(7.8 short tons)
Water cap3,500 imp gal (16,000 l; 4,200 US gal)
Firebox:
 • Firegrate area		27.07 sq ft (2.515 m2)
Boiler pressure225 psi (1.55 MPa)
Heating surface:
 • Tubes and flues		1,686.60 sq ft (156.690 m2)
 • Firebox154.78 sq ft (14.380 m2)
Superheater:
​
 • Heating area4-element: 191.8 sq ft (17.82 m2),
6-element: 253.38 sq ft (23.540 m2)
CylindersTwo, outside
Cylinder size18.5 in × 30 in (470 mm × 762 mm)
Performance figures
Tractive effort28,875 lbf (128.44 kN)
Career
OperatorsGreat Western Railway,
British Railways
Power classGWR: D; BR: 5MT
Numbers6800–6879
Axle load classGWR: Red
First run1936
Retired1960–1965
DispositionAll original locomotives scrapped, GWR 6880 Betton Grange being built

Background

The GWR locomotive standardisation policy pursued by G.J. Churchward envisaged a range of locomotive classes which would be suitable for the majority of duties, and yet which would share a small number of standard components.[1] Amongst the designs suggested in 1901 was a 4-6-0 with 5-foot-8-inch (1.727 m) diameter driving wheels, and the Standard No. 1 boiler.[2] Although planned in 1901, none were built during Churchward’s lifetime. C.B. Collett, (Churchward’s successor at Swindon Works) rather introduced the Hall class with 6-foot (1.829 m) diameter driving wheels.

The 4300 Class of 2-6-0 tender locomotives had been introduced on the GWR for mixed traffic duties in 1911, and by 1932 there were 342 in service.[3] However, by the mid 1930s some of the earlier examples were in need of attention and the class as a whole was struggling with some of the duties expected of them. Collett therefore revived the Churchward proposal, but modified the design to include a cab and controls to the current style.[4] Between 1936 and 1939, one hundred 4300 Class were taken out of service and replaced by new 4-6-0 locomotives, eighty of which were of the 6800 (or Grange) class, whilst the remaining 20 were of the 7800 (or Manor) class.[5] It had been intended to replace all of the 4300 Class in this way, but the Second World War stopped the programme.[5][6]

Design and Production

The Granges were effectively a smaller-wheeled version of the GWR Hall Class.[6]

The wheels, valve motion and tenders were taken from the withdrawn engines, reconditioned and then used in the construction of the 100 new locomotives;[4][6][7] the components from one old locomotive were spread amongst more than one of the new engines.[8] The cylinders of the Granges were of the same size as those used on the 4300 Class, but the old cylinders could not be re-used because the cylinders and valves shared a common casting, and the new design called for the separation between cylinder and valve centre lines to be increased by 2 1⁄2 inches (64 mm). This was done in order to make the cylinders level with the axles, but still allow the use of the old valve motion parts.[9][10]

The locomotives were built in two batches to a single order (Lot No. 308): Nos. 6800-6859 were built between August 1936 and December 1937, and Nos. 6860-6879 appeared between February and May 1939. They were all named after Granges in the area covered by the GWR. Further construction of the class was cancelled due to the outbreak of war.[11] They were originally fitted with Churchward 3,500 imp gal (16,000 l; 4,200 US gal) tenders taken from withdrawn members of the 4300 Class. However, after the second world war several were fitted with newer 3,500 imp gal (16,000 l; 4,200 US gal) and 4,000 imp gal (18,000 l; 4,800 US gal) types.[12]

Performance

Although built to a thirty five-year old design, in service they proved to be reliable performers.[4][13] With their power and mixed traffic characteristics they could handle most duties on the network.[4] Their smaller driving wheels giving them a higher tractive effort than the Hall Class. They were often used for the haulage of perishable goods, such as fruit and broccoli, and for excursion trains.[14] However their axle loading prevented their use on some cross-country routes previously operated by the 4300 class. As a result, a lighter version in the form of the Manor Class was introduced for these duties.[7]

No. 6827 'Llanfrechfa Grange' at Swindon Works 29 November 1964.

The BR power classification of the Grange class was 5MT, its GWR power class was D and its route availability colour code was red.[15]

Accident
  • On 21 September 1962, 6800 Arlington Grange was hauling a freight train which overran signals at Steventon and was derailed.[16]

Withdrawal and Preservation

The entire class was withdrawn from service between 1960 and 1965 and no examples were preserved. 6853 Morehampton Grange was a candidate for preservation by the GWS at Didcot, 7808 was however purchased instead. However, GWR 6880 Betton Grange, the next Grange that was due to be built originally, is currently being built at Llangollen Railway.[17]

Table of withdrawals
YearQuantity in
service at
start of year		Number withdrawnQuantity
withdrawn		Locomotive numbers
196080116801.
196179236802/05.
196277146865.
196376596807/09/14/28/35.
19647126356800/04/06/08/10–11/18/21–22/24–25/32/34/39/42–46/50/52/63/67/73/75/78.
19654545806803/12–13/15–17/19–20/23/26–27/29–31/33/36–38/40–41/47–49/51/53–62/64/66/68–72/74/76–77/79.

List of Locomotives
gollark: Without the global supply chains we have I would lack nice things like computers or possibly orange juice.
gollark: I don't agree, trade is generally pretty positive-sum for everyone.
gollark: It would be more than "oh no, I have slightly worse food choices".
gollark: Full anarchoprimitivism, as komrad suggested, would *not* have that, and pre-industrial-revolution you have way worse productive capacity (so less of those things/worse things), and no access to modern medicine.
gollark: You still have access to presumably clean water of some form, the knowledge that you *can* go somewhere with that if you need medical treatment or whatever, and the ability to buy stuff if it's needed.

References
  1. le Fleming 1962, pp. J3–4
  2. le Fleming 1962, p. J9
  3. le Fleming 1962, p. J12
  4. Chacksfield 2002, p. 139
  5. le Fleming 1962, p. J14
  6. le Fleming 1960, p. H34
  7. le Fleming 1960, p. H36
  8. Bradley 1988, pp. 55–6
  9. Bradley 1988, p. 56
  10. Gibson 1984, pp. 144–5
  11. le Fleming 1960, p. H34-6
  12. le Fleming 1960, p. H35
  13. Gibson 1984, p. 144
  14. Holcroft 1971, p. 155
  15. le Fleming 1960, p. H35
  16. Vaughan 1983, pp. 100-05
  17. 6880 Betton Grange Project
  • Bradley, Rodger (1988). GWR Two Cylinder 4-6-0s and 2-6-0s. Newton Abbot: David & Charles. ISBN 0-7153-8894-0.CS1 maint: ref=harv (link)
  • Chacksfield, J.E. (2002). C.B. Collett: A Competent Successor. The Oakwood Library of Railway History. Usk: Oakwood Press. ISBN 0-85361-586-1. OL121.CS1 maint: ref=harv (link)
  • Gibson, John C. (1984). Great Western Locomotive Design: A Critical Appreciation. Newton Abbot: David & Charles. ISBN 0-7153-8606-9.CS1 maint: ref=harv (link)
  • Holcroft, Harold (1971) [1957]. An Outline of Great Western Locomotive Practice 1837-1947 (2nd ed.). Shepperton: Ian Allan. ISBN 0-7110-0228-2.CS1 maint: ref=harv (link)
  • le Fleming, H.M. (November 1960) [1953]. White, D.E. (ed.). Part 8: Modern Passenger Classes. The Locomotives of the Great Western Railway (2nd ed.). Kenilworth: RCTS. ISBN 0-901115-19-3.CS1 maint: ref=harv (link)
  • le Fleming, H.M. (February 1962). White, D.E. (ed.). Part 9: Standard Two-Cylinder Classes. The Locomotives of the Great Western Railway. RCTS.CS1 maint: ref=harv (link)
  • Vaughan, Adrian (1983). Signalman's Twilight. London: John Murray. ISBN 0-7195-3973-0.CS1 maint: ref=harv (link)
  • Whitehurst, Brian (1973). Great Western Engines, Names, Numbers, Types and Classes (1940 to Preservation). Oxford, UK: Oxford Publishing Company. pp. 60–61, 103, 132. ISBN 978-0-9028-8821-0. OCLC 815661.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.