GWR 6800 Class

Great Western Railway 6800 Class
6833 Calcot Grange at Bristol Temple Meads in British Railways green livery
Power type Steam
Builder Great Western Railway
Build date 1936–1939
Total produced 80
Configuration 4-6-0
UIC classification 2'C h
Gauge 4 ft 8 1⁄2 in (1,435 mm)
Leading wheel
diameter		 3 ft 0 in (0.914 m)
Driver diameter 5 ft 8 in (1.727 m)
Minimum curve 8 chains (530 ft; 160 m) normal,
7 chains (460 ft; 140 m) slow
Length 63 ft 0-1/4 in (19.20 m)
Width 8 ft 11 1⁄4 in (2.72 m)
Height 13 ft 0 in (3.96 m)
Axle load 18 tons 8 cwt (41,200 lb or 18.7 t)
Weight on drivers 55 tons 2 cwt (123,400 lb or 56.0 t)
Locomotive weight 74 tons 0 cwt (165,800 lb or 75.2 t) full
Tender weight 40 tons 0 cwt (89,600 lb or 40.6 t) full
Fuel type Coal
Fuel capacity 7 tons 0 cwt (15,700 lb or 7.1 t)
Water capacity 3,500 imp gal (16,000 l; 4,200 US gal)
Boiler pressure 225 psi (1.55 MPa)
Firegrate area 27.07 sq ft (2.515 m2)
Heating surface:
Tubes and flues		 1,686.60 sq ft (156.690 m2)
Heating surface:
Firebox		 154.78 sq ft (14.380 m2)
Superheater area 4-element: 191.8 sq ft (17.82 m2),
6-element: 253.38 sq ft (23.540 m2)
Cylinders Two, outside
Cylinder size 18.5 × 30 in (470 × 762 mm)
Tractive effort 28,875 lbf (128.44 kN)
Career Great Western Railway,
British Railways
Power class GWR: D; BR: 5MT
Number 6800–6879
Axle load class GWR: Red
First run 1936
Retired 1960–1965

The Great Western Railway (GWR) 6800 Class or Grange Class was a mixed traffic class of 4-6-0 steam locomotive. There were 80 in the class, all built at the Swindon works.

Contents

History

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 (1.73 m) diameter coupled wheels, and the Standard No. 1 boiler.[2] Although planned in 1901, none were built until 1936, by which time C.B. Collett was in charge at Swindon. He took the Churchward proposal, and modified the design of the cab and controls to the current style.[3]

The 4300 Class of 2-6-0 tender locomotives had been introduced on the GWR in 1911, and by 1932 there were 342 in service.[4] Between 1936 and 1939, 100 of these were taken out of service and replaced by new 4-6-0 locomotives, 80 being 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] The Granges were effectively a smaller-wheeled version of the GWR Hall Class.[6] In service they were reliable performers.[3][7] With their power and mixed traffic characteristics they could handle most duties on the network.[3] The class were often used for the haulage of perishable goods, such as fruit and broccoli, and for excursion trains.[8]

The wheels, valve motion and tenders were taken from the withdrawn engines, reconditioned and then used in the construction of the 100 new locomotives;[3][6][9] the components from one old locomotive were spread amongst more than one of the new engines.[10] The cylinders of the Granges (and Manors) 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.[11][12]

The GWR also built a lighter version of the Granges, the GWR 7800 Class, known as the Manor Class, which had smaller boilers.[9]

The BR power classification of the Grange class was 5MT, its GWR power class was D and its route availability colour code was red.[13]

Details

Preservation

No engines were preserved. However, GWR 6880 Betton Grange, the next Grange that was due to be built originally, is being built at Llangollen Railway.[14]

Gallery

References

  1. ^ le Fleming 1962, pp. J3–4
  2. ^ le Fleming 1962, p. J9
  3. ^ a b c d Chacksfield 2002, p. 139
  4. ^ le Fleming 1962, p. J12
  5. ^ a b le Fleming 1962, p. J14
  6. ^ a b c le Fleming 1960, p. H34
  7. ^ Gibson 1984, p. 144
  8. ^ Holcroft 1971, p. 155
  9. ^ a b le Fleming 1960, p. H36
  10. ^ Bradley 1988, pp. 55–6
  11. ^ Bradley 1988, p. 56
  12. ^ Gibson 1984, pp. 144–5
  13. ^ le Fleming 1960, p. H35
  14. ^ 6880 Betton Grange Project

External links