GCR Class 9A

GCR Classes 9A and 9A Alt.
LNER Class N4[1]

N4/2 No. 69239 at Barnsley Locomotive Depot 10 April 1949
Type and origin
Power type Steam
Designer Thomas Parker
Builder
Build date 1889–1892
Total produced 55
Specifications
Configuration:
 ​
 • Whyte 0-6-2T
 • UIC C1 n2t
Gauge 4 ft 8 1⁄2 in (1,435 mm)
Driver dia. 5 ft 1 in (1.549 m)
Trailing dia. 3 ft 6 in (1.067 m)
Wheelbase 22 ft 6 in (6.86 m)
Length
  • 9A: 36 ft 2 1⁄8 in (11.03 m)
  • 9A Alt: 36 ft 8 1⁄8 in (11.18 m)
Axle load 16.75 long tons (17.02 t)
Adhesive weight 48.15–48.40 long tons (48.92–49.18 t)
Loco weight 61.50–61.95 long tons (62.49–62.94 t)
Fuel type Coal
Fuel capacity
  • 9A: 2.75 long tons (2.79 t)
  • 9A Alt: 3.00 long tons (3.05 t)
Water cap
  • 9A: 1,300 imp gal (5,910 l; 1,560 US gal)
  • 9A Alt: 1,360 imp gal (6,180 l; 1,630 US gal)
Firebox:
 • Firegrate area		 18.3 sq ft (1.70 m2)
Boiler LNER diagram 21
Boiler pressure 160 lbf/in2 (1.10 MPa)
Heating surface 1,063 sq ft (98.8 m2)
 • Tubes 964 sq ft (89.6 m2)
 • Firebox 99 sq ft (9.2 m2)
Superheater None
Cylinders Two, inside
Cylinder size 18 in × 26 in (457 mm × 660 mm)
Valve gear Joy
Valve type Slide valves
Performance figures
Tractive effort 18,780 lbf (83.54 kN)
Career
Operators
Class
  • GCR: 9A
  • LNER: N4
Power class
  • LNER: 2
  • BR: 2MT
Axle load class LNER/BR: Route availability 4
Withdrawn 1932–1954
Disposition All scrapped

The Great Central Railway (GCR) Class 9A was a class of 0-6-2T steam locomotive built between 1889 and 1892. From 1923 the locomotives were redesignated Class N4.

Design and construction

Designed by Thomas Parker for the Manchester, Sheffield and Lincolnshire Railway (MS&LR), a total of 55 locomotives were constructed up to 1892.[2] The MS&LR changed its name to the GCR in 1897. In 1892 the final fourteen locomotives were built with a larger coal bunker, increasing their weight to 61.95 long tons (62.94 t). This last batch was classified as Class 9A Altered, sometimes abbreviated as 9A Alt.

The GCR 9A locos were reclassified as N4 under the LNER locomotive numbering and classification system when the GCR was absorbed into the London and North Eastern Railway after the 1923 grouping. The original design were N4/1 and those with extended bunkers N4/2.[3]

In 1925, shorter chimneys began to be fitted to bring the N4s within the LNER composite loading gauge, creating two further variants N4/2 (short bunker) – the existing N4/2s being recoded as N4/3s – and N4/4 (long bunker).[3]

Locomotive numbering

They were built in three batches and numbered 161, 165, 173 (later renumbered 512–514), 601–638, and 712–725. GCR locos had 5000 added to their original numbers when the line was absorbed by the LNER in 1923, resulting in numbers ranging between 5512 and 5725. As part of the LNER's numbering rationalisation scheme introduced in 1946, the surviving 24 N4s were renumbered between 9225 and 9247[4] with the earliest built receiving the lowest number, and so on. British Railways, formed on 1 January 1948, added 60000 to all LNER loco numbers.

References

  1. ↑ Boddy et al. 1977, pp. 79, 83–84.
  2. ↑ Casserley 1974, p. 74
  3. 1 2 Boddy et al. 1977, p. 81.
  4. ↑ Allan 1947, pp. 52
  • Boddy, M. G.; Brown, W. A.; Fry, E. V.; Hennigan, W.; Hoole, Ken; Manners, F.; Neve, E.; Platt, E. N. T.; Proud, P.; Yeadon, W. B. (March 1977). Fry, E. V., ed. Locomotives of the L.N.E.R., Part 9A: Tank Engines—Classes L1 to N19. Kenilworth: RCTS. ISBN 0-901115-40-1. 
  • Casserley, H.C. & Johnston, Stuart W. (1974) [1966]. Locomotives at the Grouping 2: London & North Eastern Railway. Shepperton, Surrey: Ian Allan Limited. ISBN 0-7110-0553-2. 
  • Allan, Ian (1947). ABC of LNER Locomotives 1947. Ian Allan Ltd. 
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