GWR 111 The Great Bear

The Great Bear

Official picture of the GWR 4-6-2 No.111 The Great Bear in 1908.
Type and origin
Power type Steam
Designer G.J. Churchward
Builder GWR, Swindon Works
Order number Lot 171
Serial number 2279
Build date February 1908
Total produced 1
Rebuilder GWR, Swindon
Rebuild date 7 January 1924
Number rebuilt 1
Specifications
Configuration 4-6-2
Gauge 4 ft 8 1⁄2 in (1,435 mm)
Leading wheel
diameter		 3 ft 2 in (0.97 m)
Driver diameter 6 ft 8.5 in (2.045 m)
Trailing wheel
diameter		 3 ft 8 in (1.12 m)
Wheelbase 34 ft 6 in (10.516 m)
Length 71 ft 2.025 in (21.692 m)
Axle load 20 long tons (20 t)
Weight on drivers 60 long tons (61 t)
Locomotive weight 97 long tons (99 t)
Tender weight 45.75 long tons (46.48 t)
Locomotive and tender
combined weight		 142.75 long tons (145.04 t)
Fuel type Coal
Water capacity 3,500 US gal (13,000 l; 2,900 imp gal)
Boiler pressure 225 psi (1.551 MPa)
Firegrate area 41.79 sq ft (3.882 m2)
Heating surface:
– Tubes and flues		 2,697.67 sq ft (250.622 m2)
– Firebox 158.154 sq ft (14.6930 m2)
– Total 3,400.81 sq ft (315.946 m2)
Superheater type Swindon No. 1, Field-tube, 3-row
Superheater area 545 sq ft (50.6 m2)
Cylinders 4
Cylinder size 15 in × 26 in (380 mm × 660 mm)
Performance figures
Tractive effort 27,800 lbf (124 kN) (at 85% boiler pressure)
Career
Operator(s) GWR
Class 111
Power class Special
Number in class 1
Number(s) 111
Official name The Great Bear, renamed Viscount Churchill in 1924
Axle load class Red
Locale Paddington - Bristol
First run 4 February 1908
Retired July 1953
Disposition Rebuilt to GWR 4073 Class

The Great Bear, number 111, was a locomotive of the Great Western Railway. It was the first 4-6-2 (Pacific) locomotive used on a railway in Great Britain,[1] and the only one of that type ever built by the GWR. The Great Bear was built in 1908 to satisfy demands from the directors for the largest locomotive in Britain, and much was made of the locomotive by the GWR's publicity department. She was considered the company's flagship locomotive until the building of 4073 Caerphilly Castle in 1923.[1]

Performance

In service The Great Bear was not a significant improvement on existing classes, and had a highly restrictive route availability; its 20t 9cwt axle load limiting it to the Paddington to Bristol main line, although it was once recorded to have travelled as far west as Newton Abbot.[1] Its regular engine driver was Thomas Blackall, originally from Aston Tirrold, Oxfordshire.

Rebuilding

The GWR did not pursue the Pacific wheel arrangement, and subsequently stayed with the 4-6-0 arrangement which later became synonymous with the company. Churchward's successor Charles Collett is reputed not to have liked the loco, and is alleged to have prepared the report presented to the GWR's locomotive committee recommending its rebuilding.[1] No.111 was rebuilt in 1924, as a 4-6-0 in the Castle Class, and given the name Viscount Churchill although it retained its number. No. 111 was withdrawn in July 1953.

Churchward's reaction

Churchward was disappointed to hear of The Great Bear's destruction, and upon hearing of Nigel Gresley's plans to construct a pacific for the Great Northern Railway, is said to have replied: "What did that young man want to build it for? We could have sold him ours!"

Route availability

The GWR route availability colour code of The Great Bear was Red, and although the tractive effort of 27,800 lbf (124,000 N) fell within the range for power classification "D", its GWR power classification was "Special" (denoted by a black + on the red route availability disc).[2]

References

  1. ↑ 1.0 1.1 1.2 1.3 Foster, Richard (Nov 2007). "The man and his machines: The Great Bear". Steam Railway (Peterborough: EMAP Ltd) (342): p69.
  2. ↑ 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. p. H13. ISBN 0-901115-19-3.

External links