LNER Thompson Class A1/1

Specifications
Specifications
Configuration:;
• Whyte	4-6-2
• UIC	2'C1' h3
Gauge	4 ft 8+1⁄2 in (1,435 mm)
Leading dia.	3 ft 2 in (0.965 m)
Coupled dia.	6 ft 8 in (2.032 m)
Trailing dia.	3 ft 8 in (1.118 m)
Wheelbase	63 ft 6.625 in (19.37 m)
• Engine	38 ft 5 in (11.71 m)
• Coupled	14 ft 6 in (4.42 m)
Length	73 ft 2 in (22.301 m)
Loco weight	101.5 long tons (103.1 t; 113.7 short tons)
Tender weight	60.7 long tons (61.7 t; 68.0 short tons)
Total weight	159.5 long tons (162.1 t; 178.6 short tons)
Fuel capacity	9 long tons (9.144 t)
Water cap.	5,000 imp gal (22,730.45 L; 6,004.75 US gal)
Firebox:
• Grate area	41.5 sq ft (3.86 m2)
Boiler	6 ft 5 in (1.96 m) max diameter
Boiler pressure	250 psi (1.72 MPa)
Heating surface:
• Firebox	231.2 sq ft (21.48 m2)
• Tubes	1,281.4 sq ft (119.05 m2)
• Flues	1,063.7 sq ft (98.82 m2)
• Total surface	2,576.3 sq ft (239.35 m2)
Superheater:;
• Heating area	748.9 sq ft (69.58 m2)
Cylinders	Three
Cylinder size	19 in × 26 in (483 mm × 660 mm)
Valve gear	Walschaerts
Valve type	Piston valves

Type and origin
Type and origin
Power type	Steam
Designer	Edward Thompson
Build date	1922
Rebuilder	Doncaster Works
Rebuild date	1945
Number rebuilt	1

LNER Thompson Class A1/1
LNER Thompson Class A1/1
	The single Thompson A1/1 Pacific 60113 Great Northern near Peterborough in 1959
Power type
Type and origin
Power type	Steam
Designer	Edward Thompson
Build date	1922
Rebuilder	Doncaster Works
Rebuild date	1945
Number rebuilt	1
Configuration:;
Specifications
Configuration:;
• Whyte	4-6-2
• UIC	2'C1' h3
Gauge	4 ft 8+1⁄2 in (1,435 mm)
Leading dia.	3 ft 2 in (0.965 m)
Coupled dia.	6 ft 8 in (2.032 m)
Trailing dia.	3 ft 8 in (1.118 m)
Wheelbase	63 ft 6.625 in (19.37 m)
• Engine	38 ft 5 in (11.71 m)
• Coupled	14 ft 6 in (4.42 m)
Length	73 ft 2 in (22.301 m)
Loco weight	101.5 long tons (103.1 t; 113.7 short tons)
Tender weight	60.7 long tons (61.7 t; 68.0 short tons)
Total weight	159.5 long tons (162.1 t; 178.6 short tons)
Fuel capacity	9 long tons (9.144 t)
Water cap.	5,000 imp gal (22,730.45 L; 6,004.75 US gal)
Firebox:
• Grate area	41.5 sq ft (3.86 m2)
Boiler	6 ft 5 in (1.96 m) max diameter
Boiler pressure	250 psi (1.72 MPa)
Heating surface:
• Firebox	231.2 sq ft (21.48 m2)
• Tubes	1,281.4 sq ft (119.05 m2)
• Flues	1,063.7 sq ft (98.82 m2)
• Total surface	2,576.3 sq ft (239.35 m2)
Superheater:;
• Heating area	748.9 sq ft (69.58 m2)
Cylinders	Three
Cylinder size	19 in × 26 in (483 mm × 660 mm)
Valve gear	Walschaerts
Valve type	Piston valves
Tractive effort
Performance figures
Tractive effort	37,400 lbf (166.36 kN)
Operators
Career
Operators	London and North Eastern Railway ; British Railways
Class	LNER: A1/1
Power class	BR: 8P6F
Numbers	4470/113/60113
Retired	1962
Disposition	Scrapped

The LNER Class A1/1 consisted of a single 4-6-2 "Pacific" express passenger locomotive rebuilt in 1945 from an A1 class locomotive, by Edward Thompson. It was intended as the prototype of a new design of pacific locomotives improving the A4 design of Thompson's predecessor Sir Nigel Gresley. No further examples were built due to Thompson's retirement in 1946.