South African Class GB 2-6-2+2-6-2

Specifications
Specifications
Configuration:;
• Whyte	2-6-2+2-6-2 (Double Prairie)
• UIC	1’C1'+1’C1’h4
Driver	3rd & 4th coupled axles
Gauge	3 ft 6 in (1,067 mm) Cape gauge
Leading dia.	28+1⁄2 in (724 mm)
Coupled dia.	42+3⁄4 in (1,086 mm)
Trailing dia.	28+1⁄2 in (724 mm)
Wheelbase	53 ft (16,154 mm)
• Engine	♠ 17 ft 5 in (5,309 mm) each; ♥ 17 ft 5+1⁄4 in (5,315 mm) each
• Coupled	8 ft (2,438 mm) each
Pivot centres	26 ft 6 in (8,077 mm)
Length:;
• Over couplers	59 ft 6+3⁄4 in (18,155 mm)
Height	12 ft 3 in (3,734 mm)
Frame type	Plate
Axle load	♠ 7 LT 14 cwt (7,824 kg); ♥ 8 LT (8,128 kg)
• Leading	♠ 6 LT 19 cwt (7,062 kg) front; 7 LT 1 cwt (7,163 kg) rear; ♥ 7 LT 16 cwt (7,925 kg) front; 7 LT 12 cwt (7,722 kg) rear
• 1st coupled	♠ 7 LT 10 cwt (7,620 kg); ♥ 7 LT 16 cwt (7,925 kg)
• 2nd coupled	♠ 7 LT 9 cwt (7,570 kg); ♥ 7 LT 16 cwt (7,925 kg)
• 3rd coupled	♠ 7 LT 9 cwt (7,570 kg); ♥ 7 LT 16 cwt (7,925 kg)
• 4th coupled	♠ 7 LT 13 cwt (7,773 kg); ♥ 8 LT (8,128 kg)
• 5th coupled	♠ 7 LT 14 cwt (7,824 kg); ♥ 8 LT (8,128 kg)
• 6th coupled	♠ 7 LT 14 cwt (7,824 kg); ♥ 8 LT (8,128 kg)
• Trailing	♠ 6 LT (6,096 kg) front; 6 LT 4 cwt (6,299 kg) rear; ♥ 6 LT 14 cwt (6,808 kg) front; 7 LT 1 cwt (7,163 kg) rear
Adhesive weight	♠ 45 LT 9 cwt (46,180 kg); ♥ 47 LT 8 cwt (48,160 kg)
Loco weight	♠ 71 LT 13 cwt (72,800 kg); ♥ 76 LT 1 cwt (77,270 kg)
Fuel type	Coal
Fuel capacity	5 LT (5.1 t)
Water cap.	♠ 1,450 imp gal (6,590 L) front; 550 imp gal (2,500 L) rear; ♥ 1,520 imp gal (6,910 L) front; 800 imp gal (3,640 L) rear
Firebox:
• Type	Belpaire
• Grate area	♠♥ 23 sq ft (2.1 m2)
Boiler:;
• Pitch	7 ft (2,134 mm)
• Diameter	4 ft 5+7⁄8 in (1,368 mm)
• Tube plates	♠ 10 ft 4 in (3,150 mm); ♥ 10 ft 4+3⁄8 in (3,159 mm)
• Small tubes	♠ 128: 1+7⁄8 in (48 mm); ♥ 119: 1+7⁄8 in (48 mm)
• Large tubes	♠ 21: 5+1⁄4 in (133 mm); ♥ 21: 5+1⁄2 in (140 mm)
Boiler pressure	180 psi (1,241 kPa)
Safety valve	Ramsbottom
Heating surface:
• Firebox	♠ 105 sq ft (9.8 m2); ♥ 104 sq ft (9.7 m2)
• Tubes	♠ 944 sq ft (87.7 m2); ♥ 914 sq ft (84.9 m2)
• Total surface	♠ 1,049 sq ft (97.5 m2); ♥ 1,018 sq ft (94.6 m2)
Superheater:;
• Heating area	♠ 174 sq ft (16.2 m2); ♥ 203 sq ft (18.9 m2)
Cylinders	Four
Cylinder size	12 in (305 mm) bore; 20 in (508 mm) stroke
Valve gear	Walschaerts
Valve type	Piston
Couplers	Johnston link-and-pin; AAR knuckle (1930s)

Type and origin
Type and origin
	♠ Locomotive no. 2166; ♥ Locomotive numbers 2160-2165
Power type	Steam
Designer	Beyer, Peacock & Company
Builder	Beyer, Peacock & Company
Serial number	5942, 6181-6186
Model	Class GB
Build date	1921, 1924
Total produced	7

South African Class GB 2-6-2+2-6-2
South African Class GB 2-6-2+2-6-2
	Class GB no. 2166, Voorbaai, 4 September 1997
Power type
Type and origin
	♠ Locomotive no. 2166; ♥ Locomotive numbers 2160-2165
Power type	Steam
Designer	Beyer, Peacock & Company
Builder	Beyer, Peacock & Company
Serial number	5942, 6181-6186
Model	Class GB
Build date	1921, 1924
Total produced	7
Configuration:;
Specifications
Configuration:;
• Whyte	2-6-2+2-6-2 (Double Prairie)
• UIC	1’C1'+1’C1’h4
Driver	3rd & 4th coupled axles
Gauge	3 ft 6 in (1,067 mm) Cape gauge
Leading dia.	28+1⁄2 in (724 mm)
Coupled dia.	42+3⁄4 in (1,086 mm)
Trailing dia.	28+1⁄2 in (724 mm)
Wheelbase	53 ft (16,154 mm)
• Engine	♠ 17 ft 5 in (5,309 mm) each; ♥ 17 ft 5+1⁄4 in (5,315 mm) each
• Coupled	8 ft (2,438 mm) each
Pivot centres	26 ft 6 in (8,077 mm)
Length:;
• Over couplers	59 ft 6+3⁄4 in (18,155 mm)
Height	12 ft 3 in (3,734 mm)
Frame type	Plate
Axle load	♠ 7 LT 14 cwt (7,824 kg); ♥ 8 LT (8,128 kg)
• Leading	♠ 6 LT 19 cwt (7,062 kg) front; 7 LT 1 cwt (7,163 kg) rear; ♥ 7 LT 16 cwt (7,925 kg) front; 7 LT 12 cwt (7,722 kg) rear
• 1st coupled	♠ 7 LT 10 cwt (7,620 kg); ♥ 7 LT 16 cwt (7,925 kg)
• 2nd coupled	♠ 7 LT 9 cwt (7,570 kg); ♥ 7 LT 16 cwt (7,925 kg)
• 3rd coupled	♠ 7 LT 9 cwt (7,570 kg); ♥ 7 LT 16 cwt (7,925 kg)
• 4th coupled	♠ 7 LT 13 cwt (7,773 kg); ♥ 8 LT (8,128 kg)
• 5th coupled	♠ 7 LT 14 cwt (7,824 kg); ♥ 8 LT (8,128 kg)
• 6th coupled	♠ 7 LT 14 cwt (7,824 kg); ♥ 8 LT (8,128 kg)
• Trailing	♠ 6 LT (6,096 kg) front; 6 LT 4 cwt (6,299 kg) rear; ♥ 6 LT 14 cwt (6,808 kg) front; 7 LT 1 cwt (7,163 kg) rear
Adhesive weight	♠ 45 LT 9 cwt (46,180 kg); ♥ 47 LT 8 cwt (48,160 kg)
Loco weight	♠ 71 LT 13 cwt (72,800 kg); ♥ 76 LT 1 cwt (77,270 kg)
Fuel type	Coal
Fuel capacity	5 LT (5.1 t)
Water cap.	♠ 1,450 imp gal (6,590 L) front; 550 imp gal (2,500 L) rear; ♥ 1,520 imp gal (6,910 L) front; 800 imp gal (3,640 L) rear
Firebox:
• Type	Belpaire
• Grate area	♠♥ 23 sq ft (2.1 m2)
Boiler:;
• Pitch	7 ft (2,134 mm)
• Diameter	4 ft 5+7⁄8 in (1,368 mm)
• Tube plates	♠ 10 ft 4 in (3,150 mm); ♥ 10 ft 4+3⁄8 in (3,159 mm)
• Small tubes	♠ 128: 1+7⁄8 in (48 mm); ♥ 119: 1+7⁄8 in (48 mm)
• Large tubes	♠ 21: 5+1⁄4 in (133 mm); ♥ 21: 5+1⁄2 in (140 mm)
Boiler pressure	180 psi (1,241 kPa)
Safety valve	Ramsbottom
Heating surface:
• Firebox	♠ 105 sq ft (9.8 m2); ♥ 104 sq ft (9.7 m2)
• Tubes	♠ 944 sq ft (87.7 m2); ♥ 914 sq ft (84.9 m2)
• Total surface	♠ 1,049 sq ft (97.5 m2); ♥ 1,018 sq ft (94.6 m2)
Superheater:;
• Heating area	♠ 174 sq ft (16.2 m2); ♥ 203 sq ft (18.9 m2)
Cylinders	Four
Cylinder size	12 in (305 mm) bore; 20 in (508 mm) stroke
Valve gear	Walschaerts
Valve type	Piston
Couplers	Johnston link-and-pin; AAR knuckle (1930s)
Tractive effort
Performance figures
Tractive effort	18,190 lbf (80.9 kN) @ 75%
Operators
Career
Operators	South African Railways
Class	Class GB
Number in class	7
Numbers	1650 renumbered 2166, 2160-2165
Delivered	1921, 1924
First run	1921
Withdrawn	1967

The South African Railways Class GB 2-6-2+2-6-2 of 1921 was an articulated steam locomotive.

In June 1921, the South African Railways placed a single experimental Class GB Garratt articulated steam locomotive with a 2-6-2+2-6-2 Double Prairie type wheel arrangement in service. Six more of these locomotives entered service in 1924.