South African Class 6Z 2-6-4

Specifications
Specifications
Configuration:;
• Whyte	2-6-4 (Adriatic)
• UIC	1'C2'n2t
Driver	3rd coupled axle
Gauge	3 ft 6 in (1,067 mm) Cape gauge
Leading dia.	28+1⁄2 in (724 mm)
Coupled dia.	54 in (1,372 mm)
Trailing dia.	28+1⁄2 in (724 mm)
Tender wheels	37 in (940 mm)
Wheelbase	45 ft 9+1⁄8 in (13,948 mm)
• Axle spacing; (Asymmetrical)	1-2: 5 ft 1 in (1,549 mm); 2-3: 4 ft 9 in (1,448 mm)
• Engine	28 ft (8,534 mm)
• Coupled	9 ft 10 in (2,997 mm)
• Trailing	5 ft (1,524 mm)
• Tender	10 ft (3,048 mm)
Length:;
• Over couplers	55 ft 7+1⁄4 in (16,948 mm)
Height	12 ft 10 in (3,912 mm)
Frame type	Bar
Axle load	12 LT 17 cwt (13,060 kg)
• Leading	5 LT 19 cwt (6,045 kg)
• 1st coupled	12 LT 17 cwt (13,060 kg)
• 2nd coupled	11 LT 3 cwt (11,330 kg)
• 3rd coupled	12 LT 1 cwt (12,240 kg)
• Trailing	12 LT 8 cwt (12,600 kg)
• Tender axle	Axle 1: 10 LT 8 cwt (10,570 kg); Axle 2: 10 LT 15 cwt (10,920 kg); Axle 3: 10 LT 17 cwt (11,020 kg)
Adhesive weight	36 LT 1 cwt (36,630 kg)
Loco weight	54 LT 8 cwt (55,270 kg)
Tender weight	32 LT (32,510 kg)
Total weight	86 LT 8 cwt (87,790 kg)
Tender type	YE (3-axle)
Fuel type	Coal
Fuel capacity	5 LT 10 cwt (5.6 t)
Water cap.	2,825 imp gal (12,800 L)
Firebox:
• Type	Round-top
• Grate area	25.5 sq ft (2.37 m2)
Boiler:;
• Pitch	6 ft 10 in (2,083 mm)
• Diameter	4 ft 7 in (1,397 mm)
• Tube plates	13 ft 10+7⁄8 in (4,239 mm)
• Small tubes	188: 2 in (51 mm)
Boiler pressure	170 psi (1,172 kPa)
Safety valve	Ramsbottom
Heating surface:
• Firebox	96 sq ft (8.9 m2)
• Tubes	1,366 sq ft (126.9 m2)
• Total surface	1,462 sq ft (135.8 m2)
Cylinders	Two
Cylinder size	18 in (457 mm) bore; 26 in (660 mm) stroke
Valve gear	Stephenson
Couplers	Johnston link-and-pin

Type and origin
Type and origin
Power type	Steam
Designer	Cape Government Railways; (H.M. Beatty)
Builder	Neilson, Reid and Company
Serial number	5867–5870, 6075–6078
Model	CGR 6th Class 2-6-4
Build date	1901
Total produced	8
Rebuilder	Cape Government Railways
Rebuild date	1902
Number rebuilt	4 from 2-6-2 (Prairie)

CGR 6th Class 2-6-4
South African Class 6Z 2-6-4
CGR 6th Class 2-6-4; South African Class 6Z 2-6-4
	CGR 6th Class 2-6-2 Prairie as built, before modification to 2-6-4 Adriatic
Power type
Type and origin
Power type	Steam
Designer	Cape Government Railways; (H.M. Beatty)
Builder	Neilson, Reid and Company
Serial number	5867–5870, 6075–6078
Model	CGR 6th Class 2-6-4
Build date	1901
Total produced	8
Rebuilder	Cape Government Railways
Rebuild date	1902
Number rebuilt	4 from 2-6-2 (Prairie)
Configuration:;
Specifications
Configuration:;
• Whyte	2-6-4 (Adriatic)
• UIC	1'C2'n2t
Driver	3rd coupled axle
Gauge	3 ft 6 in (1,067 mm) Cape gauge
Leading dia.	28+1⁄2 in (724 mm)
Coupled dia.	54 in (1,372 mm)
Trailing dia.	28+1⁄2 in (724 mm)
Tender wheels	37 in (940 mm)
Wheelbase	45 ft 9+1⁄8 in (13,948 mm)
• Axle spacing; (Asymmetrical)	1-2: 5 ft 1 in (1,549 mm); 2-3: 4 ft 9 in (1,448 mm)
• Engine	28 ft (8,534 mm)
• Coupled	9 ft 10 in (2,997 mm)
• Trailing	5 ft (1,524 mm)
• Tender	10 ft (3,048 mm)
Length:;
• Over couplers	55 ft 7+1⁄4 in (16,948 mm)
Height	12 ft 10 in (3,912 mm)
Frame type	Bar
Axle load	12 LT 17 cwt (13,060 kg)
• Leading	5 LT 19 cwt (6,045 kg)
• 1st coupled	12 LT 17 cwt (13,060 kg)
• 2nd coupled	11 LT 3 cwt (11,330 kg)
• 3rd coupled	12 LT 1 cwt (12,240 kg)
• Trailing	12 LT 8 cwt (12,600 kg)
• Tender axle	Axle 1: 10 LT 8 cwt (10,570 kg); Axle 2: 10 LT 15 cwt (10,920 kg); Axle 3: 10 LT 17 cwt (11,020 kg)
Adhesive weight	36 LT 1 cwt (36,630 kg)
Loco weight	54 LT 8 cwt (55,270 kg)
Tender weight	32 LT (32,510 kg)
Total weight	86 LT 8 cwt (87,790 kg)
Tender type	YE (3-axle)
Fuel type	Coal
Fuel capacity	5 LT 10 cwt (5.6 t)
Water cap.	2,825 imp gal (12,800 L)
Firebox:
• Type	Round-top
• Grate area	25.5 sq ft (2.37 m2)
Boiler:;
• Pitch	6 ft 10 in (2,083 mm)
• Diameter	4 ft 7 in (1,397 mm)
• Tube plates	13 ft 10+7⁄8 in (4,239 mm)
• Small tubes	188: 2 in (51 mm)
Boiler pressure	170 psi (1,172 kPa)
Safety valve	Ramsbottom
Heating surface:
• Firebox	96 sq ft (8.9 m2)
• Tubes	1,366 sq ft (126.9 m2)
• Total surface	1,462 sq ft (135.8 m2)
Cylinders	Two
Cylinder size	18 in (457 mm) bore; 26 in (660 mm) stroke
Valve gear	Stephenson
Couplers	Johnston link-and-pin
Tractive effort
Performance figures
Tractive effort	19,890 lbf (88.5 kN) @ 75%
Operators
Career
Operators	Cape Government Railways; South African Railways
Class	CGR 6th Class 2-6-4; SAR Class 6Z
Number in class	8
Numbers	CGR 270–277, SAR 713–720
Delivered	1901–1902
First run	1901
Withdrawn	1934

The South African Railways Class 6Z 2-6-4 of 1901 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

In 1901, the Cape Government Railways placed four 6th Class steam locomotives with a 2-6-2 Prairie type wheel arrangement in service. The engines were soon modified to a 2-6-4 Adriatic type wheel arrangement. In 1902, another four locomotives were placed in service, built with the 2-6-4 wheel arrangement. These latter four were the first tender locomotives in the world to be built with this wheel arrangement. In 1912, when they were assimilated into the South African Railways, these eight locomotives were renumbered and designated Class 6Z.