South African Class 6 4-6-0

CGR 6th Class 4-6-0 1893 OVGS 6th Class L 4-6-0 CSAR Class 6-L1 4-6-0 South African Class 6 4-6-0
No. 439, Capital Park, 24 September 2000
Type and origin ♠ Original locomotive, as built ♥ Locomotive rebuilt with Belpaire firebox Power type Steam Designer Cape Government Railways (H.M. Beatty) Builder Dübs and Company Serial number 3050-3073, 3087-3102 Model CGR 6th Build date 1893-1894 Total produced 40
Specifications Configuration: ​  • Whyte 4-6-0 (Tenwheeler)  • UIC 2'Cn2 Driver 2nd 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) Tender wheels 37 in (940 mm) Wheelbase 41 ft 9 1⁄8 in (12,729 mm)  • Engine 20 ft 3 1⁄4 in (6,179 mm)  • Leading 5 ft 4 1⁄2 in (1,638 mm)  • Coupled 11 ft (3,353 mm)  • Tender 10 ft (3,048 mm) Wheel spacing (Asymmetrical) 1-2: 4 ft 9 in (1,448 mm) 2-3: 6 ft 3 in (1,905 mm) Length: ​  • Over couplers ♠ 50 ft 8 1⁄2 in (15,456 mm) ♥ 51 ft 7 1⁄4 in (15,729 mm) Height ♠ 12 ft 8 in (3,861 mm) ♥ 12 ft 10 3⁄4 in (3,931 mm) Frame type Plate Axle load ♠ 11 LT 19 cwt 2 qtr (12,170 kg) ♥ 13 LT 8 cwt (13,620 kg)  • Leading ♠ 9 LT 15 cwt 2 qtr (9,932 kg) ♥ 10 LT 17 cwt 2 qtr (11,050 kg)  • Coupled ♥ 13 LT 8 cwt (13,620 kg)  • 1st coupled ♠ 10 LT 17 cwt 2 qtr (11,050 kg)  • 2nd coupled ♠ 11 LT 19 cwt 2 qtr (12,170 kg)  • 3rd coupled ♠ 11 LT 18 cwt 2 qtr (12,120 kg)  • Tender axle 9 LT 17 cwt (10,010 kg) average Adhesive weight ♠ 34 LT 15 cwt 2 qtr (35,330 kg) ♥ 40 LT 1 cwt (40,690 kg) Loco weight ♠ 44 LT 11 cwt (45,260 kg) ♥ 51 LT 1 cwt 2 qtr (51,890 kg) Tender weight 29 LT 11 cwt (30,020 kg) Total weight ♠ 74 LT 2 cwt (75,290 kg) ♥ 80 LT 12 cwt 2 qtr (81,920 kg) Tender type YB (3-axle) YB, YC, YE, YE1 permitted Fuel type Coal Fuel capacity 5 LT 10 cwt (5.6 t) Water cap 2,370 imp gal (10,800 l) Firebox type Round-top, Belpaire  • Firegrate area ♠ 16.8 sq ft (1.56 m2) ♥ 16.6 sq ft (1.54 m2) Boiler: ​  • Pitch ♠ 6 ft 6 in (1,981 mm) ♥ 7 ft (2,134 mm)  • Diameter ♠ 4 ft 2 in (1,270 mm) ♥ 4 ft 9 in (1,448 mm)  • Tube plates ♠ 11 ft 2 1⁄8 in (3,407 mm) ♥ 11 ft 2 1⁄8 in (3,407 mm)  • Small tubes ♠ 185: 1 3⁄4 in (44 mm) ♥ 220: 2 in (51 mm) Boiler pressure ♠ 160 psi (1,103 kPa) ♥ 180 psi (1,241 kPa) Safety valve Ramsbottom Heating surface ♠ 1,041 sq ft (96.7 m2) ♥ 1,398.5 sq ft (129.92 m2)  • Tubes ♠ 946 sq ft (87.9 m2) ♥ 1,287.5 sq ft (119.61 m2)  • Firebox ♠ 95 sq ft (8.8 m2) ♥ 111 sq ft (10.3 m2) Cylinders Two Cylinder size 17 in (432 mm) bore 26 in (660 mm) stroke Valve gear Stephenson Valve type Slide Couplers Johnston link-and-pin AAR knuckle (1930s)
Performance figures Tractive effort ♠ 16,690 lbf (74.2 kN) @ 75% ♥ 18,780 lbf (83.5 kN) @ 75%
Career Operators Cape Government Railways OVGS Imperial Military Railways Central South African Railways South African Railways Sudan Railways Class CGR & OVGS 6th Class, CSAR Class 6-L1, SAR Class 6 Number in class 40 Numbers CGR 139-160, 353-370 OVGS 60-69 CSAR 336-345 SAR 401-440 Delivered 1893-1894 First run 1893 Withdrawn 1973

The South African Railways Class 6 4-6-0 of 1893 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

In 1893 and 1894, the Cape Government Railways placed forty 6th Class steam locomotives with a 4-6-0 wheel arrangement in service, twenty-two on its Western System and eighteen on its Midland System. Ten of them were sold to the Oranje-Vrijstaat Gouwerment-Spoorwegen in 1897. At the end of the Second Boer War in 1902, these ten became the Class 6-L1 on the Central South African Railways. In 1912, all forty locomotives were renumbered and designated Class 6 when they were assimilated into the South African Railways.

To meet the increasing weight of fast passenger trains on the Western and Midland Systems, the 6th Class 4-6-0 passenger steam locomotive was conceived and designed at the Salt River works of the Cape Government Railways (CGR) at the same time as the 7th Class, both according to the specifications of Michael Stephens, then Chief Locomotive Superintendent of the CGR, and under the supervision of H.M. Beatty, then Locomotive Superintendent of the Western System. Whereas the 7th Class was conceived primarily as a goods locomotive, the 6th Class was intended to be its fast passenger service counterpart.

The 6th Class introduced the Type YB tender, a three-axle tender with a coal capacity of 5 long tons 10 hundredweight (5.6 tonnes) and a water capacity of 2,370 imperial gallons (10,800 litres). The engines and tenders were built by Dübs and Company and were delivered in 1893 and 1894, numbered in the ranges from 139 to 160 for the Western System and 353 to 370 for the Midland System.

The boiler had an operating pressure of 160 pounds per square inch (1,103 kilopascals) and was equipped with Ramsbottom safety valves, while the firebox had a brick arch. The seats of the driver and stoker were mounted on poles which allowed them to be swung around to outside the cab.

The 6th Class was to become one of the most useful classes of locomotives to see service in South Africa. They were fast, easy to handle, good steamers and had an exceptionally low maintenance cost, with long periods between major overhauls.