South African Class 6B 4-6-0

CGR 6th Class 4-6-0 1897 South African Class 6B 4-6-0
CGR 6th Class no. 206, SAR Class 6B no. 494, c. 1930
Type and origin ♠ Original locomotive, as built ♥ Locomotive equipped with Belpaire firebox Power type Steam Designer Cape Government Railways (H.M. Beatty) Builder Dübs and Company Neilson and Company Neilson, Reid and Company Serial number Dübs 3467-3468, 3472-3474 Neilson 5120-5125, 5128-5129, 5131-5159 Neilson, Reid 5273-5279, 5319-5324 Model CGR 6th Class Build date 1897-1898 Total produced 55
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 33 1⁄2 in (851 mm) as built 34 in (864 mm) retyred Wheelbase 46 ft 6 1⁄4 in (14,180 mm)  • Engine 20 ft 3 3⁄4 in (6,191 mm)  • Leading 5 ft 5 1⁄2 in (1,664 mm)  • Coupled 11 ft (3,353 mm)  • Tender 16 ft 1 in (4,902 mm)  • Tender bogie 4 ft 7 in (1,397 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 53 ft 9 3⁄4 in (16,402 mm) Height ♠ 12 ft 10 in (3,912 mm) ♥ 12 ft 10 3⁄8 in (3,921 mm) Frame type Plate Axle load ♠ 12 LT 3 cwt (12,340 kg) ♥ 13 LT 8 cwt (13,620 kg)  • Leading ♠ 11 LT 17 cwt (12,040 kg) ♥ 10 LT 17 cwt 2 qtr (11,050 kg)  • Coupled ♥ 13 LT 8 cwt (13,620 kg)  • 1st coupled ♠ 10 LT 7 cwt (10,520 kg)  • 2nd coupled ♠ 11 LT 18 cwt (12,090 kg)  • 3rd coupled ♠ 12 LT 3 cwt (12,340 kg)  • Tender bogie Bogie 1: 16 LT 12 cwt (16,870 kg) Bogie 2: 17 LT 13 cwt (17,930 kg)  • Tender axle 8 LT 16 cwt 2 qtr (8,967 kg) Adhesive weight ♠ 34 LT 8 cwt (34,950 kg) ♥ 40 LT 4 cwt (40,850 kg) Loco weight ♠ 46 LT 5 cwt (46,990 kg) ♥ 51 LT 1 cwt 2 qtr (51,890 kg) Tender weight 34 LT 5 cwt (34,800 kg) Total weight ♠ 80 LT 10 cwt (81,790 kg) ♥ 85 LT 6 cwt 2 qtr (86,690 kg) Tender type XC1 (2-axle bogies) XC, XC1, XD, XE, XE1, XF, XF1, XF2, XJ, XM, XM1, XM2, XM3, XM4 permitted Fuel type Coal Fuel capacity 5 LT 10 cwt (5.6 t) Water cap 2,600 imp gal (11,820 l) Firebox type ♠ Round-top - ♥ Belpaire  • Firegrate area ♠ 16.625 sq ft (1.5445 m2) ♥ 16.6 sq ft (1.54 m2) Boiler: ​  • Pitch ♠ 6 ft 8 in (2,032 mm) ♥ 7 ft (2,134 mm)  • Diameter ♠ 4 ft 4 in (1,321 mm) ♥ 4 ft 9 in (1,448 mm)  • Tube plates ♠♥ 11 ft 2 1⁄8 in (3,407 mm)  • Small tubes ♠ 185: 1 7⁄8 in (48 mm) ♥ 220: 2 in (51 mm) Boiler pressure ♠ 160 psi (1,103 kPa) ♥ 180 psi (1,241 kPa) Safety valve Ramsbottom Heating surface ♠ 1,116 sq ft (103.7 m2) ♥ 1,398.5 sq ft (129.92 m2)  • Tubes ♠ 1,015 sq ft (94.3 m2) ♥ 1,287.5 sq ft (119.61 m2)  • Firebox ♠ 101 sq ft (9.4 m2) ♥ 111 sq ft (10.3 m2) Cylinders Two Cylinder size 17 in (432 mm) bore 26 in (660 mm) stroke Valve gear Stephenson 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 Imperial Military Railways Benguela Railway South African Railways Sudan Railways Class CGR 6th Class, SAR Class 6B Number in class 51 Numbers CGR 202-233, 577-584, 587-593, 595-600, 663-664 IMR C502, C504-C508, C512 Benguela 22-25 SAR 490-540 Sudan M711-M712 Delivered 1897-1898 First run 1897 Withdrawn 1973

The South African Railways Class 6B 4-6-0 of 1897 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

In 1897 and 1898, the Cape Government Railways placed a third batch of 55 6th Class 4-6-0 steam locomotives in service, 32 on its Western System, 21 on its Midland System and two on its Eastern System. During the Second Boer War, seven were transferred to the Imperial Military Railways on loan, and in 1907 four were sold to the Benguela Railway in Angola. In 1912, when the remaining 51 locomotives were assimilated into the South African Railways, they were renumbered and designated Class 6B. During the Second World War, two of them were sold to the Sudan Railways.

The original 6th Class 4-6-0 passenger steam locomotive was 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 Cape Western System.

The 55 locomotives in the third group were built between 1897 and 1898 by Dübs and Company and Neilson and Company. While they were being built, in 1898, the firm of Neilson and Company changed its name to Neilson, Reid and Company. Five of these locomotives were built by Dübs and of the remaining fifty, 37 were delivered as built by Neilson and the last thirteen as built by Neilson, Reid.

All five Dübs-built locomotives, numbered in the range from 577 to 581, and the thirteen Neilson, Reid-builts, numbered in the ranges from 587 to 593 and 595 to 600, went to the Midland System. Of the 37 Neilson-builts, 32 went to the Western System, numbered in the range from 202 to 233, three to the Midland System, numbered in the range from 582 to 584, and two to the Eastern System, numbered 663 and 664. Their respective works numbers and CGR engine numbers are tabled below.