South African Class 7A 4-8-0

CGR 7th Class 4-8-0 1896 Sudan Railways Dongola Class South African Class 7A & 7AS 4-8-0
Ex CGR (Eastern System) 7th Class no. 726 SAR Class 7A no. 1009 with modified Type ZC tender
Type and origin ♠ - Original locomotive, as built ♥ - Locomotive equipped with superheating Power type Steam Designer Cape Government Railways (H.M. Beatty) Builder Sharp, Stewart and Company Dübs and Company Neilson and Company Serial number Sharp, Stewart 4145-4152, 4363 Dübs 3355-3362, 3641-3652, 3976 Neilson 4920-4931, 5160-5163, 5232-5234, 5280-5281, 5345-5347 Model CGR 7th Class Build date 1896-1898, 1901 Total produced 46
Specifications Configuration: ​  • Whyte 4-8-0 (Mastodon)  • UIC ♠ 2'Dn2 - ♥ 2'Dh2 Driver 2nd coupled axle 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) Tender wheels 33 1⁄2 in (851 mm) as built 34 in (864 mm) retyred Wheelbase 46 ft 2 in (14,072 mm)  • Engine 21 ft 3 1⁄2 in (6,490 mm)  • Leading 5 ft 3 in (1,600 mm)  • Coupled 12 ft (3,658 mm)  • Tender 16 ft 1 in (4,902 mm)  • Tender bogie 4 ft 7 in (1,397 mm) Length: ​  • Over couplers 53 ft 5 1⁄4 in (16,288 mm) Height 12 ft 10 in (3,912 mm) Frame type Plate Axle load ♠ 9 LT (9,144 kg) ♥ 9 LT 14 cwt (9,856 kg)  • Leading ♠ 10 LT 14 cwt (10,870 kg) ♥ 11 LT 2 cwt (11,280 kg)  • 1st coupled ♠ 9 LT (9,144 kg) ♥ 9 LT 8 cwt (9,551 kg)  • 2nd coupled ♠ 9 LT (9,144 kg) ♥ 9 LT 14 cwt (9,856 kg)  • 3rd coupled ♠ 8 LT 18 cwt (9,043 kg) ♥ 9 LT 10 cwt (9,652 kg)  • 4th coupled ♠ 8 LT 18 cwt (9,043 kg) ♥ 9 LT 8 cwt (9,551 kg)  • Tender axle 8 LT 10 cwt 2 qtr (8,662 kg) av. Adhesive weight ♠ 35 LT 16 cwt (36,370 kg) ♥ 37 LT 16 cwt (38,410 kg) Loco weight ♠ 46 LT 10 cwt (47,250 kg) ♥ 49 LT 2 cwt (49,890 kg) Tender weight 34 LT 2 cwt (34,650 kg) Total weight ♠ 80 LT 12 cwt (81,890 kg) ♥ 83 LT 4 cwt (84,540 kg) Tender type ZC (2-axle bogies) ZA, ZB, ZC, ZE permitted Fuel type Coal Fuel capacity 5 LT 10 cwt (5.6 t) Water cap 2,600 imp gal (11,800 l) Firebox type Round-top  • Firegrate area ♠ 17.5 sq ft (1.63 m2) ♥ 18 sq ft (1.7 m2) Boiler: ​  • Pitch ♠ 6 ft 8 in (2,032 mm) pitch ♥ 6 ft 10 in (2,083 mm)  • Diameter ♠ 4 ft 4 in (1,321 mm) ♥ 4 ft 6 in (1,372 mm)  • Tube plates ♠♥ 10 ft 9 in (3,277 mm)  • Small tubes ♠ 185: 1 7⁄8 in (48 mm) ♥ 100: 1 7⁄8 in (48 mm)  • Large tubes ♥ 18: 5 1⁄2 in (140 mm) Boiler pressure ♠ 160 psi (1,103 kPa) 170 psi (1,172 kPa) adjusted ♥ 180 psi (1,241 kPa) Safety valve Ramsbottom Heating surface ♠ 1,078 sq ft (100.1 m2) ♥ 919 sq ft (85.4 m2)  • Tubes ♠ 976 sq ft (90.7 m2) ♥ 806 sq ft (74.9 m2)  • Firebox ♠ 102 sq ft (9.5 m2) ♥ 113 sq ft (10.5 m2) Superheater: ​  • Heating area ♥ 206 sq ft (19.1 m2) Cylinders Two Cylinder size 17 in (432 mm) bore 23 in (584 mm) stroke Valve gear Stephenson Valve type ♠ Slide - ♥ Piston Couplers Johnston link-and-pin AAR knuckle (1930s)
Performance figures Tractive effort ♠ 18,660 lbf (83.0 kN) @ 75% ♠ 19,810 lbf (88.1 kN) @ 75% adjusted ♥ 22,240 lbf (98.9 kN) @ 75% Factor of adh. 4.3
Career Operators Cape Government Railways Bechuanaland Railway Imperial Military Railways Imvani-Indwe Railway Sudan Military Railway South African Railways Zambesi Saw Mills Class CGR 7th Class, SAR Class 7A Number in class 46 CGR, 44 SAR Numbers CGR 347-350, 385-398, 718-744, 758 BR 4-7 IMR C522, C523 & C525-C527 Imvani-Indwe: Named SAR 988-1031 Sudan 26-33 Delivered 1896-1901 First run 1896 Withdrawn 1972
The leading coupled axle had flangeless wheels

The South African Railways Class 7A 4-8-0 of 1896 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

Between 1896 and 1901, the Cape Government Railways placed a second batch of altogether 46 7th Class steam locomotives with a 4-8-0 Mastodon wheel arrangement in service on its Midland and Eastern Systems. In 1912, when all but two of them were assimilated into the South African Railways, they were renumbered and designated Class 7A.

In 1897 and 1898, during Kitchener's military campaign in Sudan, eight Cape 7th Class locomotives were built to the same design for the Soudan Military Railway.

The original Cape 7th Class locomotive had been designed in 1892 by H.M. Beatty, at the time the Cape Government Railways (Western System) Locomotive Superintendent.

Following on the 38 7th Class locomotives which were placed in service by the Cape Government Railways (CGR) between 1892 and 1893, a second batch of 46 slightly improved locomotives were acquired between 1896 and 1901. Outwardly, all these locomotives appeared almost identical to the first batch of 7th Class locomotives, but they had increased heating capacity as well as some other modifications. They were the first to be equipped with type ZC tenders, which rode on two two-axle bogies and had a capacity of 5 long tons 10 hundredweight (5.6 tonnes) of coal and 2,600 imperial gallons (11,800 litres) of water.

In 1896, orders were placed for 28 locomotives, distributed between three manufacturers.

In 1897, a further four 7th Class locomotives were ordered by the CGR from Neilson, for use on the new Vryburg to Bulawayo line of the fledgling Bechuanaland Railway Company (BR). The line was still under construction and was operated by the CGR on behalf of the BR at the time. These 7th Class locomotives, numbered in the range from BR4 to BR7, were eventually returned to the CGR and renumbered in the range from 347 to 350 for the Midland System.

In 1897 and 1898, Neilson also built eight Cape 7th Class locomotives for the Soudan Military Railway, where they were known as the Dongola Class.

In 1898, another ten 7th Class locomotives were taken into service by the CGR, as well as another three by the Imvani-Indwe Railway which operated a branch line from Sterkstroom to the Indwe Collieries in the Eastern Cape.