South African Class 19C 4-8-2

South African Class 19C 4-8-2

No. 2439, Outeniqua Transport Museum, 22 April 2006

Type and origin ♠ Class 19C with a steel firebox ♥ Class 19C with a copper firebox ♣ Type MT tender - ♦ Type MP1 tender Power type Steam Designer South African Railways (A.G. Watson) Builder North British Locomotive Company Serial number 24168-24217 Model Class 19C Build date 1935 Total produced 50

Specifications Configuration 4-8-2 (Mountain) 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) Trailing dia. 34 in (864 mm) Tender wheels ♣♦ 34 in (864 mm) Wheelbase ♦ 58 ft 8 3⁄4 in (17,901 mm)  • Engine 32 ft 3 in (9,830 mm)  • Leading 6 ft 4 in (1,930 mm)  • Coupled 14 ft 5 in (4,394 mm)  • Tender ♣ 20 ft 5 in (6,223 mm) ♦ 16 ft 9 in (5,105 mm)  • Tender bogie ♣ 6 ft 2 in (1,880 mm) ♦ 4 ft 7 in (1,397 mm) Wheel spacing (Asymmetrical) 1-2: 4 ft 10 in (1,473 mm) 2-3: 4 ft 9 in (1,448 mm) 3-4: 4 ft 10 in (1,473 mm) Length: ​  • Over couplers ♦ 67 ft 3 5⁄8 in (20,514 mm) Height 12 ft 10 7⁄8 in (3,934 mm) Frame type Bar Axle load ♠ 13 LT 8 cwt (13,620 kg) ♥ 13 LT 13 cwt (13,870 kg)  • Leading ♠ 14 LT 5 cwt (14,480 kg) ♥ 14 LT 7 cwt (14,580 kg)  • 1st coupled ♠ 13 LT 3 cwt (13,360 kg) ♥ 13 LT 8 cwt (13,620 kg)  • 2nd coupled ♠ 13 LT 8 cwt (13,620 kg) ♥ 13 LT 3 cwt (13,360 kg)  • 3rd coupled ♠ 13 LT 8 cwt (13,620 kg) ♥ 13 LT 13 cwt (13,870 kg)  • 4th coupled ♠ 13 LT 3 cwt (13,360 kg) ♥ 13 LT 8 cwt (13,620 kg)  • Trailing ♠ 11 LT (11,180 kg) ♥ 11 LT 4 cwt (11,380 kg)  • Tender bogie Bogie 1: ♣ 32 LT 18 cwt (33,430 kg) ♦ 27 LT 10 cwt (27,940 kg) Bogie 2: ♣ 33 LT 2 cwt (33,630 kg) ♦ 23 LT 11 cwt (23,930 kg)  • Tender axle ♣ 16 LT 11 cwt (16,820 kg) ♦ 13 LT 15 cwt (13,970 kg) Adhesive weight ♠ 53 LT 2 cwt (53,950 kg) ♥ 53 LT 12 cwt (54,460 kg) Loco weight ♠ 78 LT 7 cwt (79,610 kg) ♥ 79 LT 3 cwt (80,420 kg) Tender weight ♣ 66 LT (67,060 kg) ♦ 51 LT 1 cwt (51,870 kg) Total weight ♠♣ 144 LT 7 cwt (146,700 kg) ♥♣ 145 LT 3 cwt (147,500 kg) ♠♦ 129 LT 8 cwt (131,500 kg) ♥♦ 130 LT 4 cwt (132,300 kg) Tender type ♣ MT (2-axle bogies) ♦ MP1 (2-axle bogies) MP, MP1, MR, MT, MX, MY, MY1 permitted Fuel type Coal Fuel capacity ♣ 12 LT (12.2 t) ♦ 10 LT (10.2 t) Water cap ♣ 6,000 imp gal (27,300 l) ♦ 4,250 imp gal (19,300 l) Firebox type Round-top  • Firegrate area 36 sq ft (3.3 m2) Boiler: ​  • Model Watson Standard no. 1A  • Pitch 8 ft (2,438 mm)  • Diameter 5 ft (1,524 mm)  • Tube plates 20 ft 2 in (6,147 mm)  • Small tubes 76: 2 1⁄2 in (64 mm)  • Large tubes 24: 5 1⁄2 in (140 mm) Boiler pressure 200 psi (1,379 kPa) Safety valve Pop Heating surface 1,839 sq ft (170.8 m2)  • Tubes 1,700 sq ft (160 m2)  • Arch tubes 16 sq ft (1.5 m2)  • Firebox 123 sq ft (11.4 m2) Superheater: ​  • Heating area 404 sq ft (37.5 m2) Cylinders Two Cylinder size 21 in (533 mm) bore 26 in (660 mm) stroke Valve gear Rotary Cam Poppet Valve type Poppet Couplers AAR knuckle

Performance figures Tractive effort 31,850 lbf (141.7 kN) @ 75%

Career Operators South African Railways Class Class 19C Number in class 50 Numbers 2435–2484 Delivered 1935 First run 1935 Withdrawn 1978

The South African Railways Class 19C 4-8-2 of 1935 was a steam locomotive.

In 1935, the South African Railways placed fifty Class 19C steam locomotives with a 4-8-2 Mountain type wheel arrangement in service. It was the first South African locomotive class to use Rotary Cam Poppet valve gear, and also the first to be built new with Watson Standard boilers.

When the need for more branchline locomotives became apparent in 1934, tenders were invited by the South African Railways (SAR) for another fifty Class 19B locomotives with Walschaerts valve gear, but redesigned by Chief Mechanical Engineer (CME) A.G. Watson with his Watson Standard no. 1A boilers. When the tenders were received, it was found that the North British Locomotive Company (NBL) of Glasgow, Scotland, had also tendered for a locomotive with Rotary Cam Poppet valve gear as an alternative to Walschaerts valve gear.

Even though this would increase the cost per locomotive by £200, Watson decided to accept this tender, in view of the good reports he had received concerning poppet valve gear. This variation on the design led to these locomotives being designated Class 19C when they were delivered in 1935.

All fifty Class 19C loco­motives were erected at the Salt River shops and numbered in the range from 2435 to 2484, and many remained stationed at Cape Town while being subjected to exhaustive testing. As built, the Class 19C was delivered with Type MT tenders with a 12 long tons (12.2 tonnes) coal and a 6,000 imperial gallons (27,300 litres) water capacity, even though the axle load of 16 long tons 11 hundredweight (16,820 kilograms) of these tenders exceeded the permissible limits on the branchlines for which the Class 19B was intended. Upon delivery, their new Type MT tenders were exchanged for the smaller modified Type MP1 tenders from some of the reboilered mainline locomotives. The Type MP1 had a lighter axle load of 13 long tons 15 hundredweight (13,970 kilograms) and was therefore more suitable for branchline work. This policy was followed with all the Classes 19B, 19C and 19D, except the last batch of Class 19D which was delivered with Type MX torpedo tenders.