South African Class Experimental 4 2-8-2

This article is about one of two different Cape Government Railways locomotive types to be designated "9th Class". For the other, see South African Class Experimental 5 2-8-2.

The South African Railways Class Experimental 4 2-8-2 of 1903 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

CGR 9th Class 2-8-2 1903 South African Class Experimental 4 2-8-2
CGR 9th Class no. 806, c. 1911 SAR Class Experimental 4 no. 911
Type and origin Power type Steam Designer Cape Government Railways (H.M. Beatty) Builder Kitson and Company Serial number 4195-4196 Model CGR 9th Class Build date 1903 Total produced 2
Specifications Configuration: ​  • Whyte 2-8-2 (Mikado)  • UIC 1'D1'n2 Driver 3rd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia. 28+1⁄2 in (724 mm) Coupled dia. 48 in (1,219 mm) Trailing dia. 33 in (838 mm) Tender wheels 33+1⁄2 in (851 mm) as built 34 in (864 mm) retyred Wheelbase 50 ft 7+1⁄4 in (15,424 mm) ​  • Axle spacing (Asymmetrical) 1-2: 4 ft 7 in (1,397 mm) 2-3: 4 ft 3 in (1,295 mm) 3-4: 4 ft 3 in (1,295 mm)  • Engine 26 ft 9 in (8,153 mm)  • Coupled 13 ft 1 in (3,988 mm)  • Tender 14 ft 7 in (4,445 mm)  • Tender bogie 4 ft 7 in (1,397 mm) Length: ​  • Over couplers 58 ft 5+3⁄4 in (17,824 mm) Height 12 ft 10 in (3,912 mm) Frame type Bar Axle load 12 LT 16 cwt (13,010 kg) ​  • Leading 5 LT 5 cwt (5,334 kg)  • 1st coupled 12 LT 6 cwt (12,500 kg)  • 2nd coupled 11 LT 16 cwt (11,990 kg)  • 3rd coupled 12 LT (12,190 kg)  • 4th coupled 12 LT 16 cwt (13,010 kg)  • Trailing 10 LT 4 cwt (10,360 kg)  • Tender axle 9 LT 4 cwt 1 qtr (9,360 kg) av. Adhesive weight 48 LT 18 cwt (49,680 kg) Loco weight 64 LT 7 cwt (65,380 kg) Tender weight 36 LT 18 cwt (37,490 kg) Total weight 101 LT 5 cwt (102,900 kg) Tender type XE1 (2-axle bogies) Fuel type Coal Fuel capacity 6 LT (6.1 t) Water cap. 2,855 imp gal (12,980 L) Firebox: ​  • Type Round-top  • Grate area 26.75 sq ft (2.485 m2) Boiler: ​  • Pitch 7 ft 1 in (2,159 mm)  • Diameter 4 ft 10+3⁄4 in (1,492 mm)  • Tube plates 14 ft 10+1⁄8 in (4,524 mm)  • Small tubes 159: 2+1⁄4 in (57 mm) Boiler pressure 180 psi (1,241 kPa) Safety valve Ramsbottom Heating surface: ​  • Firebox 117.3 sq ft (10.90 m2)  • Tubes 1,391 sq ft (129.2 m2)  • Total surface 1,508.3 sq ft (140.13 m2) Cylinders Two Cylinder size 19 in (483 mm) bore 24 in (610 mm) stroke Valve gear Stephenson Couplers Johnston link-and-pin
Performance figures Tractive effort 24,370 lbf (108.4 kN) @ 75%
Career Operators Cape Government Railways South African Railways Class CGR 9th Class SAR Class Experimental 4 Number in class 2 Numbers CGR 805-806, SAR 910-911 Delivered 1903 First run 1903 Withdrawn 1930
The 2nd & 3rd coupled axles had flangeless wheels

In 1903, the Cape Government Railways placed two 9th Class steam locomotives with a 2-8-2 Mikado type wheel arrangement in service. In 1912, when they were assimilated into the South African Railways, they were renumbered and designated Class Experimental 4.

Manufacturer

The Cape 9th Class locomotive was designed by H.M. Beatty, the Locomotive Superintendent of the Cape Government Railways (CGR) from 1896 to 1910. They were the first South African locomotives to have a 2-8-2 Mikado wheel arrangement and they were built with bar frames, had Stephenson’s Link valve gear and used saturated steam. Two locomotives were delivered by Kitson and Company in 1903, numbered 805 and 806.

Characteristics

H.M. Beatty

The locomotives were delivered with Type XE1 tenders. Their intermediate and driving coupled wheels were flangeless to allow them to cope with tight curves, such as in turnouts.

With these locomotives, Beatty attempted to combine the best design features and good qualities of his Cape 8th Class 2-8-0 locomotive of 1901 with the improved steaming which was obtained from a wide firegrate. In many respects, they were enlarged versions of the two Cape 6th Class 2-6-2 locomotives which were delivered by Kitson in the same year, with many features in common.

Performance

They were placed in service on the mainline between De Aar and Kimberley.

In comparison with the Cape 8th Class, it was found that their operational and maintenance costs were much higher without any advantage in terms of efficiency. As a result, no more of the type were ordered.

Reclassification

When the Union of South Africa was established on 31 May 1910, the three Colonial government railways (CGR, Natal Government Railways and Central South African Railways) were united under a single administration to control and administer the railways, ports and harbours of the Union. Although the South African Railways and Harbours came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways were only implemented with effect from 1 January 1912.

In 1912, the locomotives were designated Class Experimental 4 and renumbered to 910 and 911 on the SAR. They were withdrawn from service and scrapped in 1930.