South African Class GC 2-6-2+2-6-2

South African Class GC 2-6-2+2-6-2
Class GC no. 2182, c. 1924
Type and origin Power type Steam Designer Beyer, Peacock and Company Builder Beyer, Peacock and Company Serial number 6187-6192 Model Class GC Build date 1924 Total produced 6
Specifications Configuration: ​  • Whyte 2-6-2+2-6-2 (Double Prairie)  • UIC 1'C1'+1'C1'h4 Driver 3rd & 4th coupled axles 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) Trailing dia. 28 1⁄2 in (724 mm) Wheelbase 56 ft 8 in (17,272 mm)  • Engine 17 ft 8 1⁄4 in (5,391 mm) each  • Coupled 8 ft (2,438 mm) each Pivot centres 29 ft 8 in (9,042 mm) Length: ​  • Over couplers 63 ft 3 3⁄4 in (19,298 mm) Height 12 ft 3 in (3,734 mm) Frame type Plate Axle load 11 LT 16 cwt (11,990 kg)  • Leading 8 LT 13 cwt (8,789 kg) front 8 LT 9 cwt (8,586 kg) rear  • 1st coupled 10 LT 16 cwt (10,970 kg)  • 2nd coupled 10 LT 14 cwt (10,870 kg)  • 3rd coupled 10 LT 14 cwt (10,870 kg)  • 4th coupled 11 LT 15 cwt (11,940 kg)  • 5th coupled 11 LT 16 cwt (11,990 kg)  • 6th coupled 10 LT 11 cwt (10,720 kg)  • Trailing 6 LT 8 cwt (6,503 kg) front 7 LT 2 cwt (7,214 kg) rear Adhesive weight 66 LT 6 cwt (67,360 kg) Loco weight 96 LT 18 cwt (98,450 kg) Fuel type Coal Fuel capacity 7 LT (7.1 t) Water cap 2,000 imp gal (9,090 l) front 1,000 imp gal (4,550 l) rear Firebox type Belpaire  • Firegrate area 34 sq ft (3.2 m2) Boiler: ​  • Pitch 7 ft 4 3⁄8 in (2,245 mm)  • Diameter 5 ft 2 in (1,575 mm)  • Tube plates 11 ft 3 5⁄8 in (3,445 mm)  • Small tubes 149: 2 in (51 mm)  • Large tubes 24: 5 1⁄2 in (140 mm) Boiler pressure 180 psi (1,241 kPa) Safety valve Ramsbottom Heating surface 1,423 sq ft (132.2 m2)  • Tubes 1,266.2 sq ft (117.63 m2)  • Firebox 156.8 sq ft (14.57 m2) Superheater: ​  • Heating area 247 sq ft (22.9 m2) Cylinders Four Cylinder size 14 in (356 mm) bore 23 in (584 mm) stroke Valve gear Walschaerts Valve type Piston Couplers Johnston link-and-pin AAR knuckle (1930s)
Performance figures Tractive effort 28,470 lbf (126.6 kN) @ 75%
Career Operators South African Railways Class Class GC Number in class 6 Numbers 2180-2185 Delivered 1924-1925 First run 1924 Withdrawn 1962

The South African Railways Class GC 2-6-2+2-6-2 of 1924 was an articulated steam locomotive.

In 1924 and 1925, the South African Railways placed six Class GC Garratt articulated steam locomotives with a 2-6-2+2-6-2 Double Prairie type wheel arrangement in branch line service.

Following the good performance of the Class GB branch line Garratts, the first locomotive to be built to the specifications of Colonel F.R. Collins DSO after he was appointed as the Chief Mechanical Engineer of the South African Railways in 1922 was a heavier 2-6-2+2-6-2 Double Prairie type Garratt, also intended for branch line work. It was designed and built to his specifications by Beyer, Peacock and Company in 1924.

Six locomotives were delivered in 1924 and were erected in the Durban shops of the SAR. They were placed in service in 1924 and 1925, designated Class GC and numbered in the range from 2180 to 2185. The locomotives were superheated, with Belpaire fireboxes, plate frames, Walschaerts valve gear and piston valves.

Like its predecessor Class GB, the heavier Class GC was also a branch line locomotive and its maximum axle load of 11 long tons 16 hundredweight (11,990 kilograms) made it suitable for light rail. It was a more powerful development of the Class GB and was very similar to the Class GK Garratts which had been acquired by the New Cape Central Railway (NCCR) in 1923, but 2 long tons (2,032 kilograms) heavier and with 1 inch (25 millimetres) smaller diameter cylinders with a 1 inch (25 millimetres) longer stroke.

The locomotives were initially placed in service on the Natal South Coast line. Although they later also worked on other branch lines, they spent their entire working lives in Natal until they were withdrawn from service in 1962.

Class GC in Durban station on the Port Shepstone train, with Station Inspector James Grossert on the platform at right, c. 1924