South African Class GD 2-6-2+2-6-2

The South African Railways Class GD 2-6-2+2-6-2 of 1925 was an articulated steam locomotive.

South African Class GD 2-6-2+2-6-2
SAR Class GD (2-6-2+2-6-2).jpg
Class GD Garratt, c. 1965
Type and origin
Power typeSteam
DesignerBeyer, Peacock and Company
BuilderBeyer, Peacock and Company
Serial number6263-6266, 6281-6290
ModelClass GD
Build date1925-1926
Total produced14
Specifications
Configuration:
 • Whyte2-6-2+2-6-2 (Double Prairie)
 • UIC1'C1'+1'C1'h4
Driver3rd & 4th coupled axles
Gauge3 ft 6 in (1,067 mm) Cape gauge
Leading dia.28+12 in (724 mm)
Coupled dia.46 in (1,168 mm)
Trailing dia.28+12 in (724 mm)
Wheelbase58 ft 4 in (17,780 mm)
 • Engine18 ft 9 in (5,715 mm) each
 • Coupled8 ft 6 in (2,591 mm) each
Pivot centres30 ft 6 in (9,296 mm)
Length:
 • Over couplers65 ft 34 in (19,831 mm)
Height12 ft 10+14 in (3,918 mm)
Frame typePlate
Axle load12 LT 15 cwt (12,950 kg)
 • Leading11 LT 7 cwt (11,530 kg) front
11 LT 16 cwt (11,990 kg) rear
 • 1st coupled12 LT 10 cwt (12,700 kg)
 • 2nd coupled12 LT 10 cwt (12,700 kg)
 • 3rd coupled12 LT 10 cwt (12,700 kg)
 • 4th coupled12 LT 11 cwt (12,750 kg)
 • 5th coupled12 LT 11 cwt (12,750 kg)
 • 6th coupled12 LT 15 cwt (12,950 kg)
 • Trailing7 LT 15 cwt (7,874 kg) front
7 LT 16 cwt (7,925 kg) rear
Adhesive weight75 LT 7 cwt (76,560 kg)
Loco weight114 LT 1 cwt (115,900 kg)
Fuel typeCoal
Fuel capacity5 LT (5.1 t) as built
9 LT (9.1 t) no. 2220
Water cap2,300 imp gal (10,500 l) front
1,500 imp gal (6,820 l) rear
Firebox typeBelpaire
 • Firegrate area40 sq ft (3.7 m2)
Boiler:
 • Pitch7 ft 9+14 in (2,369 mm)
 • Diameter6 ft (1,829 mm)
 • Tube plates10 ft 7+78 in (3,248 mm)
 • Small tubes184: 2 in (51 mm)
 • Large tubes32: 5+12 in (140 mm)
Boiler pressure180 psi (1,241 kPa)
Safety valveRamsbottom
Heating surface1,689 sq ft (156.9 m2)
 • Tubes1,517 sq ft (140.9 m2)
 • Firebox172 sq ft (16.0 m2)
Superheater:
 • Heating area370 sq ft (34 m2)
CylindersFour
Cylinder size15 in (381 mm) bore
24 in (610 mm) stroke
Valve gearWalschaerts
Valve typePiston
CouplersBell link-and-pin
AAR knuckle (1940s-1950s)
Performance figures
Tractive effort31,690 lbf (141.0 kN) @ 75%
Career
OperatorsSouth African Railways
ClassClass GD
Number in class14
Numbers2220-2223, 2228-2237
Delivered1925-1926
First run1925
Withdrawn1967

In 1925, the South African Railways placed four Class GD Garratt articulated locomotives with a 2-6-2+2-6-2 Double Prairie type wheel arrangement in branchline service. Another ten of these locomotives were delivered in 1926.[1][2][3][4][5]

ManufacturerEdit

The Class GD 2-6-2+2-6-2 Double Prairie type Garratt locomotive was marginally larger and more powerful than its predecessor Class GC, with a heavier axle loading, but also intended for branchline work. Four locomotives were delivered by Beyer, Peacock and Company in December 1925, numbered in the range from 2220 to 2223. These were followed in January 1926 by ten more from the same manufacturer, seven of them built in 1925 and numbered in the range from 2228 to 2234, and the last three built in 1926 and numbered in the range from 2235 to 2237.[1][2][3][4][5][6]

CharacteristicsEdit

They locomotives were superheated and had plate frames, Belpaire fireboxes, piston valves and Walschaerts valve gear.[3][4][5]

As built, their coal bunkers had a 5 long tons (5.1 tonnes) capacity. At some stage, the coal bunker of no. 2220 was enlarged to a 9 long tons (9.1 tonnes) capacity.[4][5]

ServiceEdit

The locomotives were placed in service on the North Coast and the Pietermaritzburg to Franklin lines in Natal. From 1926, some were allocated to Paardeneiland to work on the line from Cape Town across Sir Lowry's Pass to Caledon in the Overberg. They were the first Garratts to work the Caledon line and were later joined by the two Class GK Garratts after the New Cape Central Railway was absorbed by the SAR in 1925.[1][2][7]

The Class GD proved themselves as handy and trouble-free locomotives and gave good service for more than forty years. They were later allocated to the Cape Midland system to work across the Montagu Pass between George and Oudtshoorn for many years until they were finally all allocated to the Port Alfred branch. They remained there until they were withdrawn from service in 1967.[1][3]

IllustrationEdit

ReferencesEdit

  1. ^ a b c d Holland, D. F. (1972). Steam Locomotives of the South African Railways. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. pp. 47–48. ISBN 978-0-7153-5427-8.
  2. ^ a b c Espitalier, T.J.; Day, W.A.J. (1946). The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued). South African Railways and Harbours Magazine, January 1946. p. 12.
  3. ^ a b c d Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. p. 90. ISBN 0869772112.
  4. ^ a b c d South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 3'6" Gauge/Spoorwydte. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. p. 31.
  5. ^ a b c d South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). Locomotive Diagram Book/Lokomotiefdiagramboek, 2'0" & 3'6" Gauge/Spoorwydte, Steam Locomotives/Stoomlokomotiewe. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. p. 31.
  6. ^ Hamilton, Gavin N., The Garratt Locomotive - Garratt Locomotives produced by Beyer, Peacock, retrieved 10 November 2012
  7. ^ Soul of A Railway, System 1, Part 7: The Caledon train. Caption 42 (Accessed on 29 November 2016)