South African Class 6 4-6-0

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South African Class 6 4-6-0
ex CGR 6th Class 4-6-0
SAR Class 6 439 (4-6-0) ex CGR 368-568-OVGS 68-CSAR 344.jpg
Ex CGR, OVGS and CSAR, SAR Class 6 no. 439, Capital Park, 24 September 2000
Type and origin
Power type Steam
Designer Cape Government Railways
Builder Dübs and Company
Serial number 3050-3073, 3087-3102
Model CGR 6th Class
Build date 1893-1894 [1]
Total produced 40
Specifications
Configuration 4-6-0 Tenwheeler
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Leading wheel
diameter
28.5 in (724 mm)
Driver diameter 54 in (1,370 mm)
Wheelbase Total: 41 ft 9.125 in (12.729 m)
Engine:
5 ft 4.5 in (1.638 m) bogie
11 ft (3.353 m) coupled
20 ft 3.25 in (6.179 m) total
Tender:
10 ft 6 in (3.200 m)
Length 50 ft 8.5 in (15.456 m)
Height 12 ft 8 in (3.861 m) as built
12 ft 10.75 in (3.931 m) Belpaire
Frame Plate frame
Axle load 11.95 long tons (12.1 t) on 2nd driver as built
13.4 long tons (13.6 t) per driver Belpaire
Weight on drivers 34.75 long tons (35.3 t) as built
40.2 long tons (40.8 t) Belpaire
Locomotive weight 44.55 long tons (45.3 t) as built
51.075 long tons (51.9 t) Belpaire
Tender weight 31,560 lb (14.3 t) empty
29.55 long tons (30.0 t) w/o
Locomotive and tender
combined weight
74.1 long tons (75.3 t) as built
82.225 long tons (83.5 t) Belpaire
Tender type YB - YB, YC, YE, YE1 permitted
* 3 axle tender
* 37 in (940 mm) wheels
* Length 20 ft 5.875 in (6.245 m)
Fuel type Coal
Fuel capacity 5.5 long tons (5.6 t)
Water capacity 2,370 imp gal (10,800 l)
Boiler As built:
4 ft 2 in (1.270 m) inside diameter
11 ft 2.125 in (3.407 m) inside length
6 ft 6 in (1.981 m) pitch
Belpaire:
4 ft 9 in (1.448 m) inside diameter
11 ft 2.125 in (3.407 m) inside length
7 ft (2.134 m) pitch
Boiler pressure 160 psi (1,100 kPa) as built
180 psi (1,240 kPa) Belpaire
Firegrate area 17 sq ft (1.579 m2) as built
16.6 sq ft (1.542 m2) Belpaire
Heating surface:
– Tubes
As built:
185 tubes 1.75 in (44.4 mm) diameter
946 sq ft (87.886 m2)
Belpaire:
220 tubes 2 in (50.8 mm) diameter
1,287.5 sq ft (119.613 m2)
– Firebox 95 sq ft (8.826 m2) as built
111 sq ft (10.312 m2) Belpaire
– Total 1,041 sq ft (96.712 m2) as built
1,398.5 sq ft (129.925 m2) Belpaire
Cylinders Two
Cylinder size 17 in (432 mm) bore
26 in (660 mm) stroke
Valve gear Stephenson
Performance figures
Tractive effort At 75% boiler pressure:
16,700 lbf (74.3 kN) as built
18,780 lbf (83.5 kN) Belpaire [2]
Career
Operator(s) Cape Government Railways
OVGS
Imperial Military Railways
Central South African Railways
South African Railways
Sudan Railways [3]
Class CGR & OVGS 6th Class, CSAR Class 6-L1, SAR Class 6
Number in class 40
Number(s) CGR 139-160, 353-370 (353-355 & 360-370 renumbered 553-555, 560-570)
OVGS 60-69
CSAR 336-345
SAR 401-440 [1][4][5]
Delivered 1893-1894
First run 1893
Withdrawn 1973 [3]

The South African Class 6 4-6-0 of 1893 is a South African steam locomotive from the pre-Union era in the Cape Colony.

In 1893 and 1894 the Cape Government Railways placed forty 6th Class 4-6-0 steam locomotives in service, twenty-two on its Western System and eighteen on its Midland System. In 1897 ten of them were sold to the Oranje-Vrijstaat Gouwerment-Spoorwegen. At the end of the Second Boer War in 1902, these ten became the Class 6-L1 on the Central South African Railways. In 1912, when all forty locomotives were assimilated into the South African Railways, they were renumbered but retained their Class 6 classification.[1][3][4]

Manufacturer[edit]

The 6th Class 4-6-0 passenger steam locomotive was designed at the Salt River works of the Cape Government Railways (CGR) at the same time as the 7th Class, both locomotives according to the specifications of Michael Stephens, then Chief Locomotive Superintendent of the CGR, and under the supervision of H.M. Beatty, then Locomotive Superintendent of the Cape Western System. Whereas the 7th Class was conceived primarily as a goods locomotive, the 6th Class was intended to be its fast passenger service counterpart.[1]

Dübs works plate

The forty locomotives were built by Dübs and Company and delivered between 1893 and 1894, numbered in the ranges from 139 to 160 for the Western System and 353 to 370 for the Midland System. Fourteen of the Midland's eighteen locomotives were later renumbered.[1]

The 6th Class locomotives were the forerunners of one of the most useful classes of locomotives to see service in South Africa. They were fast, easy to handle, good steamers and had an exceptionally low maintenance cost with long periods between major overhauls. They were so advanced over previous designs that C.B. Elliot, General Manager of the CGR at the time, stated in his annual report in 1894 that they would render practicable the running of passenger trains between Cape Town and Johannesburg in 48 hours.[1]

Class 6 sub-classes[edit]

The Union of South Africa was established on 31 May 1910, in terms of the South Africa Act. One of the clauses in the Act required that the three Colonial Government railways, the CGR, the Natal Government Railways and the Central South African Railways, also be united under one single administration to control and administer the railways, ports and harbours of the Union. While the South African Railways (SAR) came into existence in 1910, the actual classification and renumbering of all the rolling stock of the three constituent railways required careful planning and was only implemented with effect from 1 January 1912.[4][6]

CGR number plate

In 1912, after some of them had also seen service on the Oranje-Vrijstaat Gouwerment-Spoorwegen (OVGS), the Imperial Military Railways (IMR) and the Central South African Railways (CSAR), these forty locomotives were renumbered in the range from 401 to 440 on the SAR, but they retained their Class 6 classification.[4][5]

The rest of the CGR’s 6th Class locomotives, together with the Class 6-L2 and 6-L3 locomotives inherited by the CSAR from the OVGS via the IMR, were grouped into thirteen more sub-classes by the SAR. The 4-6-0 locomotives became SAR Classes 6A to 6H and 6J to 6L, the 2-6-2 locomotives became SAR Class 6Y and the 2-6-4 locomotives became Class 6Z.[2]

Modifications[edit]

Several of the CSAR’s Class 6L1 to 6-L3 locomotives were modified by P.A Hyde, Chief Mechanical Engineer (CME) of the CSAR, by having their round-top fireboxes replaced with larger boilers and Belpaire fireboxes and by having larger, more sheltered cabs installed. Of the SAR Class 6 locomotives, only ex CSAR Class 6-L1 336, renumbered SAR 401, had undergone this modification. This conversion improved their performance tremendously and resulted in several of the Class 6, 6A and 6B locomotives being similarly modified by the SAR in later years, but without altering their classifications.[3][4]

During the 1930s many of them were modified once again, when the CME of the SAR at the time, A.G. Watson, displayed his aversion to Belpaire fireboxes and reboilered them with round-topped fireboxes again, but retaining the larger cabs. Once again, they retained their classifications.[2][3]

Service[edit]

South Africa[edit]

The 6th Class was introduced primarily as a passenger locomotive, but when it became displaced by larger and more powerful locomotive classes, it literally became a “Jack-of-all-trades” that proved itself as one of the most useful and successful locomotive classes ever to be designed at the Salt River shops. It went on to see service in all parts of the country except Natal and was used on all types of traffic.[1]

SAR Class 6 439 (4-6-0) ex CGR 368-568-OVGS 68-CSAR 344 ID.JPG

In Cape Town they held a monopoly over the suburban services until electrification arrived in 1928, and on the Reef they also worked these services between Randfontein and Springs until the loads became too heavy for them. They were employed on branchlines all over the country, Natal excluded, and practically every big station and many smaller ones had its quota of these handy locomotives to work the local passenger, goods and shunting services.[1]

Like the 7th Class, the 6th Class gave good service for many years. By the time the last ones were eventually retired in 1973, the Class 6 had achieved a service life of eighty years, a performance that can be matched by few, if any, other locomotive classes world wide.[1]

Sudan[edit]

During World War II sixteen of the Classes 6 to 6D were transferred to the Middle East to assist with the war effort during the North African Campaign. The seven Class 6 locomotives in this group were numbers 402, 403, 406, 417, 421, 423 and 436. They were sold to the Sudan Railways Corporation in 1942 and renumbered in the range from M700 to M706, in the same order as their former SAR running numbers.[1][3][7]

Renumberings[edit]

During their long service lives some of the 6th Class locomotives underwent multiple renumberings. All were initially numbered into the CGR’s Western and Midland Systems rosters. Fourteen of the Midland System’s locomotives, in the number ranges from 353 to 355 and 360 to 370, were later renumbered in the ranges from 553 to 555 and 560 to 570. At the time the renumbering took place, the four that were not renumbered (numbers 356 to 359) had already been sold to the OVGS.[1]

Two of the Western System and eight of the Midland System locomotives were sold to the OVGS in 1897 and renumbered to the OVGS number range from 60 to 69. It would appear that the CGR’s Western System was more concerned with having unbroken number ranges than the CGR itself was about awarding different classifications to dissimilar locomotives, even if they were of different wheel arrangements. The numbers of the two Western System locomotives that were sold to the OVGS, 155 and 160, were subsequently allocated again to two of the batch of fourteen locomotives that were delivered by Neilson, Reid and Company in 1902 and that were to become the Class 6J.[5]

When the Orange Free State was occupied by the invading British forces during the Second Freedom War, these OVGS locomotives were taken over and used by the IMR, but not renumbered. When the IMR reverted to civilian control after the war and became established as the CSAR in 1902, these ten locomotives were reclassified to CSAR Class 6-L1 and renumbered in the CSAR range from 336 to 345.[1][4][5]

All forty locomotives were eventually renumbered into the SAR’s roster in 1912, designated SAR Class 6 and renumbered in the range from 401 to 440. Only one of the Class 6 locomotives underwent all these renumberings, from CGR no. 365 to CGR no. 565, then OVGS no. 65, then CSAR no. 341, then SAR no. 436 and finally Sudan Railway no. M706. The table shows all these renumberings as well as their year in service and Dübs works numbers.[4][5]

Modifications illustrated[edit]

The main picture shows ex CGR Midland System 6th Class no. 368, later renumbered CGR no. 568, then OVGS 6th Class no. 68, then CSAR Class 6-L1 no. 344, then SAR Class 6 no. 439 and finally Rovos Rail’s restored "Tiffany". The following pictures illustrate the Class 6 in service and preserved, with different fireboxes, various headlight types that were in use over the years and, in some cases, with different types of tender.

See also[edit]

References[edit]

 
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  1. ^ a b c d e f g h i j k l Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 44–45, 57. ISBN 978-0-7153-5382-0. 
  2. ^ a b c South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
  3. ^ a b c d e f Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 41–44. ISBN 0869772112. 
  4. ^ a b c d e f g Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer’s Office, Pretoria, January 1912, pp. 8, 12, 14, 28 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  5. ^ a b c d e Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 137–138. ISBN 978-0-7153-5427-8. 
  6. ^ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
  7. ^ Class 6 to 6D sold to Sudan Railways during the WWII North African Campaign, list compiled by Austrian locomotive historian Reimar Holzinger