South African Class 6A 4-6-0

This article is about one of several different Cape Government Railways locomotive types to be designated "6th Class". For other CGR 6th Class locomotives, see Cape Government Railways 6th Class locomotives.

CGR 6th Class 4-6-0 1896
South African Class 6A 4-6-0

300px CGR no. 182, IMR no. C509, SAR no. 462, at De Aar, 15 April 1978

Type and origin ♠ Original locomotive, as built ♥ Locomotive equipped with Belpaire firebox Power type Steam Designer Cape Government Railways (H.M. Beatty) Builder Dübs and Company Sharp, Stewart and Company Serial number Dübs: 3330, 3332-3335, 3337, 3345-3347, 3437-3439, 3441-3447, 3449-3456, 3460-3466, 3469-3471, 3475-3476 Sharp Stewart: 4116-4119, 4122-4127, 4144 Model CGR 6th Class Build date 1895-1897 Total produced 50

Specifications Configuration 4-6-0 (Tenwheeler) Driver axle 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia Coupled dia 54 in (1,372 mm) Tender wheels 37 in (940 mm) Wheelbase  • Engine  • Leading  • Coupled 11 ft (3,353 mm)  • Tender 10 ft (3,048 mm) Wheel spacing (Assymetrical) 1-2: 4 ft 9 in (1,448 mm) 2-3: 6 ft 3 in (1,905 mm) Length:  • Over couplers Height ♠ 12 ft 10 in (3,912 mm) ♥ Frame type Plate Axle load ♠ ♥  • Leading ♠ ♥  • 1st coupled ♠  • 2nd coupled ♠  • 3rd coupled ♠  • Tender axle average Adhesive weight ♠ ♥ Loco weight ♠ ♥ Tender weight Loco & tender weight ♠ ♥ Tender type YC (3-axle) YB, YC, YE, YE1 permitted Fuel type Coal Fuel capacity 5 LT 10 cwt (5.6 t) Water cap Boiler:  • Pitch ♠ 6 ft 8 in (2,032 mm) ♥ 7 ft (2,134 mm)  • Diameter ♠ 4 ft 4 in (1,321 mm) ♥ 4 ft 9 in (1,448 mm)  • Tube plates ♠ ♥  • Small tubes ♠ 185: ♥ 220: 2 in (51 mm)  • Firebox type ♠ Round-top - ♥ Belpaire Boiler pressure ♠ 160 psi (1,103 kPa) ♥ 180 psi (1,241 kPa) Safety valve Ramsbottom Firegrate area ♠ 16.625 sq ft (1.5445 m2) ♥ 16.6 sq ft (1.54 m2) Heating surface ♠ 1,116 sq ft (103.7 m2) ♥ 1,398.5 sq ft (129.92 m2)  • Tubes ♠ 1,015 sq ft (94.3 m2) ♥ 1,287.5 sq ft (119.61 m2)  • Firebox ♠ 101 sq ft (9.4 m2) ♥ 111 sq ft (10.3 m2) Cylinders Two Cylinder size 17 in (432 mm) bore 26 in (660 mm) stroke Valve gear Stephenson Couplers Bell link-and-pin AAR knuckle (1950s)

Performance figures Tractive effort ♠ 16,690 lbf (74.2 kN) @ 75% ♥ 18,780 lbf (83.5 kN) @ 75%

Career Operators Cape Government Railways Imperial Military Railways Benguela Railway South African Railways Sudan Railways Class CGR 6th Class, SAR Class 6A Number in class 50 CGR, 49 SAR Numbers CGR 161-201, 371-376, 660-662 (371-376 renumbered 571-576) IMR C501, C503, C509 & C510 Benguela 21 SAR 441-489 Delivered 1896-1897 First run 1896 Withdrawn 1973

The South African Railways Class 6A 4-6-0 of 1896 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

In 1896 and 1897, the Cape Government Railways placed a second batch of fifty 6th Class 4-6-0 steam locomotives in service, forty-one on its Western System, six on its Midland System and three on its Eastern System. During the Second Boer War, four of them were transferred to the Imperial Military Railways on loan, and in 1907 one was sold to the Benguela Railway in Angola. In 1912, when the remaining forty-nine locomotives were assimilated into the South African Railways, they were renumbered and designated Class 6A.

Manufacturers

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 according to the specifications of Michael Stephens, at the time the Chief Locomotive Superintendent of the CGR, and under the supervision of H.M. Beatty, at the time the Locomotive Superintendent of the Cape Western System. Whereas the Class 7 was conceived primarily as a goods locomotive, the 6th Class was intended to be its fast passenger service counterpart.

File:H.M. Beatty.jpg

H.M. Beatty

The fifty locomotives in this second batch of the 6th Class were built between 1895 and 1897, by Dübs and Company and Sharp, Stewart and Company, and were delivered in 1896 and 1897, numbered in the ranges from 161 to 201 for the CGR's Western System, 371 to 376 for the Midland System and 660 to 662 for the Eastern System.

These locomotives differed from those of the previous order by having slightly larger boilers with an increased heating surface. They were the first to be delivered with Type YC tenders, which had the same coal capacity as the earlier Type YB tender of 1893, but with a water capacity of , compared to the of the Type YB.

Class 6 sub-classes

When the Union of South Africa was established on 31 May 1910, the three Colonial government railways (CGR, Natal Government Railways (NGR) and Central South African Railways (CSAR)) 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 required careful planning and was only implemented with effect from 1 January 1912.

File:SAR Class 6A 482 (4-6-0) ex CGR 372-572 ID.JPG

In 1912, all but one of these fifty locomotives were assimilated into the SAR, designated Class 6A and renumbered in the range from 441 to 489.

The rest of the CGR's 6th Class locomotives, together with the Class 6-L1 to 6-L3 locomotives which had been inherited by the CSAR from the Oranje-Vrijstaat Gouwerment-Spoorwegen (OVGS) via the Imperial Military Railways (IMR), were grouped into thirteen more sub-classes by the SAR. The 4-6-0 locomotives became SAR Classes 6, 6B to 6H and 6J to 6L, the 2-6-2 locomotives became Class 6Y and the 2-6-4 locomotives became Class 6Z.

Modifications

Several of the CSAR's Class 6-L1 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. 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.

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 once again, but retaining the larger cabs. Once again, they retained their classifications.

Service

South Africa

The Class 6 family of locomotives were introduced primarily as passenger locomotives, but when the class became displaced by larger and more powerful locomotive classes, it literally became a "Jack-of-all-trades" which 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 in Natal, and was used on all types of traffic.

IMR, Angola and Sudan

One of these locomotives was sold to the Benguela Railway in Angola, while another four saw service with the IMR during the Second Boer War.

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 four Class 6A locomotives in this group were numbers 465, 472, 475 and 479. They were sold to the Sudan Railways Corporation in 1942 and were renumbered in the range from M707 to M710, in the same order as their former SAR engine numbers.

Renumberings

During their long service lives, some of the Class 6A locomotives underwent multiple renumberings. All were initially numbered into the CGR's Western, Midland and Eastern Systems rosters. The Midland System's locomotives, numbered in the range from 371 to 376, were later renumbered in the range from 571 to 576. The then vacant engine numbers in the range from 371 to 376 were later re-allocated to Class 8D locomotives. which were delivered in 1902.

The four locomotives which were loaned to the IMR, were renumbered C501, C503, C509 and C510 for the duration of their service with the IMR during the Second Boer War, while the one which was sold to Angola, became the Benguela Railway's no. 21.

The remaining forty-nine locomotives were eventually renumbered into the SAR's roster in 1912, and received SAR numbers in the range from 441 to 489. The table reflects all these renumberings as well as their builders and works numbers.

Class 6A 4-6-0
Builders, works numbers and renumbering

Builder	Year built	Works no.	CGR no.	CGR new no.	IMR no.	Benguela no.	SAR no.	Sudan no.
Dübs	1895	3332	161				441
Sharp Stewart	1896	4124	162				442
Sharp Stewart	1896	4122	163				443
Sharp Stewart	1896	4123	164				444
Dübs	1895	3330	165				445
Dübs	1895	3334	166				446
Sharp Stewart	1896	4126	167				447
Dübs	1895	3335	168				448
Sharp Stewart	1896	4127	169				449
Dübs	1895	3337	170				450
Dübs	1895	3345	171				451
Sharp Stewart	1896	4125	172				452
Dübs	1895	3346	173				453
Dübs	1895	3347	174				454
Dübs	1895	3333	175				455
Sharp Stewart	1896	4144	176				456
Dübs	1897	3437	177				457
Dübs	1897	3438	178				458
Dübs	1897	3439	179				459
Dübs	1897	3441	180				460
Dübs	1897	3442	181				461
Dübs	1897	3443	182		C509		462
Dübs	1897	3444	183		C510		463
Dübs	1897	3445	184				464
Dübs	1897	3446	185			21
Dübs	1897	3447	186				465	M707
Dübs	1897	3449	187				466
Dübs	1897	3450	188				467
Dübs	1897	3451	189				468
Dübs	1897	3452	190				469
Dübs	1897	3455	191				470
Dübs	1897	3456	192				471
Dübs	1897	3460	193				472	M708
Dübs	1897	3461	194				473
Dübs	1897	3462	195				474
Dübs	1897	3463	196				475	M709
Dübs	1897	3464	197				476
Dübs	1897	3465	198				477
Dübs	1897	3466	199		C503		478
Dübs	1897	3475	200		C501		479	M710
Dübs	1897	3476	201				480
Sharp Stewart	1896	4116	371	571			481
Sharp Stewart	1896	4117	372	572			482
Sharp Stewart	1896	4118	373	573			483
Sharp Stewart	1896	4119	374	574			484
Dübs	1897	3453	375	575			485
Dübs	1897	3454	376	576			486
Dübs	1897	3469	660				487
Dübs	1897	3470	661				488
Dübs	1897	3471	662				489

lllustration

The main picture shows Sharp Stewart-built ex Western System Class 6 no. 182, later IMR no. C509, then SAR Class 6A no. 462, with a Belpaire firebox, at De Aar on 15 April 1978.

Round-top fireboxes

• SAR Class 6A 466 (4-6-0).jpg

  Dübs-built ex Western System no. 187, SAR no. 466, with a round-topped firebox and a Wynberg Tender's tender

• Class 6A no. 460.jpg

  Dübs-built ex Western System no. 180, SAR no. 460, with a round-topped firebox and bogie tender

Belpaire fireboxes

• SAR Class 6A 461 (4-6-0).jpg

  Dübs-built ex Western System no. 181, SAR no. 461, with a Belpaire firebox and Type YC three-axle tender

• SAR Class 6A 482 (4-6-0) ex CGR 372-572.JPG

  Sharp, Stewart-built ex Midland System no. 372, SAR no. 482, with a bogie tender, Koedoespoort, 30 Sept. 2009