South African Class 6B 4-6-0

CGR 6th Class 4-6-0 1897
South African Class 6B 4-6-0

CGR 6th Class no. 206, SAR Class 6B no. 494, c. 1930
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
Neilson and Company
Neilson, Reid and Company
Serial number Dübs 3467-3468, 3472-3474
Neilson 5120-5125, 5128-5129, 5131-5159
Neilson, Reid 5273-5279, 5319-5324
Model CGR 6th Class
Build date 1897-1898
Total produced 55
Specifications
Configuration 4-6-0 (Tenwheeler)
Driver 2nd coupled axle
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Leading dia. 28 1⁄2 in (724 mm)
Coupled dia. 54 in (1,372 mm)
Tender wheels 33 1⁄2 in (851 mm) as built
34 in (864 mm) retyred
Wheelbase 46 ft 6 1⁄4 in (14,180 mm)
 • Engine 20 ft 3 3⁄4 in (6,191 mm)
 • Leading 5 ft 5 1⁄2 in (1,664 mm)
 • Coupled 11 ft (3,353 mm)
 • Tender 16 ft 1 in (4,902 mm)
 • Tender bogie 4 ft 7 in (1,397 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 53 ft 9 3⁄4 in (16,402 mm)
Height ♠ 12 ft 10 in (3,912 mm)
♥ 12 ft 10 3⁄8 in (3,921 mm)
Frame type Plate
Axle load ♠ 12 LT 3 cwt (12,340 kg)
♥ 13 LT 8 cwt (13,620 kg)
 • Leading ♠ 11 LT 17 cwt (12,040 kg)
♥ 10 LT 17 cwt 2 qtr (11,050 kg)
 • Coupled ♥ 13 LT 8 cwt (13,620 kg)
 • 1st coupled ♠ 10 LT 7 cwt (10,520 kg)
 • 2nd coupled ♠ 11 LT 18 cwt (12,090 kg)
 • 3rd coupled ♠ 12 LT 3 cwt (12,340 kg)
 • Tender bogie Bogie 1: 16 LT 12 cwt (16,870 kg)
Bogie 2: 17 LT 13 cwt (17,930 kg)
 • Tender axle 8 LT 16 cwt 2 qtr (8,967 kg)
Adhesive weight ♠ 34 LT 8 cwt (34,950 kg)
♥ 40 LT 4 cwt (40,850 kg)
Loco weight ♠ 46 LT 5 cwt (46,990 kg)
♥ 51 LT 1 cwt 2 qtr (51,890 kg)
Tender weight 34 LT 5 cwt (34,800 kg)
Total weight ♠ 80 LT 10 cwt (81,790 kg)
♥ 85 LT 6 cwt 2 qtr (86,690 kg)
Tender type XC1 (2-axle bogies)
XC, XC1, XD, XE, XE1, XF, XF1, XF2, XJ, XM, XM1, XM2, XM3, XM4 permitted
Fuel type Coal
Fuel capacity 5 LT 10 cwt (5.6 t)
Water cap 2,600 imp gal (11,820 l)
Firebox type ♠ Round-top - ♥ Belpaire
 • Firegrate area ♠ 16.625 sq ft (1.5445 m2)
♥ 16.6 sq ft (1.54 m2)
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 ♠♥ 11 ft 2 1⁄8 in (3,407 mm)
 • Small tubes ♠ 185: 1 7⁄8 in (48 mm)
♥ 220: 2 in (51 mm)
Boiler pressure ♠ 160 psi (1,103 kPa)
♥ 180 psi (1,241 kPa)
Safety valve Ramsbottom
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 6B
Number in class 51
Numbers CGR 202-233, 577-584, 587-593, 595-600, 663-664
IMR C502, C504-C508, C512
Benguela 22-25
SAR 490-540
Sudan M711-M712
Delivered 1897-1898
First run 1897
Withdrawn 1973

The South African Railways Class 6B 4-6-0 of 1897 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

In 1897 and 1898, the Cape Government Railways placed a third batch of fifty-five 6th Class 4-6-0 steam locomotives in service, thirty-two on its Western System, twenty-one on its Midland System and two on its Eastern System. During the Second Boer War seven were transferred to the Imperial Military Railways on loan, and in 1907 four were sold to the Benguela Railway in Angola. In 1912, when the remaining fifty-one locomotives were assimilated into the South African Railways, they were renumbered and reclassified to Class 6B. During the Second World War, two of them were sold to the Sudan Railways.[1][2][3]

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, then Chief Locomotive Superintendent of the CGR, and under the supervision of H.M. Beatty, then Locomotive Superintendent of the Cape Western System.[1]

H.M. Beatty

The fifty-five locomotives in the third group were built between 1897 and 1898 by Dübs and Company and Neilson and Company. While they were being built, in 1898, the firm of Neilson and Company changed its name to Neilson, Reid and Company. Five of these locomotives were built by Dübs and of the remaining fifty, thirty-seven were delivered as built by Neilson and the last thirteen as built by Neilson, Reid.[1][4]

All five Dübs-built locomotives, numbered in the range from 577 to 581, and the thirteen Neilson, Reid-builts, numbered in the ranges from 587 to 593 and 595 to 600, went to the Midland System. Of the thirty-seven Neilson-builts, thirty-two went to the Western System, numbered in the range from 202 to 233, three to the Midland System, numbered in the range from 582 to 584, and two to the Eastern System, numbered 663 and 664. Their respective works numbers and CGR engine numbers are tabled below.[1]

These locomotives were, to all intents and purposes, identical to the previous fifty which became the Class 6A, except that they had Type XC1 bogie tenders, instead of the three-axle Type YC tenders which were used with the earlier 6th Class locomotives.[1]

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 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 required careful planning and was only implemented with effect from 1 January 1912.[2][5]

In 1912, all but four of these fifty-five locomotives were assimilated into the SAR, designated Class 6B and renumbered in the range from 490 to 540.[2][6][7]

The rest of the CGR's 6th Class locomotives, together with those Class 6-L1 to 6-L3 locomotives which were inherited by the Central South African Railways (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, 6A, 6C to 6H and 6J to 6L, the 2-6-2 locomotives became Class 6Y and the 2-6-4 locomotives became Class 6Z.[2][6][7]

Modifications

Several of the CSAR's Class 6-L1 to 6-L3 locomotives had been modified by P.A Hyde, Chief Mechanical Engineer (CME) of the CSAR, by having their round-top fireboxes replaced with larger 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.[3]

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.[3][7]

Service

Imperial Military Railways

Seven of these locomotives saw service with the IMR during the Second Boer War, on loan from the CGR and temporarily renumbered for the duration of the war.[1]

South African Railways

The 6th Class series 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 Natal, and on all types of traffic.[1]

Benguela Railway

In 1907, four of these locomotives were sold to the Benguela Railway (Caminho de Ferro de Benguela – CFB) in Angola. These, therefore, did not see SAR service. In the mid-1930s, in order to ease maintenance, modifications were made to the running boards and brake gear of the CFB locomotives. The former involved mounting the running boards higher, thereby getting rid of the coupled wheel fairings. This gave the locomotives a much more American rather than British appearance.[8][9]

Sudan Railways

During the Second World War, 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 two Class 6B locomotives in this group were numbers 534 and 538. They were sold to the Sudan Railways Corporation in 1942 and renumbered M711 and M712, in the same order as their former SAR engine numbers.[1][3][10]

Renumberings

During their long service lives, some of the Class 6A locomotives underwent multiple renumberings. All were initially numbered into the CGR's three systems, in the number ranges from 202 to 233 on the Western System, 577 to 584, 587 to 593 and 595 to 600 on the Midland System, and 663 and 664 on the Eastern System. The seven locomotives which were loaned to the IMR, were renumbered C502, C504 to C508 and C512 for the duration of their military service, while the four sold to Angola became the Benguela Railway's numbers 22 to 25.[1]

On the four Benguela locomotives, sources are inconclusive about the renumbering, in respect of which particular CGR locomotive became which particular CFB locomotive. The numbers as listed were arrived at by a process of elimination.[8]

In 1912, the remaining fifty-one locomotives were renumbered in the number range from 490 to 540 on the SAR. The table reflects all these renumberings, as well as their builders and works numbers.[1][2][4][6]

Illustration

The main picture shows Neilson-built ex CGR Western System 6th Class no. 206, later renumbered to SAR Class 6B no. 494 and reboilered with a Belpaire firebox, on the old Cape Town turntable. The locomotives in the following pictures all have round-top fireboxes.

References

  1. 1 2 3 4 5 6 7 8 9 10 Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 46–47, 57. ISBN 978-0-7153-5382-0.
  2. 1 2 3 4 5 Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer's Office, Pretoria, January 1912, pp. 8, 12, 14, 30-31 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  3. 1 2 3 4 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 41–44. ISBN 0869772112.
  4. 1 2 Neilson, Reid works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  5. ↑ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
  6. 1 2 3 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.
  7. 1 2 3 South African Railways and Harbours Locomotive Diagram Book, 2'0" & 3'6" Gauge Steam Locomotives, 15 August 1941, as amended
  8. 1 2 Information supplied by Peter Bagshawe
  9. ↑ British Overseas Railways Historical Trust, Journal No. 8 & 9
  10. ↑ Class 6 to 6D sold to Sudan Railways during the WWII North African Campaign, list compiled by Austrian locomotive historian Reimar Holzinger
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