South African Class 6K 4-6-0

The South African Railways Class 6K 4-6-0 of 1901 was a steam locomotive from the pre-Union era in the Cape of Good Hope.

CGR 6th Class 4-6-0 1901 Baldwin
South African Class 6K 4-6-0
Ex CGR 6th Class, SAR Class 6K
Type and origin
Power typeSteam
DesignerCape Government Railways
Baldwin Locomotive Works
BuilderBaldwin Locomotive Works
Serial number18319-18322, 18348-18353
ModelCGR 6th Class
Build date1901
Total produced10
Specifications
Configuration:
 • Whyte4-6-0 (Tenwheeler)
 • UIC2'Cn2
Driver2nd coupled axle
Gauge3 ft 6 in (1,067 mm) Cape gauge
Leading dia.28+12 in (724 mm)
Coupled dia.54 in (1,372 mm)
Tender wheels33 in (838 mm)
Wheelbase50 ft 1 in (15,265 mm) ​
 • Axle spacing
(Asymmetrical)
1-2: 5 ft (1,524 mm)
2-3: 6 ft 8 in (2,032 mm)
 • Engine21 ft 4 in (6,502 mm)
 • Leading6 ft (1,829 mm)
 • Coupled11 ft 8 in (3,556 mm)
 • Tender13 ft 8 in (4,166 mm)
 • Tender bogie4 ft 8 in (1,422 mm)
Length:
 • Over couplers57 ft 6+14 in (17,532 mm)
Height12 ft 6 in (3,810 mm)
Frame typeBar
Axle load13 LT 13 cwt (13,870 kg) ​
 • Leading9 LT (9,144 kg)
 • 1st coupled12 LT 13 cwt (12,850 kg)
 • 2nd coupled13 LT 13 cwt (13,870 kg)
 • 3rd coupled12 LT 18 cwt (13,110 kg)
 • Tender bogieBogie 1: 15 LT 4 cwt (15,440 kg)
Bogie 2: 17 LT 8 cwt (17,680 kg)
Adhesive weight39 LT 4 cwt (39,830 kg)
Loco weight48 LT 4 cwt (48,970 kg)
Tender weight32 LT 12 cwt (33,120 kg)
Total weight80 LT 16 cwt (82,100 kg)
Tender type2-axle bogies
Fuel typeCoal
Fuel capacity5 LT (5.1 t)
Water cap.3,360 imp gal (15,300 L)
Firebox:
 • TypeRound-top
 • Grate area19 sq ft (1.8 m2)
Boiler:
 • Pitch6 ft 11 in (2,108 mm)
 • Diameter4 ft 10+34 in (1,492 mm)
 • Tube plates11 ft 10+58 in (3,623 mm)
 • Small tubes182: 2 in (51 mm)
Boiler pressure180 psi (1,241 kPa)
Safety valvePop
Heating surface:
 • Firebox113 sq ft (10.5 m2)
 • Tubes1,195 sq ft (111.0 m2)
 • Total surface1,308 sq ft (121.5 m2)
CylindersTwo
Cylinder size17+12 in (444 mm) bore
26 in (660 mm) stroke
Valve gearStephenson
CouplersJohnston link-and-pin
Performance figures
Tractive effort19,910 lbf (88.6 kN) @ 75%
Career
OperatorsCape Government Railways
South African Railways
ClassCGR 6th Class, SAR Class 6K
Number in class10
NumbersCGR 301-305, 795-799
SAR 649-658
Delivered1901
First run1901
Withdrawn1928
The 2nd coupled axle had flangeless wheels

In 1901, ten American-built 6th Class bar-framed steam locomotives with a 4-6-0 wheel arrangement were placed in service by the Cape Government Railways. In 1912, when they were assimilated into the South African Railways, they were renumbered and designated Class 6K.[1][2][3]

Manufacturer edit

The original Cape 6th Class locomotive was designed at the Salt River works of the Cape Government Railways (CGR) at the same time as the 7th Class.[1]

Three new versions of the 6th Class locomotive entered service on the CGR in 1901, two American-built and one British-built. Of the two American-built versions, one was designed and built by Baldwin Locomotive Works to the specifications of the CGR locomotive department. These ten engines were consequently somewhat different in appearance from most previous Cape 6th Class locomotives.[1]

Characteristics edit

They were larger than any of the previous 6th Class locomotives. Like the Schenectady-built Class 6G, they had larger boilers, large cabs and 17+12 inches (444 millimetres) bore cylinders, compared to the 17 inches (432 millimetres) bore cylinders of all the British-built 6th Class locomotives. They had bar frames, stovepipe chimneys and large domes and were the only 6th Class locomotives which were not delivered with Ramsbottom safety valves, having been equipped with the Pop type.[1]

Apart from the stovepipe chimney, a visually obvious distinction was their coupled wheel counterweights, which were shaped like bent rectangles, instead of the usual curved and tapered counterweights which were used on most South African locomotives. Like other second generation 6th Class locomotives, they had higher running boards without driving wheel fairings. They were numbered in the range from 301 to 305 for the CGR’s Western System and in the range from 795 to 799 for the Eastern System.[1][4]

Class 6 sub-classes edit

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 were only implemented with effect from 1 January 1912.[2][5]

When these ten locomotives were assimilated into the South African Railways (SAR) in 1912, they were renumbered in the range from 649 to 658 and designated Class 6K.[2][6]

The rest of the CGR's 6th Class locomotives, together with the Central South African Railways (CSAR) Classes 6-L1 to 6-L3 locomotives which had been inherited 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 to 6H, 6J and 6L, the 2-6-2 locomotives became Class 6Y and the 2-6-4 locomotives became Class 6Z.[2][4][6]

Service edit

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. It went on to see service in all parts of the country, except Natal, and was used on all types of traffic.[1]

In SAR service, the Class 6K locomotives worked on the East London mainline until they were withdrawn by 1928.[3]

Renumbering edit

The Class 6K engine number sequence does not correspond with its builder's works number sequence. The table lists the Class 6K works numbers, CGR engine numbers and SAR renumbering.[1][2][6]

References edit

  1. ^ a b c d e f g Holland, D.F. (1971). Steam Locomotives of the South African Railways. Vol. 1: 1859–1910 (1st ed.). Newton Abbott, England: David & Charles. pp. 50–52, 56. ISBN 978-0-7153-5382-0.
  2. ^ a b c d e Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer's Office, Pretoria, January 1912, pp. 8, 12, 14, 33 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  3. ^ a b Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 41–44. ISBN 0869772112.
  4. ^ a b South African Railways and Harbours Locomotive Diagram Book, 2'0" & 3'6" Gauge Steam Locomotives, 15 August 1941, as amended
  5. ^ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
  6. ^ a b c Holland, D. F. (1972). Steam Locomotives of the South African Railways. Vol. 2: 1910-1955 (1st ed.). Newton Abbott, England: David & Charles. p. 138. ISBN 978-0-7153-5427-8.