South African Class 6K 4-6-0

South African Class 6K 4-6-0
Ex CGR Class 6, SAR Class 6K
Power type Steam
Designer Cape Government Railways
Baldwin Locomotive Works
Builder Baldwin Locomotive Works
Serial number 18319-18322, 18348-18353
Model CGR Class 6
Build date 1901[1]
Total produced 10
Configuration 4-6-0 "Ten-wheeler" (USA)
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: 50 ft 1 in (15.265 m)
Engine:
6 ft (1.829 m) pilot
11 ft 8 in (3.556 m) coupled
21 ft 4 in (6.502 m) total
Tender:
4 ft 8 in (1.422 m) bogie
13 ft 8 in (4.166 m) total
Length 57 ft 6.25 in (17.532 m)
Height 12 ft 6 in (3.810 m)
Frame Bar frame
Axle load 13.65 long tons (13.9 t) on 2nd driver
Weight on drivers 39.05 long tons (39.7 t)
Locomotive weight 48.2 long tons (49.0 t)
Tender weight 32.6 long tons (33.1 t)
Locomotive & tender
combined weight		 80.8 long tons (82.1 t)
Tender type 2 axle bogies
Wheels 33 in (838 mm) dia
Fuel type Coal
Fuel capacity 5 long tons (5.1 t)
Water capacity 3,360 imp gal (15,300 l)
Boiler 4 ft 10.75 in (1.492 m) int dia
11 ft 10.625 in (3.623 m) int length
6 ft 11 in (2.108 m) pitch
Boiler pressure 180 psi (1,240 kPa)
Firegrate area 19 sq ft (1.765 m2)
Heating surface:
Tubes		 182 tubes 2 in (50.8 mm) ext dia
1,195 sq ft (111.019 m2)
Heating surface:
Firebox		 113 sq ft (10.498 m2)
Heating surface:
Total		 1,308 sq ft (121.517 m2)
Cylinders Two
Cylinder size 17.5 in (445 mm) bore
26 in (660 mm) stroke
Valve gear Stephenson
Tractive effort 19,910 lbf (88.6 kN) at 75% boiler pressure[1]
Career Cape Government Railways
South African Railways
Class CGR Class 6, SAR Class 6K
Number in class 10
Number CGR 301-305, 795-799
SAR 649-658[1][2][3]
Delivered 1901
First run 1901
Withdrawn 1928[4]
Disposition Retired

In 1901 ten American built Class 6 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 reclassified to Class 6K.[1][2][4]

Contents

Manufacturer

The Class 6 was designed at the Salt River works of the Cape Government Railways (CGR) at the same time as the Class 7. Whereas the Class 7 was conceived primarily as a goods locomotive, the Class 6 was intended to be its fast passenger service counterpart.[1]

The ten Class 6 locomotives that were placed in service by the CGR in 1901 were designed and built by the Baldwin Locomotive Works to the specifications of the CGR locomotive department and were consequently somewhat different in appearance from most previous Cape Class 6 locomotives. They were larger than any of the previous Class 6 locomotives. Like the Schenectady built Class 6G, they had larger boilers, large cabs and 17.5 inches (445 millimetres) bore cylinders compared to the 17 inches (432 millimetres) bore cylinders of all other Class 6 locomotives. They had bar frames, stovepipe chimneys and large domes and were the only Class 6 locomotives which did not have Ramsbottom safety valves, having been equipped with the "pop" type.[1]

Apart from the stovepipe chimney, a visually obvious distinction was their driving wheel counterweights that were shaped like bent rectangles, instead of the usual curved and tapered counterweights that were used on most South African locomotives. Like other second generation Class 6 locomotives, they had higher running boards without driving wheel fairings. They were numbered 301 to 305 for the Western System of the CGR and 795 to 799 for the Eastern System.[1][5]

Class 6 sub-classes

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

The rest of the CGR’s Class 6 locomotives, together with the Central South African Railways (CSAR) Classes 6-L1 to 6-L3 locomotives that were inherited from the Oranje-Vrijstaat Gouwermentspoorwegen (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][3][5]

Service

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" 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]

In SAR service the Class 6K locomotives worked on the East London main line until they were withdrawn by 1928.[4]

Renumberings

The Class 6K running number sequence does not correspond with its builder’s works number sequence. The table shows the Class 6K works numbers, CGR running numbers and SAR renumbering.[1][2][3]

See also

References

  1. ^ a b c d e f g h i Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 50-52, 56. ISBN 0715353829. 
  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 c Holland, D.F. (1972). Steam Locomotives of the South African Railways, Volume 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. p. 138. ISBN 0715354272. 
  4. ^ a b c Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 41-44. ISBN 0869772112. 
  5. ^ a b South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended