South African Class 8Z 2-8-0

South African Class 8Z 2-8-0
ex CGR 8th Class 2-8-0

Ex CGR 8th Class no. 825, SAR Class 8Z no. 904
Type and origin
Power type Steam
Designer Cape Government Railways
Builder North British Locomotive Company
Serial number 16095-16102 [1]
Model CGR 8th Class (2-8-0)
Build date 1904 [2]
Total produced 8
Specifications
Configuration 2-8-0 "Consolidation"
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Leading wheel
diameter		 28.5 in (724 mm)
Driver diameter 48 in (1,220 mm)
Wheelbase Total: 47 ft (14.326 m)
Engine:
14 ft 6 in (4.420 m) coupled
21 ft 8 in (6.604 m) total
Tender:
4 ft 7 in (1.397 m) bogie
14 ft 7 in (4.445 m) total
Length 54 ft 9.5 in (16.701 m)
Height 12 ft 10 in (3.912 m)
Frame Bar frame
Axle load 13 long tons (13.2 t) on 3rd & 4th drivers
Weight on drivers 41.4 long tons (42.1 t)
Locomotive weight 56.4 long tons (57.3 t)
Tender weight 42,234 lb (19.2 t) empty
41.6 long tons (42.3 t) w/o
Locomotive and tender
combined weight		 92.85 long tons (94.3 t)
Tender type XE1
* 2 axle bogies
* 34 in (864 mm) wheels
* Length 22 ft 1.625 in (6.747 m)
Fuel type Coal
Fuel capacity 10 long tons (10.2 t)
Water capacity 2,855 imp gal (12,980 l)
Boiler 4 ft 11 in (1.499 m) inside diameter
12 ft 5.6875 in (3.802 m) inside length
7 ft 31 in (2.921 m) pitch
Boiler pressure 180 psi (1,240 kPa)
Firegrate area 32 sq ft (2.973 m2)
Heating surface:
– Tubes		 194 tubes 2 in (50.8 mm) diameter
1,355 sq ft (125.884 m2)
– Firebox 106 sq ft (9.848 m2)
– Total 1,461 sq ft (135.731 m2)
Cylinders Two
Cylinder size 18.5 in (470 mm) bore
24 in (610 mm) stroke
Valve gear Stephenson
Performance figures
Tractive effort 23,110 lbf (103 kN) at 75% pressure
Career
Operator(s) Cape Government Railways
South African Railways [2]
Class CGR 8th Class (2-8-0)
SAR Class 8Z
Number in class 8
Number(s) CGR 821-828, SAR 900-907 [3]
Delivered 1904
First run 1904
Withdrawn 1935 [4]

The South African Class 8Z 2-8-0 of 1904 is a South African steam locomotive from the pre-Union era in the Cape Colony.

In 1904 the Cape Government Railways placed its last eight 8th Class 2-8-0 Consolidation type steam locomotives in service. Most other Cape 8th Class locomotives were built with a 4-8-0 Mastodon type wheel arrangement. In 1912, when they were assimilated into the South African Railways, these eight were renumbered and reclassified to Class 8Z.[2][3]

Manufacturer

The first locomotive in the Cape Government Railways (CGR) 2-8-0 Consolidation type 8th Class, later to become the South African Railways (SAR) Class 8X, was designed by H.M. Beatty, the CGR’s Chief Locomotive Superintendent from 1896 to 1910.[2]

In 1904 a third batch of eight of these locomotives was ordered from the North British Locomotive Company of Glasgow, Scotland. All eight were allocated to the Cape Western System of the CGR, numbered in the range from 821 to 828. After these, all subsequent CGR 8th Class locomotives were built with a 4-8-0 Mastodon wheel arrangement.[1][2]

Characteristics

These locomotives were very similar to the previous four Kitson-built Consolidations, but slightly larger in boiler and firegrate area dimensions. They also used saturated steam and cylinders with overhead slide valves actuated by inside Stephenson valve gear. Of the three models of type XE1 tender that were in use at the time, these locomotives were equipped with the version that had the largest coal capacity.[2][3][4]

Class 8 sub-classes

The Union of South Africa was established on 31 May 1910, in terms of the South Africa Act, enacted by the Parliament of the United Kingdom. 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.[5]

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.[3]

In 1912 these locomotives were designated Class 8Z on the SAR and renumbered in the range from 900 to 907.[2][3][4]

In spite of the difference in wheel arrangement, the CGR grouped its 2-8-0 Consolidation and post Class 7 4-8-0 Mastodon locomotives together as the 8th Class. In 1912 all these 2-8-0 and 4-8-0 locomotives, together with the Class 8-L1 to Class 8-L3 4-8-0 Mastodon locomotives from the Central South African Railways (CSAR), were grouped into ten different sub-classes by the SAR. The 4-8-0 locomotives became SAR Classes 8 and 8A to 8F and the 2-8-0 locomotives became Classes 8X to 8Z.[2][4][6]

Service

In SAR service, the 2-8-0 Class 8Z was used mainly in the Western Cape, shedded at Touwsrivier. A few later ended up at Bloemfontein in the Orange Free State and Klerksdorp in Transvaal. They were withdrawn by 1935.[4]

Sides illustrated

The main picture and the following serve to illustrate the locomotive from both sides.

See also

References

  1. ↑ 1.0 1.1 North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Holland, D.F. (1971). Steam Locomotives of the South African Railways, Volume 1: 1859-1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 64–66. ISBN 978-0-7153-5382-0.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer’s Office, Pretoria, January 1912, pp. 9, 12, 15, 36 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  4. ↑ 4.0 4.1 4.2 4.3 4.4 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. p. 50. ISBN 0869772112.
  5. ↑ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
  6. ↑ South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended