South African Class NG7 2-6-0

South African Class NG7 2-6-0
ex CGR Type A 2-6-0

Baldwin works photograph, circa 1902
Type and origin
Power type Steam
Designer Baldwin Locomotive Works
Builder Baldwin Locomotive Works
Serial number 19456, 19649, 19650, 36375
Build date 1901-1911 [1]
Total produced 4
Specifications
Configuration 2-6-0 "Mogul"
Gauge 2 ft (610 mm) narrow gauge
Driver diameter 838 mm (33 in)
Wheelbase 3.912 m (12 ft 10.0 in) engine
2.134 m (7 ft 0 in) coupled
Length 43 ft 9.75 in (13.354 m)
Frame Bar frame
Axle load 5.9 t (5.8 long tons) per driver
Weight on drivers 17.6 t (17.3 long tons)
Locomotive weight 19.9 t (19.6 long tons) w/o
Tender weight 21.1 t (20.8 long tons) w/o
Locomotive and tender
combined weight
41 t (40.4 long tons) w/o
Fuel type Coal
Boiler pressure 1,240 kPa (180 psi)
Firegrate area 0.71 m2 (7.6 sq ft)
Heating surface:
– Tubes
35.39 m2 (380.9 sq ft)
– Firebox 3.75 m2 (40.4 sq ft)
– Total 39.14 m2 (421.3 sq ft)
Cylinders Two
Cylinder size 298 mm (11.7 in) bore
406 mm (16 in) stroke [2]
Valve gear Stephenson
Performance figures
Tractive effort 9,032 lbf (40 kN) at 75% pressure
Career
Operator(s) Cape Government Railways
South African Railways
Class Class NG7 [1]
Number in class 4
Number(s) CGR 1-4
SAR NG22-NG24, NG35 [3]
Delivered 1902-1911
First run 1902
Withdrawn 1926 [1]

The South African Class NG7 2-6-0 of 1902 is a South African steam locomotive from the pre-Union era in the Cape Colony.

In 1902 the Cape Government Railways placed three steam locomotives with a 2-6-0 Mogul wheel arrangement in service on the Hopefield narrow gauge branchline that was being constructed from Kalbaskraal. A fourth locomotive was ordered in 1911.[1][3]

In 1912, when these locomotives were assimilated into the South African Railways, they were renumbered with an "NG" prefix to their numbers. When a system of grouping narrow gauge locomotives into classes was eventually introduced somewhere between 1928 and 1930, they were to be classified as Class NG7 but had already been withdrawn from service.[1][3]

Manufacturer

The Cape Government Railways (CGR) ordered three narrow gauge tender locomotives with a 2-6-0 Mogul wheel arrangement from Baldwin Locomotive Works in 1901. They were numbered 1 to 3 when they were delivered in 1902 and was known as the CGR Type A. A fourth locomotive, identical to the first three, was ordered from the same manufacturer in 1911 and became CGR number 4 upon delivery in that same year.[1]

Characteristics

The locomotives were of a standard type that was being used on the narrow gauge railroads of Maine in the United States of America. They had bar frames and used Stephenson valve gear.[1]

Service

Type A no. 2 at Hopefield, Feb 1903

The first three locomotives were acquired for use during the construction of the narrow gauge branchline from Kalbaskraal to Hopefield. They remained in service on that line after it was completed in 1903 and were joined by the fourth locomotive in 1911. In 1913 the line was extended to Saldanha, with a branch to Vredenburg. The four locomotives were withdrawn from service when these lines were widened to Cape gauge in 1926.[1][4]

Renumbering

The Union of South Africa was established on 31 May 1910, in terms of the South Africa Act. 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. 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][4]

In 1912 narrow gauge locomotives were included in the SAR’s narrow gauge numbering scheme and were allocated engine numbers prefixed with the letters NG for narrow gauge. The three 1902 locomotives were allocated SAR numbers NG22 to NG24, while the 1911 locomotive became no. NG35.[3]

Narrow gauge classification

A system of grouping narrow gauge locomotives into classes was only adopted at some time between 1928 and 1930. However, these locomotives did not survive in service long enough to become the Class NG7 that had apparently been reserved for them when the classification system was being planned.[1]

See also

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 104, 112. ISBN 0869772112.
  2. CGR Nr. NG 1 bis 3 – German Wikipedia article
  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. 12, 16, 47 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  4. 4.0 4.1 The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.