South African Class NG8 4-6-0

South African Class NG8 4-6-0
Bagnall works photograph, circa 1903
Power type Steam
Designer W.G. Bagnall
Builder W.G. Bagnall
Kerr, Stuart and Company
Serial number Bagnall 1741-1746, 1967
Kerr, Stuart 1345-1346[1]
Model CGR Type B
Build date Bagnall 1903-1913
Kerr, Stuart 1913[2]
Total produced 9
Configuration 4-6-0 "Ten-wheeler" (USA)
Gauge 2 ft (610 mm)
Driver diameter 838 mm (33.0 in)
Wheelbase 3.988 m (13 ft 1.0 in) engine
1.905 m (6 ft 3.0 in) coupled
Length 13.535 m (44 ft 4.9 in)
Frame Bar frame[1]
Axle load 5.7 t (5.6 long tons) per driver
Weight on drivers 17 t (16.7 long tons)
Locomotive weight 20.6 t (20.3 long tons) w/o
Tender weight 21.1 t (20.8 long tons) w/o
Locomotive & tender
combined weight		 41.7 t (41.0 long tons) w/o
Fuel type Coal
Boiler pressure 180 psi (1,240 kPa)
Firegrate area 0.71 m2 (7.6 sq ft)
Heating surface:
Tubes		 35.38 m2 (380.8 sq ft)
Heating surface:
Firebox		 3.76 m2 (40.5 sq ft)
Heating surface:
Total		 39.14 m2 (421.3 sq ft)
Cylinders Two
Cylinder size 11.75 in (298 mm) bore
16 in (406 mm) stroke[2][3]
Valve gear Stephenson
Tractive effort 9,032 lbf (40.2 kN) at 75% boiler pressure[2]
Locomotive brakes Vacuum
Career Cape Government Railways
South African Railways
Class CGR Type B, Improved B
SAR Class NG8
Number in class 9
Number CGR 33-38[4]
SAR NG27-NG32, NG36-NG38
Delivered 1903-1914
First run 1903
Withdrawn 1931[2]
Disposition Retired

In 1903 the Cape Government Railways placed six "Type B" 4-6-0 steam locomotives in service on the Avontuur narrow gauge line in the Langkloof. In 1912, when these locomotives were assimilated into the South African Railways, they were renumbered with an "NG" prefix to their numbers.[2][4]

A further three "Improved B" locomotives were placed in service by the South African Railways in 1914. 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was eventually introduced somewhere between 1928 and 1930, they were to be classified as Class NG8 but had already been withdrawn from service.[2]

Contents

Manufacturer

The Cape Government Railways (CGR) ordered six narrow gauge locomotives with a 4-6-0 wheel arrangement and eight wheeled bogie tenders from W. G. Bagnall in 1903. They were numbered 33 to 38 when they were delivered in that same year, and were classified as Type B by the CGR.[2]

Characteristics

The design of the locomotive was based on the Baldwin built 2-6-0 locomotives that had been acquired for use on the Hopefield line a year earlier and, although these were built by a British company, they had the same typically American construction and appearance as the Baldwin locomotives. The order initially specified the same 2-6-0 wheel arrangement, but experience with the three Hopefield locomotives led to the decision to alter the design specifications to 4-6-0. They had bar frames, copper fireboxes and used Stephenson valve gear.[2]

South African Railways

In 1912, when the three colonial railways were amalgamated into the South African Railways (SAR), narrow gauge locomotives were included in the SAR’s narrow gauge numbering scheme and were allocated running numbers with an "NG" prefix. The six Type B locomotives were allocated SAR numbers NG27 to NG32.[4]

A further three locomotives with slightly longer boilers were ordered by the SAR in 1913. The first one of these was also built by Bagnall and delivered in 1914, numbered NG36. The other two were built by Kerr, Stuart and Company, also delivered in 1914 and numbered NG37 and NG38. These three locomotives were commonly referred to as the Improved B.[1][2]

Service

They were all placed in service on the Langkloof line between Port Elizabeth and Avontuur and became the mainstay of motive power on the Avontuur branch. Although they worked mainly in the Langkloof, some of them did end up on temporary service in Deutsch-Südwest-Afrika (DSWA, now Namibia) during World War I, while some also assisted on the Kalbaskraal branch to Saldanha and, judging from photographs, possibly in Natal as well.[2]

The nine locomotives were all withdrawn from service by 1931. One of them, number NG27, was sold to the Eastern Province Cement Company (EPCC) and employed to haul limestone on its industrial line that met with the Avontuur branch at Chelsea.[2]

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 NG8 that had apparently been reserved for them when the classification system was being planned.[2]

See also

References

  1. ^ a b c Plant, K.P. (1971). Kerr Stuarts for South Africa. The Industrial Railway Record, No. 37, June 1971. pp. 78-85.
  2. ^ a b c d e f g h i j k l Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 104, 113, 156. ISBN 0869772112. 
  3. ^ CGR-Typ B – German Wikipedia article
  4. ^ a b c 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)