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South African Class A 4-8-2T

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NGR Class D1 & D2 4-8-2T
South African Class A 4-8-2T
SAR Class A Belpaire no. 196, ex NGR no 133, at Masons Mill, Pietermaritzburg, 10 December 2010
Type and origin
♠ - Round-top firebox
♥ - Belpaire firebox
Power typeSteam
DesignerNatal Government Railways
(William Milne)
BuilderDübs and Company
South African Railways
Serial number2446-2451, 2499-2504, 2604-2628, 2965-2967, 3317-3322, 3363-3368, 3477-3486, 3604-3605, 3556-3567, 3811-3834
Build date1888-1915
Total produced102
RebuilderSouth African Railways
Rebuild date1926
Number rebuilt21 to Class 17 4-8-0TT (Mastodon)
Specifications
Configuration:
​
 • Whyte4-8-2T (Mountain)
Driver2nd coupled axle
Gauge3 ft 6 in (1,067 mm) Cape gauge
Leading dia.25+3⁄4 in (654 mm)
Coupled dia.39 in (991 mm)
Trailing dia.25+3⁄4 in (654 mm)
Wheelbase24 ft 9 in (7,544 mm) ​
 • Leading5 ft (1,524 mm)
 • Coupled11 ft (3,353 mm)
Length:
​
 • Over couplers32 ft 6+1⁄2 in (9,919 mm)
Height♠ 12 ft 1⁄2 in (3,670 mm)
♥ 12 ft 2+1⁄2 in (3,721 mm)
Frame typePlate
Axle load♠ 8 LT 9 cwt (8,586 kg)
♥ 9 LT 4 cwt (9,348 kg) ​
 • Leading♠ 7 LT 18 cwt (8,027 kg)
♥ 7 LT (7,112 kg)
 • 1st coupled♠ 8 LT 2 cwt (8,230 kg)
♥ 8 LT 9 cwt (8,586 kg)
 • 2nd coupled♠ 8 LT 9 cwt (8,586 kg)
♥ 9 LT 4 cwt (9,348 kg)
 • 3rd coupled♠ 8 LT 2 cwt (8,230 kg)
♥ 8 LT 14 cwt (8,840 kg)
 • 4th coupled♠ 8 LT 2 cwt (8,230 kg)
♥ 8 LT 17 cwt (8,992 kg)
 • Trailing♠ 6 LT 10 cwt (6,604 kg)
♥ 6 LT 8 cwt (6,503 kg)
Adhesive weight♠ 32 LT 15 cwt (33,280 kg)
♥ 35 LT 4 cwt (35,760 kg)
Loco weight♠ 47 LT 3 cwt (47,910 kg)
♥ 48 LT 12 cwt (49,380 kg)
Fuel typeCoal
Fuel capacity♠♥ 2 LT 5 cwt (2.3 t)
Water cap.♠ 1,062 imp gal (4,830 L)
♥ 1,358 imp gal (6,170 L)
Firebox:​
 • Type♠ Round-top
♥ Belpaire
 • Grate area♠ 15.7 sq ft (1.46 m2)
♥ 23.5 sq ft (2.18 m2)
Boiler:
​
 • Pitch♠ 6 ft 7+1⁄2 in (2,019 mm)
♥ 7 ft (2,134 mm)
 • Diameter♠ 3 ft 11 in (1,194 mm)
♥ 3 ft 10+3⁄4 in (1,187 mm)
 • Tube plates♠♥ 10 ft 10+1⁄8 in (3,305 mm)
 • Small tubes♠ 178: 1+3⁄4 in (44 mm)
♥ 187: 1+3⁄4 in (44 mm)
Boiler pressure♠ 140 psi (965 kPa)
♥ 160 psi (1,103 kPa)
Safety valve♠ Salter & Ramsbottom
♥ Ramsbottom
Heating surface:​
 • Firebox♠ 90.18 sq ft (8.378 m2)
♥ 62 sq ft (5.8 m2)
 • Tubes♠ 888.20 sq ft (82.516 m2)
♥ 929.5 sq ft (86.35 m2)
 • Total surface♠ 978.38 sq ft (90.894 m2)
♥ 991.5 sq ft (92.11 m2)
CylindersTwo
Cylinder size17 in (432 mm) bore
21 in (533 mm) stroke
Valve gearStephenson
Valve typeSlide
CouplersBell link-and-pin
AAR knuckle (1950s)
Performance figures
Tractive effort♠ 16,340 lbf (72.7 kN) @ 75%
♥ 18,660 lbf (83.0 kN) @ 75%
Factor of adh.3.99
Career
OperatorsNatal Government Railways
South African Railways
Class♠ NGR Class D1, SAR Class A
♥ NGR Class D2, SAR Class A Belpaire
Number in class102
NumbersNGR 49-148
SAR 97-186, 187-196, 332-333
Delivered1888-1915
First run1888
Withdrawn1962
The leading coupled axle had flangeless wheels

The South African Railways Class A 4-8-2T of 1888 was a steam locomotive from the pre-Union era in the Natal Colony.

In 1888, the Natal Government Railways placed the first five of its eventual one hundred Class D 4-8-2T tank steam locomotives in service. The last was delivered in 1899. They were the first locomotives in the world to be built with a 4-8-2 wheel arrangement, later to become known as the Mountain type. In 1912, when these locomotives were assimilated into the South African Railways, they were renumbered and designated Class A. In 1915, another two Class A locomotives were built from spare parts.[1][2]

Manufacturers

The Natal Government Railways (NGR) Class D 4-8-2T tank locomotive was designed by William Milne, the Locomotive Superintendent of the NGR from 1877 to 1896, and was built by Dübs and Company. The first 42 locomotives, with an operating boiler pressure of 140 pounds per square inch (965 kilopascals) and numbered in the range from 49 to 90, were placed in service during Milne's term. They proved to be such good engines that, when G.W. Reid took over as Locomotive Superintendent in 1896, he continued to place further orders for another 58, numbered in the range from 91 to 148, but with the boiler pressure increased to 160 pounds per square inch (1,103 kilopascals). These 100 locomotives, initially known on the NGR as the Dübs A, were delivered in ten batches by Dübs between 1888 and 1899.[1][3][4]

As far as is known, the Dübs A locomotives were the first in the world to be designed and built with a 4-8-2 wheel arrangement, later to become known as the Mountain type.[1]

Modifications

The performance in service of the Dübs A was gradually improved by various modifications. New boilers were fitted as and when the originals needed replacement, with a working pressure of 160 pounds per square inch (1,103 kilopascals) instead of the as-delivered 140 pounds per square inch (965 kilopascals) of the first few batches. This increased their tractive effort at 75% boiler pressure from 16,340 pounds-force (72.7 kilonewtons) to 18,670 pounds-force (83.0 kilonewtons). The coal bunkers were also enlarged and the connecting rod big-ends were changed to the marine type, to increase ground clearance.[1][3]

Beginning in 1905, after D.A. Hendrie took over from Reid as Locomotive Superintendent, these locomotives were gradually fitted with Belpaire fireboxes with wider firegrates. The flat-topped Belpaire firebox had the advantage of an increased area of the water-line at the hottest part of the boiler, together with increased steam space over the firebox. In order to accomplish this, Hendrie raised the boiler's pitch by 4+1⁄2 inches (114 millimetres) and cut away the frame under the firebox to accommodate the wider grates. The wider firebox required that the water tanks also had to be moved out and the opportunity was taken to enlarge the tanks. The cabs were also improved, to offer the engine crew better protection, and new brass-capped chimneys replaced the original straight flared chimneys. These modified locomotives were known as the Improved Dübs A.[1][3]

When a locomotive classification system was introduced on the NGR, the Dübs A locomotive family was designated Class D. The unmodified locomotives became the Class D1, while the modified locomotives with Belpaire fireboxes became the Class D2.[1][5][6]

South African Railways

When the Union of South Africa was established on 31 May 1910, the three Colonial government railways (Cape Government Railways, NGR 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 required careful planning and was only implemented with effect from 1 January 1912.[7][8]

In 1912, these engines were designated Class A and were renumbered in the range from 97 to 196, with the unmodified Class D1 locomotives receiving the numbers in the range from 97 to 186 and the ten, at the time, already reboilered Class D2 locomotives receiving the numbers in the range from 187 to 196. In South African Railways (SAR) service, the Improved Dübs A locomotives became known as the Class A Belpaire.[7][9]

In 1915, to help counter wartime motive power shortages, brought about by the diminished ability to order new locomotives from European builders because of the hostilities, another two Class A locomotives were built from spare parts by the SAR in their Durban shops. These two locomotives were numbered 332 and 333.[9]

Service

In the NGR era, the Class D fleet remained in service on the Natal mainline, until they were eventually displaced by more modern locomotives. They continued to serve on the Dundee-Hlobane branchline, the Harrismith-Ladysmith section and on the north coast line to Empangeni well into the SAR era. The last of the Class A was withdrawn from service in 1962.[9]

Several locomotives continued to serve in industrial use for many years. A few survive in preservation.[1]

  • Ex NGR no. 84, SAR no. 130 named "Patrys", is plinthed at the Reefsteamers Depot in Germiston.[10]
  • Ex NGR no. 90, SAR no. 136 named "Umbilo", is in the care of the Umgeni Steam Railway.[11]
  • Ex NGR no. 55, SAR no. 103, was moved from Witbank to the Outeniqua Transport Museum in George in August 2014.
  • Ex NGR no 133, SAR Class A Belpaire no. 196, is plinthed at Masons Mill in Pietermaritzburg.

Rebuilding to Class 17 4-8-0TT

Class 17 4-8-0TT

When a shortage of suitable shunting locomotives developed in 1926, the SAR modified 21 Class A and Class A Belpaire 4-8-2T locomotives by removing the trailing bissel bogie and coal bunker, shortening the main frame and adding a tender to increase their coal and water capacity.[3][9]

Tenders from various scrapped locomotive types were used, probable tender models being three-axle Type YB, YC (as in the picture alongside), YE and YE1 tenders, as well as the Type XC1 four-axle tender, as depicted in the official SAR locomotive diagram.[2]

These 21 rebuilt locomotives became the SAR Class 17 4-8-0 tank-and-tender locomotives, numbered in the range from 1415 to 1435. They were used as shunting locomotives around Durban and Port Elizabeth, until they were withdrawn from service by 1961.[3][9]

Works numbers

The builder's works numbers, years built, NGR and SAR numbers, firebox type and Class 17 numbers are listed in the table.

Illustration

The main picture shows SAR Class A Belpaire no. 196 at Masons Mill, Pietermaritzburg, on 10 December 2010. The following pictures illustrate some of the post delivery changes which were made, such as the altered cab for better crew protection.

  • NGR Class D1 no. 105, as built, c. 1900, SAR Class A no. 151
    NGR Class D1 no. 105, as built, c. 1900, SAR Class A no. 151
  • NGR Class D1 no. 72, as built, c. 1900, SAR Class A Belpaire no. 192
    NGR Class D1 no. 72, as built, c. 1900, SAR Class A Belpaire no. 192
  • NGR Class D1 no. 84, SAR Class A no. 130, Reefsteamers, 17 May 2009
    NGR Class D1 no. 84, SAR Class A no. 130, Reefsteamers, 17 May 2009

References

  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. 90–93. ISBN 978-0-7153-5382-0.
  2. ^ a b South African Railways and Harbours Locomotive Diagram Book, 2'0" & 3'6" Gauge Steam Locomotives, 15 August 1941, as amended
  3. ^ a b c d e Espitalier, T.J.; Day, W.A.J. (1944). The Locomotive in South Africa - A Brief History of Railway Development. Chapter III - Natal Government Railways. (Continued). South African Railways and Harbours Magazine, June 1944. pp. 422-423.
  4. ^ Pattison, R.G. (1997). The Cape Seventh Class Locomotives (1st ed.). Kenilworth, Cape Town: The Railway History Group. p. 6. ISBN 0958400946.
  5. ^ Durrant, AE (1989). Twilight of South African Steam (1st ed.). Newton Abbott: David & Charles. p. 15. ISBN 0715386387.
  6. ^ The Railway Report for year ending 31 Dec. 1908, Natal Government Railways, p. 39, par 14.
  7. ^ a b Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer's Office, Pretoria, January 1912, pp. 7, 13, 20-22 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  8. ^ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
  9. ^ a b c d e Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 10–11, 26–27, 68. ISBN 0869772112.
  10. ^ Germiston, Reefsteamers Germiston Depot, "PATRYS" SAR Class A No 130
  11. ^ Class Dübs "A" "Umbilo"
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