South African Class 1A 4-8-0 Explained

NGR Class B 4-8-0 1910
South African Class 1A 4-8-0
Powertype:Steam
Designer:Natal Government Railways
(D.A. Hendrie)
Builder:North British Locomotive Company
Serialnumber:19051-19071
Buildmodel:NGR Hendrie B
Builddate:1910
Totalproduction:21
Whytetype:4-8-0 (Mastodon)
Uicclass:2'Dn2
Driver:2nd coupled axle
Leadingdiameter:NaN0NaN0
Coupleddiameter:460NaN0
Tenderdiameter:300NaN0
Wheelbase:50feet
Engine Total:22feet
Leading:60NaN0
Coupled:12feet
Tender Total:16feet
Tenderbogie:4feet
Over Couplers:57feet
Height:12feet
Frametype:Plate
Axleload:14lt
Leadingbogie/Pony:13lt
Coupled 1:14lt
Coupled 2:14lt
Coupled 3:13lt
Coupled 4:14lt
Tenderbogieload:Bogie 1: 20lt
Bogie 2: 20lt
Tenderaxle:10lt
Weightondrivers:57lt
Locoweight:70lt
Tenderweight:40lt
Locotenderweight:111lt
Tendertype:TJ (2-axle bogies)
TJ, TL, TM permitted
Fueltype:Coal
Fuelcap:61NaN1
Watercap:3500sigfig=3NaNsigfig=3
Fireboxtype:Belpaire & combustion chamber
Firearea:34square feet
Pitch:7feet
Diameterinside:5feet
Lengthinside:12feet
Smalltubediameter:325: 20NaN0
Boilerpressure:1900NaN0
Safetyvalvetype:Ramsbottom
Totalsurface:2188square feet
Tubearea:2056square feet
Fireboxarea:132square feet
Cylindercount:Two
Cylindersize:NaN0NaN0 bore
240NaN0 stroke
Valvegear:Walschaerts
Valvetype:Murdoch's D slide
Piston on no. 33
Coupling:Johnston link-and-pin
AAR knuckle (1930s)
Tractiveeffort:31240lbf @ 75%
Operator:Natal Government Railways
South African Railways
Operatorclass:NGR Class B
SAR Class 1A
Numinclass:21
Fleetnumbers:NGR 13-33
SAR 1289-1309
Deliverydate:1910
Firstrundate:1910
Withdrawndate:1974
Notes:The leading coupled axle had flangeless wheels

The South African Railways Class 1A of 1910 was a steam locomotive from the pre-Union era in the Colony of Natal.

In 1910, the Natal Government Railways placed 21 improved Class B Mastodon type tender locomotives in service. In 1912, when these locomotives were assimilated into the South African Railways, they were renumbered and designated Class 1A.[1]

Manufacturer

By 1909, more locomotives were required for goods operation on the lower sections of the Natal mainline and a further 21 locomotives of the Mastodon design were ordered by the Natal Government Railways (NGR). They were delivered and placed in service in 1910, built by the North British Locomotive Company with Type TJ tenders and numbered in the range from 13 to 33. These locomotives were also officially designated Class B and, since they incorporated various improvements on the locomotives of 1904, they became commonly known as the Class Improved Hendrie B.[1] [2] [3]

Characteristics

Like their predecessors, they had Belpaire fireboxes with combustion chambers and Walschaerts valve gear. While they were practically identical to the 1904 locomotives in most respects, their boilers had been raised by NaN0NaN0, which raised the boiler pitch by 10NaN0 to 7feet and gave a better rake on the sides of the ash pan.[1]

With one exception, they used Murdoch's D slide valves like the 1904 locomotives. The last locomotive, no. 33, was an experimental locomotive equipped with piston valves.[1]

Hendrie's steam reverser

They were built with Hendrie’s steam reversers. The Hendrie steam reversing gear consisted of a NaN0NaN0 diameter steam cylinder and a 50NaN0 diameter oil cylinder, arranged in line on a bracket which was fixed to the main engine frame on the driver's side. The cylinders had a common piston rod which had a slot in the centre, between the cylinders. This slot accommodated a sliding crosshead which engaged with an arm fixed to the reversing shaft.[1]

By means of a small lever, the driver could admit steam to either end of the steam cylinder, which would open a cataract valve arranged on top of the oil cylinder to allow oil to flow from either end of the oil cylinder to the other. A pointer in the cab would indicate the exact position of the reversing gear and, when the desired position was reached, bringing the hand lever to the central position would close the cataract valve and fix the gear in the forward or reverse position.[1]

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 were only implemented with effect from 1 January 1912.[4] [5]

In 1912, these locomotives were renumbered in the range from 1289 to 1309 and designated Class 1A on the South African Railways (SAR).[4]

Service

When new, they were used to haul fast passenger and goods trains between Durban and Pietermaritzburg. In SAR service, they were also used on mainline workings out of Port Elizabeth. In later years they were relegated to shunting, particularly working in Natal but also in Cape Town, Port Elizabeth, East London and in Transvaal. None of them was reboilered with a Watson Standard boiler with a round-topped firebox.

In their last years, few Class 1 and Class 1A locomotives were still at work. As at April 1973, for example, there were still three working at Mason’s Mill in Pietermaritzburg and one in the Eastern Transvaal, two of them Class 1A. The last Class 1A locomotive was retired by the SAR in November 1974.

In industrial service, no. 1301 survived longer and was still in service as Apex Mines no. 3 at Greenside in 1984. In 2019, 1301 was donated by Apex Mines to UK based North British Locomotive Preservation Group. It is planned to restore the locomotive at the Wonderboom Transport Museum, Pretoria before repatriating it to the UK.[6] [7]

Works numbers and renumbering

Their works numbers, numbering and SAR renumbering are listed in the table.[4] [2]

Preservation

One example has survived into preservation.

Illustration

The main picture shows a Class 1A locomotive with a modified Type TJ tender, while the following picture shows one with a Type TL tender which was rebuilt from a Type TJ tender c. 1930.[3]

Notes and References

  1. 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, July 1944. p. 505.
  2. North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  3. South African Railways and Harbours Locomotive Diagram Book, 2’0" & 3’6" Gauge Steam Locomotives, 15 August 1941, as amended
  4. Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer’s Office, Pretoria, January 1912, pp. 7, 12, 15, 44 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  5. The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
  6. NBL Group Aims to Repartiate Scottish-Designed 4-8-0 Steam Railway issue 499 November 2019 page 8
  7. North British Group save Hendrie-designed loco in South Africa The Railway Magazine issue 1424 November 2019 page 96