South African Class 1B 4-8-2

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NGR Class B 4-8-2 1906
South African Class 1B 4-8-2
SAR Klasse 1B.jpg
SAR Class 1B no. 1445, ex NGR Class B no. 324
Type and origin
Power typeSteam
DesignerNatal Government Railways
(D.A. Hendrie)
BuilderNorth British Locomotive Company
Natal Government Railways
Serial number16414-16419
ModelNGR Class B
Build date1906
Total produced6
RebuilderSouth African Railways
Rebuild date1926-1928
Number rebuilt6 to SAR Class 1 4-8-0 (Mastodon)
 • Whyte4-8-2 (Mountain)
 • UIC2'D1'n2
Driver2nd coupled axle
Gauge3 ft 6 in (1,067 mm) Cape gauge
Leading dia.28 12 in (724 mm)
Coupled dia.45 12 in (1,156 mm)
Trailing dia.28 12 in (724 mm)
Tender wheels30 in (762 mm)
Wheelbase49 ft 58 in (14,951 mm)
 • Engine27 ft 6 in (8,382 mm)
 • Leading6 ft (1,829 mm)
 • Coupled12 ft 9 in (3,886 mm)
 • Tender15 ft 6 in (4,724 mm)
 • Tender bogie4 ft 6 in (1,372 mm)
 • Over couplers56 ft 4 78 in (17,193 mm)
Height12 ft 6 in (3,810 mm)
Frame typePlate
Axle load14 LT 17 cwt (15,090 kg)
 • Leading12 LT 2 cwt (12,290 kg)
 • 1st coupled14 LT 2 cwt (14,330 kg)
 • 2nd coupled14 LT 17 cwt (15,090 kg)
 • 3rd coupled14 LT (14,220 kg)
 • 4th coupled13 LT (13,210 kg)
 • Trailing2 LT 10 cwt (2,540 kg)
 • Tender bogieBogie 1: 18 LT 18 cwt (19,200 kg)
Bogie 2: 19 LT 1 cwt (19,360 kg)
 • Tender axle9 LT 10 cwt 2 qtr (9,678 kg)
Adhesive weight55 LT 19 cwt (56,850 kg)
Loco weight70 LT 11 cwt (71,680 kg)
Tender weight37 LT 19 cwt (38,560 kg)
Total weight108 LT 10 cwt (110,200 kg)
Tender typeSH (2-axle bogies)
SH, SK permitted
Fuel typeCoal
Fuel capacity6 LT (6.1 t)
Water cap3,225 imp gal (14,700 l)
Firebox typeBelpaire & combustion chamber
 • Firegrate area34 sq ft (3.2 m2)
 • Pitch7 ft 3 in (2,210 mm)
 • Diameter5 ft 4 34 in (1,645 mm)
 • Tube plates12 ft 1 in (3,683 mm)
 • Small tubes325: 2 in (51 mm)
Boiler pressure190 psi (1,310 kPa)
Safety valveRamsbottom
Heating surface2,222.8 sq ft (206.50 m2)
 • Tubes2,094.17 sq ft (194.555 m2)
 • Firebox128.63 sq ft (11.950 m2)
Cylinder size20 12 in (521 mm) bore
24 in (610 mm) stroke
Valve gearWalschaerts
Valve typeMurdoch's D slide
CouplersJohnston link-and-pin
AAR knuckle (1930s)
Performance figures
Tractive effort31,600 lbf (141 kN) @ 75%
OperatorsNatal Government Railways
South African Railways
ClassNGR Altered Class B
SAR Class 1B
Number in class6
NumbersNGR 319-324
SAR 1440-1445
First run1906
The leading coupled axle had flangeless wheels

The South African Railways Class 1B 4-8-2 of 1904 was a steam locomotive from the pre-Union era in the Colony of Natal.

In 1904, the Natal Government Railways placed fifty Class B locomotives with a 4-8-0 Mastodon wheel arrangement in service. Of these, six were modified in 1906 to Altered Class B locomotives, the first tender engines in the world with a 4-8-2 Mountain wheel arrangement. In 1912, when these six engines were assimilated into the South African Railways, they were renumbered and designated Class 1B.[1][2][3][4]


At the time when D.A. Hendrie was appointed as the Locomotive Superintendent of the Natal Government Railways (NGR), it had a large fleet of tank locomotives with an inherent limited coal and water range. It was also often necessary to double- and even triple-head trains over the worst sections of the mainline with its steep 1 in 30 (3⅓%) gradients. Hendrie was therefore tasked to produce a locomotive of greater power and capable of longer distances without refuelling or rewatering. His resulting Hendrie B achieved this and fifty such locomotives were delivered from the North British Locomotive Company (NBL) in 1904.[1][2][4][5]


D.A. Hendrie

The engines used saturated steam and had plate frames, Belpaire fireboxes, Walschaerts valve gear and "D" slide valves. While the boiler was not pitched very high, Hendrie had still managed to extend the firebox sideways over the trailing driving wheels, with the result that the grate was almost on a level with the bottom of the boiler shell. To prevent the fire from entering the lower row of tubes, Hendrie arranged a vertical firewall towards the front of the grate, which created a dry combustion chamber.[2][4]


The first Mountain[edit]

In 1906, six of these locomotives with numbers in the range from 319 to 324, were modified to a 4-8-2 wheel arrangement by adding a trailing bissel truck below the cab. The modification was deemed necessary to ensure extra smooth running while hauling fast passenger trains. This modification turned them into the NGR’s Altered Class B, the first 4-8-2 Mountain type tender locomotives in the world.[1][2][6]

Steam reverser[edit]

Beginning in 1907, these locomotives were equipped with steam reversing gear, also designed by Hendrie. All Hendrie’s locomotives also came equipped with piston tail rods, but since they were difficult and costly to maintain, they were removed in 1925.[1][2][4]

South African Railways[edit]

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.[3][7]

Class 1B 1440 (4-8-2).JPG

In 1912, these six Mountain types were renumbered in the range from 1440 to 1445 and designated Class 1B on the South African Railways (SAR).[1][2][3][4]

Between 1926 and 1928, new locomotives replaced the SAR Class 1B on mainline passenger service in Natal. Their trailing bissel trucks were then removed and, since they were once again identical to their sister Class 1 4-8-0 Mastodon types, they were all reclassified to Class 1. Instead of replacing the cabside number plates upon reclassification, the "B" of "1B" was ground or milled off.[1][4]


In their later years, the locomotives were relegated to shunting, particularly working in Natal but also in Cape Town, Port Elizabeth, East London and in Transvaal. The last of the class was withdrawn in 1975. In industrial service, no. 1443 was still in service in 1984 as Gledhow Sugar Mill's no. 1, Chaka. The engine still survives and is owned by the North British Locomotive Preservation Group.[4][5][8]

Works numbers and renumbering[edit]

The works numbers and renumbering of the Class 1B are listed in the table.[1][9][10]


  1. ^ a b c d e f g Holland, D.F. (1971). Steam Locomotives of the South African Railways. 1: 1859–1910 (1st ed.). Newton Abbott, Devon: David & Charles. pp. 99–101. ISBN 978-0-7153-5382-0.
  2. ^ a b c d e f 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. pp. 504-505.
  3. ^ a b c Classification of S.A.R. Engines with Renumbering Lists, issued by the Chief Mechanical Engineer’s Office, Pretoria, January 1912, pp. 7, 12, 15, 45 (Reprinted in April 1987 by SATS Museum, R.3125-6/9/11-1000)
  4. ^ a b c d e f g Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 34–35. ISBN 0869772112.
  5. ^ a b Durrant, A. E. (1989). Twilight of South African Steam (1st ed.). Newton Abbott, London: David & Charles. p. 54. ISBN 0715386387.
  6. ^ South African Railways and Harbours Locomotive Diagram Book, 2’0” & 3’6” Gauge Steam Locomotives, 15 August 1941, as amended
  7. ^ The South African Railways - Historical Survey. Editor George Hart, Publisher Bill Hart, Sponsored by Dorbyl Ltd., Published c. 1978, p. 25.
  8. ^ Sandstone Heritage Trust - 2017016 Locomotive status - January 2017. (Accessed on 3 December 2017)
  9. ^ North British Locomotive Company works list, compiled by Austrian locomotive historian Bernhard Schmeiser
  10. ^ Holland, D. F. (1972). Steam Locomotives of the South African Railways. 2: 1910-1955 (1st ed.). Newton Abbott, Devon: David & Charles. p. 137. ISBN 978-0-7153-5427-8.