South African Class 1B 4-8-2

This article is about one of several different Natal Government Railways locomotive types to be designated "Class B". For other NGR Class B locomotives, see Natal Government Railways Class B locomotives.

NGR Class B 4-8-2 1906
South African Class 1B 4-8-2

SAR Class 1B no. 1445, ex NGR Class B no. 324

Type and origin Power type Steam Designer Natal Government Railways (D.A. Hendrie) Builder North British Locomotive Company Natal Government Railways Serial number 16414-16419 Model NGR Class B Build date 1906 Total produced 6 Rebuilder South African Railways Rebuild date 1926-1928 Number rebuilt 6 to SAR Class 1 4-8-0 (Mastodon)

Specifications Configuration 4-8-2 (Mountain) Driver axle 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia Coupled dia Trailing dia Tender wheels 30 in (762 mm) Wheelbase  • Engine 27 ft 6 in (8,382 mm)  • Leading 6 ft (1,829 mm)  • Coupled 12 ft 9 in (3,886 mm)  • Tender 15 ft 6 in (4,724 mm)  • Tender bogie 4 ft 6 in (1,372 mm) Length:  • Over couplers Height 12 ft 6 in (3,810 mm) Frame type Plate Axle load  • Leading  • 1st coupled  • 2nd coupled  • 3rd coupled  • 4th coupled  • Trailing  • Tender bogie Bogie 1: Bogie 2:  • Tender axle Adhesive weight Loco weight Tender weight w/o Loco & tender weight w/o Tender type SH (2-axle bogies) SH, SK permitted Fuel type Coal Fuel capacity 6 LT (6.1 t) Water cap Boiler:  • Pitch 7 ft 3 in (2,210 mm)  • Diameter  • Tube plates 12 ft 1 in (3,683 mm)  • Small tubes 325: 2 in (51 mm)  • Firebox type Belpaire with combustion chamber Boiler pressure 190 psi (1,310 kPa) Safety valve Ramsbottom Firegrate area 34 sq ft (3.2 m2) Heating surface 2,222.8 sq ft (206.50 m2)  • Tubes 2,094.17 sq ft (194.555 m2)  • Firebox 128.63 sq ft (11.950 m2) Cylinders Two Cylinder size bore 24 in (610 mm) stroke Valve gear Walschaerts Valve type "D" slide valves Couplers Bell link-and-pin

Performance figures Tractive effort 31,600 lbf (141 kN) @ 75%

Career Operators Natal Government Railways South African Railways Class NGR Altered Class B SAR Class 1B Number in class 6 Numbers NGR 319-324 SAR 1440-1445 Delivered 1906 First run 1906 Withdrawn 1935-1975

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 Natal Colony.

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 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 classified as Class 1B.

Manufacturer

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.

Characteristics

File:D.A. Hendrie.jpg

D.A. Hendrie

The engines used saturated steam and had plate frames, Walschaerts valve gear with "D" slide valves, and Belpaire fireboxes. 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.

Modifications

The first Mountain

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.

Steam reverser

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.

South African Railways

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

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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.

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).

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.

Service

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 the 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.

Works numbers and renumbering

The works numbers and renumbering of the Class 1B are listed in the table.

NGR Class B 4-8-2 of 1906
SAR Class 1B 4-8-2

Works no.	NGR no.	SAR no.
16414	319	1440
16415	320	1441
16416	321	1442
16417	322	1443
16418	323	1444
16419	324	1445