South African Class 3 4-8-2

NGR Class B 4-8-2 1909 South African Classes 3 & 3R 4-8-2
NGR Class B no. 332, later SAR Class 3 no. 1448
Type and origin ♠ Class 3 as built with a Belpaire firebox ♥ Class 3R rebuilt with a Watson Standard boiler ♣ - Type TJ tender, 1st batch (1909) ♦ - Type TM tender, 2nd batch (1911) Power type Steam Designer Natal Government Railways (D.A. Hendrie) Builder North British Locomotive Company Serial number 18829-18833, 19217-19241 Model NGR Hendrie D Build date 1909-1910 Total produced 30
Specifications Configuration: ​  • Whyte 4-8-2 (Mountain)  • UIC ♠ 2'D1'n2 - ♥ 2'D1'h2 Driver 2nd coupled axle Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia. 28 1⁄2 in (724 mm) Coupled dia. 45 1⁄2 in (1,156 mm) Trailing dia. 30 in (762 mm) Tender wheels 30 in (762 mm) Wheelbase 55 ft 7 3⁄4 in (16,961 mm)  • Engine 30 ft 9 in (9,373 mm)  • Leading 6 ft (1,829 mm)  • Coupled 12 ft 9 in (3,886 mm)  • Tender 16 ft 6 in (5,029 mm)  • Tender bogie 4 ft 6 in (1,372 mm) Length: ​  • Over couplers 63 ft 2 1⁄2 in (19,266 mm) Height ♠ 12 ft 6 in (3,810 mm) ♥ 12 ft 4 3⁄4 in (3,778 mm) Frame type Plate Axle load ♠ 15 LT 2 cwt (15,340 kg) ♥ 15 LT 11 cwt (15,800 kg)  • Leading ♠ 11 LT 13 cwt 2 qtr (11,860 kg) ♥ 14 LT 4 cwt (14,430 kg)  • 1st coupled ♠ 14 LT 8 cwt (14,630 kg) ♥ 15 LT (15,240 kg)  • 2nd coupled ♠ 15 LT 2 cwt (15,340 kg) ♥ 15 LT 11 cwt (15,800 kg)  • 3rd coupled ♠ 14 LT 8 cwt 2 qtr (14,660 kg) ♥ 15 LT 1 cwt (15,290 kg)  • 4th coupled ♠ 15 LT (15,240 kg) ♥ 14 LT 18 cwt (15,140 kg)  • Trailing ♠ 9 LT 10 cwt (9,652 kg) ♥ 9 LT 18 cwt (10,060 kg)  • Tender bogie Bogie 1: ♣ 20 LT 1 cwt (20,370 kg) ♦ 21 LT 14 cwt (22,050 kg) Bogie 2: ♣ 20 LT 10 cwt (20,830 kg) ♦ 21 LT 16 cwt (22,150 kg)  • Tender axle ♣ 10 LT 5 cwt (10,410 kg) ♦ 10 LT 18 cwt (11,070 kg) Adhesive weight ♠ 58 LT 18 cwt (59,850 kg) ♥ 60 LT 10 cwt (61,470 kg) Loco weight ♠ 93 LT (94,490 kg) ♥ 84 LT 12 cwt (85,960 kg) Tender weight ♣ 40 LT 11 cwt (41,200 kg) ♦ 43 LT 10 cwt (44,200 kg) Total weight ♠♣ 133 LT 11 cwt (135,700 kg) ♠♦ 136 LT 10 cwt (138,700 kg) ♥♣ 125 LT 3 cwt (127,200 kg) ♥♦ 128 LT 1 cwt (130,100 kg) Tender type TJ (2-axle bogies) - 1446-1450 TM (2-axle bogies) - 1451-1475 TJ, TL, TM permitted Fuel type Coal Fuel capacity ♣ 6 LT (6.1 t) ♦ 8 LT 5 cwt (8.4 t) Water cap ♣ 3,500 imp gal (15,900 l) ♦ 4,000 imp gal (18,200 l) Firebox type ♠ Belpaire ♥ Round-top  • Firegrate area ♠ 34 sq ft (3.2 m2) ♥ 37 sq ft (3.4 m2) Boiler: ​  • Type ♥ Watson Standard no. 2  • Pitch ♠ 7 ft 4 in (2,235 mm) ♥ 7 ft 5 1⁄2 in (2,273 mm)  • Diameter ♠ 5 ft 6 1⁄8 in (1,680 mm) ♥ 5 ft 7 1⁄2 in (1,714 mm)  • Tube plates ♠ 18 ft 6 in (5,639 mm) ♥ 19 ft 4 in (5,893 mm) steel f/b 19 ft 3 5⁄8 in (5,883 mm) copper f/b  • Small tubes ♠ 237: tubes 2 1⁄4 in (57 mm) ♥ 87: 2 1⁄2 in (64 mm)  • Large tubes ♥ 30: 5 1⁄2 in (140 mm) Boiler pressure 190 psi (1,310 kPa) Safety valve ♠ Ramsbottom ♥ Pop Heating surface ♠ 2,721 sq ft (252.8 m2) ♥ 2,075 sq ft (192.8 m2)  • Tubes ♠ 2,582 sq ft (239.9 m2) ♥ 1,933 sq ft (179.6 m2)  • Firebox ♠ 139 sq ft (12.9 m2) ♥ 142 sq ft (13.2 m2) Superheater: ​  • Heating area ♥ 434 sq ft (40.3 m2) Cylinders Two Cylinder size 21 in (533 mm) bore 24 in (610 mm) stroke Valve gear Walschaerts Valve type Murdoch's D slide Couplers Johnston link-and-pin AAR knuckle (1930s)
Performance figures Tractive effort ♠ 34,890 lbf (155.2 kN) @ 75% ♥ 32,790 lbf (145.9 kN) @ 75%
Career Operators Natal Government Railways South African Railways Class NGR Class B SAR Classes 3 & 3R Number in class 30 Numbers NGR 330-334, 345-369 SAR 1446-1475 Nicknames Hendrie D Delivered 1909, 1911 First run 1909 Withdrawn 1974
The leading coupled axle had flangeless wheels

The South African Railways Class 3 4-8-2 of 1909 was a steam locomotive from the pre-Union era in the Colony of Natal.

In 1909, the Natal Government Railways placed the world’s first true Mountain type locomotive in service when five Class B 4-8-2 tender locomotives were commissioned. Another 25 were placed in service in 1911. In 1912, when they were assimilated into the South African Railways, they were renumbered and designated Class 3. The Mountain wheel arrangement went on to become the most numerous steam locomotive wheel configuration in use in South Africa.

With increasing coal traffic in Natal, the demand arose for more powerful locomotives. The Class B of 1909, also known as the Hendrie D, was a heavy 4-8-2 locomotive, designed by Natal Government Railways (NGR) Locomotive Superintendent D.A. Hendrie. They entered service in October 1909 and were put to work to handle coal traffic on the upper Natal mainline.

The locomotive design was based on Hendrie's Class B 4-8-0 in its modified form of 1906 as the Altered Hendrie B 4-8-2. This time, however, Hendrie made full use of the potential of the pony truck under the cab to carry additional weight by positioning the firebox to the rear of the driving wheels, which made an improved grate and ashpan possible. To accomplish this, the plate frame was equipped with a bridle casting at the rear to accommodate the larger firebox. Five locomotives were built by the North British Locomotive Company (NBL) and delivered in 1909, numbered in the range from 330 to 334.

The first five locomotives were delivered with the first Type TJ tenders, which had a 6 long tons (6.1 tonnes) coal and 3,500 imperial gallons (15,900 litres) water capacity. They were put to work between Estcourt and Charlestown on the Transvaal border, where they regularly hauled loads of 225 long tons (229 tonnes), as well as fast perishable goods traffic. They proved to be highly successful in use, which led to an order for another 25 locomotives from NBL in 1910. These were delivered in 1911 and numbered in the range from 345 to 369 on the NGR roster. They were identical to the first batch of engines in all respects, except that they had Type TM tenders, which had an 8 long tons 5 hundredweight (8.4 tonnes) coal and 4,000 imperial gallons (18,200 litres) water capacity.