South African Class 3A 4-8-2

Specifications
Specifications
Configuration:;
• Whyte	4-8-2 (Mountain)
• UIC	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	57 ft 7 in (17,551 mm)
• Engine	30 ft 6 in (9,296 mm)
• Leading	6 ft (1,829 mm)
• Coupled	12 ft 9 in (3,886 mm)
• Tender	17 ft 10 in (5,436 mm)
• Tender bogie	5 ft 10 in (1,778 mm)
Length:;
• Over couplers	65 ft 5+7⁄8 in (19,961 mm)
Height	12 ft 6 in (3,810 mm)
Frame type	Bar
Axle load	14 LT 11 cwt (14,780 kg)
• Leading	11 LT 16 cwt (11,990 kg)
• 1st coupled	13 LT 14 cwt 2 qtr (13,950 kg)
• 2nd coupled	13 LT 18 cwt 2 qtr (14,150 kg)
• 3rd coupled	13 LT 9 cwt (13,670 kg)
• 4th coupled	14 LT 11 cwt (14,780 kg)
• Trailing	9 LT 1 cwt (9,195 kg)
• Tender bogie	Bogie 1: 20 LT 7 cwt (20,680 kg); Bogie 2: 22 LT 10 cwt (22,860 kg)
Adhesive weight	55 LT 13 cwt (56,540 kg)
Loco weight	76 LT 10 cwt (77,730 kg)
Tender weight	42 LT 17 cwt (43,540 kg)
Total weight	119 LT 7 cwt (121,300 kg)
Tender type	2-axle bogies
Fuel type	Coal
Fuel capacity	8 LT 5 cwt (8.4 t)
Water cap.	4,000 imp gal (18,200 L)
Firebox:
• Type	Belpaire
• Grate area	36.25 sq ft (3.368 m2)
Boiler:;
• Pitch	7 ft 4 in (2,235 mm)
• Diameter	5 ft 4+5⁄8 in (1,641 mm)
• Tube plates	18 ft 7+3⁄8 in (5,674 mm)
• Small tubes	172: 2+1⁄4 in (57 mm)
• Large tubes	15: 5+1⁄4 in (133 mm)
Boiler pressure	160 psi (1,103 kPa)
Safety valve	Ramsbottom
Heating surface:
• Firebox	149 sq ft (13.8 m2)
• Tubes	2,268 sq ft (210.7 m2)
• Total surface	2,417 sq ft (224.5 m2)
Superheater:;
• Type	Cole
• Heating area	457 sq ft (42.5 m2)
Cylinders	Two
Cylinder size	24 in (610 mm) bore; 24 in (610 mm) stroke
Valve gear	Walschaerts
Valve type	Piston
Couplers	Johnston link-and-pin; AAR knuckle (1930s)

Type and origin
Type and origin
Power type	Steam
Designer	American Locomotive Company
Builder	American Locomotive Company
Serial number	46176
Model	NGR America D
Build date	1909
Total produced	1

NGR Class B 4-8-2 1910
South African Class 3A 4-8-2
NGR Class B 4-8-2 1910; South African Class 3A 4-8-2
	NGR Class B no. 335, SAR Class 3A no. 1476
Power type
Type and origin
Power type	Steam
Designer	American Locomotive Company
Builder	American Locomotive Company
Serial number	46176
Model	NGR America D
Build date	1909
Total produced	1
Configuration:;
Specifications
Configuration:;
• Whyte	4-8-2 (Mountain)
• UIC	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	57 ft 7 in (17,551 mm)
• Engine	30 ft 6 in (9,296 mm)
• Leading	6 ft (1,829 mm)
• Coupled	12 ft 9 in (3,886 mm)
• Tender	17 ft 10 in (5,436 mm)
• Tender bogie	5 ft 10 in (1,778 mm)
Length:;
• Over couplers	65 ft 5+7⁄8 in (19,961 mm)
Height	12 ft 6 in (3,810 mm)
Frame type	Bar
Axle load	14 LT 11 cwt (14,780 kg)
• Leading	11 LT 16 cwt (11,990 kg)
• 1st coupled	13 LT 14 cwt 2 qtr (13,950 kg)
• 2nd coupled	13 LT 18 cwt 2 qtr (14,150 kg)
• 3rd coupled	13 LT 9 cwt (13,670 kg)
• 4th coupled	14 LT 11 cwt (14,780 kg)
• Trailing	9 LT 1 cwt (9,195 kg)
• Tender bogie	Bogie 1: 20 LT 7 cwt (20,680 kg); Bogie 2: 22 LT 10 cwt (22,860 kg)
Adhesive weight	55 LT 13 cwt (56,540 kg)
Loco weight	76 LT 10 cwt (77,730 kg)
Tender weight	42 LT 17 cwt (43,540 kg)
Total weight	119 LT 7 cwt (121,300 kg)
Tender type	2-axle bogies
Fuel type	Coal
Fuel capacity	8 LT 5 cwt (8.4 t)
Water cap.	4,000 imp gal (18,200 L)
Firebox:
• Type	Belpaire
• Grate area	36.25 sq ft (3.368 m2)
Boiler:;
• Pitch	7 ft 4 in (2,235 mm)
• Diameter	5 ft 4+5⁄8 in (1,641 mm)
• Tube plates	18 ft 7+3⁄8 in (5,674 mm)
• Small tubes	172: 2+1⁄4 in (57 mm)
• Large tubes	15: 5+1⁄4 in (133 mm)
Boiler pressure	160 psi (1,103 kPa)
Safety valve	Ramsbottom
Heating surface:
• Firebox	149 sq ft (13.8 m2)
• Tubes	2,268 sq ft (210.7 m2)
• Total surface	2,417 sq ft (224.5 m2)
Superheater:;
• Type	Cole
• Heating area	457 sq ft (42.5 m2)
Cylinders	Two
Cylinder size	24 in (610 mm) bore; 24 in (610 mm) stroke
Valve gear	Walschaerts
Valve type	Piston
Couplers	Johnston link-and-pin; AAR knuckle (1930s)
Tractive effort
Performance figures
Tractive effort	36,460 lbf (162.2 kN) @ 75%
Operators
Career
Operators	Natal Government Railways; South African Railways
Class	NGR Class B; SAR Class 3A
Number in class	1
Numbers	NGR 335, SAR 1476
Nicknames	Maud Allan
Delivered	1910
First run	1910
Withdrawn	1935
	The leading coupled axle had flangeless wheels

The South African Railways Class 3A 4-8-2 of 1910 was a steam locomotive from the pre-Union era in the Colony of Natal.

Early in 1910, the Natal Government Railways commissioned a single American-built Class B 4-8-2 Mountain type locomotive, also known as the America D. It was the first superheated locomotive to be acquired by the Railways in Natal and also the first with a bar frame. In 1912, when it was assimilated into the South African Railways, it was renumbered and designated Class 3A.