South African Class 15E 4-8-2

South African Class 15E 4-8-2
Henschel-built no. 2878 at Magaliesburg, 26 July 1992
Type and origin ♠ Robert Stephenson and Hawthorns engines ♥ Henschel & Berliner engines Power type Steam Designer South African Railways (A.G. Watson) Builder Robert Stephenson & Hawthorns Henschel and Son Berliner Maschinenbau Serial number RSH 4090–4109 Henschel 23000-23010, 23111-23115 Berliner 10585-10592 Model Class 15E Build date 1935–1936 Total produced 44
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. 30 in (762 mm) Coupled dia. 60 in (1,524 mm) Trailing dia. 34 in (864 mm) Tender wheels 34 in (864 mm) Wheelbase 65 ft 6 1⁄4 in (19,971 mm)  • Engine 35 ft 8 in (10,871 mm)  • Leading 6 ft 10 in (2,083 mm)  • Coupled 15 ft 9 in (4,801 mm)  • Tender 20 ft 5 in (6,223 mm)  • Tender bogie 6 ft 2 in (1,880 mm) Length: ​  • Over couplers 73 ft 6 in (22,403 mm) Height 12 ft 11 1⁄2 in (3,950 mm) Frame type Bar Axle load ♠ 18 LT 12 cwt (18,900 kg) ♥ 18 LT 14 cwt (19,000 kg)  • Leading ♠ 18 LT 6 cwt (18,590 kg) ♥ 19 LT 5 cwt (19,560 kg)  • 1st coupled ♠ 18 LT 3 cwt (18,440 kg) ♥ 17 LT 14 cwt (17,980 kg)  • 2nd coupled ♠ 18 LT 12 cwt (18,900 kg) ♥ 18 LT 14 cwt (19,000 kg)  • 3rd coupled ♠ 18 LT 10 cwt (18,800 kg) ♥ 18 LT 1 cwt (18,340 kg)  • 4th coupled ♠ 18 LT 3 cwt (18,440 kg) ♥ 17 LT 14 cwt (17,980 kg)  • Trailing ♠ 17 LT 6 cwt (17,580 kg) ♥ 16 LT 17 cwt (17,120 kg)  • Tender bogie Bogie 1: 33 LT 18 cwt (34,440 kg) Bogie 2: 35 LT 10 cwt (36,070 kg)  • Tender axle 17 LT 15 cwt (18,030 kg) Adhesive weight ♠ 73 LT 8 cwt (74,580 kg) ♥ 72 LT 3 cwt (73,310 kg) Loco weight ♠ 109 LT (110,700 kg) ♥ 108 LT 5 cwt (110,000 kg) Tender weight 69 LT 8 cwt (70,510 kg) Total weight ♠ 178 LT 8 cwt (181,300 kg) ♥ 177 LT 13 cwt (180,500 kg) Tender type JT (2-axle bogies) JT, JV permitted Fuel type Coal Fuel capacity 14 LT (14.2 t) Water cap 6,000 imp gal (27,300 l) Firebox type Round-top  • Firegrate area 63 sq ft (5.9 m2) Boiler: ​  • Model Watson Standard no. 3B  • Type Domeless  • Pitch 9 ft 2 1⁄2 in (2,807 mm)  • Diameter 6 ft 2 1⁄4 in (1,886 mm)  • Tube plates 22 ft 6 in (6,858 mm)  • Small tubes 136: 2 1⁄2 in (64 mm)  • Large tubes 36: 5 1⁄2 in (140 mm) Boiler pressure 210 psi (1,448 kPa) Safety valve Ross-pop Heating surface 3,400 sq ft (320 m2)  • Tubes 3,168 sq ft (294.3 m2)  • Arch tubes 26 sq ft (2.4 m2)  • Firebox 206 sq ft (19.1 m2) Superheater: ​  • Heating area 676 sq ft (62.8 m2) Cylinders Two Cylinder size 24 in (610 mm) bore 28 in (711 mm) stroke Valve gear Rotary cam Valve type Poppet Couplers AAR knuckle
Performance figures Tractive effort 42,340 lbf (188.3 kN) @ 75%
Career Operators South African Railways Rhodesia Railways CF de Mocambique Class Class 15E Number in class 44 Numbers 2858-2901 Nicknames Bongol Delivered 1935–1937 First run 1935 Withdrawn 1973

The South African Railways Class 15E 4-8-2 of 1935 was a steam locomotive.

Between 1935 and 1937, the South African Railways placed forty-four Class 15E steam locomotives with a 4-8-2 Mountain type wheel arrangement in service.

The Class 15E 4-8-2 Mountain type mixed traffic steam locomotive was a refinement of the Classes 15C and 15CA. It was designed by A.G. Watson, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1929 to 1936, and incorporated many of the improvements which had been developed by him, some of which were a vastly enlarged standardised boiler, a large and wide fire grate and a Watson cab.

They were built by three manufacturers. In 1935, British locomotive builders Robert Stephenson and Hawthorns (RSH) delivered twenty locomotives, numbered in the range from 2858 to 2877. Henschel and Son of Kassel in Germany built and delivered sixteen in two batches in 1936, numbered in the range from 2878 to 2893. Also in 1936, German locomotive builders Berliner Maschinenbau built another eight locomotives which were delivered in 1937, numbered in the range from 2894 to 2901. The British-built locomotives were 15 long hundredweight (762 kg) heavier than the German-built ones.

The Class 15D classification was never used by the Railways, possibly to have this locomotive’s class letter match that of the Class 16E which was delivered in the same year.

Because of the free running that was achieved with the Classes 15E, 16E and 19C which all entered service in 1935 and were all equipped with rotary cam poppet valve gear, Watson decided to adopt this type of valve gear for all his future designs. Most valve gear components of the Class 15E were interchangeable with similar parts of the Class 16E. Like the other classes with poppet valve gear, the Class 15E was fast, but some trouble was initially experienced with the valve gear in the reverse position. This was corrected by modifying the reversing cams and these, as well as new forward cams, were manufactured at the Salt River shops in Cape Town.