South African Class 15E 4-8-2

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.
==Manufacturers:==
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 standardized 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.
==Characteristics:==
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.
The Class 15E, nicknamed Bongol, was delivered with a Watson Standard no. 3B boiler and a Watson cab. In the 1930s, Watson designed a standard boiler type and a cab with an inclined front as part of his standardisation policy. New locomotives which were acquired in the Watson era and later, such as the Class 15E, were built with such boilers and cabs. The boiler pitch was 9 feet 2+1⁄2 inches (2,807 millimetres) above the top of the rail.
The locomotives were initially equipped with two large inclined Ross-pop safety valves, mounted on the upper sides of the boiler just ahead of the firebox and aimed about 80 degrees apart. When these inclined valves blew off under a station canopy, bystanders often received a shower of slimy wet soot. After the war, they were replaced by smaller Ross-pop valves at the highest point of the boiler that blew off straight up.
Some of the locomotives that worked on sections with tunnels were equipped with smoke deflecting cowls around their chimneys.
The 24 inches (610 millimetres) bore by 28 inches (711 millimetres) stroke cylinders were interchangeable with those of the Class 16E. A 4+1⁄2 inches (114 millimetres) thick cast-iron liner was fitted between the smokebox and its saddle to obtain this interchangeability. The cylinders had cast-iron liners and the steam and exhaust valve seatings were renewable. The connecting and coupling rods were fitted with floating bronze bushes and all crank pins were hollow bored. Soft grease lubrication was used for the motion, while the coupled wheel axle boxes were hard grease lubricated.
The buffing gear between engine and tender consisted of a laminated spring, contained in a steel casting attached to the tender's front buffer beam. The tender was the Type JT which was first introduced in 1935 along with the Class 15E Mountain type and Class 16E Pacific type. The tender had a coal capacity of 14 long tons (14.2 tonnes), a water capacity of 6,000 imperial gallons (27,300 litres) and an axle load of 17 long tons 15 hundredweight (18,030 kilograms).
==Service:==
===South African Railways:===
The Class 15E was placed in service on the mainline between Cape Town and Beaufort West. Later, when the Classes 15F and 23 were placed in service, the Class 15E locomotives were relocated further north to work between Beaufort West and De Aar. During 1954–1955, upon the arrival of the Class 25 condensers and Class 25NC, they were displaced from the Cape mainline and all 44 Bongols were relocated, this time to Bloemfontein.
In the 1960s they went to Bethlehem in the Orange Free State, from where they worked to Harrismith, Bloemfontein and Kroonstad. They were all withdrawn from regular service in 1973, except no. 2878 which was retained in running order for excursion trains.
===Other operators:===
Eleven of the Class 15E locomotives were eventually sold to neighbouring countries or into industrial service. Six of them were sold to Rhodesia Railways (RR) in 1970, where they retained their 15E classification but were renumbered by omitting the first digit of their SAR numbers. In Rhodesia they were stationed only at Bulawayo, and used virtually exclusively on trains to and from Gwelo. The Rhodesian locomotives did not last long in RR service, however, and were scrapped in 1973.
Three locomotives were sold to Caminhos de Ferro de Mocambique (CFM) in 1972, where they were renumbered 721, 722 and 723 respectively.
Two locomotives were sold to Dunn's Locomotive Works, to be employed at Durban Navigation Collieries (Durnacol) at Dannhauser in Natal.
The table shows the Class 15E engine numbers, builders, years built, works numbers and post-SAR owners.
Class 15E 4-8-2Builders, Works Numbers & Disposal
SAR No.	Builder 	Year	WorksNo.	Soldto	NewNo.
2858 	RSH 	1935	4090 	 	
2859 	RSH 	1935	4091 	 	
2860 	RSH 	1935	4092 	 	
2861 	RSH 	1935	4093 	 	
2862 	RSH 	1935	4094 	 	
2863 	RSH 	1935	4095 	 	
2864 	RSH 	1935	4096 	 	
2865 	RSH 	1935	4097 	 	
2866 	RSH 	1935	4098 	 	
2867 	RSH 	1935	4099 	 	
2868 	RSH 	1935	4100 	 	
2869 	RSH 	1935	4101 	 	
2870 	RSH 	1935	4102 	CFM 	721
2871 	RSH 	1935	4103 	 	
2872 	RSH 	1935	4104 	Dunn 	
2873 	RSH 	1935	4105 	 	
2874 	RSH 	1935	4106 	 	
2875 	RSH 	1935	4107 	 	
2876 	RSH 	1935	4108 	 	
2877 	RSH 	1935	4109 	 	
2878 	Henschel	1936	23000 	 	
2879 	Henschel	1936	23001 	 	
2880 	Henschel	1936	23002 	 	
2881 	Henschel	1936	23003 	RR 	881
2882 	Henschel	1936	23004 	RR 	882
2883 	Henschel	1936	23005 	RR 	883
2884 	Henschel	1936	23006 	 	
2885 	Henschel	1936	23007 	RR 	885
2886 	Henschel	1936	23008 	RR 	886
2887 	Henschel	1936	23009 	 	
2888 	Henschel	1936	23010 	 	
2889 	Henschel	1936	23111 	 	
2890 	Henschel	1936	23112 	 	
2891 	Henschel	1936	23113 	CFM 	722
2892 	Henschel	1936	23114 	 	
2893 	Henschel	1936	23115 	 	
2894 	Berliner	1936	10585 	CFM 	723
2895 	Berliner	1936	10586 	Dunn 	
2896 	Berliner	1936	10587 	 	
2897 	Berliner	1936	10588 	 	
2898 	Berliner	1936	10589 	RR 	898
2899 	Berliner	1936	10590 	 	
2900 	Berliner	1936	10591 	 	
2901 	Berliner	1936	10592 	 	
==Preservation:==
Number	Works nmr 	THF / Private	Leaselend / Owner	Current Location 	Outside South Africa	?
2878 	HENSC 23000	THF 	 	Bloemfontein Locomotive Depot	 	
==Trivia:==
* The main picture shows preserved Henschel-built no. 2878 with elephant ear smoke deflectors at Magaliesburg, Transvaal, on 26 July 1992.
* While the following pictures in illustrate some differences in appearance over the years.
== Gallery: ==
File:Class 15E 2879 (4-8-2).jpg|Henschel-built no. 2879 with smoke deflecting cowl, c. 1940
File:Class 15E 2897 (4-8-2).jpg|Berliner-built no. 2897 at Paardeneiland, Cape Town, c. 1940
File:Class 15E 2878 (4-8-2).jpg|Henschel-built no. 2878 at Paardeneiland, Cape Town, c. 1940
File:SAR Class 15E 2878 Breyten 260481.jpg|Henschel-built no. 2878 at Breyten, 26 April 1981