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South African Class 15E 4-8-2

From Alfawiki
South African Railways Class 15E
Company typeSteam locomotive class
IndustryRailway transport
Founded1935–1937
FounderA.G. Watson (designer)
Headquarters
South Africa
ProductsSteam locomotives
Number of employees
44 (units produced)

South African Railways Class 15E 4-8-2 Steam Locomotive

The Class 15E steam locomotive, featuring a 4-8-2 Mountain wheel configuration, was introduced by the South African Railways during the period from 1935 to 1937. A total of forty-four units were commissioned and integrated into service within these years. This class was designed specifically for the South African Railways and represented a significant development in the era's steam locomotive engineering.

Manufacturers

The Class 15E 4-8-2 Mountain type mixed traffic steam locomotive represented an advancement over the earlier Classes 15C and 15CA. This design was the work of A.G. Watson, who served as Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1929 until 1936. It incorporated several enhancements developed under his leadership, including a significantly larger standardized boiler, an expansive fire grate, and the distinctive Watson cab.[1][2]

Production of these locomotives was carried out by three different manufacturers. In 1935, British firm Robert Stephenson and Hawthorns (RSH) supplied twenty units, assigned numbers from 2858 to 2877. The German company Henschel and Son, based in Kassel, delivered sixteen locomotives in two batches during 1936, numbered between 2878 and 2893. Additionally, another eight locomotives were produced by German manufacturer Berliner Maschinenbau in 1936 and delivered in 1937, bearing numbers from 2894 to 2901. Notably, the British-built locomotives were approximately 15 long hundredweight (762 kg) heavier than their German counterparts.[1][2][3][4]

Characteristics

The SAR never assigned the Class 15D designation to this locomotive, possibly to maintain alignment with the Class 16E introduced in the same year.[5] [6]

File:A.G. Watson.jpg
A.G. Watson

Due to the smooth performance demonstrated by the Classes 15E, 16E, and 19C, all introduced in 1935 with rotary cam poppet valve gear, Watson chose to implement this valve gear type in all subsequent designs. Many valve gear components of the Class 15E were compatible with those used on the Class 16E. While these poppet valve-equipped classes were known for their speed, initial difficulties arose with valve operation in reverse. This issue was resolved by redesigning the reversing cams; both these revised reversing cams and new forward cams were produced at the Salt River workshops in Cape Town.[1][2]

The Class 15E, colloquially known as Bongol, was delivered featuring a Watson Standard no. 3B boiler coupled with a Watson cab. During the 1930s, Watson introduced a standardized boiler design alongside a cab featuring an inclined front as part of his standardization efforts. Locomotives procured during and after his tenure, including the Class 15E, incorporated these boilers and cabs. The boiler was positioned at a height of 9 feet 2+1⁄2 inches (2,807 millimetres) above rail level.[2][3][5][6]

Originally, each locomotive was fitted with two large inclined Ross-pop safety valves mounted on the upper sides of the boiler just ahead of the firebox, angled approximately 80 degrees apart. When these valves released steam beneath station canopies, bystanders often experienced showers of wet soot mixed with moisture. Post-war modifications replaced them with smaller Ross-pop valves positioned at the highest point on the boiler that discharged steam vertically upwards.[7] [8] [9]

Certain locomotives operating on routes featuring tunnels were equipped with smoke deflector cowls surrounding their chimneys.[1]

The cylinders measured 24 inches (610 millimetres) bore by 28 inches (711 millimetres) stroke and were interchangeable with those fitted on the Class 16E. To facilitate this compatibility, a 4+1⁄2 inches (114 millimetres) thick cast-iron liner was installed between the smokebox and its saddle. The cylinders included cast-iron liners and featured renewable steam and exhaust valve seatings. Both connecting and coupling rods utilized floating bronze bushes, while all crank pins were hollow bored. Motion lubrication employed soft grease, whereas hard grease was applied to lubricate the coupled wheel axle boxes.[2]

The buffing gear linking engine and tender consisted of a laminated spring housed within a steel casting attached to the tender’s front buffer beam. The tender type was Type JT, first introduced in tandem with the Class 15E Mountain type and Class 16E Pacific type in 1935. This tender had a coal capacity of 14 long tons (14.2 tonnes), water capacity of 6,000 imperial gallons (27,300 litres), and an axle load rating of 17 long tons 15 hundredweight (18,030 kilograms).[1][2]

South African Railways

File:Class 15E no. 2881 ID.jpg

The Class 15E locomotives initially operated on the main route connecting Cape Town and Beaufort West. Subsequently, with the introduction of the Classes 15F and 23, these engines were reassigned to run between Beaufort West and De Aar. Between 1954 and 1955, following the deployment of the Class 25 condensers and Class 25NC, the Class 15E units were removed from the Cape mainline service. All 44 locomotives, nicknamed Bongols, were then transferred to Bloemfontein.[3][10]

During the 1960s, their operations shifted to Bethlehem in the Orange Free State, where they served routes extending to Harrismith, Bloemfontein, and Kroonstad. Regular service for all units ended in 1973, except for locomotive no. 2878, which was kept operational for special excursion runs.[3]

Other operators

A total of eleven Class 15E locomotives were eventually sold outside South Africa, either to neighboring countries or industrial users. In 1970, six were purchased by Rhodesia Railways (RR), retaining their Class 15E designation but receiving new numbers by dropping the initial digit from their original SAR identifiers. These engines operated solely out of Bulawayo, primarily hauling trains to and from Gwelo. However, their tenure with RR was short-lived, as they were dismantled by 1973.[11]

In 1972, three units were acquired by Caminhos de Ferro de Mocambique (CFM), where they were assigned numbers 721, 722, and 723 respectively.[11]

Additionally, two locomotives were sold to Dunn's Locomotive Works for use at Durban Navigation Collieries (Durnacol) located in Dannhauser in Natal.[11]

The following table details the Class 15E locomotives by their SAR numbers, manufacturers, production years, works numbers, and subsequent owners after leaving SAR service.[11]


Preservation

Number Works number THF / Private Leaselend / Owner Present Location Outside South Africa ?
2878 HENSC 23000 THF Bloemfontein Locomotive Depot

Illustration

The primary image features the preserved Henschel-built locomotive no. 2878, equipped with elephant ear smoke deflectors, captured at Magaliesburg, Transvaal, on 26 July 1992. The subsequent photographs display variations in design and condition over different periods.

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Cite error: Invalid <ref> tag; no text was provided for refs named Holland 2
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Cite error: Invalid <ref> tag; no text was provided for refs named SAR&H Oct 1946
  3. ↑ 3.0 3.1 3.2 3.3 Cite error: Invalid <ref> tag; no text was provided for refs named Paxton-Bourne
  4. ↑ Henschel-Lieferliste (Henschel & Son works list), compiled by Dietmar Stresow
  5. ↑ 5.0 5.1 Cite error: Invalid <ref> tag; no text was provided for refs named Diagram-book 1
  6. ↑ 6.0 6.1 Cite error: Invalid <ref> tag; no text was provided for refs named Diagram-book 2
  7. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Soul of a Railway 7-2
  8. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Soul of a Railway 7-10
  9. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named Soul of a Railway 7-12
  10. ↑ Soul of A Railway, System 5, Part 1: Bloemfontein. Caption 1. (Accessed on 1 March 2017)
  11. ↑ 11.0 11.1 11.2 11.3 Template:Durrant-Twilight
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