The South African Railways Class of 1974 is a diesel-electric locomotive.
Between 1974 and 1977, the state-owned South African Iron and Steel Corporation placed forty-four General Electric type U26C diesel-electric locomotives in service. They were employed on Iscor's 1974-built Sishen-Saldanha iron ore line and as heavy shunters at the Sishen mine. In 1977, another two locomotives were built for the Douglas Colliery near Witbank. Also in 1977, thirty-nine of the Iscor locomotives were transferred to the South African Railways where they were initially designated "Class ex Iscor" and later became commonly known as Class .
Manufacturer
The Class type GE U26C diesel-electric locomotive, also known as "Class ex Iscor", was designed by General Electric and built for the South African Iron and Steel Corporation (Iscor) by the South African General Electric-Dorman Long Locomotive Group (, later Dorbyl). Forty-four locomotives were delivered to Iscor on three orders: Twenty-two were delivered between 1974 and 1975, of which twenty were numbered in the range from 1D to 20D and geared for mainline service while two were numbered G01 and G02 and geared for shunting work. Twenty more were delivered between 1976 and 1977, numbered in the range from 21D to 40D and geared for mainline service. Another two were delivered in 1977, geared for shunting and numbered G03 and G04.
In 1977, two locomotives were also built for the Douglas Colliery near Witbank in Transvaal, numbered D5 and D6. Of the Iscor mainline locomotives, 39 were transferred to the South African Railways in that same year.
Distinguishing features
The Iscor locomotives were delivered with a fuel tank to cope with the lack of en route refuelling points on the Sishen-Saldanha line. To facilitate the larger fuel tank, the inter-bogie linkage found on all other South African U26C models was omitted on these locomotives. To maintain its lateral balance, a slab of metal was attached to each bogie in place of the removed linkage.
As built, the GE Classes , and locomotives were visually indistinguishable from each other. Many of the Class locomotives could be distinguished from the others by the air conditioning units mounted on their cab roofs, but not all of them were so equipped. When it was still a feature unique to them, they could also be distinguished by their running board-mounted handrails. All South African diesel-electric locomotives have their side handrails mounted along the upper edges of their long hoods. The ex Iscor Class , however, were equipped with additional removable running board-mounted handrails. Since these handrails are slide-fit into brackets welded onto the running boards, they are easily removed.
Since c. 2009, other mainline diesel-electric locomotive types also emerged from the Koedoespoort Transwerk shops with running board-mounted handrails after major overhauls.
At some stage during the mid-1980s, all Class , and locomotives had saddle filters installed across the long hood, mounted just to the rear of the screens behind the cab on the sides. Since then, Class locomotives could be distinguished from the older models by the absence of the saddle filter.
Electronic control system
Beginning in 2010, some locomotives were equipped with electronic fuel injection and GE "Bright Star" control systems. On some of the first locomotives to be so modified, externally visible evidence of the modification is a raised middle portion of the long hood.
Service
Changes in ownership
In 1977, all mainline rail operations on the Sishen-Saldanha iron ore line was taken over from Iscor by the South African Railways (SAR). Between November 1977 and June 1978, 39 of the Iscor mainline locomotives were transferred to the SAR. They were initially designated "Class ex Iscor" and renumbered in the range from 34-501 to 34-539, but these units were also commonly referred to as Class from their SAR number range. This eventually became the accepted official classification.
Five locomotives were retained by Iscor to work at the Sishen mine, numbers G01 to G04 and 40D. These are now Kumba Iron Ore’s units numbers 01 to 05, with no. 40D having become Kumba no. 05.
The Douglas Colliery locomotives are now in Sheltam livery, initially as Sheltam numbers 5 and 6 and later renumbered to 2602 and 2603 respectively.