Power type Electric | Build date 1985-1987 | |
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Builder 11-001 - 11-030 GMSA11-031 - 11-045 Delta Serial number GMSA 119.01-119.30Delta 119.31-119.45 | ||
The South African Railways Class 11E of 1985 is an electric locomotive.
Contents
Between 1985 and 1987, the South African Railways placed forty-five Class 11E electric locomotives with a Co-Co wheel arrangement in mainline service on the Coalink line.
Manufacturers
The 25 kV AC Class 11E electric locomotive was designed for the South African Railways (SAR) by General Motors (GM), while the thyristor traction technology was provided by Allmänna Svenska Elektriska Aktiebolaget (ASEA) of Sweden. It was built in South Africa by General Motors South Africa (GMSA), whose corporate name was changed to Delta Motor Corporation two-thirds through the locomotive building process. Altogether forty-five locomotives were delivered between 1985 and 1987 and numbered in the range from 11-001 to 11-045.
Appearance
Following the Class 9E in 1978 and the Class 7E1 in 1980, the Class 11E was the third single-cab mainline electric locomotive to be acquired by the SAR. Until the Class 9E was introduced, all South African mainline electric locomotives were dual cab units, but since the Class 11E locomotives were designed to be used in a service where multiple unit operation was the normal practice, a second cab was deemed unnecessary.
Brakes
At the time, they were the most powerful locomotives in SAR service, with a continuous power output of 3,900 kilowatts (5,200 horsepower), compared to the 3,840 kilowatts (5,150 horsepower) of the Class 9E. Four units can haul two hundred loaded coal wagons in a train weighing more than 21,000 tonnes (21,000 long tons). Since they are used on a route where loaded trains face steeper descending than ascending grades, the locomotive was designed to produce 4,500 kilowatts (6,000 horsepower) of rheostatic braking power.
Bogies
The Class 11E was built with sophisticated traction linkages on the bogies, similar to the bogie design which was introduced on the Class 6E1 in 1969. Together with the locomotive's electronic wheel-slip detection system, these traction struts, mounted between the linkages on the bogies and the locomotive body and colloquially referred to as grasshopper legs, ensure the maximum transfer of power to the rails without causing wheel-slip, by reducing the adhesion of the leading bogie and increasing that of the trailing bogie by as much as 15% upon starting.
Works numbers and delivery dates
The table lists the Class 11E works numbers and the date on which each locomotive was delivered to the SAR.
Service
Until 1978, all electrified routes in South Africa used 3 kV DC. Beginning in 1978, 25 kV AC was introduced on all new mainline electrification projects bar one, the exception being the Orex iron ore line from Sishen to Saldanha, where 50 kV AC was used. There are four isolated 25 kV AC routes.
The Class 11E was designed primarily for export coal hauling on the 25 kV AC Coalink line between the Mpumalanga coalfields, around Ermelo, and the Richards Bay Coal Terminal, via Vryheid in KwaZulu-Natal.
Illustration
The main picture shows the left side of no. 11-009 at Vryheid on 15 August 2007, in the Spoornet blue livery with outline numbers. The locomotives depicted below are all in the Spoornet blue livery with solid numbers.