The South African Railways Class 4E of 1952 was an electric locomotive.
Between 1952 and 1954, the South African Railways placed forty Class 4E electric locomotives with a 1Co+Co1 wheel arrangement in temporary service on the Natal mainline and from 1954 on the mainline from Cape Town across the Hex River rail pass to Touws River in the Karoo.
Manufacturer
The 3 kV DC Class 4E electric locomotive was designed for the South African Railways (SAR) by the General Electric Company (GEC) and was built by the North British Locomotive Company (NBL) in 1952 and 1953. They were delivered between 1952 and 1954 and were numbered in the range from E219 to E258. The Class 4E was amongst the most powerful electric locomotives in the world at that time.
Orientation
These dual cab locomotives had two large grilles on one side and a corridor linking the cabs on the opposite side. When observing the locomotive from the side with the grilles, the number 1 end would be to the right. As on the earlier Class 3E, the unit had side doors on both sides behind each cab. It had roof access ladders on the smooth left side only, one aft of each side door. Like the Classes 1E, 2E and 3E, the Class 4E had bogie-mounted pilots and draft gear and an articulated inter-bogie linkage, therefore no train forces were transmitted to the locomotive body.
As delivered, the Class 4E units did not have the "eyebrow" sunshades above the front windscreens. These were later fitted in Cape Town to prevent pantograph grease from befouling the windscreens.
The Class 4E had a 1Co+Co1 wheel arrangement, with an additional bissel truck at the outer end of each of the two three-axle powered bogies. The Classes 32-000 and 32-200 diesel-electric locomotive types also used this wheel arrangement, but the Class 4E was unique amongst South African electric locomotives in this respect.
Service
The Class 4E was specifically acquired for use on the mainline from Cape Town across the Hex River rail pass to Touws River, from where Class 23 and later Class 25 and Class 25NC steam locomotives would take over across the stretch of unelectrified mainline to De Aar and from there to either Kimberley or Bloemfontein.
Since the completion of Eskom's high-tension power feeds in the Cape was late, the first locomotives to be delivered in 1952 were placed in service on the Natal mainline while awaiting electrification from Wellington via Worcester to Touws River. They were to be transferred to the Cape as soon as the wires were energised, but they eventually had to be withdrawn from Natal earlier because the severe curvature of the Natal mainline caused their frames to crack.
Class leader no. E219 was the first unit to be relocated to Cape Town in March 1953, where it initially ran on the 1.5 kV DC power which was still being used for Cape Town's suburban trains until the upgrading of the Cape Town lines to 3 kV DC was completed in November 1954. The 3 kV DC electrification from Worcester had reached Touws river in April 1954. Until then, the locomotive's load capacity and mobility were restricted. In Cape service, some teething troubles were experienced with their bogies, particularly when going faster than . The problem was hunting which became increasingly severe at higher speed and the units were therefore employed mainly on goods traffic until 1956, by which time their bogie faults had been ironed out.
The Class 4E was rated at double the load of a Class 15F without banker over the Hex River rail pass, 770 tons against 360 tons for the same train length. With assistance from a banker between De Doorns and Matroosberg, a Class 15F and Class 14CRM combination could almost match the Class 4E, but between Cape Town and De Doorns an unaided Class 4E could haul half as much again as a Class 15F, 1264 tons as against 820 tons.
Two Class 4E units briefly served on the Western Transvaal System while being relocated from Natal via Transvaal to the Cape. That system was granted permission to use no. E247 and one other for between four and six weeks, working from the Electric Running Shed at Braamfontein, before the locomotives were forwarded to Cape Town.
From 1954 onwards, the Class 4E took over working of the Blue Train with increasing regularity, long before the last Class 15Fs were drafted away to the Cape Midland System in September 1957.