South African Class 4E

South African Class 4E

No. E238 at the Salt River Depot, Cape Town, 7 January 1966

Type and origin Power type Electric Designer General Electric Company Builder North British Locomotive Company Serial number 26859-26898 Model GEC 4E Build date 1952-1953 Total produced 40

Specifications AAR wheel arr 1-C+C-1 UIC class (1Co)(Co1) Gauge 3 ft 6 in (1,067 mm) Cape gauge Leading dia 762 mm (30 in) Wheel diameter 1,295 mm (51.0 in) Wheelbase 18,390 mm (60 ft 4.0 in)  • Bogie 6,833 mm (22 ft 5.0 in) Wheel spacing (Assymetrical) 1-2: 2,337 mm (7 ft 8.0 in) 2-3: 2,286 mm (7 ft 6.0 in) Length:  • Over couplers 21,844 mm (71 ft 8.0 in)  • Pivot centres 10,795 mm (35 ft 5.0 in)  • Panto shoes 14,122 mm (46 ft 4.0 in) Height:  • Pantograph 4,140 mm (13 ft 7.0 in)  • Body height 3,924 mm (12 ft 10.5 in) Axle load 21,845 kg (48,160 lb)  • Leading 13,209 kg (29,121 lb) Adhesive weight Loco weight 157,488 kg (347,202 lb) Power supply Catenary Current collection Pantographs Traction motors Six GEC WT580  • Rating 1 hour 377 kW (506 hp)  • Continuous 313 kW (420 hp) Gear ratio 21:75 Loco brake Regenerative Train brakes Air & Vacuum Couplers AAR knuckle

Performance figures Maximum speed 97 km/h (60 mph) Power output:  • 1 hour 2,262 kW (3,033 hp)  • Continuous 1,878 kW (2,518 hp) Tractive effort:  • Starting 322 kN (72,000 lbf)  • 1 hour 185 kN (42,000 lbf)  • Continuous 141 kN (32,000 lbf)

Career Operators South African Railways Class Class 4E Power class 3 kV DC Number in class 40 Numbers E219-E258 Nicknames Groen Mamba (Green Mamba) Groot Mamba (Large Mamba) Delivered 1952-1954 First run 1952

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 service on the mainline from Cape Town across the Hex River rail pass to Touws River in the Karoo.

Manufacturer

File:SAR Class 4E E258 BPF.JPG

GEC and NBL logos on the end doors

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) between 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

File:Plate NBL 4E (E258).JPG

NBL works plate, no. E258

These dual cab locomotives have two large grilles on one side and a passage 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. Like the Classes 1E, 2E and 3E, the Class 4E has bogie mounted draft gear and an articulated inter-bogie linkage, therefore no train forces are transmitted to the locomotive body.

The Class 4E has a 1Co+Co1 wheel arrangement, with an additional bissel truck (pony 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 built 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 took over across the stretch of unelectrified mainline to De Aar and from there to either Kimberley or Bloemfontein.

File:SAR Class 4E E258 ID.JPG

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The first locomotives to be delivered, were placed in service on the Natal mainline while electrification from Worcester to Touws River was being completed, but they eventually had to be withdrawn from Natal because the severe curvature of the Natal mainline caused their frames to crack.

No. E219 was the first Class 4E locomotive to be relocated to Cape Town, where it initially ran on 1.5 kV DC power, which was still being used for the Cape Town suburban trains, until the upgrading of the lines to 3 kV DC was completed in November 1954. This restricted the locomotive's load capacity and mobility.

One Class 4E locomotive even briefly served on the Western Transvaal system while being relocated from Natal to the Cape in 1957, when that system was granted permission to use no. E247 for between four and six weeks, before the locomotive was forwarded on to Cape Town.

Hex River tunnel scheme

The Class 4E purchase was part of a scheme to eliminate the 1 in 40 (2½%) gradients and severe curves of the Hex River rail pass, which would entail the construction of a series of four tunnels through the Hex River Mountains. The tunnel system would have enabled a single Class 4E locomotive to haul 1,000 ton trains up the resulting 1 in 66 (1½%) gradients.

The Hex River Tunnels scheme (Hexton) was initially started in 1945, but was deferred indefinitely in 1950 as a result of financial constraints. The tunnel scheme was briefly resuscitated in 1965 but was deferred once again in 1966. Work was eventually resumed in 1974 and included the remodelling of the lower section of the deviation between De Doorns and Osplaas stations as well as the construction of the short twin tunnels. This was completed in 1976, at which point financial constraints resulted in yet another postponement. Authority to proceed was only given once again in late 1979.

When the project was resumed, the eastern portal of the longest tunnel was relocated a short distance to the southeast of the original site, while the location of the western portal remained as originally planned during the first attempt. The tunnel system was opened on 27 November 1989, by which time the Class 4Es were already retired, after having spent their entire careers double-heading trains across the Hex River rail pass.

Liveries

The Class 4E was delivered in an all over bottle green livery with red cowcatchers. The colour and the almost 22 metres (72 feet) length of the locomotive quickly earned it the nickname Groen Mamba (Green Mamba). This changed to Groot Mamba (Large Mamba) when the much shorter Class 5E was introduced in 1955 and nicknamed Klein Mamba (Little Mamba).

Soon after they entered service, however, Hex River Valley farmers complained that the bottle green all over colour scheme made the locomotives difficult to see when they were approaching through the vineyards. Yellow lines were then added all around the locomotive to improve its visibility, with various line patterns being used before eventually settling on the V shaped whiskers on the ends which extended onto the sides, and multiple lines around the number plates on the sides. The attractive whiskers livery was eventually adopted for all the electric locomotives of the SAR.

Beginning in 1960, a Gulf Red and yellow whiskers livery gradually replaced the green and yellow.

Works numbers

The NBL works numbers of the Class 4E are listed in the table.

Class 4E

Loco no.	Works no.
E219	26859
E220	26860
E221	26861
E222	26862
E223	26863
E224	26864
E225	26865
E226	26866
E227	26867
E228	26868
E229	26869
E230	26870
E231	26871
E232	26872
E233	26873
E234	26874
E235	26875
E236	26876
E237	26877
E238	26878
E239	26879
E240	26880
E241	26881
E242	26882
E243	26883
E244	26884
E245	26885
E246	26886
E247	26887
E248	26888
E249	26889
E250	26890
E251	26891
E252	26892
E253	26893
E254	26894
E255	26895
E256	26896
E257	26897
E258	26898

Illustration

The main picture shows number E238, in the bottle green and whiskers livery, at the Salt River Depot in Cape Town on 7 January 1966, while the following pictures serve to illustrate some of the other liveries used on the Class 4E during its service lifetime.

• Class 4E no. E258 b.jpg

  No. E258 in an earlier green and yellow line livery, at Vlottenburg station, 24 May 1993

• Class 4E no. E258 a.jpg

  No. E258 showing the length which earned it the Green Mamba nickname, 24 May 1993

• SAR Class 4E E258.JPG

  Right side of no. E258, with its no. 1 end at right, Bloemfontein, 18 September 2015

• Class4E-E219.jpg

  No. E219 in Gulf Red and whiskers livery, Millsite Depot, 14 December 2010