South African Class 17E


The Spoornet Class 17E of 1993 was a South African electric locomotive.
During 1993 and 1994, Spoornet modified several Class 6E1, Series 7, 8 and 9 locomotives to improve their braking and traction reliability for service on the Natal mainline. These modified locomotives were reclassified to Class 17E.

Manufacturer

The 3 kV DC Class 6E1 electric locomotive was built for the South African Railways by Union Carriage & Wagon in Nigel, Transvaal, with electrical equipment supplied by the General Electric Company. UCW did not allocate works numbers to the locomotives which it built for the SAR, but used the SAR unit numbers for their record keeping.

Characteristics

Bogies

The Class 6E1 was built with sophisticated traction linkages on their bogies. 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, ensured 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. This feature was controlled by electronic wheel-slip detection devices and an electric weight transfer relay which reduced the anchor current to the leading bogie by as much as 50A in notches 2 to 16.

Brakes

The locomotive itself used air brakes, but it was equipped to operate trains with air or vacuum brakes. While hauling a vacuum braked train, the locomotive's air brake system would be disabled and the train would be controlled by using the train brakes alone to slow down and stop. While hauling an air braked train, on the other hand, the locomotive brakes would engage along with the train brakes. While working either type of train downgrade, the locomotive's regenerative braking system would also work in conjunction with the train brakes.
When the locomotive was stopped, the air brakes on both bogies were applied together. The handbrake or parking brake, located in cab no. 2, only operated on the unit's last axle, or no. 7 and 8 wheels.

Orientation

These dual cab locomotives had a roof access ladder on one side only, just to the right of the cab access door. The roof access ladder end was marked as the no. 2 end. A corridor along the centre of the locomotive connected the cabs, which were identical apart from the fact that the handbrake was located in cab 2. A pantograph hook stick was stowed in a tube mounted below the lower edge of the locomotive body on the roof access ladder side.

Modification to Class 17E

Class 17E locomotives were modified and reclassified from Class 6E1, Series 7, 8 or 9 locomotives during 1993 and 1994. Key modifications included improved regenerative braking and wheel-slip control to improve their reliability on the steep grades and curves of the KwaZulu-Natal mainline.
A stumbling block was that the regeneration equipment at many of the sub-stations along the route was unreliable and since there was no guarantee that another train would be in the same section to absorb the regenerated energy, there was always the risk that line voltage could exceed 4.1 kV, which would make either the sub-station or the locomotive trip out. As a result, the subsequently rebuilt Class 18E locomotives were not equipped with regenerative braking.
Unlike the Class 16E locomotives, which were renumbered and reclassified but otherwise unmodified semi-permanently coupled pairs of Class 6E1, Series 3 to Series 9 locomotives that merely had their no. 1 end cabs abandoned in terms of maintenance, the Class 17Es retained their original unit numbers after reclassification, but with a "17E" marking applied below the locomotive's unit number behind the driver's side window.
Apart from the "17E" markings, they were visually indistinguishable from unmodified Class 6E1s. Those in SAR Gulf Red and yellow whiskers livery that still carried number plates even still showed "6E1" on the plates. Altogether 139 Class 6E1 locomotives were modified to Class 17E, of which 14 were Series 7, 55 Series 8 and 70.

Rebuilding to Class 18E

In 2000, Spoornet began a project to rebuild Series 2 to 11 Class 6E1 locomotives to Class 18E, Series 1 and Series 2 at the Transnet Rail Engineering workshops at Koedoespoort. In the process the cab at the no. 1 end was stripped of all controls and the driver's front and side windows were blanked off to have a toilet installed, thereby forfeiting the locomotive's bi-directional ability.
Since the driving cab's noise level had to be below 85 decibels, cab 2 was selected as the Class 18E driving cab, primarily based on its lower noise level compared to cab 1 which was closer and more exposed to the compressor's noise and vibration. Another factor was the closer proximity of cab 2 to the low voltage switch panel. The fact that the handbrake was located in cab 2 was not a deciding factor, but was considered an additional benefit.
While the earlier Class 6E1, Series 2 to 7 locomotives had been built with a brake system which consisted of various valves connected to each other with pipes and commonly referred to as a "bicycle frame" brake system, the Class 6E1, Series 8 to 11 locomotives were built with an air equipment frame brake system, commonly referred to as a brake rack. Since the design of the rebuilt Class 18E locomotives included the same brake rack, the rebuilding project was begun with the newer series 8 to 11 locomotives to reduce the overall cost of rebuilding.
Between 2002 and 2007, all but three of the Class 17Es were rebuilt to Class 18E, Series 1. The exceptions are numbers E1778, E1803 and E2035, which are presumed to have been scrapped. The table lists their Class 6E1 series and numbers, Class 18E numbers and year of rebuilding.

Count		17E
no.		6E1
series		Year
built		18E
no.		Year
rebuilt
1E17497197718-3322007
2E17757197718-2922006
3E17767197718-3262007
4E17777197718-2892006
5E180171977-7818-3312007
6E180571977-7818-2602006
7E181071977-7818-2942006
8E182271977-7818-0972003
9E182671977-7818-3442007
10E182771977-7818-2832006
11E18327197818-3072007
12E18437197818-2702006
13E19008197918-2622006
14E19018197918-2982006
15E19048197918-0872003
16E19058197918-3112007
17E19068197918-2842006
18E19078197918-3302007
19E19088197918-2882006
20E19098197918-0612002
21E19108197918-2952006
22E19138197918-3402007
23E192181979-8018-3412007
24E192281979-8018-3062007
25E192481979-8018-3342007
26E19318198018-2022005
27E19338198018-3202007
28E19348198018-0942003
29E19358198018-0182002
30E19368198018-2742006
31E19378198018-2162005
32E19388198018-2932006
33E19398198018-2032005
34E19408198018-0842003
35E19448198018-1972005
36E19458198018-2072005
37E19468198018-0622002
38E19478198018-2902006
39E19498198018-0642002
40E19628198018-0702003
41E19648198018-3292007
42E19658198018-3162007
43E19668198018-1782005
44E19678198018-2632006
45E19688198018-2222005
46E19698198018-2012005
47E19718198018-2692006
48E19768198018-2562006
49E19798198018-3372007
50E19828198018-2722006
51E19838198018-2962006
52E198481980-8118-2262005
53E198581980-8118-3122007
54E198681980-8118-2152005
55E198781980-8118-3242007
56E19898198118-3032006
57E19908198118-3102007
58E19918198118-2252005
59E19928198118-2782006
60E19938198118-3362007
61E19948198118-3052006
62E19958198118-2792006
63E19968198118-3152007
64E19978198118-1562004
65E19988198118-2372006
66E19998198118-0652002
67E20008198118-3092007
68E200391981-8218-2852006
69E200591981-8218-3082007
70E200691981-8218-3252007
71E200791981-8218-2362005
72E200891981-8218-2752006
73E201191981-8218-2552006
74E201291981-8218-2732006
75E201591981-8218-2612006
76E201691981-8218-2322005
77E201791981-8218-2992006
78E201891981-8218-2492006
79E201991981-8218-2522006
80E202091981-8218-1942005
81E202291981-8218-2112005
82E202391981-8218-2672006
83E202491981-8218-2592006
84E202591981-8218-1932005
85E202691981-8218-1962005
86E202791981-8218-3192007
87E202891981-8218-2102005
88E202991981-8218-3272007
89E203091981-8218-2232005
90E203191981-8218-3042006
91E203291981-8218-3012006
92E203391981-8218-2462006
93E203491981-8218-2542006
94E203691981-8218-2472006
95E203791981-8218-0372002
96E203891981-8218-0742003
97E203991981-8218-2302005
98E204091981-8218-2412006
99E204191981-8218-2762006
100E204291981-8218-2272005
101E204391981-8218-2342005
102E20449198218-2192005
103E20459198218-2382005
104E20469198218-2712006
105E20479198218-2682006
106E20489198218-2582006
107E20509198218-2392006
108E20519198218-2292005
109E20529198218-2182005
110E20539198218-0932003
111E20549198218-2572006
112E20559198218-0282002
113E20569198218-0792003
114E20579198218-2402005
115E20589198218-2532006
116E20599198218-3212007
117E20609198218-2502006
118E20629198218-2822006
119E20639198218-2422006
120E20649198218-2812006
121E20659198218-1922005
122E20669198218-2122005
123E20679198218-2452006
124E20689198218-3022006
125E20699198218-2912006
126E20709198218-2242005
127E20719198218-3282007
128E20739198218-2432006
129E20759198218-0732003
130E20769198218-2282005
131E20779198218-2442006
132E20799198218-1272004
133E20819198218-2512006
134E20829198218-2352005
135E20849198218-2172005
136E20859198218-2142005

Illustration

The main picture shows Class 17E no. E1826, ex Class 6E1, Series 7, at Capital Park in Pretoria on 28 September 2006. The "17E" markings below the locomotive numbers on this and the following picture were the only means to visually distinguish Class 17E locomotives from unmodified Class 6E1 locomotives.