Other basic features of the first power stations were:

i. the steam pressure was 220 lb/sq.in. and the boilers were fitted with chain grate stokers,

ii. the major switchgear was housed indoors, a cellular type of construction being adopted,

iii. water cooling was used on generator and coupling transformers,

iv. Merz-Price circulating current protection was provided on generators and transformers,

v. the alternators were either 4 or 6 pole machines, operating at 1500 or 1000 rev/min respectively,

vi. provision was made for separate excitation from the station battery in case of failure of the exciter,

vii. most of the essential auxiliaries at the power stations were steam driven, which was a desirable feature during system disturbances and times of low frequency operation,

viii. the alternators were directly connected to step-up transformers, except the 3 MW sets at Simmerpan, which soon had to be rewound and have transformers installed (because of breakdowns occurring following electrical faults on the system).

(Fenwick and Torr, Electric Power Supply to the Mining Industry…1961:1-2; Troost and Norman, Electricity Supply in South Africa 1909-1969:178:)

The Rand Central Electric Works and the Driehoek Power Stations were closed down soon after the Brakpan and Simmerpan Power Stations were commissioned. Extensions were made at the new stations as demand increased. (Fenwick and Torr, Electric Power Supply to the Mining Industry …1961:24)

OTHER SERVICES

At the same time that the initial system was established, three other important services were established:

i. A system control centre was established at Simmerpan. This centre controlled load despatching at power stations and supervised all switching, linking and earthing of high voltage apparatus on the system in accordance with a comprehensive set of safety regulations. This centre has grown to be the present national control centre, which directs Eskom’s entire transmission network today.

ii. A central workshop was established for the repair and overhaul of all major items of plant. This workshop was taken over by Eskom Enterprises when formed in 1999. The major workshops are still at Rosherville in Gauteng. Branch operations are situated throughout South Africa and also in other countries, where it has been awarded significant contracts.​

i. A testing department was established, which was responsible for metering, instruments and electrical protection apparatus. This has now become the Protection, Telecommunications and Metering (PTM) division of Eskom Enterprises.

(Fenwick and Torr, Electric Power Supply to the Mining Industry…1961:2; Eskom Enterprises Annual Report 2000)

1922 RAND REVOLT

A sharp drop in the price of gold in 1921 led to a decrease in mine-worker’s wages, which in turn led to industrial unrest and the 1922 Rand Revolt. The Prime minister, General Smuts, mobilised the Army and martial law was declared. The VFP power stations were cordoned off by the Army and were kept going by all available staff. At Brakpan Power Station sniping occurred but no damage was done to the plant. By 16 March the revolt had been crushed, but at a price of over 200 lives. (Symphony of Power 2000:67)

MERZ AND MCLELLAN REPORTS – ESCOM ESTABLISHED

A report entitled “South African Railways – Report on the Introduction of Electric Traction”, was completed in June 1919 by the British firm of consultants, Merz and McLellan. The report was addressed to Sir William Hoy, General Manager of the South African Railways. A second report, entitled “Electric Power Supply in the Union of South Africa”, was submitted to the government headed by Jan Christiaan Smuts in April 1920. A government appointed committee investigated the implications of this report. The findings of the committee led to the Government passing the Electricity Act in September 1922 and the establishment of Escom in 1923. The name was changed to Eskom in 1987. (Merz and McLellan Reports, 1919 and 1920)

WITBANK POWER STATION

After World War I and the 1922 Rand Revolt additional power was urgently required. The VFP, who virtually held the monopoly for supplies to the gold mines, planned a new power station to be situated in the Witbank coal fields and connected to the existing system at Brakpan by means of a double circuit 132 kV transmission line. It was planned to install 20 MW sets. There were distinct economic advantages in building the power station at Witbank on account of the large quantity of duff (fine) waste coal, which could be bought at a very moderate cost. The cost of transport over the Government railways would also be avoided. The low cost of fuel would more than compensate for the additional costs in locating the station 100 km to the west. The plans included the construction of spray ponds at site and the building of a dam across the Olifants River. Make-up water would be pumped over a distance of about 10 km. (Jacobs AM, The Development of Electrical Power Supply in the Union of South Africa, In: Transactions of the SA Institute of Electrical Engineers, Aug 1941:262; Fenwick and Torr, Electric Power Supply to the Mining Industry…1961:2)

When the RMPS Co was formed in 1908, the Central Mining-Rand Mines Group had insisted on being supplied by a separate system upon which their mines would have first call. The Group was therefore supplied by the Rosherville and Vereeniging stations and the remaining mines from Brakpan and Simmerpan. The VFP suggested that with Witbank in operation, a pooled system would be more reliable and also cheaper because of the low costs at Witbank. The Central Mining-Rand Mines Group agreed to link the systems, which thereafter became one organisation from an operational point of view. (Report of the Power Companies Commission 1909:11-13; Symphony of Power 2000:83-84)

The VFP made application in 1923 for an amendment of its Licence in order to build the power station, but this was opposed by the newly established ESCOM. Dr van der Bijl, the Chairman, argued that the VFP did not supply electricity at cost. Prime Minister Jan Smuts requested Charles Merz to intervene. Merz suggested that Witbank be financed and owned by ESCOM, but designed, built and operated by the VFP. The compromise satisfied the interests of both parties and the power station was brought into operation in May 1926. Three 20 MW sets were initially installed, operating at 3000 rev/min and a steam pressure of 220 lb/sq.in. The line from the power station to Brakpan was the first 132 kV transmission line to be in operation in the British Empire at that time. (ESCOM Annual Report 1969:15; Symphony of Power 2000:82-3)

DISASTERS IN 1925 AND 1927

In December 1925 one of the generator rotor shafts at Vereeniging Power Station sheared and the heavy rotor tore through the stator. Massive pieces of metal were hurled through the power station roof and end of the building, some landing two kilometres away in the Free State on the other side of the Vaal River. Miraculously, nobody was hurt, although the building was extensively damaged and the machine was wrecked. The set was later replaced by a 20 MW turbo-alternator. (VFP Chairman, In: SA Mining Journal, Aug 1927:747; Symphony of Power 2000:37-8)

A less fortunate accident occurred at Brakpan Power Station in October 1927, when four workers were killed and others seriously injured. A boiler exploded and the dished ends of the steam drum were hurled a considerable distance. The boiler was totally wrecked and the buildings extensively damaged. (SA Mining and Engineering Journal, Oct 1927:191; Symphony of Power 2000:32)

Due to further plant shortages, the power system had to be sectionalised in 1928 and the electrical frequency on one section raised to 51,5 Hz in order to boost output of the air compressors. This condition persisted until well into the 1930’s. (Fenwick and Torr, Electric Power Supply to the Mining Industry…1961:2)

KLIP AND VAAL POWER STATIONS

The total installed capacity of the existing stations feeding into the Rand-Witbank area in 1932 was 360 MW, but it was not practical to extend these stations sufficiently to meet the expected growth in demand. A similar agreement was entered into between the VFP and ESCOM by which the Klip Power Station would be financed and owned by ESCOM, but be constructed and operated by the VFP on behalf of ESCOM. The same principle was also followed in the development of new transmission and distribution networks in the Rand Extension licensed area. Klip Power Station had the distinction of being the largest steam power station in the Southern Hemisphere, having a total of 424 MW of installed plant. The rate of construction and commissioning was a world record and it possibly had the greatest output of any power station in the world at that time as well as the lowest cost of production. It was the first in Escom to have cooling towers. When completed in 1940, the station capacity was over four times that of Witbank Power Station, previously the largest station owned by ESCOM. (Pickles and Trelease, Klip Generating Station, In: Transactions of the SA Institute of Electrical Engineers, May 1940)​

Even the large power resources of the Klip Power Station, started up in March 1936, were not expected to keep pace with the ever-increasing demand for electricity. In co-operation with the VFP, ESCOM therefore decided in 1938, to build the Vaal Power Station​. It was to be constructed on the Free State side of the Vaal River and would be the first ESCOM station to be built in the Free State. As in the case of Witbank and Klip, the station would be financed and owned by ESCOM, but be constructed and operated by the VFP on behalf of ESCOM. Like Klip, it was also a pithead station and the same arrangements were made for the extension of the network in order to supply the new gold fields in the Free State. (ESCOM Annual Report 1943:12; Fenwick and Torr, Electric Power Supply to the Mining Industry…1961:26)

TAKE-OVER BY ESCOM

In 1945, negotiations were started that led to the take over of the VFP and the purchase by ESCOM of its assets. A clause in the Power Act of 1910 of the old Transvaal Colonial Government, made provision for the expropriation of the VFP after a duration of 35 years. The clause was included in the Electricity Act No. 42 of 1922. A stalemate developed regarding the date of expropriation because of the different dates of the two Acts. By June 1948, ESCOM had already contributed about one-half of the capital required for the supply of power to the mining industry. Negotiations eventually led to the purchase by Escom of the electricity undertaking of the VFP for £14,5 million. This took place on 1 July 1948 and was the biggest merger ever in South Africa up to that time. As from the date of take-over the system became Escom’s “Rand Undertaking”, but this was later changed to “Rand and Orange Free State (or R&OFS) Undertaking”. The compressed air plant totalled 117,6 MW when taken over in July 1948. (ESCOM Annual Report 1948:7; Escom Golden Jubilee 1923-1973:21; Fenwick and Torr, Electric Power Supply to the Mining Industry…1961:6, 26; Symphony of Power 2000:100-106)