Salt River Power Station

Salt River Power Station was built by ESCOM at the old mouth of the Salt River (see Historical Notes below), with the primary objective of supplying power for the electrification of the Cape Town suburban railway system and to satisfy the requirements of the Harbour and Railway Workshops. The initial installed capacity was 30 MW and generation commenced on 15 February 1928 when load was taken by the
 Sea Point railway line. As power was made available to the Cape Town City Council and other municipalities and consumers in the Western Cape, the station was extended to a capacity of 90MW by June 1936. After World War II (1939-1945) a second station, Salt River 2, was built adjacent to the first, which then became known as Salt River 1.
 

Salt River 1 was the first coal-fired power station to be both built and operated by ESCOM. At the time of making the extensions in 1932-33, it was the first power station in South Africa to operate at a steam pressure of 425lb/sq.in. [3,0MPa (abs)] and a temperature of 750°F [399°C] at the boiler outlet. The previous maximum pressure had been 300lb/sq.in. [2,17MPa (abs)]. Salt River 1 was also the first outside of Great Britain to generate at a voltage of 33kV. At the time of commissioning Salt River 2 in 1955, the boiler steam temperature of 915°F [491°C] was again the highest of any power station in South Africa.

 Note: Witbank Power Station, which was financed and owned by ESCOM, started operating in May 1926. It was the first entirely new coal-fired power station to be started since the establishment of ESCOM, but it was designed, built and operated by the Victoria Falls and Transvaal Power Company Limited on behalf of ESCOM. Colenso Power Station was taken over by ESCOM in January 1927, but the station had been built and originally commissioned by the Railway Administration.  (Troost & Norman 1969:182; ESCOM Golden Jubilee 1923-1973:14)

The Salt River mouth at the time the South African Railways and Harbours selected the site to build the power station - Photo: National Archives R1575

As demand in the Western Cape increased, Salt River 2 was extended until it had an installed capacity of 240MW in 1967. At that stage it was decided to meet future growth in load from a national grid, which was then under construction, generating electricity from power stations built at the coalfields. A site for the erection of a nuclear power station, approximately 28km from Cape Town, was also purchased in July 1967. The Western Cape became linked up to the national grid on 7 October 1969 and generation at Salt River was substantially reduced after 1970. The first unit at Koeberg Nuclear Power Station was commissioned in July 1984. The formal closing ceremony for Salt River 2 Power Station was held ten years later, on 12 August 1994. The main switch-house was then converted into a sub-station and continued to supply power to the Railways and Harbours, as mandated in 1925. During a period of almost 67 years, from February 1928 to August 1994, Salt River 1 and 2 stations sent out 29 693GWh (gigawatt hours) or 29 693 million units of electricity and burnt 16,5 million metric tons of coal.  (ESCOM Ten Years 1923-1933:17-18; ESCOM Golden Jubilee 1923-1973:36; ESCOM Annual Reports 1969:8, 1984:17 and Tables of Power Station Operating Statistics)


THE COUNCIL, THE RAILWAYS AND ESCOM

1908-1910: Cape Town City Council agrees to supply Government Departments

The Cape Town City Council (the Council) had a power station in operation at [the old] Dock Road, which was opened on 14 April 1904. Prior to 1909 the Railways had a number of moderate-sized, for that time, power stations at various centres in the country for their workshop needs. In Cape Town they had their own generating plant for charging train lighting accumulators, lighting for the Cape Town Railway Station and the Salt River Workshops, and power for the workshop machinery. The Harbour Board also had a power station in the Docks. During 1908 an agreement was drawn up between the Government and the Council whereby the Railway Administration and the Harbour would take electric power in bulk from the Council. The agreement was for a term of 15 years, commencing from 1 July 1909, with a minimum guaranteed annual consumption of 1,250GWh. (Energy actually purchased from 1 July 1909 to the end of the year amounted to 0,588GWh). In order to meet the requirements of the Railway and Harbour Departments, the Council installed two 400kW two-phase alternators at Dock Road. These were the first alternating current machines installed by the Council.

The Dock Road Power Station owned by the Cape Town City C​ouncil opened on 14 April 1904. It was decommissioned on 5 September 1961 and demolished during 1962.

 [The first turbine driven alternators at the Council’s Dock Road Power Station were installed in 1913 and 1914. The power stations of the Harbour Board, built in 1891 and another in 1902, should not be confused with the Council’s Dock Road Power Station commissioned in 1904. The building of the Harbour Board power station erected in 1902 was still in existence in 2004, close to the Maritime Museum, in what became Dock Road under the V&A Waterfront development. More than a century after being built, and with the engine room crane still in position, it became the “Dock Road Theatre” and later the “Compact Disc Wherehouse”. The Council’s Dock Road Power Station was demolished in 1962 and stood approximately where Lower Long Street has been built. The Council’s Table Bay Power Station, adjacent to it, was demolished in 1988-89. That portion of the original Dock Road where the Council power stations existed has been remade and renamed as Hans Strijdom Avenue.]  (Cape Town Mayor’s Minutes year ending 17 Sept 1908:42; Annual Report of the City Electrical Engineer year ending 30 June 1909:(i), 30 June 1910:(iv), 31 Dec 1913:(iv); Pask 1922:421-426; Shorten 1963:305; Palser 1895-1995:21&28) 1912-1920: Railway Electrification Proposals and Merz and McLellan Report of 1919

The New Electric Lig​ht Works, 1 July 1891, Cape Town Docks Photo: National Archives 15538

Charles Merz (later Dr) arrived personally in Cape Town on 16 August 1919. His visit was to have been earlier, but the Government of Great ritain could not spare him sooner from his advisory duties there. Travelling in Sir William Hoy’s private saloon, Mills conducted him over all the lines reported on. The report was laid before Parliament during the special session of September 1919. In this report Merz and McLellan suggested that a power station be built at Cape Town, initially with four 8MW sets and with a further four sets being added when the main line to Touws River was electrified. The report also suggested a power station be built at Durban consisting of four 8MW sets and another on the Buffalo River near Glencoe consisting of three 8MW sets. A White Paper was laid before Parliament in June 1920, in which it was recommended that funds be voted immediately for the electrification of the Cape Town-Simonstown suburban line and the Durban-Pietermaritzburg main line. Parliamentary authority was given, but due to the serious financial situation, it was decided to postpone electrification of the Cape Town-Simonstown line.  (Annual Reports of the General Manager of Railways and Harbours presented to Parliament 1912:22 [UG 46-1913], 1914:32 [UG 25-1915], 1917:10 [UG 43-’18], 1918:9 [UG 59-’19], 1919:11 [UG 66-’20]; Merz and McLellan 1919:(v)-(vi) & Table IX; Mills 1919:737-8; Sir William Hoy 1922:358; Pask 1926:90-92; Lydall 1928:1021-2; Christie 1984:78-79)   1921: The Railways select sites for Power Stations on the Tugela and at the Salt River Mouth

In 1921 the Railway Administration selected a site for a power station on the Tugela River at Colenso, and proposed a site in Cape Town at the mouth of the [Old] Salt River. The Administration was authorised, under the Railways Construction Act, 1922, to build its own power stations for the electrification of railways. The Salt River site was about 3,5km from the centre of the city. It comprised approximately 24,5 acres [9,9ha] of Crown land, much of which was below the high water mark, and approximately 4,5 acres [1,8ha] of private property belonging to Milnerton Estates Ltd.  (SAR drawing 164-R-2 dated 3-5-1921 [ESCOM drwg. 1.02/2]; Annual Report of the General Manager of Railways and Harbours 1921:xvi [UG 37-’22])  1919-1923: Merz Report of 1920 and Establishment of ESCOM
 
The Government also requested Merz and McLellan, in January 1919, to make a study of the general question of electric power supply in South Africa. Merz devoted a portion of his visit in 1919 to this matter and submitted a report to the Prime Minister, General Smuts, in April 1920. Merz envisaged power networks springing up as offshoots of railway electrification, and advocated the concentration of power production in a small number of large generating stations. In 1921 the Government appointed a Committee under the chairmanship of Sir Robert Kotze to consider the Merz report. The recommendations of this committee resulted in Parliament passing the Electricity Act of 1922, and the establishment of the Electricity Supply Commission (ESCOM) on 1 March 1923. [The name was changed to Eskom in 1987.]   (Merz and McLellan 1920:(iii); Sir William Hoy, 1922:358-359; Sir Robert Kotze, 1922:376-378; ESCOM Ten Years 1923-1933:7–8; ESCOM Twenty-five Years 1923-1948:16) 1921-1923: Conflict between Railway and City Council proposals – Council purchases site
 
While Merz was in South Africa in 1919, the Council appointed his firm as their consultants. Merz submitted a report to the Council in March 1920, in which he advised that a site for a new power station should be found, as the Dock Road site would probably be fully developed by 1928. The chairman of the newly formed Electricity Supply Commission, Dr HJ van der Bijl, tabled four projects as priorities at the first meeting, which was held in Cape Town on 20 March 1923. One of these was taking over responsibility for the electrification of the Cape Town suburban railway system. The interests of the Railways clashed with those of the Council, which wanted to maintain their right to supply electricity within their own boundaries. The Council feared that if the Railways built their own power station they would lose the profitable load they had been supplying since 1909. If not renewed, the 15-year term for this supply agreement would lapse in 1924. The Council entered into negotiations for the purchase of the land described as Lot PI 2, approximately 8,0ha in extent, from Milnerton Estates Ltd. This land was adjacent to the site the Railways proposed, and included the 1,8 ha of private property they had in mind. The Council purchased the site in 1923 for £13 788.  (ESCOM Annual Report 1923:4; Deed of Transfer 380/1924 dated 22 January 1924; Palser 1895-1995:28) 1922-1924: Parliamentary Authority for Railway Electrification – Colenso built first
 
Due to rapid development in coal traffic in Natal, the whole position was reviewed and Mr Lydall carried out a fresh investigation in South Africa. It was decided to proceed with the electrification of the Natal line from Glencoe to Pietermaritzburg, and to postpone the Durban to Pietermaritzburg line. A further White Paper was laid before Parliament in February 1922. The Railway Administration appointed Merz and McLellan as Consulting Engineers for the project, which included construction of the Colenso Power Station to provide power. Excavation work was commenced at Colenso in September 1922 and by September 1924 the first generator had been run on test. Parliament gave final authority to proceed with the electrification of the Cape Town suburban lines in 1924.
(Annual Reports of the General Manager of Railways and Harbours presented to Parliament 1920:7 [UG 42-’21], 1921:10 [UG 37-’22], 1922:21 [UG 40-’23], 1923:6 [UG 43-’24]; South African Railways and Harbours Magazine, May 1922:350-353, May 1923:416, Nov.1924:1087; June 1926:766; ESCOM Annual Report 1923:8-9; Lydall 1928:1021-2) 
 
CONSTRUCTION
 
The power station site adjacent to the Salt River estuary was important because fresh water supplies were scarce in Cape Town and sea water could be used for cooling. The power station was initially planned to have an installed capacity of 30 MW, although licensed to a rated capacity of up to 50 MW (ESCOM Annual Report 1924: 22). During the years of highest generation, 1967 to 1977, Salt River 1 and 2 Power Stations circulated approximately 300 thousand megalitres of sea water annually (ESCOM Annual Reports). If fresh water had to be used in cooling towers, about 4 thousand megalitres per annum during these years would have been lost in evaporation (based on 3,5 litre/kWh). The cold sea water of Table Bay also improved the efficiency of the stations and would have saved more than 100 thousand tons of coal over the operating lifetime of Salt River 1 and 2 stations (based on 0,5 to 0,7% improvement in efficiency). (D Fowler 2002).
 
In 1923 ESCOM appointed consulting engineers, Messrs Merz & McLellan, to design the power station. As the upper soil-levels were sandy and unsuitable for carrying the weights of the boilers and generators, piles had to be driven to the underlying bedrock. The building was a steel-framed brick construction, using 1 350 tons of British steel imported from Head, Wrightson & Co. Ltd. The structural work including foundations, buildings, spray ponds and intake works for the sea water intake were contracted to Dougall & Munro Ltd., Durban (ESCOM Annual Reports 1924 &1925).
 
The sea water intake works were constructed so that the sea water entered through submerged openings in a circular concrete tower offshore. From the tower two six-foot [1,8 m] concrete pipes ran into a pumping bay 1 205 feet [367 m] away. The pipes were embedded in concrete “forming a monolith below the floor of the sea” (Engineering, June 1933:665). Between the two pipes was a gallery passageway containing a narrow-gauge railway connecting the tower with the access well. Beyond the access well were a sand trap and screens to filter the water before entering the pumps (ESCOM Annual Report 1928).
 
 Note: The original plans called for the intake ducts to follow a straight line 1 300 feet [396 m] long from the settling tank to intake tower (ESCOM drwg. 0.02/203 dated 5 June 1926). Due to the wreck of the “City of Lincoln”, stranded during a storm in August 1902, the duct had to be aligned at an angle approximately 15 degrees north of the travel of the waves during the Cape north-west storms. It was planned that the driving of the piles and consolidation of the coffer dam would be completed by the end of April 1927 before the bad weather was expected. However, heavy N.W. swells occurred from early March and extensive damage was done to the piling and ultimately caused several months in delays. It was later decided to form a bend in the duct, just beyond the wreck, and the coffer dam could then be driven directly head on to the N.W. (Kanthack 1930). This bend, and the wreck, can be seen in the photograph included in the Transactions of the South African Institute of Electrical Engineers, June 1930:141. The bend is also shown on the “as constructed” drawing at a point 819 feet [250 m] from the settling tank (ESCOM drwg. 0.02/203 Revised 1-8-29). The final “as constructed” length was 1 205 feet [367 m].
 
 Babcock & Wilcox Ltd supplied four chain-grate water-tube boilers, with drums of riveted construction. The three 10 MW single-cylinder turbines were supplied by James Howden & Co. Ltd. with alternators by English Electric, and the coal and ash-handling plant by The Mitchell Conveyer & Transporter Co. Ltd. (The Engineer August 1935). The boilers had a nominal capacity of 60 000 lb. of steam per hour [7,6 kg/s] at 270 lb/sq.in. [2,0 MPa (abs)] and 700° F [371°C] (ESCOM Annual Report 1924). The railway siding connecting the power station to Cape Town Railway Station and the Harbour had to be completed for construction traffic before any of the large pieces of equipment could be transported to the site (ESCOM Annual Report 1925).
view of Salt River 1 (1935) from the position where Salt River 2 was later built. The stores building on the right was demolished to make way for Salt River 2. The boiler house is completed with 4 chimney stacks.
By 1925 it was already apparent that the power station would not be adequate for the rapid growth in demand for electricity in Cape Town and the surrounding rural areas. ESCOM decided to extend the engine room to accommodate a fourth generating set and complete the piling foundations for a fifth set. The boiler house was also extended to allow space for an eventual eight boilers (ESCOM Annual Report 1925). As construction of the sea water intake had been delayed by storms, the spray ponds would be used to cool the circulating water (ESCOM Annual Report 1926:21& 22). Construction was completed for trial start-up in February 1928. By December 1928 when construction work on the power station, traction sub-stations and transmission system in the Cape Peninsula were complete the Cape Town Undertaking had capital expenditure costs of £1 501 367 (ESCOM Annual Report 1928).
  
The “pooling agreement” of May 1932 provided for the immediate extension of Salt River Power Station by the installation of a 20 MW turbo-alternator and four boilers to cope with projected demand. The new plant was to be accommodated in the additional space provided in the original construction programme of the turbine and boiler houses (ESCOM Annual Report 1931:33&34). A year later as these extensions were nearing completion, another order was placed for a further, identical 20 MW turbo-alternator set and ancillary plant to meet the demand for electricity (ESCOM Annual Report 1932). This second generator was installed in late 1933/1934, and a third ordered (ESCOM Annual Report 1934). The third and last set (No. 6) was commissioned in June 1936. The turbo-alternators were supplied by C.A. Parsons & Co. Ltd., Heaton-on-Tyne England and the riveted-drum boilers by Babcock & Wilcox Ltd. The boilers produced steam at 100 000 lb/h [12,6 kg/s] working at a pressure of 425 lb/sq.in. [3,0 MPa (abs)] and 750° F [399°C]. This pressure and temperature was the highest of any power station in South Africa at the time. The steam system from the new boilers was linked up to that of the low pressure boilers through a reducing valve and the new generating sets were coupled to the existing system through 11/33 kV 6 000 kVA transformers at the step-up sub-station (The Engineer August 1935). In 1936, two of the original smaller low pressure boilers (numbers 3 and 4) were replaced by two high pressure 425 lb/sq.in. boilers. The two low pressure boilers were transferred to Colenso Power Station (ESCOM Annual Report 1936 & 1937: 27). Capital expenditure for the Cape Town Undertaking at the end of 1935, after the third 20 MW turbo-alternator was installed and brought into power was £2 202 304 (ESCOM Annual Report 1935).
 
These Parsons generators were the first outside Great Britain to generate current directly at 33 kV, thus producing a savings in cost, space occupied and running expenses in not requiring a step-up transformer. Parsons maintained that under full-load conditions the efficiency of the high-voltage machine was about 1% higher than the combined efficiency of the ordinary alternator and step-up transformer. Additional features were its ability to be started up very quickly from cold as a result of its “inherent freedom from the vice of disc vibration” (Engineering, November 1933:561). Both “Engineering” (November 1933) and “The Engineer” (March 1934), British professional engineering journals, carried substantial articles describing the Parsons turbo-alternators for Salt River Power Station. Unfortunately a number of blading failures and stator earth faults occurred on these 33 kV turbo-alternators in later years. All three stators had to be completely rewound, one being sent back to England for this. However, failures still occurred (D Fowler 2001). (See also “Operating Problems Encountered” below).
 
 In 1937 plans were drawn up replacing the old sea water intake with a new intake, as the old system had created constant problems. The proposed Cape Town Foreshore and Harbour development afforded ESCOM the opportunity to construct a new circulating water mole with its intake in the harbour basin where it would not be exposed to sand and seaweed (ESCOM Annual Report 1937:27). The hollow mole, designed by ESCOM’s Consulting Civil Engineer Dr FE Kanthack, had a breadth of 37,5 feet [11,4 m] and a depth of water of 12 feet [3,7 m] at low tide, sufficient to provide water to a generating station of over 450 MW. The top portion of the intake opening was curtained off so that it would remain 2 feet [600 mm] below the water level to prevent intake of oil or debris from the harbour (ESCOM Twenty-Five Years 1948:53). A new circulating water pump house was constructed on land belonging to the Harbour Administration on the harbour side of the Salt River, from where a 60-inch [1,5 m] main was laid to the power station. The circulating water pumps inside the power station were transferred to this new pump house. This work was virtually completed by the end of 1939 (ESCOM Annual Reports 1938:33&1939:18). Later, when Salt River 2 was constructed, the intake culvert was extended as an open culvert, with an under-pass at the Salt River, to the pump house at the new station.
  
World War II and the commissioning of the Council’s Table Bay Power Station in 1939, meant that no further additions to Salt River Power Station were contemplated before 1947. To meet the increasing demands for power after the war, ESCOM planned to build a new station on the site adjoining the existing Salt River Power Station to be known as Salt River 2 (ESCOM Annual Reports 1948:31&1949:9). During 1947/8 Mr HA Eastman, the City Electrical Engineer and Mr HH Jagger, Manager of ESCOM’s Cape Town Undertaking, visited Britain to obtain information regarding the “latest and most suitable types of plant and equipment” (ESCOM Annual Report 1947:38). From the specifications being prepared it was expected that Salt River 2 would probably have the highest thermal efficiency of any station in South Africa (The South African Electrical Review, October 1948:19).
 
A view of Salt River 1 (1934) after the engine room had been extended to its final length. The 12kV switchgear control room and the offices were in the annex on the right.
In 1949 contracts totalling £2 173 824 were placed for the installation of one 30 MW turbo-generator and two 260 000 lb/h boilers [32,8 kg/s 4,48 MPa (abs) 491° C], to be operational by mid 1954. A further 30 MW turbo-generator and two boilers were ordered for 1955 (ESCOM Annual Report 1949). The estimated costs for the two generators and four boilers was £5 464 100. Negotiations were proceeding with a view to ordering a further two generators and associated boiler plant (ESCOM Annual Report 1951:10). Up to April 1953, orders had been placed for four generators and six boilers at a total cost adjusted to £10 350 000. The initial installation consisting of two generators and four boilers (the “A” section) and the additional two generators and two boilers (the 1952 extension or “B” section) were planned to follow in a programme of continuous construction (ESCOM Annual Report 1952:8). Generators 3 and 4 were installed earlier than necessary for ESCOM’s consumers, in order to meet the needs of the Council during the period of construction of their Athlone Power Station, pending termination of the pooling agreement in May 1957 (ESCOM Annual Report 1957:13).
  
ESCOM’s consulting engineers Merz & McLellan were appointed to design Salt River 2 (ESCOM Annual Report 1949:9), but progress was slow and by March 1949 it was reported that only a limited amount of work on the foundations had been completed. By October 1952 reports stated the workshops were erected and work on the pile-driving for the main station buildings and the cooling water canals was proceeding (The South African Electrical Review). The piles were driven onto bedrock some twenty-eight feet [8,5 m] below ground level. The bedrock itself was blasted a further 20 feet [6 m] for the coal tippler (Plan Section C-C). 4 500 tons of steel were used in the framework of the building, erected by Cape Steel from November 1952 (South African Electrical Review, March 1954). 

Extensive use of steel sheet-piling was necessary below ground level as the site was only 11 feet [3,3 m] above the sea’s low water of ordinary spring tide (LWOST). A pumping system cleared groundwater during construction of the cooling water canal and other underground works. The basement of the circulating water pump house was 13,5 feet [4,1 m] below LWOST (D Fowler 2001). The floor area of Salt River 2 was approximately 80 000 square feet [7 400 m2], and the height of the building was 130 feet [39,6 m]. By March 1954 one of the two 300-foot [91 m] chimneys had reached a height of 200 feet [61 m], and the foundations of the other had been laid. The base diameter of the chimney was 20 feet [6,1 m] and each would have used, when complete, an estimated 900 000 bricks (The South African Electrical Review, March 1954).

Delays in the delivery of the boilers, the largest ever installed in the Western Province, led to delays in construction on site, with the result that the first boiler was placed in service only by November 1954 (ESCOM Annual Report 1955). This initially fed steam to Salt River 1 via a pressure reducer and de-superheater. The inter-connector could pass sufficient steam to supply a 20 MW generator at full load, and was extensively used for the remaining life of Salt River 1 (D Fowler 2001). By the end of 1954 a further two boilers and the first generator were in an advanced stage of construction (ESCOM Annual Report 1955).

Salt River 2 under construction (1954). The building for the 33 kV switchgear control room and offices is on the left, in the first view. The second view is taken from the coal yard.

Power was generated for the first time on 27 April 1955 when Mr VL Benning, Superintendent of the “pooled” power stations, turned the control switch and synchronised the generator to the electrical network. Mr Benning had also synchronised the first generator at Salt River 1 twenty-seven years previously (The South African Electrical Review, June 1955). Boiler two was commissioned in April 1955 and boiler three in September 1955. In November 1955 and July 1956 generators two and three were commissioned, and generator four in December 1956. Boilers four and five were commissioned in January and September 1956 respectively, and boiler six in January 1957 (ESCOM Annual Report 1956). Boilers one to six were supplied by Babcock & Wilcox Ltd. and had solid-forged drums manufactured in Scotland. International Combustion of Africa Ltd. (ICAL) supplied the chain-grate stokers and Metropolitan Vickers the four turbines and generators. The generators were connected to 33 kV Reyrolle metal-clad indoor switchgear through 11/33 kV 36 MVA generator transformers (D Fowler 2001).
 
In 1964 orders were placed for the “C” extensions consisting of two 60 MW hydrogen-cooled turbo generators from Escher Wyss & Oerlikon of Switzerland, and four Babcock and Wilcox boilers, scheduled to be in operation in 1967 (ESCOM Annual Report 1964:21). The generators were connected directly to the Acacia Distribution Station via 11/132 kV 67 MVA generator transformers and 132 kV underground cables, and were also inter-connected with the 33 kV switch house via 75 MVA and 80 MVA coupling transformers. The generator circuit breakers were outdoor-type 132 kV breakers installed indoors in an annexe. Generator five was commissioned in March followed by generator six in May 1967. The boilers had welded drums manufactured in South Africa and were of slightly different design, but the same rating as boilers 1 to 6 (D Fowler 2001). In 1965 piles were driven for the “C” extensions and a large portion of the steelwork erected by Consani’s Engineering. In January 1966 the brickwork began, and the contractors were on site for the erection of the plant (ESCOM Annual Report 1965:21). A second coal tippler was constructed in 1967. The bulk of the work was completed on schedule (ESCOM Annual Report 1967:21). This was the last extension at Salt River, although piles had been driven for additional boilers and a third chimney, because ESCOM had taken the decision to build a 400 kV transmission system to the Cape from the northern pool (ESCOM Annual Reports 1964:21, 1965:21, 1967:21, 1969:8; D Fowler 2001).
A view of Salt River 1 from the South East taken before the grit collectors were installed in 1955.
FINANCE
  
The initial capital required to finance the building of Salt River Power Station and the other early projects was obtained as advances from the Treasury. The cost of raising the loans, and interest charges during construction, were added to the sum advanced and repayment of the capital began from the date the station was placed in commercial service. This “commercial” date differed from the “commissioning” date when power was first produced at the station. The commissioning process took place from start-up to the hand-over to the Undertaking when the plant was still under the supervision of the consulting engineers (ESCOM: Twenty-five years 1923-1948:32; D Fowler 2001).
 
 In December 1929 ESCOM decided to convert the Treasury advances into two loans, one being £5 million with a longer, 50-year redemption period to cover the capital costs of Salt River and Colenso power stations. Interest on this loan was 5,015% (ESCOM Annual Reports 1929 & 1932). In 1932 the first public loans were raised to pay for, amongst other projects, the extensions at Salt River Power Station. £500 000 was raised at 4,75%, repayment over 20 years, for Salt River (ESCOM Annual Report 1932). In 1939 a further loan of £2 million was raised at 3,75% to pay for the new circulating sea water works at the station. Further loans raised by public subscription in the Union of South Africa paid for later additions (ESCOM Twenty-five Years 1923-1948). In 1951 ESCOM raised a foreign loan of US $30 million at interest of 4% over 20 years with the International Bank for Reconstruction and Development to pay for imported materials, mainly from the United Kingdom, including the plant for Salt River 2 (Conradie & Messerschmidt 2000).
 
OPERATION
 
A commercial service of electric trains on the Cape Town-Sea Point line was started on 17 October 1927. The power required for the working of this line did not justify the staffing and starting up of Salt River Power Station so far in advance of the commencement of electric operation of the Cape Town-Wynberg-Simonstown line. The power required for the Sea Point line was therefore generated at Dock Road. On 15 February 1928 Salt River was started up and took the load on the Sea Point line for one shift (Letter from GH Swingler to Dr HJ van der Bijl dated 22 February 1928). After further testing, it was placed under load for one shift per day, except at week ends. The running of electric trains on the Simonstown line commenced, for trial purposes, in June 1928 and arrangements were made to run three shifts at Salt River (ESCOM Annual Report 1927: 17-18).
 
A partial electric train service was in operation from 19 June 1928, on which date two electric trains were placed in commission between Cape Town and Fish Hoek, 14 trips being made daily. Full electric working was introduced between Cape Town and Simonstown on 13 August 1928 (South African Railways and Harbours Magazine – General Manager’s Bulletin, August 1928:1256 & September 1928:1432).
 
From July 1928 the station was in continuous operation as it took over, in addition to supplying the railway traction and rural supplies, the supplies to the Railway Workshops, Cape Town Railway Station and Table Bay Docks. The thermal efficiency of the station was at that stage only 13,6%. Net generation at Salt River 1 in 1929, the first full year of operation, amounted to 48,8 GWh and maximum power produced was 16 MW. In 1932 the net generation was 65,2 GWh and thermal efficiency had improved to 15,3%. (ESCOM Annual Reports).
A view showing completed sets 4, 5 and 6 at Salt River 1. These were the first 33 kV generato​rs outside Great Britain.
The control room at Salt River 1 taken at the closing ceremony in 1979. Mr RPA Myburgh (Regional Manager) is standing in front of generator 2 control panel. Next to him is Mr DR Ford (Power Station Manager).

After the 20 MW sets were commissioned, Salt River 1 began exporting a considerable amount of power to the Council. In 1933 net generation was over 100 GWh, and with its higher thermal efficiency it became the base load station for the “pool”, while the Council’s Dock Road provided back-up in case of break-downs and peak-time coverage. Thermal efficiency in 1936 was 21,7%, which was the highest during the operating life of the station. The year of maximum generation at Salt River 1 was 1938, when electricity sent out amounted to 333,6 GWh (of which 239,4 GWh was supplied to the Council) and maximum power produced was 78 MW. From 1939 Table Bay provided the base load, and the electricity sent out from Salt River fell to 129,2 GWh in 1939 (about 121% of the ESCOM system sales) and maximum power produced was 62 MW. In 1940 the figures had dropped further to 57,6 GWh (only 48% of the ESCOM system sales) and 46 MW respectively. Salt River continued to act as the back-up station during the years of World War II (1939 to 1945) sending out 131,3 GWh in 1945, almost 80% of the ESCOM system sales, but only 22,7% of the whole system’s power (ESCOM Annual Report 1945:29).

With post-war increases in demand, generation increased again to over 200 GWh by 1948 (about 90% of the ESCOM system sales). A decision had been taken to extend the capacity of the Council’s Table Bay Power Station, but delays in delivery meant that the extensions were not ready by the winter of 1947 (ESCOM Annual Report 1945:29). The unreliability of the electrical distribution system created additional headaches for those involved with the Royal Visit. Duplicate supplies were provided to all key points on the railway line so that there would be no temporary breakdown of supplies from cable failure or failure of overhead equipment (The South African Electrical Review April 1947).
In​side the turbine house at Salt River 1 showing sets 1 to 3. These were the first steam-driven sets ordered and commissioned by ESCOM.

As the new plant at Hex River Power Station in Worcester (from May 1952) and at Salt River 2 (from April 1955) came on line, running hours at Salt River 1 were reduced (ESCOM Annual Report 1956:27). Salt River 2 became the base load station for the Undertaking, particularly after the termination of the Pooling Agreement in 1957 (ESCOM Annual Report 1957). Net generation at Salt River 1 was only 4 GWh in 1957 and 55 GWh in 1964. But due to a breakdown of a generator at Salt River 2 at the end of 1965, Salt River 1 was required to generate as much as possible during peak periods. The old low pressure boilers, which had been mothballed for eight years, were recommissioned (ESCOM Annual Report 1966:22). As a result, generation increased to 165,2 GWh for 1966 (12% of the ESCOM system sales). During the years 1971 to 1973 generation was almost zero, but increased again from 1974 to 1976 (62,2 GWh in 1975) due to a general shortage of power on the [then] interconnected national power system. When the position improved in 1978, internal consumption exceeded generation and it was decided to decommission Salt River 1.

Between the years 1952 and 1956 ESCOM started up seven new power stations, six with the turbine inlet pressure of 600 lb/sq.in. [4,2 MPa (abs)] but varying temperatures. Of these power stations, the rated steam temperature at Salt River 2, namely 900°F [482°C] was the highest. The combination of the high steam temperature and cold sea water used in the condensers resulted in Salt River 2 taking the lead in thermal efficiency over all the other power stations, except for the first five years at Taaibos, which had larger units installed and a slightly higher efficiency. But from 1960 onwards, the efficiency at Salt River 2 was consistently higher than at Taaibos. The highest annual figure for overall thermal efficiency before the “C” extensions were built was 27,1% in 1961 and again 1964. After the “C” extensions were commissioned the highest was 27,4% in 1968. (ESCOM Annual Reports – Tables of power station operating statistics).
                    
Note: The rated temperatures at the other new stations were: Hex River and West Bank 800°F [427°C], Vierfontein and Taaibos 825°F [441°C], Umgeni and Wilge 850°F [454°C]. More expensive alloy steels have to be employed where high steam temperatures are in use. The lower cost of coal at the pit-head stations did not always justify the use of expensive steels to secure the highest possible efficiency (ESCOM: Golden Jubilee 1923 to 1973: 51). But at Salt River the cost of coal was approximately three times that at Taaibos. When Highveld came into service in 1959, a steam temperature of 900°F [482°C] was also employed but the pressure at the turbine inlet was 900 lb/sq.in. [6,3 MPa (abs)] giving an efficiency initially over 29%.

Generation at Salt River 2 peaked in 1968 and 1969 before the Cape Western Undertaking (the name changed from Cape Town Undertaking on 1 January 1949) drew electricity from the pooled stations of the Rand and Orange Free State Undertakings. This significant event took place on 7 October 1969 when the 400 kV transmission system linked up at the Droërivier Distribution Station near Beaufort West (ESCOM Annual Report 1969:8). Maximum generation at Salt River 2 was in 1969, when a net amount of 1 458,7 GWh was sent out, which was 78% of the electricity used in the Cape Western Undertaking (ESCOM Annual Report 1969). When the Central Generating Undertaking (the CGU) was established on 1 January 1972, all ESCOM power stations including Salt River, were transferred to this entity and management and control of the power station then no longer fell under the Cape Town office. Establishment of the CGU enabled ESCOM to obtain the maximum advantage from pooling (Conradie & Messerschmidt 2000:142). Because coal costs at the stations near to the pit-heads were very much lower and it was more economic to import power via the 400 kV system, by 1978 Salt River 2 supplied only 550 GWh. This was less than 10% of the energy needs of the Cape Western Undertaking. The figures increased again in 1981 to 933 GWh or 13% of the requirements in the Cape Western Undertaking, due to shortage of plant up country, but in 1985 net generation was only 175 GWh. In 1986 and again in 1988, internal consumption exceeded generation. During the five years 1989 to 1993 the annual energy sent out was only about 10 GWh. The station was decommissioned in August 1994. (ESCOM Annual Report 1969:8; Conradie & Messerschmidt 2000:142).

Views of Salt River 2 from the beachfront. Salt River 1 is on the left. The entrance building (1928) and the two wings of the 33 kV switch house can be seen on the right. Both of these still remain. The switch house has been converted into a sub-station. Devil’s Peak and Table Mountain are in the background. In the foreground is the circulating water outlet to the sea.
 
 Salt River 2 often produced a net maximum power of 10% above rated capacity. The highest net maximum power produced was 256 MW in the year 1981, which was 112% of the rated net maximum capacity of 228 MW. This achievement was in part due to Salt River 2 having extra boiler plant. However, as a result of surplus power on the ESCOM system, half the power station was “mothballed” in 1986. Some of the larger and more efficient power stations were completely mothballed shortly after (Conradie & Messerschmidt 2000:260), but the 60 MW sets at Salt River 2 were kept operational to provide stand-by off-site power for Koeberg Nuclear Power Station, if required. On occasions that the station was run for national requirements, the net maximum power produced by this “non-mothballed” plant was still approximately 10% above rated output (Conradie & Messerschmidt 2000:260; D Fowler 2001).
Control room at Salt River 2. At top left are two clocks for controlling system frequency. One clock shows standard time and the other electrical time. The centre shows the difference in seconds.
OPERATING PROBLEMS ENCOUNTERED
 
Over the years there were a number problems at Salt River, some disrupting the normal supply of electricity. These included many originating in the circulating sea water system. In July 1935 and again in June 1937 severe storms damaged part of the screening plant and swept sand and seaweed up into the pipes where it was drawn into the condensers of the turbo-generators. These machines had to be eased off peak loading and cleaned one at a time by means of constant swop-overs of the operating generators (ESCOM Annual Report 1937:35). ESCOM decided to build the new circulating system with its intake in the deeper water of the harbour but the second sea water intake system also had its problems. If not constantly maintained, plastic debris and small mussels would pass through the screens. The plastic caused blockages and the mussels could attach themselves inside the condensers tubes resulting in corrosion of the tube-surfaces around the mussels. Pinhole leaks would occur causing salt water to enter the steam system. Once a leak was located, the tube could be plugged off. Intermittent chlorination of the water at the pump house was later employed to stunt growth of marine life in the condensers. (ESCOM Annual Report 1937:35; The South African Electrical Review, May 1949 & February 1951; D Fowler 2001).
 
 A breakdown occurred on one of the 20 MW 33 kV generators in June 1937. Pending repairs, the power station staff made an ingenious interim arrangement whereby the turbine was coupled up to a stator and rotor held as spares for the 10 MW sets. This enabled it to be operated at half its normal capacity up to the end of January 1938 when the damaged stator and rotor were repaired. A further breakdown in November 1937 put another 20 MW set out of service for three months (Escom Annual Report 1937:25). During 1955 a 33 kV stator was rewound on site following a winding failure (Escom Annual Report 1955:26). The stator of another 20 MW set faulted in June 1958 and was out of service for three months (Escom Annual Report 1958:23).
 
At 4 p.m. on 9 October 1939 an explosion occurred in the 33 kV switch house at Salt River 1 (later known as switch house “B”), due to a switch tank bursting when clearing an underground cable fault. Nearly half the building was wrecked and power supply as far afield as Franschoek, Paarl and Malmesbury disrupted for two hours. The suburban train service was interrupted and the Cape Town Broadcasting service was off the air. Staff at the station worked through the night to restore services using alternative feeders. Much of the switchgear was irreparably damaged and replacements had to be ordered from Britain, a situation made difficult by the war conditions. Tragically, one person was killed in the incident. A twenty-one year old police constable, HJ Fourie, on special guard duty at the power station because of the war, was seriously injured when the wall of the switch house collapsed on him. He died of his injuries three days later. A power station apprentice was struck on the head by debris but was discharged from hospital after treatment (Cape Times 10-13 October 1939).
Damage from the explosion in the 33 kV switch house at Salt River 1 on 9 October 1939. A switch tank burst
 
 when the circuit breaker cleared a fault on an underground cable in the distribution system.
 
 
A view inside the turbine hall at Salt River 2 showing all six generators. Generators 5 and 6 in the foreground were rated at 60 MW and were capable of providing stand-by off-site power for Koeberg Nuclear Power Station on a completely independent and dedicated system. Because of this capability, the operating life of the station was extended from 1986, when other stations were being mothballed, until 1994.
 Towards the end of 1965, before the commissioning of the “C” extensions, a breakdown occurred when Generator 1 at Salt River 2 was being run-down for maintenance. There was extensive damage to the high-pressure spindle and all the inter-stage labyrinth seals were destroyed (ESCOM Annual Report 1965). The damaged spindle was sent back to the manufacturers in England for repairs and after some months was returning to the power station on the ship, “S.A. Seafarer”, when it was wrecked off the Green Point lighthouse on 1 July 1966 (Escom Annual Reports 1967 & 1968). All cargo was lost, but as the wreck lay only about 3 km along the coast from the harbour entrance, flotsam and wreckage from the ship was swept by the currents into the sea water intake and caused considerable damage to the circulating water screens (D Fowler 2001). A new spindle had to be ordered from England, for delivery in August 1967, to replace the one lost in the wreck (Escom Annual Report 1966). The generator was out of commission for two years (Escom Annual Reports 1965, 1966, 1967, 1968; D Fowler 2001).
This incident reduced the capacity of Salt River 2 by 25%. As much steam as possible was fed from Salt River 2 via the inter-connector to the turbines at Salt River 1 (see also “Operation” above), and generation at Salt River 2 dropped by 12% (ESCOM Annual Report 1966). Although generation at Hex River Power Station was also increased to capacity, ESCOM was unable to meet the consumers demand without assistance from the Council. The Council agreed to provide 30 MW or more, if required, on a daily basis by running the systems in parallel at peak periods (ESCOM Annual Reports 1965, 1966&1967).
 
In 1974 Salt River was able to reciprocate by providing the Council with 60 MW via redundant 33 kV cables which were re-instated for this purpose, so that generation at Table Bay Power Station could be reduced. Due to constraints on the Council network, this supply could not, at that time, be provided from the main ESCOM network. Table Bay Power Station had then been converted to oil-firing and when the world-wide oil crisis arose in November 1973, the cost of fuel oil became prohibitive. The price of oil shot up from R10 per ton to over R50 per ton almost overnight. By the end of 1975 it had rocketed to nearly R94 per ton. The modified boilers were also proving a pollution problem in the city (Palser1995: 41,42). The additional supply given to the Council caused an extraordinary surge in the growth of sales by the Cape Western Undertaking (ESCOM Annual Reports 1974:95, 1975 &1976:83; Palser 1895-1995:41,42).
 
For several months during construction of the second coal tippler for the “C” extensions at Salt River 2, ground-water was pumped into the sea water intake canal. The ground-water was contaminated with sulphurous salts which unwittingly attacked certain of the condenser tubes, causing them to become brittle and suddenly burst. One such tube failure resulted in the immediate shutdown of two or three boilers, and very nearly the entire station. If quantities of sea water entered the boilers, it would cause foaming in the boiler drum. Should water then be carried over with the steam, it could prove disastrous for the turbines (D Fowler 2001).
Generator 5 at Salt River 2. Sets 5 and 6 were 60 MW sets made in Switzerland.
A completed 30 MW generator at Salt River 2. The control panel can be seen on the right.
Operating staff in front of a 30 MW generator at Salt River 2.
30 MW generators 4, 3 and 2 with number 1 obscured in the background at Salt River 2. Just above the clock can be seen the passageway to the engine room at Salt River 1
COAL SUPPLIES
 

Coal was railed to Salt River from various coalfields in the Witbank area. During the 1960s and 1970s it was often railed to Maputo or Richard’s Bay and then shipped to Cape Town, where it had to be loaded into trucks again to be brought to site. The use of shipping was a Railway arrangement in order to relieve the congestion on the main line. Before the construction of the coal tipplers for Salt River 2, the coal had to be off-loaded manually via off-loading pits. A fireless locomotive, charged with steam and water from the low-pressure steam range, was first used for shunting coal trucks. A steam locomotive, and also a diesel replaced this. (D Fowler 2001).

 During the early years of Salt River 1 very high quality coal, chiefly “peas” 1/4 inch to 3/4 inch [6 mm to 19 mm] of high calorific value over 13 100 Btu/lb [30,5 MJ/kg] was received (ESCOM Ten Years 1923 to 1933: 51 &ESCOMTwenty-five Years 1923 to 1948: 42). The calorific value decreased over the years from above 30 MJ/kg before 1940 to 29 MJ/kg by 1950, 28 MJ/kg by 1954, 27 MJ/kg by 1960, and after 1975 sometimes below 26 MJ/kg. The lowest annual figure was 23,96 MJ/kg in 1977 (ESCOM Annual Reports). Between 1946 and 1951 the ESCOM Annual Reports mention 1) the “precarious” state of coal stocks at Salt River, 2) that full requirements of “pea coal” were not supplied and “round coal” [above 35mm], which needed crushing locally, had to be resorted to (ESCOM Annual Report 1946:35), and 3) that coal prices continued to rise. The shortage of reserves in 1948 was “an extremely serious problem” (ESCOM Annual Report 1948:34) and in 1951 reserves were at times “almost nil” (ESCOM Annual Report 1951:29). In 1955, 1964 and 1965 coal stocks were again extremely low (ESCOM Annual Reports 1955:26, 1964:21, and 1965:21).

 Note: Between 1945 and 1950 the coal crusher at Table Bay Power Station processed nearly a quarter of a million tons of coal for the pooled stations. In July 1948 there was barely sufficient coal for 24-hours operation. A few years later, when reserves again fell to dangerous levels, suburban train services were curtailed and “it was decided to completely cut off the supply of electricity throughout the Western Cape as from midday on Saturday, 30 June 1951, until five o’clock the following Monday morning…… Fortunately, however, through the intervention of the Minister of Economic Affairs, coal supplies from other sources were urgently diverted to the Cape and a shut down of the “pooled” power stations narrowly averted.” (Palser 1995:41; ESCOM Cape Western Undertaking Manager’s Annual Report 1951:10).
 

The contracts for Salt River 2 specified that the boilers were to be designed for “mixed smalls” (0 to 25 mm), the higher quality peas being reserved largely for export. The mixed smalls supplied often contained 50% of “duff” (below 3 mm down to powder) which could create blockages and combustion problems with the chain-grate stokers. This sizing of coal was vulnerable to spontaneous combustion, as occurred in 1959 and 1966. The resulting smoke caused a traffic obstruction on the adjacent N1 freeway when the wind changed to north. As spraying the burning coal with water only made the situation worse, the hottest sections had to be lifted and fed into the boilers. Salt River 1 was fired-up to speed up the process, while generation at Hex River was reduced and coal supplies to Salt River were suspended for 16 days. A rubber-tired bulldozer was purchased to compact coal-heaps to prevent a repeat of the situation (ESCOM Annual Reports 1959:27& 1966:22 and D Fowler 2001).

 The cost of coal per ton (2 000 lb which is approximately equal to 0,9 metric ton) in 1929 was 2/- [20 cents] in Witbank, on the Natal coast 8/- [80 cents] and in Cape Town 23/10p [R2,38]. Railage accounted for 85% of the cost in Cape Town (ESCOM Annual Report 1929). In 1965 the cost per metric ton was R1,72 at Taaibos and R5,97 at Salt River. In 1975 the figures were R4,52 at Taaibos, R2,33 at Hendrina and R12,92 at Salt River (ESCOM Annual Report 1975:60). The cost at Cape Town was thus three to five times as much as near the coal-fields. In 1977 the cost at Salt River was over R20 per ton (ESCOM Annual Report 1977:21). The last time coal was purchased for Salt River was in 1993 when the price was R171,50 per ton (records at Peaking Generation). Coal remaining at decommissioning of the station was sold to a local coal merchant for re-sale in the area (ESCOM Annual Reports 1929, 1975:60, 1977:21; Records at Peaking Generation, 2002).
 
In 1958 the cost of producing a kWh of electricity in the Rand, Orange Free State and Eastern Transvaal was under 0,5 pence while in Cape Town it cost 1,1758 pence (The South African Electrical Review, November 1958). Many municipalities gave up producing their own electricity in the Fifties and bought bulk supplies from ESCOM. Cape Town was one of the exceptions as it had a considerable investment in its own generating plant. As the cost of transporting coal continued to rise “the scales” eventually “tipped” in favour of transmission of power (Conradie & Messerschmidt 2000:126 & 133).
 
ECONOMIC IMPACT ON INDUSTRY IN THE SUPPLY AREA
 
The agreement between ESCOM and the Council made in April 1924 recognised the authority of the Council to supply the area of the Peninsula bounded by a line drawn on the map between Milnerton and Strandfontein (Shorten 1963: 307). ESCOM arranged with the Council that any extensions in demand for supply within this area would be met by the station in which power could be most economically produced. ESCOM was primarily to supply the area belonging to the Railways within a radius of 110 miles [177 km] of the generating station. Power could also be provided to an area within 5 miles [8 km] on either side of any railway line within this 110 mile [177 km] radius, but excluding any area under the jurisdiction of the Council (ESCOM Annual Report 1924: 7).
 
At the time of establishment of the Cape Town Undertaking there was a considerable potential load in the “rural areas outside the Cape Peninsula” and ESCOM took action to secure this load in order to make a rural distribution scheme a feasible proposition (ESCOM Annual Report 1926: 10, 11). This was before generation at Salt River was available and electricity was purchased at 12 kV from Dock Road and stepped up to 33 kV at Salt River. Among the first consumers supplied were the Hume Pipe Co. (May 1926), Bellville Brick and Tile Works (June 1926), Paarl Municipality (December 1926) and the Cape Explosives Ltd. near Somerset West (September 1927) (ESCOM Annual Reports 1925:11 and 1926:22). At the end of 1927 there were 71 miles [114 km] of 33 kV distribution lines extending from Salt River Power Station (ESCOM Annual Report 1927: 17).
 
In 1928 the load on the Cape rural system was 9,8 GWh. At the end of 1929, the first full year of generation at Salt River, the 33 kV network also extended into the Stellenbosch and Malmesbury districts. The load on the rural system amounted to 11,2 GWh or 23% of the total sent out from Salt River, and traction load amounted to 28,9 GWh or 59%. The Railways closed the Sea point line in April 1929, the load on this line having previously been equivalent to approximately 4 GWh per annum (ESCOM Annual Report 1929:31).
 
It had been Dr van der Bijl’s ambition to assist farming and industry by supplying cheap power to promote development (ESCOM Annual Report 1923). In 1932 a supply was commenced to 49 consumers in the Eerste River to Firgrove and Somerset West area, principally to wine farmers, a farming college and a winery for domestic, wine-pressing and other power purposes. This was one of the first “Rural Electrification Schemes inaugurated in South Africa” (ESCOM Annual Report 1931: 31,32). Farmers electrified their water-pumps and wine-presses, increasing production and thus giving impetus to the development of the Cape wine industry (ESCOM Annual Report 1931:32). Two new, electrified, facilities in the docks for agricultural exports stimulated other sections of the farming industry in the Cape. The first was the meat chilling plant installed in 1933. This substantially increased the export of meat from Cape Town and boosted the industry (Engineer, June 1933). The second assisted the development of the export trade in deciduous fruit, which was dependent on the introduction of pre-cooling technology preparing the fruit for shipment. Engineering states: “From trifling proportions in pre-war days, the exports of deciduous and citrus fruits from South Africa had risen to a value of nearly £2 000 000 in 1934, roughly half the total being exported from Cape Town”. A large new pre-cooling shed was built in the “C” Berth of the new basin in 1934 to cope with the increase in demand (ESCOM Annual Reports 1923, 1931:31,32; The Engineer, June 1933; Engineering, December 1935:605).
 
The year 1938 was the year of maximum generation at Salt River 1, and 239,4 GWh were supplied to the Council (72% of the total sent out by Salt River 1). The balance, after allowing for losses, was sold as follows: Bulk 12,5%, Traction 52,5%, Industrial 28,4%, Domestic and Lighting 6,6%. At this stage, the railway traction load was still the predominant ESCOM consumer, after the Council.
 
As the demand taken by other consumers increased over the years, the traction load became to represent a smaller percentage of the total sales in the undertaking. In 1930 traction load represented almost 60% of the total sales. By 1940 the figure was below 50%, and by 1950 about 20%. With the electrification of the line to Touws River in the mid 1950s the figure increased to over 30% and again in the early 1960s when the line was electrified to Beaufort West. By 1970 the figure had dropped below 20% again and by 1980 below 10%. The fluctuations in the traction load, called “traction pulls”, could at times prove quite onerous on the power station staff, particularly the boiler attendants. But after the national link-up with the 400 kV system, these pulls were no longer a problem. (D Fowler 2002).
 
In 1950 ESCOM extended its Oakdale-Langebaanweg line to supply consumers in the canning and fishing industry in the Saldanha Bay/Vredenburg area (ESCOM Annual Report 1949). The wine, the deciduous fruit and the fishing industries are all specifically identified with the Cape. ESCOM endeavoured to support industrial growth in the region by supplying demand. Extensions were made to the Ascot Substation during the year 1966 to enable a duplicate supply of 15 MW to be given to Fisons who started construction of a large fertiliser factory. The Caltex oil refinery was also supplied from this substation (ESCOM Annual Reports 1949, 1966:22).
 
ENVIRONMENTAL IMPACT
 
At the beginning of the twentieth century about half of the power station site was below the high water mark. The land surrounding the site was partially reclaimed land and undeveloped in the 1920s. The Woodstock beach was on the north and the Diep River overflow and railway lines on the south. The beach was reclaimed in the 1970s for the harbour extensions. (Photographs, Macmillan Collection, UCT and SAR drawing 164-R-2 dated 3-5-1921 Escom drwg. 1.02/2 and 0.02/24 dated Dec. 1904). There are no recorded complaints about the visual impact of the buildings, noise, coal dust or smoke emissions in the reference material studied.

There was no outdoor high voltage yard and except for the original rural 33 kV distribution line, power was exported from the site via underground cables. Sea water was used for cooling which meant there were no massive cooling towers to intrude on the view. The intake and outfall canals were below road level. The outfall water was discharged on the beach until the harbour extensions in the 1970s and the outfall was then extended below ground level to the breakwater, and now forms part of the Paarden Eiland storm water drainage system. A small quantity of the warmer condenser outlet water was pumped via an underground pipeline for a distance of approximately 1,5 km to the Woodstock swimming baths until these were demolished for the harbour extensions about 1939. (This swimming pavilion is shown on SAR drawing 164-R-2 dated 3-5-1921 (ESCOM drwg. 1.02/2) and stood approximately between the present Lower Church Street exit from the N1 and the Marine Drive exit to Paarden Eiland).

Fresh water was taken from the Council’s underground water mains. The specific water consumption of Salt River normally averaged between 0,25 and 0,35 litre/kWh depending on the load factor (ESCOM Annual Reports 1969 to 1977).

The installation of grit collectors at Salt River 1 was completed in 1955 (ESCOM Annual Report 1955: 26). This greatly improved the emission of grit from the chimneys. The emissions from the 300-foot high chimneys at Salt River 2 were largely clear of visible particulate matter, as the boilers were fitted with grit arrestors. During “soot-blowing” operations dark smoke was sometimes released and complaints were occasionally received, but smoke was generally blown out to sea by the “South-Easter”, the prevailing summer wind. Water sprays were used at the coal tipplers to control the dust during tippling operations (D Fowler 2001).

The Cape Brick Co. had premises on the site and used the power station ash waste to make clinker bricks. Thus there were no permanent ash dumps. When a building slump reduced demand for the bricks, the ash was used for the road foundation of the new Marine Drive, which was at the time being constructed on the seaward side of the power station. In contrast, the asbestos waste that had to be disposed of during the dismantling operations created a costly problem (estimated at well over R1 million). The demolition contractor had to comply with the relevant legislation for hazardous waste, and employed an independent agent to monitor air-borne asbestos pollution levels. The asbestos was taken to the Vissershok hazardous materials burial ground (D Fowler 2001).

During the later years of Salt River 2 there were sometimes complaints from the public about the noise when steam was blown off. This occurred when two-shifting or when the plant was being warmed up and brought on line after standby shutdown periods. The area around the power station had, in 70 years, become considerably more developed and the general public had become far more sensitive to environmental issues such as noise pollution by the late C20th (D Fowler 2001).
 
 STAFF
 
Salt River Power Station had, according to the accounts of some of its pensioners and staff, some exceptional superintendents who engendered a feeling of camaraderie amongst the staff. Perhaps, as a result, there were a number of staff members who had long periods of service with the station and there were a number of families with two generations working at the station. Staff were interested in each other’s news and the station produced an “in-house” news bulletin edited by Jimmy Boyd keeping staff informed with general interest stories and photographs (G Jacobs, J Boyd & D Ford 2001). The “Basement Bulletin”, so named “because that was where all the stories started” (D Ford 2001), ran from 1955 to 1984. Some staff with long service were: Vic Benning (30+ yrs); “Nobbie” Gray (47 yrs); Carl Boltney (45+ yrs) who saw six Power Station Superintendents retire; Dick Fowler (43 yrs); Bob Rosslee and Don du Toit (39 yrs); Tommy Green (38+ yrs); Walter Oosthuizen (34 yrs); Dennis Ford (33 yrs Eskom/25 yrs Salt River); Jimmy Boyd, Noel Warrington and Fred Vollenhoven (30 yrs); Jannie Marais, Colin Campbell, Derek Grobbelaar and Pieter van Dieman (29 yrs); Ben van As (26 yrs); Willie Henning, Fred Avery and Jimmy Smith (24 yrs); Robin Clacher and William Snell (23 yrs); “Boetie” Basson (22 yrs); William de Smidt (20 yrs) and many others for whom there are no longer staff records. In 1980, Dennis Ford, Arthur Bertoni, Tommy Green and Harry Cole had 142 years service between them. When Lew Trim, James Smith, Basil Coetzee, Peter de Vries, Arnoldus van Geuns, Frans Wijtenburg and Aalbert Heusdens retired in 1986 they had 203 years service between them. ESCOM Megawatt No.29/1973:36, No.34/1975:39, No.39/1976:32, No.52/1979:18, No.60/1980:24, ESCOM News No.61/1986:3) 2001).
 
Father/son groups were van Diemans, Bielhs, and Vollenhovens. Mr Dennis Ford stated that at one stage all the engine room and boiler house staff seemed to have some family connection to the Rosses or Smals. Mr Ford also mentioned that Mr Gray had “borrowed” his older brother’s birth certificate, as he was too young to obtain work. This fact came to light when Mr Gray retired. Mr William de Smidt started with the Cape Town Undertaking in 1926 when it had only three staff members: the manager Mr George Swingler, a clerk and Mr de Smidt as engineer. In 1940, before the road was made, he and his technical assistants surveyed the power line route over the Du Toit’s Kloof Mountains. He retired as distribution superintendent engineer in 1946. In the mid 1970s staff numbers peaked at about 850 to fall to 600 in 1986 and 18 at decommissioning in 1994. In the last days of operation pensioners were sometimes called in to help run the station. (The South African Electrical Review, February 1947; ESCOM: Megawatt No.24/1972:14; D Fowler 2001).
 
In the early days of the power station many staff members walked to work, while a few came by donkey cart. The donkeys were outspanned in the fields surrounding the power station. With high tides and stormy weather the sea washed in under the entrance arches. The beach was a short walk through the arches and across Marine Drive until the 1960s when the new Marine Drive dual carriageway was constructed, and lunch-time on a fine day could be a picnic on the beach. The staff sometimes had a “catch” of crayfish to take home when the sea water intake-screens were cleaned. Staff enjoyed working at Salt River. (ESCOM: Megawatt No.47/1978:14-19; D Fowler 2001).
 
From the time Salt River 1 was shut down staff began to take early retirement, a number leaving in the early 1980s. Most staff did not want to relocate to other areas. A few were placed at Koeberg, at Acacia Power Station, in Peaking Generation at Durbanville and in Distribution. Derek Grobbelaar and Jannie Marais stayed on after early retirement as contractors to assist with dismantling. Dick Fowler, Production Manager, was the last of the staff to leave Salt River Power Station. The Power Station Superintendents/Managers were: Messrs Harry H Jagger, “ET” Clifford-Jones, Victor L Benning, George G Meek, Dennis R Ford, Frans J Wijtenburg, Charles C Geldard and Jeff Lomey. The position held the title of “Power Station Superintendent” until 1972. Thereafter, with the establishment of the CGU, it was “Power Station Manager” (D Ford 2001). Before coming to Salt River, Mr Harry Jagger was Resident Engineer at Colenso Power Station after Mr JA West, the first Resident Engineer. (ESCOM: Megawatt No.25/1972:19).
 
FACILITIES PROVIDED
 
As the power station was so close to the city and residential areas, no facilities such as schools, sports fields, recreational halls or housing (other than home ownership loans) were provided. In the 1960s Mr Dennis Ford initiated a soup kitchen chiefly for the benefit of the labourers, where a mug of nourishing soup and a few slices of bread could be had at a nominal cost. Often the labourers came to work on an empty stomach and the soup provided them with stamina. When the CGU was established, a canteen was provided with the necessary staff to prepare a very wholesome meal at lunch-time as well.
 
Mr Dennis Ford also initiated a medical clinic on the site staffed with a qualified industrial nursing sister. The caretakers quarters at the entrance building were converted into the clinic and the Eskom doctor visited the site once or twice a week for consultations. This clinic improved the absenteeism rate appreciably.
 
 AWARDS

In August 1972, under Mr Dennis Ford’s management, Salt River was presented with an award for one million man-hours worked without a disabling injury. This was recorded on 23 June 1972, completing 435 days after the last disabling injury. On 16 July 1978 Salt River achieved three million man-hours without a disabling injury. At a function held on 20 October 1978, Mr (later Dr) IC McRae handed the RL Straszacker floating trophy to Mr Dennis Ford. Salt River was only the second accident prevention unit in ESCOM to receive this trophy. Two million man-hours were again achieved on 22 August 1980 for a second time, with Dennis Ford still manager. By June 1981, three million man-hours had again been achieved, Frans Wijtenburg then being manager. Salt River went on to attain four million man-hours without a disabling injury. At a celebration held on 12 November 1982, Mr G F Hellström, Western Cape Regional Manager, handed Frans Wijtenburg a certificate to commemorate this achievement. (ESCOM Annual Report 1972:24; ESCOM Megawatt No.26/1972:10, No.50/1978:17, No.51/1978:17, No.63/1980:24, No.69/1981:27, ESCOM News No.3/1983:5)  In 1978 Salt River was awarded a trophy for the Best Plant Performance in Group B (chain grate stokers). A presentation was made by Mr R B Cliff, Assistant Manager (Engineering Services), CGU. (ESCOM: Megawatt No.47/1978:19). 
Closing ceremony for Salt River 1 on 12 November 1979. Standing in the centre is Bob Rosslee (Master of Ceremonies) and seated on his right is Dennis Ford (Power Station Manager). Seated on the right on the photo is Ronald Myburgh (Regional Manager).
DE-COMMISSIONING AND DEMOLITION
 
On 12 November 1979 a closing ceremony for Salt River 1 was held in the turbine house. Mr Clifford-Jones, Mr Gray and Mr Ford shut the valves (Megawatt, December 1979). Salt River 1 had been the first thermal power station to be built AND operated by ESCOM (Megawatt, December 1979). In the fifty-one years that it was in operation, its boilers burnt nearly 3,3 million tons of coal and 4 910 GWh of electricity were sent out. By comparison, Koeberg Nuclear Power Station has produced more than double that amount in a single year (Eskom Statistical Yearbook 1995). Eskom concluded an Agreement of Sale of R1 million for a subdivided portion of the site on which Salt River 1 was built with a property developer, Meridien Corporation, on 14 November 1990. This subdivided portion, 1,19 ha in extent, was sold “voetstoots” including the buildings plant and structures. Wreckers Dismantling (Pty) Ltd. first removed the asbestos and then demolished the power station in 1991 and 1992. A new break-bulk warehouse/container link was built on the site in 1993/1994 (D Fowler 2001).
The official closing ceremony for Salt River 2 was held at the power station on 12 August 1994, with Mr Bruce Crookes, Executive director: Generation, officiating and Mr Basson, Mr Henning and Mr Marais shutting the valves (Die Burger 13-8-1994). Mr Crookes had worked at the station in his youth. In its 40 years of operation Salt River 2 had burnt over 13,2 million tons of coal and sent out 24 762 GWh of electricity. In that time, generators 1 to 4 had each run for over 160 000 hours and 5 and 6 approximately 120 000 hours, well above the 100 000 hour design life (D Fowler 2001).
 
 
 Eskom signed an Agreement with Wreckers Dismantling (Pty) Ltd. whereby the demolition company bought and would dismantle the power station buildings, structures and equipment. The demolition was to commence on 16 October 1995 and be completed by 30 June 1997. Explosive charges were used on several occasions, the final one being for toppling the two chimneys on Sunday 15 June 1997, when a large crowd of spectators was present. Michael Rego, aged 9, one of a group of deaf schoolchildren who had been invited to see the big event, “pushed the button” to detonate the explosives at 4pm. The entrance building, the main switch house-administration building and certain transformers still required by Eskom, were excluded from the Agreement. During the period of demolition Eskom converted the 33 kV switch house into a sub-station to continue supplying Metrorail (the suburban railway) and Portnet (the harbour) with electricity. Power is now imported by Salt River for distribution to the railways and harbours. Although indirectly as a substation, Salt River still continues, as mandated by the Electricity Control Board on 6 April 1925, to supply the Railways and Harbours (D Fowler 2001, ESCOM Annual Report 1924). The substation has retained the name “Salt River”. The rest of the site was sold for re-development. (ESCOM Annual Report 1924; Cape Times June 16, 1997:1&3; Conradie & Messerschmidt 2000:260; D Fowler 2001)
 
 NOTES ON THE NAME OF THE SALT RIVER
 
The Salt River was formerly the lower section of the Diep River which has its source near Riebeeck-Kasteel. Today the Diep River flows into Rietvlei and the Milnerton Lagoon. Present-day maps show the Salt River, which has been canalised, as forming the boundary between Paarden Eiland and Brooklyn and draining the Liesbeeck and Black Rivers. Previously there were two exits, and the Liesbeeck and an overflow from the Diep River entered the sea at the site where the power station was built. Paarden Eiland was then actually an island. Because the water was brackish, van Riebeeck called it the Zout Rivier. The original Salt River estuary, after which the power station was named, has also been canalised and extended underground to exit in the container basin of the Table Bay docks extension. Maps now show it as the “Old Salt River”. Eskom drawing 1.02/2 (SAR drwg. 164-R-2) dated 27-4-1921 shows the interconnection between the two former mouths as “overflow from Diep River”. All that is left today of this interconnection is a concrete culvert running next to the N1 and forming a storm water channel. (See also the Standard Encyclopaedia of Southern Africa.)
 
Salt River is the only ESCOM power station that can be officially translated. It appears in the ESCOM Afrikaans annual reports as “Soutrivier”. Hex River is also translated as “Hexrivier” but in this case only the “River” portion of the name is translated and not the “Hex” portion. The names of no other power stations may be translated, for example, Taaibos cannot be translated as “Sticky-bush Power Station”, or Vaal as “Grey Power Station” or Tutuka as “Progress Power Station” or Koeberg as “Mt. Cow Power Station.”
 
BIBLIOGRAPHY
 
(Included are references to sources used for Dick Fowler’s history of the Salt River).
 
This information on the Salt River Power Stations was produced by Vanessa Bowen, a historical researcher from Cape Town University and D Fowler, a retired Eskom employee who worked at Salt River Power Stations.
Burman, Jose. Safe to the Sea. Human & Rousseau, Cape Town, 1962
Burman, Jose. Great Shipwrecks off the coast of Southern Africa. Struik, Cape Town, 1968
The Bay of Storms – Table Bay 1503-1860. Human & Rousseau, Cape Town, 1976
Cape Town Mayor’s Minutes (including City Electrical Engineer’s Annual Report), 1908-1910
Christie, R. Electricity, Industry and Class in South Africa. Macmillan, 1984
Commissioners of the Table Bay Harbour Board. The Harbour Works, Table Bay, Cape Colony 1656-1895. Published 1895
Conradie, SR & Messerschmidt, LJM – A Symphony of Power. The Eskom Story. Johannesburg: Chris Van Rensburg Publications (Pty) Ltd. 2000
Dictionary of Business Biography, Volume 4 – edited by David J Jeremy. Butterworths, London 1985
ESCOM/Eskom Annual Reports 1923-1995
ESCOM: Golden Jubilee 1923-1973
ESCOM: Letter from GH Swingler to Dr HJ van der Bijl dated 22 February 1928
Eskom: Statistical Yearbook 1995
ESCOM: Ten Years – A record of the progress and achievements of the Electricity Supply Commission, 1923-1933
ESCOM: Twenty-five Years – A record of the origin, progress and achievements of the Electricity Supply Commission, 1923-1948
General Manager of Railways and Harbours, Annual Reports 1912-1935, (Union Government Annexures presented to Parliament)
Green, Lawrence G – Almost Forgotten, Never Told. Howard Timmins, Cape Town, 1965
Hoy, Sir William – Railway Electrification in South Africa. In: South African Railways and Harbours Magazine, May 1922:355-360
Ingpen, B – South African Merchant Ships. Balkema, Cape Town/Rotterdam, 1979
Kanthack, [Dr] FE – Circulating Water Intake and Discharge Works for the Salt River Power Station. In: The Transactions of the South African Institute of Electrical Engineers, P
art 6 of Vol. XXI, June 1930
Knox-Johnston, R – The Cape of Good Hope – A Maritime History. Hodder & Stoughton, London 1989
Kotze, Sir Robert – Electricity Supply in South Africa. In: South African Railways and Harbours Magazine, May 1922:376-378
Lydall, F – The Electrification of the Pietermaritzburg-Glencoe Section of the South African Railways. In: The Journal of the Institution of Electrical Engineers (London), Vol. 66, 1928, pages 1021 to 1064
Merz and McLellan – South African Railways – Report on the Introduction of Electric Traction, June 1919
Merz and McLellan – Electric Power Supply in the Union of South Africa, April 1920
Mills, FW – Electrification of the South African Railways. In: South African Railways and Harbours Magazine, November 1919:737-738
Palser, D – Lighting Up The Fairest Cape 1895 to 1995. A Historical Record Commemorating the Centenary of the City of Cape Town Electricity Undertaking. (References and quotations by courtesy of the Cape Town City Council Electricity Department)
Pask, TP – The Past and Present in the South African Railways Electrical Department. In: South African Railways and Harbours Magazine, May 1922:420-426
Pask, TP – An Introduction to the Study of Electric Traction in Natal. In: The Transactions of the South African Institute of Electrical Engineers, Vol. XVII, Part 5, May 1926
Picard H – Cape Epic. Khenty Press, Natal 1977
Shorten JR 1963. The City Electrical Engineer’s Department. In: The Golden Jubilee in Greater Cape Town: 303-311. Cape Town: JR Shorten (Pty) Ltd.
South African Who’s Who, Published by Ken Donaldson
Standard Encyclopaedia of Southern Africa
Theal, GMcC – History of South Africa before 1795. Reproduced by Struik, Cape Town 1964
Troost, Dr N & Norman HB, Electricity Supply in South Africa 1909-1969. In: The Transactions of the South African Institute of Electrical Engineers, Sept 1969
Turner M, – Shipwrecks and Salvage in South Africa-1505 to the present. Struik, Cape Town, 1988
van Riebeeck, Jan A – Daghregister/Journal of van Riebeeck. Dutch and English versions, edited by HB Thom, (English translated from the original Dutch by WPL van Zyl, Chief Translator of the House of Assembly). AA Balkema, Cape Town 1952
Veitch N – Waterfront and Harbour. Cape Town’s Link with the Sea. Human & Rousseau, Cape Town 1994
 
Notes on the Authors
 
Hoy, Sir William (born 1868 in Scotland) joined the Cape Government Railways in 1889 and became Assistant General Manager from 1 January 1909. After establishment of the Union of South Africa in 1910, he became General Manager of the South African Railways and Harbours. He was appointed a member of the Committee to consider the Merz Report of 1920.
 
Kanthack, Dr Francis Edgar (born 1872 in England), Consulting Engineer to ESCOM.
 
Kotze, Sir Robert N (born 1870 in South Africa) became the Government Mining Engineer from 1908-1926 and was appointed by the Government as Chairman of the Committee to consider the Merz Report of 1920. The deliberations of this committee resulted in Parliament passing the Electricity Act of 1922 and the establishment of ESCOM in 1923. Sir Robert and
 
Dr van der Bijl did the major part of the Committee’s work.
 
Merz, Dr Charles Hesterman (1874-1940), a very capable Consulting Engineer in Great Britain who took William McLellan (1874-1934) as a partner in 1909. In 1913 the firm employed a staff of 73. Merz, with two of his children, were tragically killed during World War II by a direct hit on their Kensington home. (Dictionary of Business Biography).
 
Mills, Frederick William (born 1870 in England) came to Natal in 1895 for Messrs Woodhouse and Rawson, a firm of electrical engineers. He joined the Natal Government Railways in 1896 and introduced train lighting by electricity. He became the Chief Electrical Engineer for the SAR on 1 November 1911 and made initial reports and estimates on railway electrification. He conducted Merz over the proposed railway electrification routes in South Africa in 1919 and visited the major railway electrification schemes in America and Europe in 1920-1921.
 
Palser, Dennis C – City Electrical Engineer of Cape Town 14 November 1974 to 10 August 1986
 
Pask, TP (born 1873) became Superintendent (Electrical and Telegraphy) for the South African Railways and Harbours in 1920, and Chief Electrical Engineer in 1925. He was a member of the Committee appointed by the Government to consider the Merz Report of 1920.
 
(Pask 1922:422; South African Who’s Who; ESCOM: Golden Jubilee 1923-1973:11; Palser 1895-1995:181).
 
Journals & Newspapers
 
Engineering 1924-1940
 
ESCOM/Eskom Annual Reports 1923-1995
 
Eskom Campus
 
Megawatt 1978 &1979
 
South African Railways and Harbours Magazine 1928
 
The Cape
Argus
 
The Cape Times
 
The Electrician 1923-1928
 
The Engineer 1924-1958
 
The South African Electrical Review 1928-1958

Interview
 
Mr Dick Fowler.

Additional Telephonic Contributions From :
 
Ms Elizabeth Sinovich, Mr Dennis Ford, Mr Jimmy Boyd, Mr Bob Rosslee,
 
Mr Roeloff Potgieter & Mr Godfrey Jacobs.