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Congella Power Station

 OVERVIEW

Congella Power Station in Durban, and Salt River Power Station in Cape Town, were the first coal-fired power stations to be both built and operated by the Electricity Supply Commission (ESCOM, and which was changed to Eskom in 1987). Salt River was commissioned in February 1928 and Congella in July 1928. Although Witbank Power Station, which was financed and owned, started operating in May 1926 and was the first entirely new coal-fired power station to be started since the establishment of ESCOM in 1923, it was designed, built and operated by the Victoria Falls and Transvaal Power Company Limited. Colenso Power Station was taken over by ESCOM in January 1927, but the station had been built and originally commissioned by the Railway Administration for the electrification of the Glencoe to Pietermaritzburg line.  (ESCOM Golden Jubilee 1923-1973:14; ESCOM Annual Report 1926:5, 15)

 The primary objective in building Congella was to supply the growing needs of the Durban Corporation, and the station was to be extended immediately the Railway Administration decided to electrify the Durban to Pietermaritzburg line. Electrification of this line was completed eight years after Congella was commissioned, but power was supplied from Colenso. Although the first sets were designed to carry traction loads, traction load was not supplied from Congella until 20 years after the station had been commissioned. (ESCOM Annual Reports 1923:10&11, 1948:12; van der Bijl & Damant 1933:62; South African Railways and Harbours Magazine January 1937:9)

 
colenso11.jpg 
​ Congella 1 turbine house before 1939​
 

Congella had an initial installed capacity of 24 MW in 1928, which had been extended to 98 MW by 1938. Shortly before the outbreak of World War II (1939-1945) it was decided to build Congella 2 station on the same site and the first station became known as Congella 1. A 40 MW set was ordered, the largest then in ESCOM. (The Cape Town City Council commissioned the first 40 MW set in South Africa at their Table Bay Power Station in February 1939, and had three 40 MW sets in full commercial operation by November 1939. Table Bay Power Station used the highest steam pressure and temperature of any power station in South Africa at that time. The set ordered for Congella was a similar set and from the same manufacturer, Parsons & Co). The first set and three boilers manufactured for Congella 2 were commandeered by the British Government and installed at Earley Power Station in Great Britain to provide power for war industries. The replacement set was lost at sea in 1943 when the ship delivering it was sunk by enemy action. The first set was eventually commissioned after the war in 1946. A second 40 MW set was commissioned in 1948 and a third in 1951, but the boiler plant ordered with this last set was not completed until 1954. The installed plant capacity at Congella 2 was then 120 MW and at Congella 1 was 86 MW, as two 6 MW sets had been transferred to Kimberley. The total final installed capacity was thus 206 MW. (ESCOM Annual Reports 1940:18, 1943:10&17, 1944:35, 1946:37, 1949:31, 1951:34, 1954:37; ESCOM Golden Jubilee 1923-1973:19; Palser 1895-1995:38, 173)

 
colenso12.jpg 
Congella 1 Power Station before World War 2
 

Congella 1 was one of the world's most advanced power stations in its day. It was the first station in South Africa to burn pulverised coal and the first to be equipped with electrostatic precipitators, yet its nickname, Old Smokey, persisted. Congella had been in service for more than 50 years when it was finally decommissioned at the end of 1978. The total electrical energy sent out from Congella 1 and 2 was 22 154 GWh and the total quantity of coal burnt 15,089 million metric tons.  (ESCOM Annual Report 1984:9 and Tables of Power Station Operating Statistics)

(Note: Where energy sent-out figures were not reported (1941-1943), calculations have been made from the figures of sent-out heat rate and coal burnt. In the ESCOM Statistical Yearbook 1995, gross production figures were used for these years and the grand total given is therefore slightly higher than the figure above).

 
 cong3_350.jpgcong4_350.jpg
Congella 1 and 2 Power Stations before erection of 300-foot                 Congella 1 and 2 Power Stations in 1948 after erection of the 300
foot chimneys for station 1 (c.1946)

EARLY HISTORY

The first street lamps in Durban were introduced in 1865 and were lit by oil. A small electric lighting plant was installed in the Market Square in 1886 to provide lighting for the Town Hall (which was opened in October 1885 and later became the Post Office when the new City Hall was built). The plant was operated under contract by the English firm, Woodhouse and Rawson (see also FW Mills under "Bibliography"). The Royal Hotel and Central Hotel were given supplies from this plant as well, and the Railway Station to charge accumulators for train lighting. The Durban Harbour Department installed a small generating plant at the "Point" in 1892 consisting of a Robey engine and boiler of 35 horse power, one dc dynamo and one arc lighting machine. The Natal Government Railways soon after erected their own plant of 12 kW capacity for charging train lighting accumulators, and later a "modern" power station for their growing workshop load. This power station consisted of two 1 MW Willans Parsons turbines driving 6,6 kV alternators and four high-speed reciprocating engines driving dc dynamos, and ran until 1912, when a bulk supply was taken from the Municipality. The plant was disposed of and continued to give service at Pretoria and Uitenhage. (Henderson 1904:125, 157, 251-271; Pask 1922:422-424; McIntyre c1935:45 & 50-51)

 The municipal supply of electricity in Durban was authorised by powers under concession from the Natal Government in 1897. A power station was established at Bamboo Square, The Point, in conjunction with the sewerage works (John Roberts was sent out to South Africa to superintend the erection of this machinery - see also "Staff" below). Sewage would be pumped by day and electric power for lighting generated at night. There were four Thomson-Houston dc dynamos for street arc-lighting and six Peach high speed vertical engines totalling 800 horsepower coupled to alternators generating at 2,5 kV for incandescent lighting. The electric lighting was inaugurated with the Diamond Jubilee of Queen Victoria in June 1897. When conversion from animal-drawn to electric traction of the tramway service was contemplated in 1899, a site for a new power station was selected abutting Alice Street. The first section of the tramway service equipped for electric traction was opened on 1 May 1902 and the arc lighting machinery at the Point Power Station was thereafter decommissioned. (Henderson 1904:172-174, 251-271, 276&281; Merz & McLellan 1920:37; McIntyre c1935:50-52)

  
 The plant installed at the Alice Street Power Station in 1904 was as follows:
 
(Data source: Henderson 1904:254-258)
Principal Equipment Manufacturer Rating Description
4 Boilers 160 lb/sq.in.
4 Boilers 160 lb/sq.in.
3 Boilers 160 lb/sq.in.
Danks
Babcock & Wilcox
Hornsby
250 horse power each
220 horse power each
730 horse power each
Dry-back return tubular
With superheaters
Upright, with superheaters
4 Traction Dynamo
   Engines
English Electric
Yates and Thom
250 kW each 500-550 V dc
450 horse power, 3 ft stroke
160 lb/sq.in.  100 r/min
Supplied by Dick Kerr & Co
Horizontal, cross compound,
condensing, 14 ton flywheel
3 Lighting Alternators
1 Lighting Alternator
1 Lighting Alternator
3 Engines
1 Engine
1 Engine
ECC, Dick Kerr
ECC, Dick Kerr
ECC, Dick Kerr
Willans
Willans
Willans
350 kW each
500 kW
800 kW
575 horse power each
800 horse power
1200 horse power
Electric Construction Co (ECC)
Electric Construction Co (ECC)
Electric Construction Co (ECC)
Vertical, condensing, 320 r/min
Vertical, condensing, 320 r/min
Vertical, condensing, 320 r/min
 

 The station was extended in 1908, and in 1912 two 2 MW turbines and two B&W boilers were installed. By 1916 most of the old plant was about to be decommissioned and new boiler and turbine rooms constructed to house larger equipment including B&W marine type boilers of 56 000 lb/h [7,1 kg/s] rating and 3 MW turbine-driven alternators supplied by BTH. (Durban Mayor's Minutes 1908:97, 1910:13, 1912:91, 1916:52, 1917:7)

 Municipal supplies commenced during the year ending 31 July 1898, and amounted to 0,184 GWh for that year. Sales increased from 0,854 GWh for the year ending 31 July 1902 to 2,499 GWh the following year, after electric traction of the tramways was introduced. Sales amounted to 6,026 GWh by 1908 and 21,998 GWh by 1917, the installed capacity at the Alice Street Power Station then being 10 MW. By 1924 sales amounted to 41,872 GWh and by 1932 Municipal sales were 100,362 GWh. (Durban Mayor's Minutes 1910-1932; Merz & McLellan 1920:37)

 
THE RAILWAYS AND ESCOM
 ​

By 1912 the Railways were considering the possible electrification of the Natal railway line and had already made cost estimates when World War I (1914-1918) broke out. Sir William Hoy, General Manager of the South African Railways, realised that since there was no other power station available, the Railways would have to build their own. With this in mind, Messrs Merz and McLellan, Consulting Engineers from Great Britain and world leaders in the field of railway electrification, were appointed by the Railway Administration in 1917, to report on railway electrification in South Africa. In the latter part of the year, Mr F Lydall, an expert from Merz and McLellan arrived in South Africa to conduct investigations and collect data, and a report was submitted dated June 1919. Charles Merz (later Dr) arrived personally in South Africa on 16 August 1919 and was conducted by FW Mills, Chief Electrical Engineer of the South African Railways and Harbours, over the various sections reported on. They travelled in Sir William Hoy's private saloon. (Other sources report that Merz had paid a previous visit to South Africa in 1918 but this is not borne out by Hoy, Pask, Mills or Lydall.) The report was laid before Parliament in September of that year. Acting on the advice of Sir William Hoy, the Government had requested Merz and McLellan, in January 1919, to study the general question of electric power supply in South Africa, and Merz devoted a portion of his visit to this. He departed from Durban on 2 October 1919 on a visit to Melbourne, and submitted his report to the prime minister, General Jan 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 deliberations 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 ESCOM was changed to Eskom in 1987). Dr Hendrik Johannes van der Bijl was appointed the first chairman. (South African Railways and Harbours Annual Reports to Parliament 1912-1919; Mills 1919:737/8; Merz & 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 1923-1948:6&16; ESCOM: Golden Jubilee 1923-1973:10-11; Conradie & Messerschmidt 2000:47) 

 In their report of June 1919, Merz and McLellan reported on the possibilities and advantages of the electrification of (among others) the Cape Town-Simonstown suburban line and the Durban-Glencoe main line. The report pointed out the profitability of electrifying the Durban-Glencoe line, which was expected to give a return on net capital outlay of 40,3%. It suggested a power station be erected at Durban (four 8 MW sets) and another on the Buffalo River near Dundee, in the middle of the coalfields (three 8 MW 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 and Durban-Pietermaritzburg lines. Funds were provided, but the serious financial depression which intervened necessitated postponement of the Cape Town-Simonstown line (the Salt River Power Station would be built to supply power for this project). The original intention in Natal was to commence electrification of the line from the Durban end and work north to the coalfields. However, rapid development in coal traffic in 1921 showed that work should be started from Glencoe Junction, near the coalfields, instead of from Durban.  (Merz & McLellan 1919:(v)-(vi), 25 & Table IX; Sir William Hoy, 1922:358-359; ESCOM Annual Report 1923:8-9)

 The whole position was reviewed, together with the Consulting Engineers, in the light of the changed conditions. Mr Lydall carried out a fresh investigation and a further White Paper was submitted to Parliament in February 1922. The Minister of Railways and Harbours (the Hon JW Jagger) stated in April 1922, that to delay improvement in the carrying capacity of the Natal line would be a "national misfortune" as the line was nearing the limit of its capacity with steam locomotives. It had become a question of doubling the line vs. electrification and it was decided to electrify the Glencoe-Pietermaritzburg section, which was mainly a single line of 171 route miles [274 km]. This decision, "during a period of acute financial stringency was a momentous one, but, on the reports submitted, was more than justified". The 71 mile [114 km] Durban-Pietermaritzburg section was already a double line (the Clairwood-Mariannhill-Cato Ridge deviation with 10 tunnels had been opened in February 1921) and electrification of this line could be postponed. Merz and McLellan were appointed consulting engineers for the Natal electrification project, which included construction of the Colenso Power Station on the Tugela River (not on the Buffalo River as originally suggested) to provide power. Excavation work at Colenso was commenced in September 1922 and by September 1924 the first of five 12 MW generators had been run on test. The scheme was the second biggest railway electrification scheme in the world, second only to the Chicago line.  (South African Railways and Harbours Magazine, 1919:277, 1921:100,157,303, 1922:350/1&438, 1923:416, 1924:1087, 1926:972/3; South African Railways and Harbours Annual Reports to Parliament 1920-1924; The Hon JW Jagger 1922:352/3; Sir William Hoy 1922:358/9; ESCOM Annual Report 1923:8&9; Lydall 1928: 1021-2; Standard Encyclopaedia of Southern Africa Vol.3, 1971:130

 Since 1917 the Durban Corporation had been considering finding a site for an entirely new power station to meet their growing needs. The Corporation also appointed Merz and McLellan as their consultants. At a conference held in Durban on 25 April 1923, it was unanimously agreed between the Durban Corporation, ESCOM and the Railway Administration that one large power station should be erected at Durban to meet the needs of the area - railway, municipal and private. Merz was again in South Africa in September and October 1923, and proposed that ESCOM erect the new power station for the purpose of giving a supply to the Corporation and that the station be extended immediately the Railway Administration decided to electrify the Durban to Pietermaritzburg line.  (Durban Mayor's Minutes 1917:65; ESCOM Twenty-five Years 1923-1948:6&25)

 On 21 April 1925, ESCOM and the Durban Municipality agreed that ESCOM would erect a new station at Congella, approximately 3 miles [5 km] from the centre of the city and for ESCOM to supply the Municipality in bulk. The station would be built on approximately 20 acres [8 hectares] of land belonging to the Railway Administration, which would be transferred to ESCOM, and was proposed to be in commercial operation not later than 31 October 1927. The power station would be interconnected with the existing Alice Street Power Station, and later the Colenso Power Station. However, in the interim, additional plant would be installed at Alice Street, but the plant would be suitable for transference to the new station. Some of the old plant would be decommissioned. The Licence granted to ESCOM by the Electricity Control Board was dated 29 June 1927. The area of supply covered the Railway and Harbour supplies for a radius of 42 miles [68 km] including 5 miles [8 km] on either side of the rail line, but excluding the Natal Central Undertaking and any area under the jurisdiction of urban local authorities.  (Durban Mayor's Minutes 1923:8, 1924:206; ESCOM Twenty-five Years 1923-1948:25; ESCOM Annual Reports 1923:5&8-11, 1924:29, 1926:25-27)

 

cong5_350.jpg 
 ​ Congella 1 and 2 after 1948​

  cong6_350.jpg

Congella 1 and 2 after erection of 300 foot chimneys (c1948)

​CONGELLA CONSTRUCTION
 

The power station site was all reclaimed land, which had previously been a marshy waste. The "permanent reclamation level" was 12 feet [3,7 m] above LWOST (low water ordinary spring tide). It was situated over an underground plateau of hard shale, which reduced the cost of the foundations to a minimum. The foundations were taken down to solid rock, the maximum depth being about 20 feet [6 m] and the minimum about 10 feet [3 m}. The site was situated close to the Durban Bay thus ensuring an adequate supply of cooling water. The intake works for the circulating water were placed near the entrance to the Graving Dock. Sea water was supplied initially via three 48-inch [1,2 m] concrete pipes to the station about 900 yards [820 m] away. By 1948, five pipelines had been installed.   (van der Bijl & Damant 1933:52-54; ESCOM Annual Report 1948:36)

The principal contractors for the initial construction of the station were as follows:
 Pauling & Co. (Foundations)
International Combustion, SA. (Pty.) Ltd. (Boilers and Pulverisers)
Parsons & Co. Ltd. (12 MW generators)
Reyrolle & Co. Ltd. (High Voltage Switchgear)
Gilbert Hamer. (Steel Frame Buildings)
(ESCOM Annual Report 1925:16)
    

The initial plant consisted of two 12 MW generators and four boilers. The generators were rated for 20 MW momentary traction load in anticipation of the electrification of the railway line. (The Colenso 12 MW sets were also rated for 20 MW momentary traction load and were built by the same manufacturer, Parsons & Co, but the turbines were of two cylinder construction whereas the Congella turbines were of single cylinder design. The Congella sets were the first single cylinder turbines constructed with a duplex exhaust and proved very successful. - Parsons RH, 'The Development of the Parsons Steam Turbine', Constable 1936:202.) The boilers burnt pulverised fuel and were the first outside America to have automatic load control. Before the original plant was in operation, the Durban Corporation made application for an increased supply, with the result that an order was placed for two more identical boilers, nos. 2 and 4. The Durban Corporation was, at first, the only consumer and supplies were commenced in July 1928. The transfer of two 6 MW sets installed at Alice Street in 1924 and 1927, then proceeded and were installed in a separate annexe building. The original intention in 1925 was to transfer two stoker-fired boilers as well and to convert them to burn pulverised fuel, but this plan was not carried out. The final settlement of the amount to be paid for the second hand plant purchased from the Corporation for Congella amounted to £56 676-15s-11d. After transfer of these sets in 1929 and 1930, the station capacity was 36 MW and there were six boilers of 60 000 lb/h [7,6 kg/s] normal rating each, or 80 000 lb/h [10,1 kg/s] maximum, all burning pulverised fuel milled from "dross" (below 9,5 mm). The central system was adopted by which the coal was all milled in one central plant and then conveyed by screw conveyor to the bunkers above the boilers. Total capital expenditure up to the end of 1929 amounted to £787 746. (ESCOM Annual Reports 1925:14&18, 1927:21, 1928:29, 1929:35; ESCOM Ten Years 1923-1933:53; Durban Mayor's Minutes 1931:52; van der Bijl & Damant 1933:52-54, 62&84)

By 1931 construction of an additional 12 MW generator and two boilers of 100 000 lb/h [12,6 kg/s] economic rating each (120 000 lb/h [15,1 kg/s] maximum capacity), was in progress and completed in May 1932. Total capital expenditure up to the end of 1932 amounted to £996 373. Another generator, rated at 20 MW, was ordered "to provide a reasonable reserve of spare plant". This set was commissioned in 1934, bringing the installed capacity to 68 MW with six generators, all generating at 6,6 kV, and eight boilers. A thermal storage plant was installed in 1935, whereby feed water was stored and heated during off-peak periods, enabling the boilers to steam at greater output over the peak period. Capital expenditure up to the end of 1935 amounted to £1 088 995 and at the end of 1936 was £1 121 291. An additional 30 MW generator, generating at 33 kV, and two 120 000 lb/h [15,1 kg/s] boilers were ordered in 1936 to be installed by the winter peak of 1938. A new system of ash extraction by electrostatic precipitators, the first in South Africa, was ordered for these boilers and installation completed in November 1938, bringing the station capacity up to 98 MW. Capital expenditure to the end of 1938 was £1 453 334, but this included expenditure on the South Coast distribution system.  (ESCOM Ten Years 1923-1933:25&53; ESCOM Annual Reports 1931:35, 1932:22, 1933:5, 1934:5, 1935:22&23, 1936:29, 1937:31, 1938:37&84)

It was then decided to build a second station on the same site, to be known as Congella 2 and the old station became known as Congella 1. A 40 MW generator, which would then be the largest set in ESCOM, (similar to the three sets commissioned by the Cape Town City Council at Table Bay Power Station in 1939), and three 200 000 lb/h [25,2 kg/s] boilers, were ordered. Construction at site commenced during 1939. Unlike Congella 1, each boiler at Congella 2 was to have its own mills for pulverising the coal. However, World War II broke out before delivery of the plant, which was released to the British Government, by agreement with ESCOM, to provide power for war industries (see also "Overview" above). The construction programme was thus seriously delayed. The replacement set sent out in 1943 was lost at sea when the ship delivering it was sunk by enemy action, delaying the programme still further. The first set at Congella 2 (designated No.7) was eventually commissioned after the war, being put on load for the first time on 27 February 1946. These delays meant that the station output had to be stretched to its limits throughout the war, a situation that greatly aggravated the emission of grit and fly-ash from the chimneys. A second 40 MW set (No.8) was commissioned in 1948 and a third (No.6) in 1951, but the boiler plant for the final extension was not completed until May1954. (The bay in the turbine house allocated to set No.6 in 1939 remained a spare bay until the set was actually installed - KM Nero 2003). The installed plant capacity at Congella 2 was then 120 MW and at Congella 1 was 86 MW, as the two 6 MW sets had been transferred to Kimberley in 1949. The total final capacity was thus 206 MW.  (ESCOM Annual Reports 1940:18, 1942:6, 1943:10&17, 1944:35, 1945:33, 1946:37, 1947:41, 1949:31, 1950:35, 1951:34, 1954:37; Conradie & Messerschmidt 2000:80&81)

 The principal equipment installed at Congella 1 consisted of the following:
 
Boiler Nos: Economic Rating Pressure Temperature Commissioned
1,3,5,7  ICL 60 000 lb/h [7,6 kg/s] 270 lb/sq.in. [1,96 MPa (abs)] 720 °F [382 °C] July 1928
2&4      ICL 60 000 lb/h [7,6 kg/s] 270 lb/sq.in. [1,96 MPa (abs)] 720 °F [382 °C] Jan 1930
6&8      ICL 100 000 lb/h [12,6 kg/s] 300 lb/sq.in. [2,17 MPa (abs)] 720 °F [382 °C] May 1932
9&10    ICL 100 000 lb/h [12,6 kg/s] 300 lb/sq.in. [2,17 MPa (abs)] 720 °F [382 °C] Nov 1938
 
The 60 000 lb/h boilers had a maximum rating of 80 000 lb/h
       
The 100 000 lb/h boilers had a maximum rating of 120 000 lb/h

 
Generation Plant: Manufacturer Capacity Voltage Commissioned
Generators 6A&B ** Metro-Vickers  6 MW 6,6 kV 1924&1927 **
Generators 1&2 Parsons 12 MW 6,6 kV July 1928
Generator 3 Parsons 12 MW 6,6 kV May 1932
Generator 4 Parsons 20 MW 6,6 kV 1934
Generator 5 Parsons 30 MW  33 kV Nov 1938
Total installed   98 MW    

** The 6 MW sets were transferred from Alice Street in 1929&1930 and then to Kimberley in 1949&1950
       
The 12 MW sets were rated for 20 MW momentary traction load, similar to the Colenso sets
The turbine inlet steam conditions of the 12 MW sets were:  250 lb/sq.in. [1,8 MPa (abs)]   700 °F [371 °C]
A small 380 V petrol driven alternator was also installed capable of starting up the auxiliaries on one boiler in case of a complete shut-down, using town water for cooling the condensers. (Trans. SAIEE March 1933:65)
 
The principal equipment installed at Congella 2 consisted of the following:
 
Boiler Nos: Capacity Pressure Temperature Commissioned
11to13   ICL 200 000 lb/h [25,2 kg/s] 625 lb/sq.in. [4,41 MPa (abs)] 825 °F [441 °C] 1946
14&16   ICL 200 000 lb/h [25,2 kg/s] 625 lb/sq.in. [4,41 MPa (abs)] 825 °F [441 °C] 1948&1949
15&17   B&W 200 000 lb/h [25,2 kg/s] 625 lb/sq.in. [4,41 MPa (abs)] 825 °F [441 °C] Apr/Aug 1953
    18    B&W 200 000 lb/h [25,2 kg/s] 625 lb/sq.in. [4,41 MPa (abs)] 825 °F [441 °C] May 1954
 
 
Generation Plant: Manufacturer Capacity Voltage Commissioned
Generator 7 Parsons 40 MW 33 kV February 1946
Generator 8 Parsons 40 MW 33 kV 1948
Generator 6 Parsons 40 MW 33 kV March 1951
Total installed   120 MW ​   
 
 Turbine steam inlet conditions:  610 lb/sq.in. [4,3 MPa (abs)]   815 °F [435 °C]   (the highest in ESCOM at the time).  (Data source: ESCOM Twenty-five Years 1923-1948:43, ESCOM Annual Reports and Trans. SAIEE March 1933)
 
cong7_350.jpg 
Congella 1 and 2 in 1951. Congella 2 is on the left.
 
 
PULVERISED FUEL AND DUST NUISANCE
 

When the original tenders were called for, alternative prices for boilers fired by means of pulverised fuel were requested. Analysis of the tenders showed that firing by pulverised fuel would offer the most favourable proposition. Factors weighing in favour over against stoker firing were the estimated saving in coal due to higher efficiency, greater flexibility in operation, quicker response to changes in load (an important consideration in view of the problems caused by traction loads at Colenso) and lower annual charges. Dross coal, of which large quantities were accumulating in the country, and which up to that time was regarded as waste discard, could be used. Dr van der Bijl, ESCOM's founding Chairman, therefore decided to utilise this latest technology instead of installing chain grate stokers. Congella was one of the first stations in the Southern Hemisphere to burn pulverised fuel and the consulting engineers considered the technology had not yet been sufficiently proved, although today pulverised fuel is used exclusively in ESCOM's giant coal-fired boilers. However, Dr van der Bijl maintained that "the method [had] been in commercial use for some years in America with marked success, and [was] being rapidly adopted in Europe". But the new technology led to a number of major problems at Congella. During the first few months of operation, excessive amounts of fine ash particles were carried by the prevailing winds to residential areas, resulting in inconvenience to the residents. A system of ash extraction was designed and installed, the flue gasses being passed through large chambers equipped with salt water sprays, which removed roughly 90% of the solids. But the problem was not eliminated and residents continued to complain. The moist gasses also set up corrosion in the steel stacks, which were later lined with gunite over which a silicate coating was applied. A new system of ash extraction by electrostatic precipitators was specified with the last two boilers ordered for Congella 1 in 1936. These were the first in South Africa. However, the problem was still not eliminated.  (ESCOM Ten Years 1923-1933:38-39; ESCOM Annual Reports 1925:15, 1929:36, 1936:29; van der Bijl & Damant 1933:52-54&58; ESCOM Golden Jubilee 1923-1973:47; Conradie & Messerschmidt 2000: 20, 79, 81)

  The power station site in 1926 was in a swampy area away from residential areas and industrial activities, but over the years these moved closer in. In 1945 ESCOM was "gravely concerned over complaints regarding coal and ash deposits from the station". Loading conditions attributable to the war and the non-delivery of the new plant for Congella 2, had not helped matters. ESCOM was prepared to spare "no expense or effort….to effect an abatement of the nuisance as early as possible". The precipitators installed with the first 200 000 lb/h [25,2 kg/s] boilers for Congella 2 in 1946 also fell far short of the guaranteed efficiency. In 1946 work was begun on two new 300 ft. [92 m] concrete and brick chimneys to take the outlet gasses from the no.1 boiler house. The second chimney was completed in 1948. It was expected that "on completion of these, and the installation of new precipitators having a guaranteed efficiency of 98%, only a wisp of smoke [would] appear and a very small quantity of fly ash [would] be spread over a wide area. When in addition the modification of the precipitators in the no.2 boiler house [had] been effected, the dust nuisance at Congella [would] cease". Electrostatic precipitators were installed on boilers 5 to 8 and Howden multiple cyclone dust collectors on boilers 1 to 4. By 1950, when power generation was some seven times greater than at first, the dust nuisance had been "much reduced and few complaints were received". After Umgeni Power Station had been commissioned in 1954, boiler outages were easier to arrange and further modifications were carried out on the precipitators at Congella 2 to improve their efficiency.  (ESCOM Annual Reports 1945:33-35, 1946:37, 1948:35, 1949:31, 1950:35, 1955:39; Troost 1951:73; KM Nero 2003) 

PRODUCTION

cole8_350.jpg 
 
 
The installed capacity of the Durban Corporation's Alice Street Power Station when negotiations were started with ESCOM was 14,95 MW (including 1,5 MW of obsolete plant) and the maximum demand on the municipal system was only 9 MW. During 1929, the first full year of production at Congella, the net maximum power produced was 15,5 MW and the electricity sent out amounted to 78,873 GWh. By 1939 net production had grown to 62,5 MW and 233,929 GWh. In 1949 the figures were 115,2 MW and 505,358 GWh.  (ESCOM Annual Reports 1929:11&36, 1939:68, 1943:10, 1949:93).
 

​A transmission line along the South Coast was in service late in 1935 and power for this system was initially purchased from the Durban Corporation. The Corporation ceased to be the sole consumer in 1938 when supplies were given from Congella Power Station to the Railway Workshops and Graving Dock.  (ESCOM Annual Reports 1935:24, 1936:30, 1938:37)

The electrified train service from Glencoe to Pietermaritzburg was inaugurated on 14 June 1926. Electrification of the Pietermaritzburg to Cato Ridge railway line was completed in 1931. The Cato Ridge to Durban section (approximately 70 km and which included the doubling of many miles of track and ten tunnels in the hilly countryside) was officially opened on 1 December 1936. The Hon. O Pirow, K.C., M.P., Minister of Railways and Harbours and of Defence, performed the opening ceremony, arriving at 10:00 on the first electric train to enter Durban station. Dr van der Bijl, Chairman of ESCOM, and Mr TH Watermeyer, General Manager of the South African Railways and Harbours, were among the dignitaries who had also travelled on this special train from Rossburgh to Durban. The Mayor of Durban and a large crowd including a military band met them. However, power was supplied from Colenso Power Station for the whole of the railway traction load in Natal, which then extended 186 miles [299 km] south-east from Colenso to Durban and by 1938 also 135 miles [217 km] northwards to Volksrust and 142 miles [229 km] towards Bethlehem. Electrification of the old section of the Natal main line between Rossburgh and Hillcrest was started in 1938, but was abandoned for the duration of World War II due to delays in delivery of equipment. In 1939, an interconnection between Congella and the Booth Sub-station (on the railway route near the power station) made it possible for Congella and Colenso to render limited assistance to each other in case of emergency. The interconnection made it possible to ascertain the characteristics and loading of the section of electrified railway system adjacent to Durban. This interconnection, via a 15 MVA 33/88 kV transformer, proved of great mutual advantage on many occasions. The Durban Undertaking sold 2,157 GWh to the Natal Central Undertaking through this interconnection in 1939.  (ESCOM Ten Years 1923-1933:25; South African Railways and Harbours Magazine July 1926:972, January 1937:9-13  ESCOM Annual Reports 1936:8-9, 1938:23, 1939:20, 1940:8, 1944:20; KM Nero 2003)

Due to growth in load at Congella and the difficulties and delays in obtaining additional plant during the war years, it became possible to transfer some of the traction load to Congella only after the second new 40 MW generator was commissioned in 1948. Congella commenced a permanent supply of power to the electrified section of the main line from Durban to Cato Ridge (approximately 10 MW) on 26 December 1948. This was twenty years after the station had been commissioned with the original 12 MW generators designed to carry a traction load. Traction sales by the Durban Undertaking in 1949 amounted to 42,592 GWh, which was 8,4% of the total sales in the Undertaking.  (van der Bijl & Damant 1933:62; ESCOM Annual Reports 1943:10&17, 1948:12, 23&36, 1949:30)

 In 1952 and in 1953, Colenso assisted Congella with peak loading via the distribution network, and from March 1954 a 132 kV interconnector between Colenso and Umgeni Power Station was in service. Generation at Umgeni commenced at the beginning of April 1954, and Congella, Umgeni and Colenso were operated in parallel. The Durban Undertaking then became the Natal Southern Undertaking. Maximum annual net electricity production at Congella was in the year 1954, amounting to 750,539 GWh. Maximum net power produced occurred in the year 1960, and amounted to 174,0 MW. Ingagane Power Station was started up in 1963, and in 1964 the Natal Southern and Natal Central Undertakings were amalgamated to form the Natal Undertaking. The Natal Undertaking was first linked up to the national 400 kV network in October 1971 by a single transmission line. Duplication of the 400 kV line was completed in September 1972 and this enabled the less efficient power stations in Natal to reduce output. Net production at Congella reduced from 642,491 GWh in 1971 to 372,206 GWh in 1972 and only 230,200 GWh in 1973, as a result of the 400 kV interconnection (see chart).  (ESCOM Annual Reports 1953:39, 1954:37-38&99, 1957:39, 1960:94, 1963:50, 1964:9&35, 1971:6, 76& 106, 1972:66, 1973:76)

Thermal efficiency at Congella in 1930 was 18,0% on a net basis, and the highest achieved before Congella 2 was commissioned was 19,3%. When Congella 2 was commissioned, the higher steam conditions resulted in an improvement to over 20%. (For steam conditions see tables of principal equipment installed under "Construction" above). The highest thermal efficiency was 21,5% and was achieved in the year 1951. With an installed capacity of 206 MW, the assigned sent out rating was 191 MW. Own usage in the power station amounted to approximately 7,0% (1950) to 7,8% (1940).  (ESCOM Annual Reports: - Tables of Power Station Operating Statistics)

 

 Statistics for the following years are given below:

 1929    The first full year of production
 1932    The year installed capacity was increased to 48 MW
 1939    The first full year with Congella 1 at its final installed capacity of 98 MW
 1945    The final year before Congella 2 was started up
 1949    The first full year after the second set at Congella 2 had been commissioned
 1951    The year in which the final set had been commissioned, also the year of highest thermal efficiency
 1954    The year of maximum net production (GWh) and also the year in which Umgeni was started up
 1960    The year of maximum net power (MW)
 1971    The year Natal was first linked up to the national 400 kV network by a single transmission line
 1973    The year after Natal was linked up to the national 400 kV network by duplicate transmission lines
 1978    The final year of operation
 
YEAR
Net
Generation
GWh
Net Max
Power
MW
Installed
Capacity
MW
Load
Factor (net
basis) %
Thermal
Efficiency
net basis %
Coal
Consumed
metric ton
Calorific
Value of
Coal MJ/kg
Cost of
Coal
R/metric ton
1929  78,9   15,5 *   24 Not available 17,8   52 274 30,52 1,45
1932 109,8   30,0 *   48 Not available 18,0   74 565 29,56 1,69
1939 233,9   62,5 *   98 42,7 19,3 154 206 28,47 1,68
1945 338,0   76,8 *   98 50,2 17,0 252 280 28,47 1,69
1949 505,4 115,2 * 166 50,1 20,6 311 973 28,38 1,98
1951 596,4 131,8 * 206 51,6 21,5 356 603 28,05 2,20
1954 750,5 168,9 * 206 50,7 20,5 484 359 27,24 2,99
1960 733,2 174,0 * 206 52,8 20,7 483 712 26,31 4,18
1971 642,5 168,3 * 176 43,6 19,0 487 969 24,89 5,44
1973 230,2 108,1 # 107 27,1 18,9 177 418 24,73 6,39
1978 307,1 103,0 # 107 36,1 17,6 265 007 23,04 Not available
 * ½ hour # 1 hour

 Water for boiler make up was supplied from the Durban Municipality. Figures of water consumption before 1973 are not available. The specific consumption from 1973 was approximately 1,0 litre/kWh sent out.  (ESCOM Annual Reports - Tables of Power Station Operating Statistics)

 MAJOR BREAKDOWNS

 No.1 Turbine required almost complete re-blading in 1947. (ESCOM Annual Report 1947:41).
 

There were several power failures at Congella due to switchgear faults. On 30 June and on 1 July 1949 two complete failures of supply from the power station occurred. On the first the switchgear failed to operate and on the second a fault on the 6,6 kV switchgear burnt away a portion of the busbars. On 2 December 1949 a severe fault on the traction system caused a complete shutdown of the power station for an ½ hour. This fault occurred between 01:00 and 02:00 and other consumers were therefore not too badly inconvenienced. A busbar fault on 19 April 1952 caused a shut down of No.2 station. Outages to consumers lasted from a few minutes to 3½ hours. On 13 May 1955, failure of a 33 kV circuit breaker caused all supplies to be interrupted for a short period. Another 33 kV circuit breaker failure on 27 May caused a partial interruption of supplies.  (ESCOM Annual Reports 1949:31, 1952:36, 1955:39)

In 1956 the condenser of set no.7 was re-tubed with cupro-nickel tubes due to leaks (the original tubes were of admiralty brass). In 1957 the condenser of set no.8 was also re-tubed with cupro-nickel tubes and a new waterbox fitted to the front end.  (van der Bijl & Damant 1933:76; ESCOM Annual Reports 1956:37, 1957:39

The electrical rotor of generator 6 was rewound at Rosherville Workshops in 1958 and generator 8 rotor in 1959. Extensive re-blading of the turbines was also necessary at Congella 2.  (ESCOM Annual Report 1958:33)

There were also failures of 33 kV stator windings and problems with the exciters. At one time two spare exciters were borrowed from Table Bay Power Station.  (ESCOM Annual Report 1952:36; KM Nero 2003)

cong11_350.jpgcong9_350.jpgcong13_350.jpgcong10_350.jpg 

  COAL SUPPLIES

 Coal was supplied mainly from several of the Natal fields and was classified "dross", size minus 3/8 inch [9,5 mm]. The volatile content of the coal varied from one colliery to the next and this could cause combustion difficulties on the boiler plant. For the first 10 years of operation, the coal had a calorific value of over 29 MJ/kg. But this dropped steadily, as was the case at other power stations, until the 1970s when it was below 25 MJ/kg. At the end of the operating life of the station the calorific value was below 24 MJ/kg. (ESCOM Ten Years 1923-1933:53; ESCOM Annual Reports - Tables of Power Station Operating Statistics; KM Nero 2003)

 In 1949, the shortage of coal caused "grave anxiety." On one occasion it became necessary to shut Congella down for some hours as supplies were exhausted. Shortage of coal continued to cause grave concern in 1951 and on several occasions stocks fell below one day's usage. From April to July 1954, stocks were again down to less than one day's usage on several occasions.  (ESCOM Annual Reports 1949:31, 1951:34, 1954:38)

ASH DISPOSAL
 

The power station ash was initially run into a sump from where it was pumped to settling dams in low lying areas of the neighbourhood which were being reclaimed. After the water had drained away, the deposit had reasonable load bearing qualities. Some of the railway marshalling yards nearby were built on land reclaimed by ash. In 1944 another system was being designed to transport the fly-ash by rail. Ash was grabbed to trucks and utilised by the Railway Administration for reclamation purposes. An additional reclamation area was made available which would accommodate the ash for a further 2½ years. In 1948 the disposal of 200 tons per day of ash was presenting a problem and a new ash disposal plant was ordered. Work was begun in 1949 on a pneumatic system of ash disposal from the precipitator hoppers to a central ash-bin. During 1956 ash disposal was by dumping alongside the main road to the Bluff.  (van der Bijl & Damant 1933:60-61; ESCOM Ten Years 1923-1933:39-40; ESCOM Annual Reports 1944:37, 1945:35, 1948:36, 1949:31, 1952:37, 1956:37)

 FLOODS

On the night of 3 August 1937, an exceptional rainstorm caused extensive flood damage at Congella Power Station resulting in complete shut-down of the station for 10 hours from 22:00. Over 11 inches [280 mm] of rain had fallen in the vicinity of the station within 2 hours. The boiler house basement and the coal staithes were flooded. With the aid of three engines from the City Fire Brigade partial supply was restored by 08:00 next morning and normal supplies 30 hours later. A train derailed due to a wash-away had also brought the South Coast transmission line down. ESCOM's Annual Report paid tribute to all staff working under the trying and difficult conditions.  (ESCOM Annual Report 1937:31)

 Mr Fred Rogers, who started work at Congella in February 1936, remembered the incident in an article in Megawatt (no.27). The flood situation was made even more serious by the fact the power station was the sole source of electricity for the whole city of Durban. The station was located on low-lying level ground at Durban’s bay-head and the flooding was caused by the overflowing of an open stormwater drainage canal close to the boundary of the power station property. The canal emptied into the bay, but on that particular occasion the flow of the storm water was adversely affected by a high tide. This caused the water from the bay to advance nearly 500 m up the canal. "At the height of the flood, water was entering the power station in waves, such was the quantity of water being fed into the flooded area from the surrounding high ground drainage system". The water flooded into the building entrances, underground basements and tunnels. As the level of water continued to increase, "water entered the boiler furnaces via the ashing doors where it erupted into steam, necessitating the shutting-down of the boilers and thus the turbo-generators also. The power station had drowned!" With no electric power available, the City Fire Brigade brought their engine-mounted pumps to assist, but there was nowhere to discharge the water until the general flood level had subsided. ESCOM Megawatt No.26/1972:15, No.27/1973:38-39)

 Mr Jeffrey Fairbanks, who started at Congella as ESCOM's first apprentice fitter and turner in Natal and worked at Congella for 46 years, recalled the flood as well: "I didn’t go home for three days. All electric motors had to be disconnected and dried. Water had flooded into the coal staithes and washed coal into the conveyor tunnel. We were assisted in clearing the coal belt by dock workers who arrived at the station with big baskets used for loading the coal ships".  (ESCOM Megawatt No.46/1978:19)

 Another account in Megawatt (no.27) described "The Day Congella Died of Thirst". Since the station drew its cooling water from the sea, its suction chamber was located below sea level from where the water was pumped to the condensers. The account recalled the curious phenomenon where millions of small fish swam about quite freely in the suction chamber despite the strong suction. On one particular day a school of jellyfish blocked the grated opening of the suction chamber preventing water from entering. This resulted in the pumps emptying the suction chamber and "millions of little fish" were drawn into the condensers, thus blocking them. The result was that "the station literally died of thirst and ground to a halt". The station workers had to clear the condensers of dozens of barrow loads of small fish.  (ESCOM Megawatt No.27/1973:39)

Congella Power Station experienced another flood, which began on the evening of Thursday 29 December 1977 when a severe storm caused the Umbilo River Canal to burst and flood the power station. On 30 December at 02:45, the Shift Supervisor was alerted to the problem by a Security Guard. At 04:14 the one generator on load had to be switched out as water was over 500 mm deep in the turbine and mill basements. By 11:00 all water above ground level had been cleared though equipment below ground level, such as the ash pumps and coal conveyor tunnels, were completely flooded. The Durban Fire Department also gave willing and valuable assistance. More heavy rain fell the next night and the floodwater rose even higher than before. Work continued through the week to restore the plant to service and most of the restoration work was completed by 7 January 1978. Fortunately the loss of station output did not affect consumers, as power was available from the national grid and the other Natal stations. The local demand was also low on account of the holiday period, but the staff had to forfeit their New Year weekend.  (ESCOM Megawatt No.46/1978:10-11)

 STAFF
 

Mr John Roberts (1870-1937) was born in Scotland and was sent out to South Africa in 1896 by the Electric Construction Co of Wolverhampton to superintend the erection of the machinery for the Durban Corporation's first power station at The Point (see "Early History" above). On 26 October 1897 he was appointed by the Durban Corporation as Borough Electrical Engineer, and when ESCOM established the Durban Undertaking he was appointed also as Local Manager in a dual capacity. Mr Roberts died within a month of his retirement in 1937. The first Power Station Manager at Congella, Mr EL Damant, was chosen by Dr van der Bijl for his "sound scientific and technical knowledge". A detailed paper describing the power station and some early operating experiences was written jointly by Dr van der Bijl and Mr Damant, and read by Mr Damant before the South African Institute of Electrical Engineers in March 1933. Mr Damant later became Manager of the Natal Undertakings.  (Henderson 1904:253; South African Who's Who 1927-1928:256; Transactions of the SA Institute of Electrical Engineers, March 1933:84; ESCOM Ten Years 1923-1933:24; ESCOM Twenty-five Years 1923-1948:21;ESCOM Megawatt o.38/1976:36)

 Many of the staff from Congella Power Station went on to hold senior positions at Eskom's Head Office. Congella provided a training ground for Mr GRD Harding who became Secretary of ESCOM and later, from 1948 to 1968, General Manager. Mr EE Robinson, who was Power Station Superintendent at Congella in 1950, and after holding various other positions, was appointed Senior Manager Operations in 1976, reporting directly to the General Manager. Mr HK Groenink started his career at Congella doing vacation work as a student. He was appointed as Graduate Engineer in 1946 and Assistant Shift Engineer in 1947, advancing to Power Station Superintendent at Colenso in 1960, Power Station Superintendent at Ingagane in 1963 and Area Generation Engineer at Durban Office in 1966. He was later appointed Assistant Manager (Resources Control) at the Central Generating Undertaking (CGU) Head Office. Mr KM Nero, who served altogether 19 years at Congella, was appointed Graduate Engineer in 1948, Assistant Power Station Superintendent in 1956 and Power Station Superintendent from 1958 to 1967. He became Senior Engineer (Electrical) at the CGU Head Office and later Principal Engineer (System Performance) and then Chief Engineer (Electrical). Mr RB Cliff started as Graduate Engineer at Colenso in 1951, became Assistant Superintendent at Congella in 1959, and after various positions at Ingagane, Grootvlei and Arnot, was promoted to Assistant Manager (Engineering Services) at the CGU Head Office. Other former Congella employees were appointed in the Natal Area Office of the CGU. These included Mr WG Tredre, who joined ESCOM as Engineering Assistant at Congella in 1953 and became Principal Area Engineer in 1972, Mr FStJ Rogers (Senior Area Engineer), Mr D Muller (Senior Area Chemist) and Mr G Cornelius (Senior Clerk).  (ESCOM Megawatt No.4/1966:5, No.18/1970:2, No.24/1972:24-25, No.27/1973:23, No.30/1974:20, No.36/1975:24, No.38/1976:29, No.40/1977:30, No.46/1978:18, No.48/1978:18, No.52/1979:23&27, No.60/1980:25, No.69/1981:29-30; Conradie & Messerschmidt 2000:102, 106, 141)

 The Power Station Managers through the years were as follows (before the CGU was established the position held the title of Power Station Superintendent): Messrs EL Damant (1928-1937), Colin (Dick) Dawson (1937-1948), WA (Willie) Alexander (1948-1950), EE (Ted) Robinson (1950-1958), KM (Ken) Nero (1958-1967), FStJ (Fred) Rogers (1967-1972), WT (Bill) Oakes (1972-1977), HE (Harry) Hollyer (1977-1978).  (KM Nero 2003; WT Oakes 2003; See photograph and ESCOM Megawatt No.52/1979:27).

Jeffrey Fairbanks recalled the team spirit at the station in earlier years: "All the maintenance work was carried out at the station itself. I re-bladed two turbines with my own hands. There was no such thing as one man doing a specific job. If a man had a problem with a piece of equipment a co-worker would always be ready to assist him". Mr Dawson, who was Power Station Superintendent between 1937 and 1948, echoed these sentiments. He stated that "each man was jack of all trades and master of all". But he also recalled how in the first few months of operation, before water sprays were installed at the base of the chimneys, residents of the surrounding suburbs were extremely unhappy about the ash fall-out and complaints were rife. It was then that the power station got the nickname "Old Smokey" and it was quite common to arrive at work in the morning to find women standing at the power station gates holding shoe boxes of soot.  (ESCOM Megawatt No.46/1978:18&19)

Congella achieved a million man-hours worked without a lost time injury on 29 May 1974, with Mr Bill Oakes as Power Station Manager. A presentation was made by Mr EE Robinson, then Assistant Manager of Operations (Head Office), and Power Station Manager at Congella 20 years earlier. Mr (later Dr) IC McRae, then Manager of the CGU, Mr F van Vuuren, ESCOM's Senior Safety Officer and Mr WJ Andrews, Senior Safety Officer for the CGU, were also at the presentation.  (ESCOM Megawatt No.32/1974:28)

COMMUNITY, SPORTS AND RECREATION
 

According to Mr HP Alexander, who headed ESCOM's operations in Natal for a number of years, going to work at the station was like going to work at any other job in Durban. You went to work and went home after. There was limited interaction between employees outside of work. Unlike ESCOM townships, you did not necessarily have fellow employees as neighbours and close friends. Staff participated in sporting events and inter-undertaking competitions, but Congella Power Station did not have its own sports grounds.

 
 
 
     cong16_350.jpg
cong17_350.jpg 
 Staff at the closing ceremony
 
CLOSURE
  

The two 6 MW sets, transferred from Alice Street in 1929 and 1930, were transferred to Kimberley in 1949 and 1950, reducing the installed capacity of Congella 1 to 86 MW. After the Natal Undertaking had been linked up to the national 400 kV network in 1971, two of the small boilers at Congella 1 and 30 MW generator 5 were decommissioned, reducing the installed capacity of Congella 1 to 56 MW. After September 1972, when duplicate 400 kV transmission lines had been commissioned, all boilers at Congella 1 were decommissioned as well as one of the 12 MW generators. Installed generating plant at Congella 1 was then reduced to 44 MW, but this was only partially available using steam from Congella 2 via the steam interconnector. By the end of 1973, Congella 1 was entirely decommissioned and Congella 2 had been de-rated to two sets at 35 MW each and the third set at 37 MW, giving 107 MW installed capacity and an assigned sent out rating of 97 MW. All sets at Congella were finally decommissioned in December 1978. The formal closing ceremony was held on 8 December 1978, at which all six surviving Power Station Managers (out of a total of eight) were present. Mr GF Clothier, retired Shift Engineer, closed down the last turbine at the ceremony.  (ESCOM Annual Reports 1949:31, 1971:6&69, 1972:59, 1973:67, 1978:49&54; ESCOM Megawatt No.52/1979:27) 

BIBLIOGRAPHY
  

 This information on Congella Power Station was produced by Dick Fowler, a retired Eskom employee.

 Conradie SR & Messerschmidt LJM: A Symphony of Power - The Eskom Story - Chris van Rensburg Publications (Pty) Ltd, Johannesburg, 2000
  1. Dictionary of Business Biography, Vol.4, Edited by David J Jeremy, Butterworths, London 1985
  2. Durban Mayor's Minutes 1908-1932 (including Borough/City Electrical Engineer's Report)
  3. Electricity Supply Commission: Annual Reports, 1925-1984
  4. ESCOM: Golden Jubilee 1923-1973
  5. ESCOM: Megawatt 1966-1981
  6. ESCOM: Ten Years - A record of the progress and achievements of the Electricity Supply Commission, 1923-1933
  7. ESCOM: Twenty-five Years - A record of the origin, progress and achievements of the Electricity Supply Commission, 1923-1948
  8. Henderson WPM: Durban: Fifty Years' Municipal History 1854-1904 - Robinson & Co Ltd, Natal Mercury Printing Works, 1904
  9. Hopkins HC: Natal Railways - An Historical Sketch. In: South African Railways and Harbours Magazine, May 1922
  10. Hoy, Sir William: Railway Electrification in South Africa. In: South African Railways and Harbours Magazine, May 1922
  11. Jagger, The Hon JW: The Electrification of the South African Railways. In: South African Railways and Harbours Magazine, May 1922
  12. Kotze, Sir Robert: Electricity Supply in South Africa. In: South African Railways and Harbours Magazine, May 1922
  13. McIntyre, John: From Settlement to City. In: Durban: Past and Present, compiled by Allister Macmillan, - William Brown & Davis Ltd, Durban, c1935
  14. Merz & McLellan: Electric Power Supply in the Union of South Africa, April 1920
  15. Merz & McLellan: South African Railways - Report on the Introduction of Electric Traction, June 1919
  16. Mills FW: - Electrification of the South African Railways. In: South African Railways and Harbours Magazine, 1919, 1922
  17. Palser D: Lighting Up the Fairest Cape, 1895-1995, A Historical Record Commemorating the Centenary of the City of Cape Town Electricity Undertaking, City of Cape Town Electricity Department c1995
  18. Pask TP: The Past and Present in the South African Railways Electrical Department. In: South African Railways and Harbours Magazine, May 1922
  19. South African Railways and Harbours Magazine, 1919, Feb. & March 1921, May 1922, May 1923, November 1924, July 1926, January 1937
  20. South African Who's Who, Published by Ken Donaldson, 1912 & 1927-1928
  21. Standard Encyclopaedia of Southern Africa
  22. Troost N: Flue Gas Dust Extraction Equipment for Power Plant. In: Journal of the South African Institution of Mechanical Engineers, November 1951
  23. van der Bijl HJ & Damant EL: The Congella Power Station of the Electricity Supply Commission. In: Transactions of the South African Institute of Electrical Engineers, Vol XXIV, March1933
  24. Wilson D: - Natal Main Line Construction and Deviation. In: South African Railways and Harbours Magazine, 1919
  25. General Manager of Railways and Harbours, Annual Reports 1912-1935, (Union Government Annexures presented to Parliament)
  26. 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
  27. 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
Notes about the authors
  
  1. Henderson, William Plowman Moyese (born 1871 in England) joined the Durban Corporation staff in 1895 and was appointed Assistant Town Clerk in 1904. He published for the Durban Corporation, in 1904, "Durban: Fifty Years' Municipal History". He became a Commissioner of ESCOM from 1935 to 1949.
  2. 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. The major part of the Committee's work was done by Sir Robert and Dr van der Bijl.
  3. 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.
  4. McIntyre, John - Assistant Town Clerk, Durban, at the time of writing.
  5. Merz, Dr Charles Hesterman (1874-1940), Consulting Engineer in Great Britain who took William McLellan (1874-1934) as a partner in 1909. In 1913, the firm Merz and McLellan employed a staff of 73 and were world leaders in the field of railway electrification and power station construction. Merz, and two of his children, were tragically killed during World War II by a direct hit on their Kensington home. (Dictionary of Business Biography).
  6. Mills, Frederick William (born 1870 in England) came to Natal in 1895 for Messrs Woodhouse and Rawson (see also "Early History" above). He joined the Natal Government Railways in 1896 and introduced train lighting by electricity. He became the Chief Electrical Engineer for the SAR&H 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.
  7. Palser, Dennis C - City Electrical Engineer of Cape Town 14 November 1974 to 10 August 1986.
  8. Pask, TP (born 1873) became Superintendent (Electrical and Telegraphy) for the SAR&H in 1920 and Chief Electrical Engineer in 1925. He was appointed a member of the Committee to consider the Merz Report of 1920.
  9. Troost, N - ESCOM Head Office Staff
  10. Lydall, F - An expert from the firm of Merz and McLellan, who came to South Africa in October 1917 to collect the necessary data for the report dated June 1919 "South African Railways - Report on the Introduction of Electric Traction". Due to the change in conditions, he carried out a fresh investigation in 1921, and was Merz and McLellan's chief representative in South Africa for the duration of the project in Natal

  (South African Railways and Harbours Magazine 1919:737/8 and 1922:406-408; South African Who's Who 1927-1928; ESCOM Twenty-five Years 1923-1948:11; ESCOM: Golden Jubilee 1923-1973:11; Palser 1995:181)

 
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