Greenwich Power Station
Greenwich Power Station is a power station on the River Thames at Greenwich in south-east London.
Note: This is not the same as Blackwall Point Power Station on Greenwich Peninsula, which was constructed by The Blackheath and Greenwich District Electric Light Co Ltd.
1902 The station was originally designed by the London County Council architects' department, and built in two stages between 1902 and 1910, to provide power for the London Tram Network and London Underground which were being electrified at that time.
The station originally had a coal-fired boiler house and an engine room. This housed four 3,500 kW flywheel-type alternators with an output of 6,600 volts and 25 hertz. The alternators could produce 4374 kW in emergency overload. Each Electric Construction Co alternator was driven by John Musgrave and Sons compound reciprocating Corliss 'Manhattan'-type steam engines. Each engine comprised a horizontal and vertical cylinder either side of the alternator. The vertical high pressure cylinders were 38.5" diameter, and the horizontal low pressure cylinders were 66" diameter, the stroke being 4 ft. Speed 94 rpm, steam pressure 180 psi, supplied to the HP cylinders individually. Each LP cylinder had its own condenser, the steam first being passed through Baker oil separators. The condensate was passed through Harris-Anderson purifiers before entering the hotwells. The engines were fully-enclosed, apart from the valve gear, and had forced lubrication.
In addition to the four main generators, there were two independent DC steam sets, used for lighting the station, as standby for excitation, and for other uses. The 150 kW Dick, Kerr and Co generators were driven by 250 HP Belliss and Morcom reciprocating engines running at 375 rpm.
The main switchgear was of the oil-break, remote-control , electrically-operated type, built by the British Westinghouse Electric and Manufacturing Co of Manchester. Provision was made for eight generators and thirty-two feeders.
The feeders left the station in two groups by means of two separate tunnels. One tunnel carries the cables for supplying the north of London via the Blackwall Tunnel, and the other the cables for the south of London. Adjoining the switchboard recess a substation, contained three motor generators for supplying direct current to the local tramway lines and for station purposes. It was equipped with three motor generators by Dick, Kerr and Co. Each 500 kW machine ran at 800 rpm and transformed the 6600 volt three-phase current to direct current at 550 volts. A battery of 280 Tudor accumulator cells was provided in the basement
The condensing water was drawn from the Thames through four 30" cast iron pipes laid under the bed of the river at a point below the lowest known tide. Three of them were used either as suction or discharge pipes, and the fourth entirely as a discharge pipe. Where the suction pipes entered the outside pump house they were connected to fixed strainers, and to the strainers the centrifugal pumps were joined. After leaving the pumps the water was taken through rotating self-cleansing strainers, and thence to the condensers. On its return the condensing water was again passed through the rotating strainers, which washed out any dirt which may have been caught in the strainer inlet. In the yard, close to the outside pump house, was a 30-ton electric jib crane, by Ransomes and Rapier of Ipswich.
The above information is condensed from The Engineer [1]
The two chimneys of stage one were 249 ft high but, following objections from the nearby Royal Observatory, the chimneys of stage two were reduced to only 180 ft height.
It appears that it was intended from the outset to increase capacity using steam turbine-generators. The first, a 5000 kW machine, was made by British Westinghouse and installed in 1910. It was one of their earliest impulse turbines (as distinct from the Parsons reaction type favour by Westinghouse in the USA). It operated at the relatively low speed of 750 rpm.[2]
1913 'In order to prevent a repetition of the recent breakdown at the Greenwich generating station — which supplies the current for the London County Council tramway system — the council are purchasing two new turbo-generators at a cost of £50,000. They have also made arrangements by which a temporary supply of power is available at short notice from the London Electric Supply Corporation.' [3]
1914 'The generating plant at the Greenwich station in 1912 consisted of four 3,500 kilowatts reciprocating engines and four 5,000 kilowatts turbines, or a normal plant capacity of 34,000 kilowatts. The Council has decided to substitute a steam turbine set of 8,000 kilowatts for each of the four reciprocating engine sets. In order to reduce the damage and loss caused by short circuits current will be generated with the new machines at 2,500 volts, the pressure being raised to 6,600 volts by auto-transformers. The first of the new substituted turbines was inaugurated recently in the presence of Mr. G. Hume, Chairman of the Highways Committee of the Council, other members of the Council, and the Mayors of Greenwich and Bermondsey. The capacity of the station, when all the turbines have been submitted, will be 52,000 kilowatts.'[4]
1914 photo of one of the British Westinghouse turbines being erected here.
1921 Experimented with oil firing[5]
1922 The reciprocating engines installed during the first stage were replaced by steam turbines.
1923 One turbine with condenser plant ordered from Richardsons, Westgarth and Co, with 15 MW C. A. Parsons alternator [6]
This 1932 photo shows the turbine hall, with three British Westinghouse turbines in the foreground. Beyond those are four turbines from other manufacturers, the nearest having nozzle control. A closer view of those units can be seen here. The two furthest units are featured here.
1960s The steam turbines were replaced by Rolls-Royce gas turbine generators, used engines similar to those used in jet aircraft. These originally burned oil but were later converted to burn oil and gas. The generators are still housed in what was formerly the boiler house. They have a total capacity of 117.6 megawatts (MW), generated at 11,000 volts. This voltage can be increased to 22,000 volts for connection to the London Underground electricity system.
The station later became the backup station for Lots Road Power Station, which supplied the London Underground. However, Lots Road was decommissioned on 21 October 2002, whereas Greenwich has been refurbished, and is now powered by gas. Power for the London Underground now normally comes direct from the National Grid.
Coal was delivered to the large coal jetty in the river, which stands on 16 Doric-styled, cast iron columns. Coal was then sent to the white-painted storage bunkers on the west side of the station. The pier is no longer used