Expansion Continues 1960 - 1970
The rate of increase in sales of electricity that built up during the fifties continued into the sixties as evidenced by the following statistics. They also indicate the limits to which the resources of the undertaking continued to be stretched.
|Number of Consumers||15,435||21,507||39|
|Millions of Units Sold||37.4||130.7||250|
|Maximum Demand MW||12.1||41.0||240|
|Generating Capacity MW||16.0||54.6||240|
|Transforming Capacity MVA||18.0||55.6||208|
|Number of Substations||114||214||97|
These increases were all in the future at the beginning of January 1960, when the data to the end of 1959 was the latest information available as a guide to future plant requirements. However these earlier figures showed that the maximum demand had increased by about 8% each year during the nineteen fifties. Projecting this rate forward would give a maximum demand of about 24 MW by 1970. At the time it was the practice to calculate the plant needed to meet the maximum demand by deducting 10% from the nominal rating of the generating sets installed, and then allowing for the largest item of plant to be out of action. Following this formula, nearly thirty MW of plant would be needed in 1970, a net increase of fourteen MW.
In early 1960 these trends caused the Board to consider installing generating plant with a higher output. Although this would have the advantage of meeting the peak loads more comfortably, uneconomical running to meet the low demands of 1 MW on summer nights would counteract them. The decision was therefore taken to continue with the 2.2 MW sets for the time being. Two of these were ordered for delivery in December 1961, and to accommodate them, an extension to the engine hall was built to house a total of four of this type of set. This extension was to form a part of the building that became known as "A" engine hall to distinguish it from the "old" engine hall situated alongside the road on the north side of St Sampson's harbour.
The rate of increase in the maximum demand changed dramatically in 1960, in England as well as in Guernsey. Despite the unexceptional weather conditions it more than doubled from the average of 8% to 17½%. The contractors were delayed in the preparation of the foundations for the two new generating sets, and other delays followed. The two Petter generating sets, installed in 1948, had been dismantled to provide room for the switchgear for the new plant. Consequently, when the winter arrived, the capacity of the station was only 15 MW instead of the 17.5 MW that had been planned. During the cold spell in December 1961, the demand exceeded 14 MW, which was met by running the generating plant for extended periods on full load. The first of the additional sets was commissioned in January 1962, and the second in April of that year. The remaining two engine beds were filled in 1963 when two more KVSS12 sets were commissioned.
The surge in the maximum demand led to the construction of another extension to 'A' station in 1962 that was designed to house four more KVSS 12 sets. The first of these was commissioned in 1963, two more were added in 1964 and the last in 1965. At this time the rate at which the 11kV transmission system was being installed was increased. Consequently the alternators of these last six sets were wound to generate at the higher voltage.
KVSS12 generating sets numbers 16 and 18, installed in the extension to 'A' engine hall
Using the 1960 rate of increase in the maximum demand as the base for forecasting future peak levels, it was estimated that by 1970 the maximum demand would reach 50 MW, requiring an installed capacity of some 60 MW. The construction of the last extension of 'A' engine hall had stretched to the boundary of the Board's property. It had become apparent in 1961 that the undertaking was running out of space, and from that time suitable land in the immediate vicinity of the power station was acquired whenever the opportunity arose. A number of houses and vineries were purchased, including Ambrose Cottages, Highland, Herrandura, St. Lucia and Oak Place. They were all situated on the north-east boundary of the power station along the Hougue Jehannet.
As a consequence of these actions in 1965 although all engine halls were full, more land was available. The options for increasing the generating capacity to meet the ever rising demand appeared to be, a new engine hall to accommodate more base load Diesel plant, a peak load lopping gas turbine or a steam powered generator. In 1964 Ewbank and Partners, the consultants to the Board, recommended that the load forecasts should be scaled down and that a 3 MW gas turbine set should be installed at the airport. This proposal was based on a forecast maximum demand of 45 MW in 1980. In the meantime Mirrlees had redesigned the KVSS type generator to drive an alternator that would produce 3.5 MW, and the final decision, supported by the consultants, favoured this option.
Following on from this decision, the Board appointed Building Design Partnership as consultant for the design and construction of a new engine hall. Initially it would house six modified type Mirrlees generating sets, known as KV Majors, but it would be capable of being extended to accommodate twelve. In order to meet the load whilst the new engine hall was being built the first production model of the KV Major generating set, with an output of 3.5 MW, was purchased and installed, as station No.20, in the old engine hall, in an area vacated by decommissioned smaller sets. It was commissioned early in 1966 and in the following year a second of the Mirrlees KV Major sets, station No. 5, by this time up-rated to 3.8 MW, was installed in the old engine hall on a bed previously occupied by a Fullagar 6Q set, commissioned in 1936.
By the time that this second KV Major was commissioned it was apparent that, with so many sets to be maintained, it would be difficult to fit all the maintenance work into the summer months when the demand was low. More capacity was needed to provide cover during the extended maintenance period. To allow for this the formula for calculating generating plant requirements was modified. In future the rated output would be reduced by 15%, instead of the 10% used in previous calculations.
The new engine hall, which was officially named the Vale Station, but was more generally known as "B" engine hall, was erected on the recently acquired land to the north of the"A" engine hall. It included a cable basement and annex for auxiliary plant and workshops. The control room, with its 48-panel control board, and the adjacent switch room, containing a switchboard with 43-panels, were situated above the cable basement, with the stores and offices above the control room. As the area in the vicinity of the power station was heavily populated, special measures were taken to reduce the noise from the engines to an acceptable level. The roof of the engine hall was acoustically treated, and the walls were lined with acoustic panels. The engine hall, with two KV Major generating sets installed in it, was commissioned in 1968, and two further sets were installed in 1969 and 1970. The Lieutenant Governor, Vice-Admiral Sir Charles Mills, officially opened the engine hall on May 21st 1970.
The Mirrlees KV Major generating set installed in 'B' engine hall
The generating plant position at this point was 24 sets installed in three engine halls. Of these only one was more than twenty years old, but four more were aged over fifteen years. The total rated capacity was 54.6 MW comprising;
|2||English Electric 6Q installed 1949, 1952||Output||2.06MW|
|2||Mirrlees HFS8 installed 1950, 1951||Output||1.83MW|
|1||English Electric 8SRL installed 1953||Output||1.00MW|
|1||Mirrlees KSS6 installed 1959||Output||1.06MW|
|12||Mirrlees KVSS12 installed 1955 to 1965||Output||26.14MW|
|6||Mirrlees Majors installed 1966 to 1970||Output||22.50MW|
The progressive installation of a number of generating sets, coupled with the exceptional increase in the demand, was accompanied by the installation of more auxiliary plant. The medium fuel oil storage capacity was increased by 3,500 tons in three new tanks. A new pipeline, for the discharge of oil cargoes, was installed in 1966. In the event of bad weather ships could not reach the old discharge point situated across the road from the old engine hall. To reduce the risk of a shortage of fuel, a new discharge point was established on the quayside, adjacent to the harbour entrance. It was electrically trace heated, so that during the pumping operation, the temperature of the medium fuel oil could be maintained at a level that would prevent it from solidifying. Another Davenport forced draught cooling tower with a water-cooling pond was added, and to keep pace with the extra fuel consumption, a new treatment plant was installed to treat the medium fuel oil.
Up-rating the 6.6 kV system to 11kV at a time when new generating plant was being installed was a big challenge for the electrical engineering department. The installation of two further KVSS sets in 1962 coincided with the commissioning of a new control room and high voltage switchgear for the additional plant and equipment that would be commissioned by the year 1965. In order to facilitate the changeover of the network to 11kV, the existing 6.6kV busbars were linked to the new 11kV bars via two 3-MW inter bar transformers which would allow energy to be transferred between the two systems. As the load increased, a further 11/6.6kV transformer was commissioned to supply the local 6.6kV network and generally to ease the situation. During 1964 and 1965 two more generating sets where changed over so that by this time 90%of the generating capacity had been up-rated to 11 kV. As security for the two systems against fire damage, CO2 fire-fighting equipment was installed in both switch-rooms. To provide a firm power supply for the electrical auxiliary systems and services on the site, a works power building was constructed to house Erskine Heap low voltage switchgear supplied from the 11kV system via two 500-kVA transformers.
The years 1967 and 1968 were occupied with planning and executing the most formidable task of the decade, the transfer of the control and switching functions to the new "B" engine hall. More than 36,000 metres of high voltage, low voltage, protection and control cables were laid along the Hougue Jehannet, between the two engine halls. The commissioning of the new control centre was due to start on 1st May 1969 and to be completed by 30th June. It started on time and, despite a delay caused by unforeseen design modifications to the voltage regulators, the transfer was completed ahead of time on 13th June, and without interruption to the supply.
In 1962, the timetable for changing over the network to 11kV was modified as the result of an application for a supply from Tektronix Guernsey Ltd. The company was proposing to establish a factory near the airport to manufacture oscilloscopes, and requested a supply of 500 kilowatts. The following month the estimate was revised to 3½ MW, which was a quarter of the island's maximum demand at the time. Since it was not possible to supply such a large load from the local network, it was decided to install feeders and a control cable from the power station to the factory site.
The high voltage metering equipment was installed at the power station in order to include all the circuit losses in the tariff, effectively making the feeders a private supply. As a safeguard against loss due to mechanical damage or some other action, two 11 kV, 0.1 sq in stranded copper cables and a pilot cable were laid along a route extending for some 10.4 km. The step-down transformer at the Tektronix end was fitted with on-load voltage adjustment equipment to maintain the supply voltage within acceptable limits to safeguard the manufacturing process. The first stage of the scheme was commenced in 1962, with the installation of cables from the power station to the Camp du Roi substation and the installation of switchgear. The decision, to bring forward the date for the introduction of the 11 kV distribution system, left a stock of 6.6 kV cable surplus to requirements. Of this 5,500 yards was sold back to the manufacturer.
The work of upgrading the high voltage ring main, the installation of new transformers, switchgear and associated low voltage cables was completed early in 1966. At one period in 1964, at the height of the operation, four gangs were employed on laying cables at the rate of 1¼ km per week. During the two years 1964 and 1965, thirty-six new substations were commissioned and a further 53 modified. 82 feeder pillars were installed along with 33 underground disconnecting boxes.
The 11kV feeder capacity had been planned to meet loads of up to 30 MW. However, with the maximum demand reaching 28 MW in 1967 the time had come to plan for the capacity to be increased to meet the load of 45 MW that was predicted for 1980. The price of cable varied with the cost of copper, which was relatively stable in the early sixties. By carefully timing the purchases, the cable used in the earlier major projects had been bought when the price of copper was between £244 and £318 per ton. In 1966 however the price became very unsettled, varying between £500 and £700 per ton. With the prospect of a major enhancement of the distribution network imminent, an evaluation of the advantages of using stranded aluminium cored cables was undertaken. Confidence in its suitability and performance was endorsed by the ESI and cable manufacturers were changing their production facilities to manufacture aluminium conductors. As a result it was decided to use this cheaper type of cable for future projects in Guernsey.
In order to increase the overall distributing capacity to 50 MW, more high voltage feeders from the power station were needed. To this end, between the years 1967 and 1968, three pairs of 0.5 sq in stranded aluminium 11kV cables were laid to existing substations located at Park Street in St Peter Port, St Andrew's Road, and Saumarez Park in the Castel. The whole project, that included additional switchgear at each substation, was commissioned during the course of 1969. At the time that the cables to the Saumarez Park substation were installed, the opportunity was taken to lay other HV cables to supply substations in the vicinity of the Bridge.
By the end of 1966 consumers in the Vale had been changed from direct to alternating current leaving only 628 connections to the old system. It was decided to leave these to be changed as it became necessary.
Another large project undertaken by the distribution department during the sixties was the installation of an extension of the network to the Fort George Development Scheme. To supply the estate, that was planned to include 55 houses, it was necessary to lay a cable from the Albert Pier substation to the site. On the estate the project involved laying high voltage and low voltage cables, erecting an out door substation, and installing three low voltage distribution pillars. Work on the project did not proceed as smoothly as had been hoped. As a result the electrical distribution system was not in place until late in the year 1964.
Throughout 1960, work proceeded on the construction of the office block in Cornet Street at the site that became known as the Albany. The lease was signed in April 1961, and in May 1962, after nearly 50 years of occupying 25, High Street, the administrative and commercial sections of the staff moved into their new accommodation.
A later picture of the Albany showroom
Later in the month, the distribution and meters sections transferred from Les Amballes. Immediate steps were taken to sell the High Street property. No other States Committee required it and the building was subsequently sold to Creaseys Ltd for use as a toyshop.
The amount paid for oil in 1960 represented some 36% of the Board's total expenditure, the cost of oil per unit generated being 0.766d. Overall the price remained relatively stable over the next few years, but the increased use of the cheaper MFO led to a saving, so that in 1967 the cost per unit generated fell to 0.5951d. By this time however, there were signs that a change was imminent. The major oil companies, sometimes known as the"Seven Sisters", had controlled the oil extraction industry up to 1960. In that year they reduced their prices, and with them the taxes paid to the countries in which the oil fields were situated. As a result, at the Baghdad Conference in September 1960, a permanent inter-governmental organisation was formed entitled the Organisation of the Petroleum Exporting Countries, better known by its acronym OPEC. It consisted of some fifteen members, the core being the four Arab States, amongst which Saudi Arabia was by far the largest exporter, and had the greatest reserves. On its formation the organisation declared that its objective was to co-ordinate the petroleum policies of member states so as to secure stable prices, produce a fair return on capital to the producers, and to provide an economic supply to consuming nations.
The formation of OPEC had little noticeable effect on oil prices until July 1967. Israel and its Arab neighbours experienced an uneasy peace after the Suez War of 1956, but this erupted into the Six-Day War of June 1967. Fifteen ships were sunk in the canal, once again effectively blocking it. On this occasion repairs took a long time, and it was not until 1975 that the canal was finally reopened. After the war the oil companies imposed a Suez surcharge which led to a rise of 2d per gallon in the price of oil. The use of the cheaper stocks, delivered before the price went up, kept costs stable for the rest of the year but in 1968 the oil cost per unit rose to 0.6417d. In 1969 the removal of the surcharge allowed it to fall back to 0.581d, saving the Board from the need to increase tariffs.
The need to modernise the accounting equipment became urgent in 1960, and with more office space available in 1962, a National Cash Register 'Computronix' accounting machine was installed. In 1967 the States decided to follow the U.K. and to decimalise the currency with effect from February 1971. As the Computronix machines could not be modified to operate in decimal currency there was another review of the accounting machinery. Guided by the advice of the Technical Secretary of the Central Computer Committee of the Electricity Council and of Mr. McReady of Till, Robertson& McKewat, in May 1968 the Board decided to lease an ICL 1901A computer. The configuration of the equipment installed in the following year comprised,
|1||Central processor with 8k core store|
|1||600 line per minute printer|
|4||Key operated cardpunches|
|1||300 cards per minute card reader|
|2||Twin disk magnetic store drives|
The 8k store was soon found to be inadequate for the task of handling the Board's billing routine, and by the end of 1969 a further 8k store had been added. The transfer of consumer account records to the computer had been completed by the autumn of 1970, at which time it was decided to calculate the charges in decimal currency. To program the system to calculate bills in a currency that would soon be abandoned seemed to be an unnecessary waste of resources, and therefore the Board decided to introduce a new tariff based on the metric system from October 1st 1970.
To meet increased expenditure in 1962 the Board had been obliged to raise the secondary rate charges on the block tariffs from 1½d to 1¾d. Two years later the street lighting charges were increased to 2½d. Otherwise, there were no changes to the tariffs until 1970. In the last six months of that year there were three increases in the price of oil and another notified to come into effect on January 1st 1971. These brought the price to almost 50% above that ruling at the beginning of 1970. The price-wage-price spiral had started at a point in time when other factors were putting pressure on the financial resources of the Board. The opening of a second engine hall and the introduction of a five days working week, led to the employment of more staff, and an increase in the wages bill. Over the previous decade growth in sales had enabled extra expenditure to be absorbed, but now that oil had joined the demand for more money, this was no longer possible.
The new metric tariffs were approximately 10% higher than those that were in force previously, but meter rents were abolished. On the domestic and commercial block tariffs the primary rate became 3p per unit and the secondary blocks 0.8p per unit. The flat rate lighting tariff was also charged at 3p per unit and the heating and power tariff at 1.2p.
An increase in the sale of electricity during off peak times was needed to improve the load factor, and to this end its promotion received special attention throughout the sixties. In 1962 the charge for these units was reduced to 1d and by 1964 there were 215 off peak consumers, with a connected load of 2 MW. The rise in sales was helped by the introduction of fan assisted space-heating appliances. The following year a modified tariff was introduced aimed in particular at the tourist market. During the summer the supply was available throughout the day, for those installations where the appliances were capable of storing heat. The tariff for this service was increased to 1¼d per unit. The introduction of the Electricaire heater with thermostatically controlled output in 1968, along with the additional water heating connections, led to a situation in which there was a danger that the off peak load would itself produce peaks. By 1970 sales of electricity metered for the off peak tariff exceeded seven million units and the load factor had improved to 43%.
The activities of the commercial section, including the contracting section and the showroom, assisted the finances of the Board with profits varying between £5,000 and £1,000 a year. The variations were due, in part, to the need to employ contracting staff internally. The wiring of the new "B" engine hall was an example of this, but there was also continuing work on changing over consumer installations from direct to alternating current. Amongst the major contracting projects carried out at this time there was a scheme to floodlight Castle Cornet. The section also wired the desalination plant for the States Water Board, the Guernsey Gas Company's butane plant, and the Creux Mahe sewage treatment plant.
The commercial department also had to deal with two fundamental problems during this decade. The first arose from complaints made in 1964, that some landlords, who had installed their own pre-payment meters in rented accommodation, were calibrating them at a level that produced an unreasonably high charge. After the commercial department had monitored and confirmed the claims, the Board initiated action that led in 1966 to an Order in Council being registered, authorising the Board to set a limit on the maximum that could be charged for the re-sale of electricity.
The second problem was not so easily solved. In common with water supply authorities in the United Kingdom, the States Water Board began to use non-metallic pipes in place of metal pipes for water reticulation. It had long been the practice for consumers to earth their installations by connecting them to the water pipes, a method that was no longer safe. In 1966 the newly issued 14th Edition of the Institution of Electrical Engineers Wiring Regulations stipulated that water pipes should not be used for earthing electrical installations. The commercial department carried out a survey of all properties and, where modifications were necessary, the occupiers were advised of the result. The installation of Earth Leakage Circuit Breakers as a means of satisfying the requirements of the IEE Wiring Regulations, in accordance with the 1933 Electricity Law, soon became a common method of earthing installations.
There was only a modest increase of 149 in the number of street lamps installed in this period. They included a scheme of 51 lamps in St. Julians Avenue, another of 28 in the Castel parish and a few more on the South Esplanade. Of the total of 1574 installed at the end of 1970, all but 440 were operated by the Plessey rhythmatic control system. The contribution made by electricity to road safety was extended when, on October 24th 1962, Guernsey's first two sets of traffic lights installed by the Telephone Council, were switched on at Braye Road and Elm Grove.
An incident, that in later years would have seemed unusual, occurred in 1963 when, by a majority, the Royal Court approved an application from the Gaumont Cinema to install a hot dog cabinet. During the consideration of the matter the term "hot dog" was explained, and the Electricity Board confirmed that it had no objection to supplying power to the equipment.
The availability of additional space in the new office block allowed the showroom staff to extend its activities. It presented more cookery demonstrations and displayed a greater variety of major appliances in the larger area at its disposal. Initially, the greater interest in the major appliances, engendered by better display, was offset by a fall in the sale of small appliances following the move from the High Street to the new premises at the Albany. Agency agreements were entered into with all the main national ice cream manufacturers for the maintenance of their equipment. The year 1967 saw the 20,000th consumer connected to the electricity supply. In February, Mr. and Mrs. T.F. Dowinton who owned the newly connected property at Sandy Lane, L'Islet, were presented with a vacuum cleaner and spin dryer, to mark the occasion. The following year another milestone was reached, when the number of units generated in the year reached 108 million, exceeding one million for the first time.