Nineteen forty-nine not only saw the birth of Water Power magazine but also the beginning of a revival in hydroelectric developments in Scotland. The Scottish industry, like others worldwide, grew with the magazine and many of the well-known and established mechanical and electrical engineering contractors who contributed to the new developments in Scotland were advertising and writing articles in Water Power from the beginning.

These contractors were the manufacturers and suppliers of turbines, generators, transformers, gates, valves, screens and other equipment. Many of them were using manufacturing facilities in Scotland and were to compete with each other for substantial contracts in this re-awakening industry, and in the subsequent hydroelectric projects in many countries worldwide.

The companies included: Boving & Co; Gilbert Gilkes and Gordon; Harland Engineering; J M Henderson & Co; British Thomson Houston; and the English Electric Company. Indeed the first issue of Water Power contained their advertisements.

Today, as the pattern of power generation has changed and fewer hydroelectric stations are being ordered, some of these companies have remained in the same ownership but have diversified into other activities. Others have been amalgamated into larger organisations and a few names have disappeared. This 50th anniversary of Water Power is an opportunity to remember their achievements and to remind ourselves of their problems and successes in building these early power stations.

Post-war period

For some of these companies their commercial development, and their overseas achievements in the immediate post-war period were boosted by their activity in building hydro power stations in Scotland. There had been several previous proposals in the inter-war years for hydroelectric schemes in Scotland but local opposition had stopped many of them. The key to starting the new schemes in Scotland had been the creation in 1943 of the North of Scotland Hydroelectric Board (NSHEB). The Board’s duty was to generate and distribute electricity throughout northern Scotland, but its plans to build new hydroelectric schemes were again likely to run into opposition from those who thought such schemes would spoil the local amenities.

In answer, the then-Chairman, Tom Johnston, noted the loss of sporting and visual amenities enjoyed by the summer visitor and the sportsman. But he contrasted it with the gain in comfort and the improved standard of living which the supply of electricity would bring villages which previously had been without electricity for lighting, heating or cooking.

Parliament must have agreed that it was time the attraction of oil lamps could be relegated to the past, and it eventually approved NSHEB’s proposals to start building new hydroelectric power stations. In the course of time the number of visitors to the new power stations demonstrated that they had in fact encouraged more visitors than before.

The first major project for NSHEB was the Loch Sloy scheme on the west side of Loch Lomond. This is a particularly favourable site for hydroelectric development and a number of schemes had been promoted since 1906, one of which was for a 360MW pumped storage scheme.

NSHEB’s proposal was more modest and included a buttress dam on Inveruglas Water and a 130MW power station, with four Francis turbines operating under a net head of 247m, on the west shore of Loch Lomond. This power station is still the largest conventional hydroelectric power station in the country. The English Electric Company was the selected supplier for the four machines and while the pages of the first edition of Water Power were being set by the printers the spiral casings for the Sloy turbines were being set on their concrete foundations.

In the late 1940s, in the years after the end of the war, all contractors were suffering from a shortage of skilled labour. At Sloy this shortage, together with the remote location, significantly delayed the work of the civil contractors.

The delayed building works also affected the construction programmes of the mechanical and electrical contractors who had, at this site in particular, their own problems in making, transporting and assembling what at the time were considered to be large turbines and rotors. At the site of the power station the spiral casings and turbines were installed before the walls of the power station had been completed and before the overhead cranes, which are usually made available to the mechanical engineering contractor, had been installed. Despite these problems the first machine was successfully started in February 1950, just after Water Power had celebrated its first birthday.

The Sloy scheme involved another company which was an advertiser in the first issue of Water Power. At the dam the concrete was placed using a skip slung from an aerial ropeway (a blondin) running between towers at either end of the dam. Aberdeen-based J M Henderson & Company supplied this aerial ropeway.

At the same time the English Electric Company had received orders for 32 vertical axis Francis turbines and three impulse turbines together with the associated equipment in Portugal and Spain, and for four Kaplan turbines in New Zealand. The alternators supplied for the Francis turbines were both of the two-bearing type (of a similar design to those used at Sloy) and of the umbrella design.

Major contracts were also received from Canada. These included:

•110MW alternators at Kemano. At the time this was the largest capacity power station using impulse turbines and also the largest underground power station.

•Five 150MW Francis turbines at Chute-des-Passes, Quebec which were the largest capacity Francis turbines at the time.

•Four 130MW Francis turbines at Bersimis I for the Quebec Hydro-Electric Commission. In operation the Bersimis turbines (built in Canada to British designs) developed nearly 150MW under maximum output.

Before 1945 there were relatively few Francis turbines operating at heads in excess of 250m, but by the 1950s the maximum design head had virtually doubled. British designers and manufacturers had made important contributions to the development of the high head Francis turbine. Such turbines were supplied to both the Snowy Mountains Hydroelectric Authority, who ordered four 100MW turbines under a head of 330m, and for the pumped storage power station at Ffestiniog in Wales where English Electric supplied four 78MW turbines under a head of 300m. Francis turbines were also supplied to India, the US, Brazil and Turkey.

For the lower head power stations English Electric was the successful contractor for a number of installations using axial flow turbines. A 20MW Kaplan turbine under a head of 51m was supplied to the Invergarry power station in Scotland in 1955 and two 39MW Kaplans were supplied to Hirakud in India. For the St Lawrence scheme in Canada English Electric supplied 16 fixed blade propeller turbines each of 56MW. For the Priests Rapids power station on the Columbia river above the junction with the Snake river in Washington, US, they supplied 10 Kaplan turbines with a nominal output of 80MW each together with umbrella generators and transformers. The Priests Rapids turbines had a runner diameter of 7.2m.

An innovative design developed by English Electric’s chief designer, Paul Deriaz, was the movable blade Francis turbine. This was developed from an attempt to design a Kaplan turbine for heads in excess of the present limit of about 60m, but studies indicated that with the conventional axial flow arrangement of the Kaplan turbine the runner hub would become so large and the vanes so narrow that an appreciable loss of efficiency would result. Therefore it was decided to revert to the mixed flow arrangement of the Francis turbine but to use movable blades.

In the Deriaz turbine the axis of the runner vanes, instead of being at right angles to the shaft axis, is inclined to it so that the hydraulic limitations of the Kaplan turbine for high heads are overcome. The Deriaz turbine can be used for heads up to about 180m. The runner is surrounded by a conventional gate apparatus which, in combination with the movable runner vanes, gives the flat efficiency curve and overload capacity previously associated only with the Kaplan turbine.

The Deriaz turbine is very suitable for use as a pump turbine, and since the runner vanes are movable the gate apparatus can be dispensed, within certain instances. An important advantage is that the movable runner vanes give quantitative regulation of the pump as well as of the turbine. When the runner vanes are closed and the runner is started in water very little torque is required because the closed vanes form a virtually smooth curve. Therefore there is no need for the complicated apparatus required to enable the runner to be started in air.

The first installation of the Deriaz reversible pump turbines was in the Sir Adam Beck No 2 pumped storage power station of the Hydroelectric Power Commission of Ontario in Canada, where six Deriaz units have been installed. As a turbine each unit operates under a head varying from 14-28m and each unit generates a maximum of 33MW. As a pump each unit requires an input of 40MW.

One of the last major contracts the English Electric Company undertook was again in Scotland. This was for two of the four innovative 100MW reversible pump-turbines for the high head Cruachan pumped storage scheme. The scheme had been promoted in 1957 and the novel problems in starting and stopping these machines under high water pressure needed to be analysed and solved by using model tests. These tests were undertaken by English Electric at their hydraulic laboratories in Rugby, and the results were published in Water Power in January 1966. Further work was done at the laboratories of Sulzer Bros in Switzerland. The final design, a compromise between the best turbine performance and the best pump performance, was checked and approved by the consulting engineers, Merz and McLellan.

Cruachan was also innovative at that time in that the power station was built underground, partly for amenity reasons because this avoided the need for high pressure pipelines which would be visible on the steep side slopes of the Pass of Brander, and partly because there was not sufficient space for a power station at ground level, where the tail race discharged on the side of Loch Awe.

By the late 1960s most of the Scottish hydroelectric schemes had been completed and there were fewer new orders world wide for hydroelectric plant. In 1969, after working on the development of a rim generator turbine, the English Electric Company merged with the General Electric Company and its name disappeared from the hydro-electric industry.

The other two reversible pump turbines at Cruachan were supplied by Boving & Co (later to be merged with the Kvaerner Energy Group and now known as Kvaerner Boving) and they too were required to undertake hydraulic tests to test the performance of the machines when starting and stopping. This work was done at the laboratories of KMW at Kristenehamn in Sweden and reported in Water Power in January 1966. Cruachan came into full operation in 1967. Following these turbines Boving received the order for the six reversible pump-turbines for the major pumped storage scheme at Dinorwig in North Wales.

Boving was also the successful contractor for the two 150MW reversible pump-turbine motor generator sets in the Foyers power station. Foyers is a modern pumped storage scheme with a power station located on the shores of Loch Ness and is on the site of an

early hydroelectric scheme owned by British Aluminium. This site is of historical interest as one of the first

major hydroelectric power stations in Britain.

Foyers was the second pumped storage scheme and the last major hydroelectric project undertaken by the North of Scotland Hydroelectric Board. The project was inaugurated in April 1975.

When Water Power started in 1949, Boving & Co had also been working in Spain on the Mino development in Galicia, one of the major hydro projects in Europe. They supplied three large Francis turbines and six large Kaplan turbines, together with all their associated equipment, for four power stations for the Spanish company Fuerzas Elecas del Noreste SA, now Iberduero SA. These orders followed a previous order for the Los Peares power station further upstream on the same river.

This was followed by an order from Australia for eight 120MW Francis turbines for the Murray 1 project of the Snow Mountains Hydroelectric Authority. This was a benchmark design, because the operating head of 513m was at that time the highest head for a Francis turbine. These units, commissioned in 1961, are still running successfully.

Another significant order was for the 223MW Francis turbines for the El Chocon project in Argentina for Hidronor SA. The runners were unusually large and heavy, 6.8m diameter and weighing 185t, so they were shipped in three pieces and assembled at site using a unique Kvaerner Boving method requiring no welding or bolting. The first three turbines (of eight) were ordered in the late 1950s and they are still running perfectly.

In the early 1980s Kvaerner Boving received the order for eight 24MW bulb turbines for the Sidney A Murray Jr project in Louisaina, US. Kvaerner Boving was the successful contractor, offering an unique proposal for completing the scheme. As the turnkey supplier of the power house and its contents Boving proposed building the power house as a prefabricated unit weighing 24,000t in a ship yard in New Orleans and then floating it 320km up the Mississippi river to the power station site. This method of construction had two advantages:

•Because the civil work was carried out at the same time as the power station was being built in the shipyard the overall construction time was reduced by at least 12 months.

•The skills and crafts required for the construction of the power house were more readily available at the shipyard.

The net result was that the scheme was completed six months ahead of the scheduled programme.

One of the few companies to continue operating under its original name from 1949 to the present day is Gilbert Gilkes & Gordon, based in Cumbria, UK. In 1949 the company had already been in existence for 93 years and had established a reputation for the design and manufacture of small turbines, especially of the patented ‘Vortex’ impulse turbine designed by Professor John Thomson. Eight Vortex turbines were supplied to Tasmania in 1894 and one Vortex turbine was supplied to Queen Victoria and installed in 1898 on the Balmoral Estate. Gilkes employed over 200 people in 1949 and the workshops were equipped with modern casting and machining facilities. In 1949 Gilkes sold 53 machines, 27 of which went to customers in Great Britain, Northern Ireland and the Republic of Ireland, while the others were exported to some 18 countries throughout the world. The orders came not only from private estates and from owners requiring power supplies for their own use, but also from generation companies and public utilities. The output of the turbines varied from 2.2kW to 2.5 MW. The smaller machines were generally supplied with their own generators or alternators, and the units were controlled by using mechanical hydraulic governors.

Today Gilbert Gilkes and Gordon still has a special reputation and capacity for supplying small turbines but the market is different. Fewer machines are being supplied, they are individually of a much larger capacity and much more of the hydroelectric work is exported.

Turbine sets have been exported to both north and south America, the Caribbean, Europe, Africa, India and Sri Lanka, Malaysia, Japan and New Zealand. The company has also recently opened sales offices in the US, Asia and Japan. The current range of machines can provide power supplies up to 20MW, ( compared with 2.5MW in 1949 ) and the average size is 1.5MW, about five times the average size in 1949.

More customers today are installing turbines to generate electricity for sale rather than just for their own consumption. This trend has been encouraged in this country by the extension of the National Grid and the preferential tariffs offered to small generators by the electricity companies under the government’s Non Fossil Fuel Obligation.

Customers today also require full M & E packages from one company and Gilkes has adapted to meet these needs. Control systems have been modernised and Gilkes now supplies units controlled by PLCs and computers. Remote controlled operations are also becoming a more common request. In addition to the established market in turbine sets Gilkes has diversified into the design, manufacture and supply of pumps for numerous applications.