HYDRO – ELECTRIC SCHEME

Timaru Herald, Volume CLVIII, Issue 23347, 2 November 1945, Page 6

HYDRO - ELECTRIC SCHEME

Progress Made At Lake Tekapo

Tunnelling Work Begun PRELIMINARY work on the Tekapo hydro-electric * scheme is all but completed. The second of the two shields is being installed, and then work at the north end will begin on the excavation of the mile-long tunnel which will convey water from 35ft below the level of the lake to a power-house on the Tekapo River. Besides supplying power to drive a single generator developing 24,000 k.v.a., the scheme entails the raising of the level of the lake by about 15 feet to provide an additional volume of water for the Wajtaki hydro during peak loading in winter months.

In company with Mr J. de Lambert, an engineer of the Public Works Department which is undertaking the project, a representative of ‘‘The Timaru Herald,” made an inspection of the scheme. Lake Tekapo is 2300 feet above sea level. It is fed by snow water and overflows into the Tekapo River, which is a tributary of the Waitaki. Adjacent to the lake, a shaft 60 feet deep has been sunk, this being 35 feet below the bed of the lake. At the base of the shaft a tunnel will be put through to* a bend in the river about a mile away where the generating plant will be installed. On the river side, workers have burrowed into the side of the hili, enabling the work of tunnelling to be undertaken from both ends. When power is generated it will be fed into the South Island network, the lines for which have already been erected. Method Of Tunnelling

The method by which the tunnel is being constructed is described as new to New Zealand, although it has been followed in Europe and in the United States for a number of years. The method was dictated by the geographical nature of the country, which is of morainic shingle. The tunnellers work inside giant steel cylinders constructed at the workships of the Public Works Department. Temuka. They are fundamentally steel containing a platform on which the miners work. As the miners excavate the face the cylinder is pushed forward three feet at a time by hydraulic jacks giving a total thrust of 2500 tons. As the shield moves forward pre-cast reinforced concrete blocks are carried into the chamber on railway trucks, and by means of a crane on the shield are swung into position and bolted together to make a circular impression lining for the tunnel. Thirteen blocks each six feet long and three feet thick and weighing 19001 b go to the circumference of the tunnel, which is 20ft 4in internal diameter. One shield is in place at the river end of the tunnel and is serving its purpose satisfactorily. Compressed air supplies power for an assortment of pneumatic and hydraulic tools used in the work. At the Lake end the other shield is being installed. It is being lowered piecemeal to the bed of the shaft and will be erected in the near future. When this has been done work will be introduced. The actual work of tunnelling is a slow and laborious process, and will take about two years to complete. The spoil from this excavation will be dumped into the lake to form a semicircle around the intake. The water will be pumped out to enable the intake to be completed. There is not much fall from the lake to the river, but the weight of water in the lake will supply ample pressure for the development of the necessary power. At the river end of the tunnel a surge chamber will be constructed to facilitate control of the flow. When shutting oil the power the flow of water will be gradually diminished by letting it into the surge chamber, thus eliminating unnecessary strain on the tunnel and the steel pipes which will connect the tunnel with the generating plant. Assisting Waitaki

To provide more water for the Waitaki Hydro during peak loading in winter time, the level of the lake will be raised about 15 feet by damming the river near the outlet. This section of the work has not yet been started, but it is not expected to present any difficulties other than making provision for perhaps a new bridge over the Tekapo River and the protection or removal of buildings on the side of the lake.

Work began on the scheme in 1940 but with the entry of Japan into the war and Che consequent drawing off of manpower, materials and accommodation to more urgent needs, work at Tekapo came practically to a standstill. Since February, 1942, between 12 and 20 men did maintenance work, together with preparatory work for the resumption of the main scheme. About a year ago the remainder of the preliminary work was put in hand. At the south end of the tunnel a shield was put in place and excavation work is now being carried out. When the shield is put in place at the north end the preliminary work will have finished.

Included in the preliminary' work was the installation of a generating plant to supply electric power for machines. When the transmission line which will take the power from Tekapo when the scheme is completed was erected, it was electrified from the South Island network and now supplants the generator. To supply compressed air to the tunnel two single diesel engines were housed in the same building as an electric pump in case the power for the latter should fail. The blocks which line the inside of the tunnel are manufactured on the site. Material excavated from the tunnel is washed, screened, weighed and mixed into concrete by a machine which ensures a uniform con-

sistency. After the concrete is moulded into blocks it is dried by heating and cured in open storage, which maintains the temperature above freezing point in winter. These undertakings formed part of the extensive preliminary work and now that they are completed only the lack of material for accommodation and a scarcity of tools for the building up of stores prevents maximum progress. Camp Amenities

From being a sparsely populated district, Tekapo has now a concentrated community of about 500, comprising mainly employees of the Public Works Department. The men are housed in five camps. In the married men's camps the houses originally consisted of three rooms. There are being enlarged by the addition of a built-in washhouse and bathroom and a kitchen, making five rooms in all. High pressure water is laid on, and the only charge to the occupants is for electricity. In the single men's quarters there are communal cook houses, bath houses and drying rooms. Included in the amenities are a Y.M.C.A., a billiards room, pictures twice a fortnight, a well equipped post office which provides for the daily delivery of mail and the sending of mail three times a week. To provide for the health of the camp a doctor from Fairlie visits the camp once a week. Plans are being made for the accommodation of a resident nurse. In each of the camps there is a grocery store and a greengrocer’s shop was noticed in one of the camps. A dance once a week provides recreation for the youth of the place. The educational needs of tlie community are supplied by a school of two rooms with two teachers who impart knowledge to 70 pupils. Periodically, sports are organised for the children who appear to be contended in their new surroundings. A pleasure launch enables families and parties to have picnics at the north end of the lake. Unlimited Power

There is unlimited power in the South Island for the generation of electricity. Other and larger schemes have been mooted and it is believed that a survey for another project is being undertaken not very far from Tekapo. If the survey is satisfactory it is expected that the machinery from the present undertaking and also the personnel will be transported there. The completion of the Highbank scheme this year gives an additional 25,000 k.v.a. to the existing network. It is generally agreed that the planning of new industries and the development of the necessary power should go hand in hand, and from this point of view there is wide scope for the creation of new industries in the South Island.

When the Lake Manapouri scheme was mooted it was stated by its advocates that sufficient power could be generated to supply the needs of many light-metal industries. The matter was left in abeyance, and no doubt will be resurrected when the full plans for rehabilitation are made known. Post-war planning will probably include the development of present industries and the creation of new ones. From the point of view of hydro-electric power in relation to these, the South Island should have a strong claim.

Secret System (Rec. 7.30 p.m.) CANBERRA. Nov. 1' The winner of the first prize of £5OOO in yesterday’s State lottery, Mr H. Brukarz, has won so much money in lotteries that he has lost count of the total. It is only eight weeks since he shared a prize. He also won the inter-State lottery of £12,000. His other prizes include two second prizes in the New South Wales lottery, three third prizes and four fourth prizes. Smaller prizes this year alone amount to more than £lOOO. Mi- Brukarz claims that it is “a secret and precious thought which brings me winnings from lotteries,” but he would not disclose his system, because he said it would not work for anybody but himself. In addition to his winnings Mr Brukarz has been one off the first prize in the State lottery six times.

“On the voyage to New Zealand,” writes Harold Reeve in “Jottings,” a London weekly, “when a fellowpassenger told me the New Zealand tobacco was toasted. I thought he was pulling my leg. But he was right. The New Zealand tobacco IS toasted—and a wonderful difference it makes! This same tobacco is the finest I ever smoked. It’s sweet and mellow, with a delicious flavour, and it smells as good as it tastes. Toasting does that —aye, and more, because it extracts the nicotine from the leaf, so that you can smoke any amount of it without fear of consequences. There are no consequences! I don't know any other tobacco of which that can be said. Most of the American brands are rather rank with nicotine, and quite unsafe to smoke constantly. As long as I lived in New Zealand I smoked tosted tobacco. It is unique.” Here are the six brands of this tobacco: Desert Gold. Riverhead Gold. Navy Cut No. 3, Pocket Edition. Cut Plug No. 10 and Cavendish Mixture, also Riverhead and Desert Gold tailormades. All toasted, and no sore throat, no cough.—Advt.