Fabulous Power

Sun (Auckland), Volume II, Issue 606, 7 March 1929, Page 8

Fabulous Power

Resources of Waikaremoana

WITH simplicity of plan its hydro-electric plant is no one turbine. Though smaller, it pr Arapuni in that it has been di time at less than the estimatec TJESERVES of power undreamed of give Waikaremoana potential!-! ties which will in time make it the j greatest power-producing lay-out in j the Southern Hemisphere, if not in j the world.

Engineers already picture a chain of power-houses built in a kind of stairway down the valley of the IVaikareTaheke River, and though there are problems to be overcome before this vision materialises, yet the ease by which the same supply of water can be used over and over again gives the plan a rare attractiveness. The great sheet of water that is

Waikaremoana is encircled by hills except where the Waikare-Taheke drains it. There the hills, dropping sharply from the majestic heights of Panekiri bluff, become little more than a narrow rim dividing the lake from the Waikare-Taheke Valley. Over this rim escape the headwaters of the Waikare-Taheke. In dry seasons like the present there is a mere trickle through the narrow passage over the rim. But a constant supply is furnished by profound and mysterious fissures that open into the bed of the stream at intervals for two or three furlongs below the outlet. Through these fissures, escaping under terrific pressure, gush the escaping- waters of Waikaremoana. In the recesses of the precipitous ravine they present a striking spectacle. The scene of present development is some little distance down the valley. Below what may reasonably be assumed are the last of the fissures, the waters of the stream with the long name are diverted into a small lake 153 acres in extent. The water is led through a short tunnel and

; keynote, the Waikaremoana >\v developing power through et-ents features foreign to eveloped within the scheduled I cost. i emerges in a circular surge cliambei ion the outer slope. Here it enters ! two immense pipe-lines, whose ae- ; scent to the powerhouse embraces a ! vertical fall of 645 feet. The head- ! works before the actual descent ot the ! water begins are compressed into the simple diversion of the river and the short tunnel to the surge cliambei. Compare this with the expense incurred at Arapuni in the erection ot the dam and the diversion of the Waikato to serve the same purpose, and the relative simplicity of Waikaremoana is at once understood. Six feet in diameter, and ice-cold to the touch, the pipe-lines seem to quiver as they conduct their racing burden down the hill. The greater strength of the steel armour, and the increased number of rivets to stand the rising pressure, are conspicuous as the line descends. In the power- | house itself there is the constant roar of the one turbine operating. » hen the second turbine is ready for action the din will be doubled. A point of interest is that the turbines are vertical, nor horizontal, as at Arapuni. The huge size of the automatic governors, the delicate adjustment of the SO-ton crane that swings in the ratters, and the complicated arrangement of the switchboards, in which red, green and blue lights glow, take the eye among the subsidiary features. STEPS AND STAIRS

From the foaming outlet under the turbine the water goes on its way to rejoin the Waikare-Taheke. It crosses a marshy flat in front of the village of Tuai, where the workers on the power-plant have formed their own cricket and football grounds, and then flows through a low ridge to begin another long descent. Ultimately the depression through which it escapes will be barred, and a wide, shallow lake will thus be formed. This will act as the reservoir for No. 3 powerhouse, which will be at the foot of the next descent. The powerhouse now erected will be No. 2-, and No. 1 will be higher up, immediately beneath the outlet from Lake Waikaremoana. To create No. 1 plant, however, the engineers will need to control the water that at present escapes through the subterranean fissures. It will be necessary to have all this water running over a spillway at the top, though the blocking of the fissures will be a very difficult and, perhaps, costly job. When the three power plants, each with three turbines going, are operating at full pressure, Waikaremoana will be developing stupendous power. Already it is supplying Gisborne, and acting as auxiliary to Mangahao. To link it with Arapuni across the wooded battlements of the Huiarau ranges will be the hardest task of all. A party of surveyors is at present working from Ruatahuna, in the heart of the Ureweras, trying to locate a practicable route for the transmission line. Erection of the lofty towers, which will have to carry the terrific stresses of long spans from ridge to ridge, will be a formidable task, an 4 if the work has to be done in winter it will involve many hardships. J.G.M.