HYDRO-ELECTRIC POWER

New Zealand Herald, Volume LVI, Issue 17297, 22 October 1919, Page 9

HYDRO-ELECTRIC POWER

PROPOSED ARAPUNI STATION.

PRELIMINARY TEST WORKS.

SATISFACTORY RESULTS.

The preliminary engineering work that has been proceeding for the last seven months on the site of the proposed hydroelectric power dam at Arapuni, on the Waikato River, is now drawing to a conclusion. Some interesting particulars oi the work were supplied yesterday by Mr. E. J. Darby, a resident of the district, who is now visiting Auckland. The object of the investigation work that is being conducted by a Public Works Department staff of about 20 men, under Mr. SeaJy, the engineer in charge, is to ! determine the suitability of the dam site, I which is just below the Arapuni Rapids. ! The work has consisted of the driving of ; two shafts and ten tunnels through the ! rhyolite rock, with a view to making a ! thorough test of the foundations. ihe \ tunnels have been driven from the banks ' of the stream above the water level, and also from the shafts, below the river bed. ■ The results are stated to be very satisfactory. Samples of the rock, which have been tested, show that it is capable of sustaining a strain from 100 to 198 tons to the square foot, whereas the restrain is calculated at only Lsi ■ tons. Satisfactory poroeity tests also have been made. The officia' report on the operations will be forwarded to the Department shortly. Site of the Power Station. The river below the dam site falls con- i siderably, and when the dam is constructed the water will be diverted into an old parallel course on a higher level for a distance of above half a mile, at which point it will be conveyed to the present river bed, a considerable distance below, through a series of tunnels, to be driven through the rock. The generators will be placed at the foot of the tunnels. The motors will each weigh nearly ICO tons, and the heaviest indivisible part of each will weigh no less than 68 tons. Each of the 10 generators, it is calculated, will be capable of producing as much current as the total generating power of the present Lake Coleridge scheme in Canterbury. During the construction of the dam the water will be carried away through two large tunnels. The building of the dam will form a lake in. the river of about 22 miles in length, with a width at the widest pari, of about half a mile. This lake, it is suggested, will be splendidly adapted for the purpose of regattas, as well as for the purnose of transit of goods and produce to and from the adjacent areas of productive country within the pumice area. Proposed Branch Railway. The necessity for providing means of transit for the enormous quantities of j material that will be required in the con- | struction of the dam and powerhouse when the work is authorised has drawn increased attention to the question of the proposed branch railway from Putaruru to Te Awamutu. Arapuni is about nine miles from Putaruru, and the railway, it to suggested, would cross the river by . means of the dam. The total distance from Putaruru to Te Awa-mtctu is about 34 miles, over country presenting no en- ; gineering difficulties, the cost of construe- ' tion_ being estimated at no more than £2UUO a mile. A scheme for constructing this railway under the Local Railways Act has lately been set on foot. It has been, suggested that in view of the favourable result of the investigation work at the dam site a canvass should be made of the Auckland and Taranaki provinces to ascertain'what quantity of current will be required by intending consumers when the hydro-electric scheme is completed.