HYDRO-ELECTRIC POWER

Dominion, Volume 15, Issue 40, 10 November 1921, Page 9

HYDRO-ELECTRIC POWER

OPERATIONS AT MANGAHAO STEADY ADVANCE REPORTED The president of the Mangahao HydrbElectrio Power League (Mr. E.yH. Grabbe), reporting to the league on a visit paid by him to the works-iif company with Mr A. Harris (chairman of the Wanganui Provincial Power Board Committee), congratulates the Public Works Department and the engineering staff on the steady advance made. "Wo consider the’development of the works is quite up to schedule,” he states, "and fully bears out the Minister’s statement that the undertaking will be completed and the power available by the end of 1522. As far as engineering difficulties are concerned, w» are assured that unless something unforseen happens this will bo accomplished. This we feel certain will he satisfactory to the league, mote especially in Mtew of rumours that have been ' dtrculated that unexpected difficulties would seriously retard the data of completion/’ At present, Mr. Crabbe writes, the labour force employed is approximately 250. As most of the preliminary works am finished and work on dams is now in full swing, this is l sufficient to fully man the works. The housing of the staff is completed, and all the labour is accommodated in a comfortable manner. Up to September 30 the Mangahao tunnel at the upper end was in 632 feet, at tho lower end 480 feet. The Toko-maru-Shannon tunnel was in 1170 feet at the Tokomaru end, while an adit of 134 feet had been, driven, in the centre of the tunnel. A total of 2600 feet of tunnelling had been finished out of a total of 12,000 feet. Power to drive thq compressor# is now supplied to all tho headings from the power house at Shannon. The country driven through by the Mangahao tunnel is now solid rock, suitable for crushing for concrete work. The Tokomaru Valley is, however, apparently in a crushed zone, 1 and the spoil from this tunnel until quite recently was of too rotten a nature to be of any use. The solid rock is now being' met with, and the stone can b« used for concrete. work. The dams have not yet been actually started, he reports, although all preliminary work haa been 'done. Crushers are erected in tfie Tokomaru Valley, rook crushing for the tunnel lining has commenced, and the actual work of lining the Arapeii tunnel is proceeding. The foundations of the Mangahao dam having to go much deeper than was anticipated, an alteration in design was necessary. The foundations of tho Tokomaru dam have also given cause for trouble. The rock, on close examination, has not proved so solid as was expected, and will necessitate deeper foundations, but in neither instance will the completion of the work be delayed. Excavation for the power house site is nearly completed. A tram line has been constructed from the power house site to the surge chamber, 900 fleet above, and is worked'by a motor at the surge chamber site. The gradients for tho pipe line are completed, and tenders for Supply of pipes have been called. The excavation of the surge chamber is now under, way. A final survey of the route for the transmission line to Wellington will shortly be completed. Largo quantities of poles have and are stored at convenient points. Steps are being taken to get these carted to Hie lines as eoon as the surveys have definitely fixed the routes.

"We desire to express our regret at the slow progress being made by the districts interested in commencing their work of reticulation,” states Mr. Crabbe in conclusion. “This refers especially to the country districts concerned. If the work is to be done in time to take advantage of the power offered, it will be jit the cost of undue competition for (labour and materials, which might have been avoided had the work been commenced earlier."