MANGAHAO HYDRO-ELECTRIC WORKS.

Manawatu Herald, Volume XLIII, Issue 2353, 10 November 1921, Page 3

MANGAHAO HYDRO-ELECTRIC WORKS.

STEADY PROGRESS MAINTAINED.

In a report on the progress of the Mangahao hydro-electric works, Mr E. H. Crabb, president of the Mangahao Hydro-Electric Power League, congratulates the department and the engineering staff on the steady advance that is evident. At present the labour force employed is approximately 250. As most of the preliminary works are now finished, and work on dams is in full swing, this is sufficient to fully man the works. The camp at Mangahao has been shifted to the bottom of the valley, which is more convenient to the work at the site of the dam. Steady progress is being made with the tunnels. The Mangahao tunnel at the upper end is in 923 ft. at the lower end 480 ft. The TokomaruShannon tunnel is in 1,170 ft. at the Tokomaru end, while an adit of 134 ft. has been driven in the centre of the tunnel. This is a total of 2,000 ft. finished out of at total of 12,000 ft. to complete the distance. Power to drive the compressors is now supplied to all the headings from the power house at Shannon. The country driven through the Mangahao tunnel is now solid rock, suitable for crushing for concrete work. The Tokomaru Valley is, however, apparently in a crushed zone, and the spoil from this tunnel until quite recently was of too rotten a nature to be of any use. The solid rock has now been met with, and the stone can be used for concrete work. The distances given for tunnel progress are for September 30th, the present month’s figures not being available. So far the dams have not been actually started, although all preliminary work has been done. Crushers are erected in the Tokomaru Valley, and rock crushing for the tunnel lining has been commenced, and the actual work of lining the Arnpeti tunnel is proceeding. As has been already stated, the foundations of the Mangahao dam having to go much deeper than was anticipated, necessitated an alteration in design. The foundations of the 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 is the obstacle met with such as will delay the completion of the work. Excavation for the power house'site is nearly completed. A tramline has been constructed from the site to the surge chamber 900 ft. above. The gradients for the pipeline arc completed, and the surge chamber excavation has been started and is now under way. A final survey of the route to Wellington is now under way, and will shortly be completed. Large quantities of poles have arrived, and are stored at convenient points. Steps are being taken to gel these carted to.lines as soon as surveys have definitely fixed routes.

From the above it will be seen |hat the undertaking 1 lie Minister has repoalodly given the League and the public, that no effort would be spared to carry Ibis great and necessary work to an early completion is being fully acted up 10, and your executive desires to express ils appreciation of the fact. In conclusion we desire to express our regret a I the slow progress being made by Ibe districts interested in commencing their work of reticulation. 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 at the cost, of undue competition for labour and materials, which might have been avoided had the work been commenced earlier.