Overview
Sun. Aug. 27.
My 17th visit to Mangahao hydro-electric works. Left Woodside at 8.30 in gig taking Maud + children.
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We arrived at the Powerhouse site at 10.15am. Left family beside Mangatangi Stn. [station] at foot of Pipe Line + took following photos: (1) 1/2pl[ate]. Powerhouse foundations under construction from Terrace at Honeymoon Farm camp (2) 1/4pl. concreted channel of Mangaore Stm. [Stream] alongside Powerhouse looking up-stream. From the NW (Northwest) corner of the Powerhouse a high curved concrete wall has been built to turn the current of the stream. All the concrete work i[s] heavily reinforced with steel bars. The waste water from the dynamos will apparently be discharged from several apertures on the west side of the Powerhouse into the concreted stream channel. Crossed Mangaore Stm just above the Mangatangi junction + climbed up to the rock-crushing and concrete-mixing plant located high up on the left bank of the Mangaore Stm. overlooking the Powerhouse site. Drew a section of this plant which is arranged as follows: The highest level is a spacious wooden platform alongside the Mangaore Valley Road via which the supply of boulders is brought to the plant. A hole in one end of the wooden platform leads down into the rock-crusher. The crushed rock passes directly into a revolving hollow iron cylinder placed in
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a horizontal position + perforated by two sizes of holes – small at one end + larger at the other. The finer particles of crushed rock (sand) drop through into one bin, larger fragments into a second bin + the largest pieces fall from the end of the cylinder into the third bin. ¼pl. photo (3) of the rock-crusher + cylindrical sieve. At a lower level is the concrete-mixer. A truck runs on rails under the bins of crushed rock + can deliver to the “mixer” rock detritus of any degree of fineness. The bags of cement are delivered to the mixer from carts on the road above via shutes. The cement, sand + rubble are tipped into flat tray tapering to a point – this is tilted up + the mixture poures into the “mixer” together with water. Finally the liquid concrete is delivered to the foundations of the Powerhouse by another shute, the length of which is adjustable in order to reach all parts of the work. 1/2pl. photo (4) looking down form the concrete-mixing plant + showing foundations of Powerhouse, foot of Pipe line with tramline bridge over Mangitangi Stn +c. Climbed hill above Honeymoon Farm Camp + took 1/4pl. photo (5) of same together with new stores of steel-bars +c +
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village of workers and officials dwellings on terrace above. Also 1/2pl. (6) looking down course of Mangaore Stm. showing base camp and construction powerhouses – this stream-bed will carry the waster-water from the Hydro-Elec. Powerhouse when the works are completed. 1/2pl. photo (7) of the Powerhouse foundations from hillside above Tokomaru Valley Road. After lunch with family went up the Pipe Line. A large number of the small concrete piers for carrying the pipes of the Pipe-Line have been made – these measure 9 inches by 4ft 6ins and stand at various heights (a few inches to 3ft or 4ft) above the pipe-line bed excavations + fillings according to whether the gradient of the earthworks is true or otherwise. The piers are in rows of four (higher up two only) 4ft 6ins apart + the rows are 18ft. apart. 1/4pl. photo (8) of small piers looking up pipe line. 1/4pl. (9) Ditto looking down pipe line. On arrival at Surge Chamber site found the pit had been excavated to a very nice circular form + to its full size [rig?] 75 ft. in diameter + practically to its full depth also 75ft. 1/2pl. photo (10) of pit for Surge Chamber from bank above. Descended to foot of Pipe Line
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+ took family up to see the rock-crushing + concrete-mixing plant. Left at 2.15 + reached Woodside about 4.10. The day was perfect – clear, cloudless + mild – + we had a very pleasant + successful outing. In evening read “Our Wonderful Selves” by Roland Pertwee.