ABOUT THE TOWN

Chronicle (Levin), 26 October 1946, Page 3

ABOUT THE TOWN

r T. S.

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SHANNON SIDE-LIGHTS

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To the average man m une street, October 23, 1942, was perhaps no different from any other day of the war years. Perhaps someone had a grouse because a petrol license had been refused. Perhaps the tea or sugar ration had run out, but on the whole it was just another of those dark days we hesitate to look back upon. But to the desert rats of Egypt, October 23 and the weeks that _ followed were, however, the most signiflcant days in the history of the Eighth Army and the 2nd New Zealand Division, for it marked the end of disheartening defensive struggle and the entry of our forces upon the road to final victory. That eventful night, just four years ago, saw the delivery of the first blows which smashed through the Alamein Line and cleared the way for the pursuit of Rommel's Afrika Korps to its eventual destruction. An inspiring memory of the early stages of Alamein is that of the pipers of the 51st Highland Division, whom the Kiwis saw playing the infantry into action, and that inspiring sight of Scotties going into action with fixed bayonets. Every now and then the sound of the pipes carne down the wind above the noise of battle, while on several occasions the pipers could be clcarly seen with the aid of field glasses far over on the Kiwis' right fiaftk. The sight of these unarmed pipers in the thick of battle did much for the rnoral of every soldier who saw them. We glory in the- menlories of this great battle and so we glory in the memory of those who fought and fell at Alamein, and every other battle in the fight for democracy. In a few days' time the Shannon district war memorial committee will be making an appeal to every citizen in the district' for support in erecting a fitting memorial to those who paid the supreme sacriflce and those who served that we may live in peacelahd comfort in a free land. Let all "support the committee and make this memorial a fact. .. Mangahao Hyrdo Scjieme Returning on our visit to the Mangahao hydro electric scheme, from the Mangahao lower dam we proceed to the upper dam. This massive structure has a concrete volume of almost 35,000 cubic yards. •The geological Cf^atures and the; design are similar to those of the lower dam. A fairly extensive high level terrace in evidence on the left bank of the river is --lihe "original Mangahao River bed, "filled in by geological action. On this terrace a concrete gravity section extension of the main dam is seen, and below this a concrete corewall- six feet wide extends down into the- rock sides and bottom of the old chan-^ nel. The main dam has^three automatic crest tilting gates, while a sluice on the lower level is an interesting feature as a jet disperser. The Tokomaru dam is an arched gravity dam of 1200_ feet radius, containing some 22,2o0 cubic yards of concrete. It was first designedas an arched dam, but as tests proved that the foundation for the west abutment was unsuitable, the consequent change in section practically doubled the quantity of concrete used. This dam is provided with a sluice valve in case it should be necessary at any time lo" empty the basin. The surge chamber is situated at the head of the pipe lines and is conical in shape, 87 feet wide at the top and 19 feet at the bottom. It is 75 feet deep. The rock excavation involved /totalled 9400 cubic yards. The chamber is lined with concrete throughout and heavily reinforced. The tunnel leading from the Tokomaru reservoir enters the bottom of the chamber on one side, and on the opposite side the pipe lines emerge. The pipe lines are carried for a length of 180 feet through two parallel tunncls, into which they are solidly concrctcd, before they begin to dcscend the spur leading to the power house. Gates and screens are provided where these pipes leave the surge chamber. Provision is made for the instaneous closing of these gates should there be a burst in either pipe. Owing to the configuration of the country, twelve angJes were required in the pipe line, each being protected by a heavy concrete anchor bloek. Where the riveted steel pipes leave the surge chamber they are two in number and six feet in diameter. Further down the hill, as the pressure increases, the diameter is reduced and the pipes ultimately branch into four, each 46 inches in diameter reducing to 36 inche§ near the power house. The formation of the pipe line , necessitated 25,000 cubic yards of excavation.