Halfway Point Reached At Maraetai

Chronicle (Levin), 22 December 1949, Page 3

Halfway Point Reached At Maraetai

The Maraetai power scheme .is half-' vvay to eompletioii. The ta.sk 'o'i settiTig5 aside what Nature in. her whim established is almost complete; the major jobs of replacing it with what a xnan ifl. his wisdom has deeided is needed for the future service of his race are just beginning. ■ j iin the great hole beneath the -Marae-; tai erags, whence the Waikato River has been barfed and-sands ahd Jgravete ' scraped back to reveal the water-worn rocks of its deepest gorges,. men, dwarfed by their surrounuings, are working to build a graeeful arch of eonerete that in its height will make th'em look even small'er pi'gmies. _ TheIS'0,000 kilowatts .of power that wiil be produced will ease diffiCulties fof almost every one in the North llsand. _ Thi-ngs loing Well. It is no secret at MMfectan that th-ings are go'ing wcll 'at the 4nolo.eh.t. One enginefer said: "For a lohg tihie everything seemed to go against us. But'sinee we started to drain the dam site Nature has been on our side. There has been less water than we allowed for, rock has been higher than we expected and ledges have proved to be just where we want them." However, a shortage of staff whicb it is hoped will 'be ovei'cohie, !an'd 'long experienee that the nnexpecfred ttiay? always occutr, niakes t-hose «a-t the hend' unwillrng to say any more than "that they hope to have t'he fo's't ttftit run-' ning before t'he winter of. t'95-2. Muc'h remains to be done befoi'e 'then. I Nearly all t'he equiphient for the; speedy building of the dam and power house is instailed and comp'lete. Hig'h in the glass-sided ca'bins of the cablewavs, which lack oniy part o'f 'ttoeir trave'rsing gear, the opetators ov-erlaok the gorge and control with a boueh of a lever the despatch from the cli'ff to the riverbed of loads up to 7J toxi'S. The eonerete batching plant has worked successfully, and the stage has been reaehed where boxing and reinforeing steel is being prepared for the pouring of maps eonerete.

The first of this wil-l go into the foundations for two of the fiv-e gener-j ating units. On top of "this more eonerete will be laid, in hundreds of tons, around wooden forins to eoiistrvct the! draught tubes by which the Water e'scapes after passing thromgh the tnrbines. Further eonerete foun&atS'onS will follow, and finally the power htfuse will rise in s1#uctural steel, suppofting heavy cranes which will be used to instal the generating machinery. At a - • later stage eonerete panels will gi've the building a more substanti&l *appearan:oe. The Maraetai power house will rival; that at Karapiro in its claim to 'be the , highest building in New Z'ealand, but h | will be only half as high as tlve dam behind which it will nestle. More rock has to be exeavated for the dam foundations and this worlc is being made much easier bv the drv eonditiQns. . Cooling of Dam. Seepage of 2000 gaiions a minute into •the area is being pumped away withont difficulty. However, the rock reveals what inight have happened had it not been sealed earlier when, as a precaution, large quantities of eement were pumped into the ground under pressure from the river banks. In -numswous plaees cracks fully filled by this cement can be seen. If these had bfeen open, gushing thousands of gallons o'f water, the diffieulties now might bes immense. ' Fairly early next year the dam is' expected to start rising in steps, haVing built into it as it goes a system of pipes to earry cooling Water "from a refrigerating plant being , speciaily constructed. This will overcome heating diffieulties which would. ot-herwise ar.ise from the laying of such 'a large eonerete mass. • Other works in connection with the power st-ation -inelude. a single arch bridge which is being ■bililt beiow the' divension tunnel outlet to carry a. permanent roadway to the power ho'use. This is well over 200ft lofig *and in other surroutidings would be regarded as a fairly major worlc.