HUIA DAM WORK

Sun (Auckland), Volume II, Issue 569, 23 January 1929, Page 11

HUIA DAM WORK

MR. H. P. TAYLOR’S VIEWS ALLEGATIONS OF EXTRAVAGANCE Mr. H. P. Taylor, who recently Cr W H U Murr am ' "! com Pany with ♦ t_.. t wu rray and others, believes followa:~ 6 a& " mten lu The Sun as un application to the town dam* wo r rks Pe ami l l ° *“«•««* Hum from Mr All urn' mf° ( n instructions WaterCv..Tl,: , ’ chairman of the that h° K Committee, he replied voters m “i 8 not in tho interests of been’ 0 , from which metal has - or^. ID ,t:- a° huge* open’* & consisting of metal spawls intermixed Hrnut UO, ; k ' the proportion being about one to ten, judging from the huge depos t of mullock already tipped ■i short distance a wav, and to a denth of about 90 feet. Aman standing*on a ledge halfway up the face was engaged in loosening, with a crowbar, metal spawls. These were sorted out from the already fallen mullock, the latter being shovelled into trucks for the tip. The spawls are hosed only in wet weather, as the vibration in transit is expected to shake off any dirt. However, spawls at the crusher show that dirt was still adhering to them, and as it is a well-known engineering fact that 5 per cent, of dirt# kills the solidity of concrete, the absence of continuous hosing is a serious matter. No boring had been done, nor tunnels made (I understand) to locate the small face of solid rock now exposed. The working on an open face is an extravagance quite unexpected. From the tramway to the crusher is about two miles. There are many and costly cuttings, up to 40 feet deep, but this portion of the work has been done well—so well, in fact, that I am of the opinion that the work is ono of the most expensive of the whole of tho works. The metal is loaded by hand into non-tipping trucks, likewise unloaded by hand at the crusher, and when the hoppers there are full, then neat stacks are made of spawls at the other side of the line, and some 3 0 or 12 feet away from the crusher. When the hoppers can absorb these, the men have to walk that distance and throw by hand into the same. In view of the short distance of. say, one and three-quarter miles, and the absence of engineering difficulties. I was astounded to find that an aerial tramway, with buckets, had not been adopted at a very much less cost than the present tramway. This would have meant a great saving in initial cost, and continuous handling, .for by pulling a lever the spawls would have fallen into hoppers by gravitation. It would be very interesting to know what the concrete is costing a yard in position. WESTERN END OF DAM Excavation was proceeding on a deep face by about 60 feet wide. Some 25 feet had then been cut into the hillside, the object in view being an exploration for a rock foundation. It is anticipated that up to a depth of 50 feet it may be found that the rock will follow the contour of the hill, and if no rock be encountered, a further 50 feet will be excavated. Should no rock be found in at 300 feet, it is probable that the concrete for the wing wall will be laid on the soil. If this is done, it will mean inevitable seepage. Two astounding features present themselves in this aspect of the woik. (1) No boring or tunnelling has been done to ascertain bow far it will be necessary to go into the hill for rock foundation. I claim, therefore, that the engineer cannot inform ratepayers what will be the ultimate cost of the dam. (2) Instead of putting a tunnel into the hill, and running a rise to the surface, so that the excavated soil could be placed into trucks by gravitation. tho soil is being sent to the bottom, shovelled into trucks: in some instances, when the depositing depot was full, emptied out. retilled later, and finally conveyed to the tip. The actual construction of the dam proper was started in 3 925, and the wire rope aerial, stretching ironi bank to bank, immediately over tho concrete work, was erected as late as the end of November last, having lain at the Huia landing for some six months. As there were several heavy lifts, viz., big beams, pipes, valves, etc., this rope should have been placed in its present position at the inception of the work, whereas derricks have been erected, dismantled, moved, and re-erected several times. A gantry, which cost approximately £6OO, has been erected in the centre of the dam bed, and is being buried as the wall of the dam rises. Already some 50 feet are out of sight. This gantry is to be used eventually to take the strain of the incline elevator track, when the latter has been extended to meet it. Why lengths of railway iron could not have been used, at a very small cost, is beyond me. The concrete elevator is primitive. The modern method, as noted in all large buildings, is to erect a perpendicular lift, from which the concrete is distributed by means of fluming in the desired directions. Time and expense would have been saved if this method had been adopted. Space will not permit the mentioning of many other points for criticism, but the foregoing will give some slight indication as to the reason for the cost forecast by me being likely to exceed the estimate by £150,000 to £-00,000 for this work. The council should provide a supervising engineer to check the manner in which this work is being done. I claim that to anyone possessing a reasonable amount of common sense, and a slight mechanical knowledge, it must have been apparent long ago that the construction is not being carried out in a reasonable ana economical manner. - I again submit that, in future, laige works should not be ea,qried out -.y the Citv Council engineering staff, but that they should be let by contract.

“FALSE ASSUMPTIONS"

CONTROVERSY DECLINED This letter was referred to the City Engineer. 11 M r. W. E. Bush and the City Council works chal ™ a ". t | l ' Dempsev, this morning. Mr. Hush deolined t'o be drawn into any ccintroversy commenced by Mr. H. P. Taylor, while Mr. Dempsey declined to go into details, but described the letter as a tHsuo of misstatements based on tallacious assumptions. Mr. Dempsey took as two examples the statement that metal was loaded by hand, which to contrary to fact, as there are hoppers capable of carrying *mme JQO vards of metal, and most of the trucks are loaded from these. The second was the statement that there should have been borings and tunnels on the site ot the dam. Mr. Dempsey pointed on?that borings and tunnels were sunk fn several places in the valley before ♦he site was chosen, and remains of them can still be seen where the new '^Further 1 "* out that Mr. Due who was brought to Auckland to U *'* waterworks, and who is preESnn ISTprofessicm pressed* Ids 'complete satisfaction with engineering methods, at all the works he n saw n6 and lb* new Huia dam was one oX them-