WAIPORI POWER

Evening Star, Issue 21634, 1 February 1934, Page 5

WAIPORI POWER

REPLACEMENT OF PIPE LINES CONSTRUCTION OF TUNNEL TENDERS TO BE GALLED Important developments in con-, nection with Waipori power took place at last night’s meeting of the City Council, which adopted the recommendation of the Electric Power and Lighting Committee that authority be given to proceed with the construction of a tunnel between the main power station and surge tank at Waipori to replace the whole of the existing pipe lines. The estimated cost or the work is £58,000, and the recommendation of the Finance Committee that this be met out of the department’s renewal funds surpluses was adopted. A lengthy discussion took place on the subject, during the course of which the seriousness of the position with regard to further slips, in the pipe lines was emphasised. The council approved _of the recommendation to invite tenders for the work. COMMITTEE’S REPORT. The E.P. and L. Committee’s report stated;— Now that the negotiations with the Government respecting the Waitaki power agreement have been completed the question of proceeding with the construction of the proposed tunnel between the main power station and surge tank at Waipori, to replace the whde of the existing pipe lines, calls for early consideration. The proposal for the tunnel arose out of and followed as a natural sequence on the lengthy investigations which were made consequent upon the’ slips which occurred in the pipe lines in July, 1929. At that time a contract had been let for an additional pipe line to operate a fifth 3,000 k.w. unit. The subsidence on the hillside, however, called for a complete review of the position, and it was subsequently decided to cancel the contract for the pipes, delivery, however, being taken of the generator which has been erected and coupled, as a temporary measure, to the original No. 2 pipe line,, so that it may be used in cases of extreme emergency at peak load. Very exhaustive investigations were subsequently made as to the whole position, with a view to determining the best course to pursue in the matter of increasing the capacity of the main station, it being eventually determined that the pressure tunnel proposal possessed outstanding advantages, not only from the economical aspect, but from the point of view of eliminating weak links such as the pipe lines, and thereby most effectively ensuring the stability and safety of the works as a whole. This conclusion was arrived at after very complete tests of the hillside by boring and by geophysical survey, supplemented by expert engineer-; ing advice. Estimates for the tunnel were subsequently got out by the department’s consulting engineer, iVJr H. Vickerman, the figure for the total cost of the work being given as £58,000. Plans and specifications have also been to a great extent completed, and it would be possible, therefore, to proceed with the work with very little delay. For the further information of councillors a copy of a report by the city electrical engineer summarising the proposal generally is furnished. The report makes it, clear that the increased capacity at the main ' station is urgently called for, while at the same time the tunnel construction work, which is estimated to take tw T o years, cannot be completed until such time as the power from Waitaki is available to carry the load while the necessary changes-over are being made. The committee recommended that authority bo given to proceed with the construction of the tunnel at the estimated cost of £58,000, and that tenders be invited for the carrying out of the work under the supervision and control of the department’s consulting engineer, Mr H. Vickerman, and in accordance with plans and specifications to be prepared by Mr Vickerman. In terms of the standing orders the finan-, cial aspect had' been referred to the Finance Committee with a recommendation that the cost be provided out of the department’s renewal fund.

CR SHACKLOCK EXPLAINS , POSITION, Moving the adoption.of the committee’s report, Cr Shaddock said that it was proposed to cut another tunnel at VVaipori. Councillors were more or less familiar' with the ground. The water was brought down from the outlet of the present tunnel through four pipes which were in , close proximity; to each other—air running over the same type of country, /The first pipe line was probably decided on before the council took over from the old Waipori Company. • He ‘had‘-not heard anything further about' the ground until comparatively recently. Geologists tqld them 1 that the pipes were oh an ancient, slip which had occured-probably about 1,000 years ago. In the course of his experience, said Cr Shaddock, they had had two serious floods, the first of which'had endangered their existing pipe lines very considerably. The second flood had once more endangered the pipes, and both had occurred after prolonged rain and snowstorms, following each other very closely. The ground became very much soaked, and the slip being a very serious one, had given rise to some very serious thought. : As a result, proceeded Cr Shackiock, complete investigations had been made, and drainage work had been undertaken which should carry off the surface water, but all the same he was not satisfied the site was a good one for heavy pipes. “ There is no guarantee that another flood will not come-at. any time,” said Cr Shacklock. He pointed out .that the Government and the Taieri River Trust had spent a considerable amount of money in forming flood protection works on the Taieri Plains. These had not yet been tested, but one could never tell when the need might arise. In the same manner, another flood might

be expected at Waiporl, and it was now suggested that this risk from floods should be taken away. In the event of anything serious happening to the pipe line, it was quite possible that the whole power station might bo put out of action for an indefinite period. The risk was so great that the department could not ask the council to carry it any longei - than was necessary. Geophysical and other surveys of the country had been taken, and the department’s consulting engineer had gone over the ground, and he now recommended that the risks be done away with, the pipe lines be given up, and the whole of the water run through a tunnel pierced through solid rock. It was suggested that this tunnel be put through solid rock, and the risk would then be obviated. Plans and specifications had been prepared, and everything was in readiness for calling for tenders for the work. Cr Shacklock emphasised the very serious position that would arise if one of these pipe lines gave way altogether. To provide for the means to pay the £58,000 that it was estimated the work would cost, Cr Shacklock said that it was suggested that they should draw from the renewal funds surpluses, and furnish the wherewithal in this way. The renewal funds had been examined, and the city treasurer was quite satisfied that the funds : would stand the drain that would be put on them. SERIOUSNESS OF BREAKDOWN. Seconding the motion, Cr Shepherd said that during the last six months he had accompanied the city electrical engineer. on his tours of inspection of this particular .area, and as a layman he thought he was well acquainted with the nature of, the work. He agreed with the engineers that there was a very grave risk at present, and he also agreed with the report that it would be a very serious thing for Dunedin generally, and the industrial section in particular, if anything happened to cause a breakdown in the continuity of supply to their factories. Ho was very pleased to find that they were in a position to finance the undertaking without further increasing the city loans. They were fortunate indeed that sufficient funds had been accumulated to allow this to be done. “A BUSINESS PROPOSITION.” Cr Marlow said that there was another aspect to be considered. The department had put in a fifth machine, another pipe line had been ordered to carry water to this machine, but owing to the flood this work had not been put in hand, and the machine was lying idle. They must have another pipe line or a tunnel, and as a business proposition he thought the work would show excellent results. They would be able to generate slightly more than 4,000 kilowatts, and if they had an outlet for this 4,000 they would get an annual income of £26,000. He did not think any public body ‘ would hesitate to spend the amount suggested with a reasonable prospect of such a return. “ PANIC LEGISLATION.” Cr Scott said that it seemed to him that if there was to be any “panic legislation ” brought on, it should have been carried out two or three years ago iistead of rushing it on without proper consideration. The chairman had referred to the drainage work that had been carried out, and the speaker said he did not think, therefore, there was such need for “ this panic legislation.” The chairman had referred to solid rock, but he did-not know that they weregoin'g to get "solid rock. That was only surmise. He would like to know what quantity of the renewal funds would be . left , when this money was taken from them. Ho thought the chairman would be wise to take this clause back and let them have a- little further time to digest it. AN AMENDMENT. Cr Silverstone said that no doubt the department considered the tunnel a necessity, and to him it looked rather a “ cheap job.” It might be done for the money suggested—he hoped it would-—but he thought that was rather doubtful. On principle, however, he was against work of such a nature being carried out by private tender. He would move as an amendment that the portion of the reconstruction relating to the calling of tenders be deleted. He thought if the work was to be proceeded with it should be done by the council itself. The amendment was seconded by Cr Jones, who declared that.they had been carrying an unnecessary risk although they had been faced with the possibility of a slip for a. number of years. The council had taken no steps other than draining to protect what might be termed the “ life blood of the city.” He believed the City Council could do the work better than a private contractor. Cr Begg said that ho was at a loss to understand how the report had reached the council in its present form. Two members of the committee had expressed themselves against it. Ho was taken with the remarks of Cr Scott, who far the last twenty years had been a member of the E.P. and L. Committee, and he would like to know what steps Cr Scott had taken in the past to remedy the position. Cr Scott had agreed to the letting of the tender for the new pipe line, and when he found out that they were on dangerous ground ho also agreed to the cancelling of the contract. Cr Scott had referred to the matter as hasty legislation, but ho knew that the committee had had it under consideration for a number of years, and the speaker for one could not see how it could be designated in the manner Cr Scott had indicated. A. PUBLIC DUTY. “ I think the council would be failing in its public duty to protect one, of the greatest assets the city has if it does not carry through this work,” said Cr M'lndoe. He could not agree to the amendment. There must be difficulties in regard to the council undertaking the work. They would have to buy plant for the work which outside tenderers would probably have. In view of the gold boom there were probably plenty of companies with the necessary equipment for rock boring. He thought there was every reason to believe they could accept the estimate lor the work that had been placed before them by the consulting engineers. Cr Marlow said that until a little over three years ago there had been no reason to doubt the stability of this country, but he thought the flood had taught them otherwise, and investigations had been going on steadily ever since, and the report was the outcome. “ And now we are told it is panic legislation,” commented Cr Marlow. So far as the tenders were concerned, ho was satisfied they could get the work done more quickly and economically by calling for tenders. The Mayor said he was glad they were going to do the work, and he was glad they could spare the money from the renewal funds. Regarding the amendment, he thought there was a little difficulty. They , would have to employ consulting engineers to carry out the work by day labour, but there was a good deal in what Or M'lndoe said about the difficulties of undertaking it by day labour. Cr Jones: The dam was built by day labour. CHAIRMAN REPLIES. In reply, Cr Shacklock said that Cr Scott’s attitude that night had been

“most extraordinary.” He characterised it as “ panic legislation,” but they had been thinking about the matter for four years. Cr Marlow: It was before us at least twelve months while I was chairinan. Cr Shacklock; And before that. There is no “ panic legislation ” about that. Cr Scott: There is never anything else in the E.P. and L. department. Cr Shacklock said that Cr Scott knew very well that what he said about nothing being done over that term of years was absoluely wrong. The surface drainage had been done. It was really to take charge of the water that fell on the site. The water that did the damage fell further back in the country, and got under the ancient slip to which he had referred. The experts suggested that it was unsafe to load this ground any further. That was the risk. Was the council going to defy the experts and take that risk? Cr Shacklock explained that it was only the surpluses from the renewal funds that would be taken to make up this £sß,ooo—the main funds remained intact. Speaking with regard to Cr Silverstone’s remarks that the cost seemed to him to be low, Cr Shacklock said that when lie heard the price he thought it quite reasonable. If Cr Silverstone and his seconder had had experience in connection with work at Waipori he did not think they would make such ridiculous statements. Cr Jones: What about the Municipal Baths, where you can pick out concrete with your hands? Cr Shacklock said that Cr M'lndoe, in opposing day labour, reminded him that they had a lot of plant awaiting sale. He thought that was one argument against doing work by day labour. Both Crs Scott and Jones referred to the risk the council had been carrying for years, but it was their desire to got rid of that risk at the earliest possible moment. Cr Shacklock pointed out to Cr Begg that the report was in proper order. He also explained that the renewal funds had increased last year by £29,500, so by the time the job was completed the funds would be as high as they were to-day. The amendment was defeated on the voices, and the motion was then carried. Subsequently the following recommendation of the Finance Committee was considered That the cost of the proposed tunnel work, estimated at £58,000, be met out of the department’s renewal funds by the utilisation of credits in respect of pipe lines and obsolete sections of plant and surpluses on other items, particulars of which will be submitted to council as contributions are called for. It is necessary to add that these transfers, if approved, will absorb practically the whole of the present apparent surpluses in the renewal fund.” Cr Shacklock, in moving the Finance Committee’s report, said that any discussion on this matter would be superfluous, since the E.P. and L. report had been carried. The recommendation was accordingly adopted.