FERRO-CONCRETE WHARVES.

Auckland Star, Volume XXXIX, Issue 183, 1 August 1908, Page 9

FERRO-CONCRETE WHARVES.

MR H. BRADNEY'S STATEMENTS. ANOTHEIi DISCUSSION AT THE JiOAJRD. Mr H. Bradney renewed his campaign regarding ferro-conerete wharves, at the meeting of the Harbour Board in committee yesterday afternoon. A report was read from the Harbourmaster (Captain Duder) regarding a pile that had been fractured by a vessel, in which he stated it was desirable that the railway wharf should be strengthened by swinging piles on the eastern side. Mr Bradney said the buffer piles were recommended in the reports of Messrs Hay and Ferguson, and were in the specifications. He understood nine were driven, and then drawn. He -wanted to know why these piles "were not put in. The Chairman: "The only one who can answer that question is not here." Mr Bradney said the totara piles would have cost about £4000. Chairman: "Totara piles are no use as buffers; tQey are too brittle." Mr Bradney said that if they were specified in the contract, he supposed they were paid for by the Board. He wanted to know if any allowance was made to the Board because the piles were not put ill as specified. The Chairman said the idea of totara piles for buffers ras abandoned. Mr Bradney: "lias the account been adjusted?" Mr W. E. Hutchison: "You may be sure the engineer would not give the contractor that benefit." Mr Bradney: "Can you show £4000 allowance for the piles not being driven?" Chairman: ''That is hardly likely, seeing the whole contract for the first section was only £8000." (Laughter.) Mr Bradney: "I may be wrong in my figure, but was any allowance made?" As far as I can see there appears to have been a variation of the contract." Mr J. B. Macfarlane suggested that no good could be done by bringing the ■matter up now, and it would be fairer to wait until Mr Hannon returned from England. Mr Bradney said he was not there to i ask for anything in the way of an inquiry, because he was going to demand it. 'When he brought the matter before the Board, some members had not even the courage of their opinions like Mr Nnpier, but walked out of the rot>iu. Mr Napier said there was practically no justification for Mr Bradney's statements. Mr Bradney: "That will do." Mr Napier: "These matters were all adjusted 18 months ago. and Mr Bradney could have got all the information from the engineer's office and from Mr Brigham. It is always well to make sure of the facts of a case."

Mr Bradney: "I demand that this question is inquired into by a special committee of the Board." Mr Napier: "It is rude to demand, and supposing the Board does not grant it?"

Mr Bradnev: "Then you'll be sorry for it." Mr. Hutchison said that this work was done at schedule rates.

The chairman said the contract was taken over, and it was a good thing for the Board the totara piles were not put in as swing buffers. Mr, Hutchison said it was evident the engineer noticed that the ferro-concrete piles were not sufficiently strong in the first section constructed, for much header ones were subsequently specified.

Mr. Kneen: It was Mr. Moore who doubled the piles. He drew up the specifications.

Chairman: The piles now ere all double ones.

It was then resolved that no further action be taken regarding the piles damaged by a vessel a-t the railway wharf.

Later on the discusison was again renewed, when the question by Mr. Bradney of reconsidering the scheme of harbour improvements was dealt with. An exhaustive report ■was submitted by the Engineer (Mr Powell), which stated the first was the broken piles caused during the berthing of a vessel, or while she "was lying at or leaving the wharf. This had occurred at those sections of the wharf which had only single ferro-concrete piles at the outside, nob backed up by solid concrete panels, and would be still more likely to happen with timber piles. It was recognised that this construction was capable of improvement, and in more recent works means were taken to strengthen them by double piles, etc. The. single piles misst -be strengthened, and a design would be submitted for this work. Repairs to the broken piles had been commenced by the company, but the inspector rightiy regarded the matter as urgent, and gave verbal instructions, which were followed by an official order. As to the necessity for delaying traffic during repairs, this had only occurred once, in the case of the Inga mishap, when the whole of the concrete in one pile ■was shattered, thus removing all the support of the deck on the outer edge. The same suspension of traffic would have been necessary whatever the construction. The matter of the substitution of solid fixed fenders for sprig buffer piles was then referred to. The latter were specified in the first and second contracts, and same were driven, but the arrangement was abandoned on account of serious difficulties in the way, and a solidly-fixed totara fonder substituted — he supposed on verbal instruction, as he could not find any record of written instruction having been issued. Mr_R. F. Moore informed him that the cost of the work substituted equalled what the fender would have cost. Damage to concrete by rusting of steel was another thing. He had come to the conclusion that this was due to insufficient concrete surrounding the steel, and the use of ferrules for joining up the vertical bars when continuing a pile up to deck leveL On making an examination on July 20, in company -with Mr Bradney, he found that many spots had developed into cracks. In the Railway Wharf there were 133 places on piles and 117 on diagonal braces, directly due to the steel. Place 3 that were broken out, cleaned, and plastered up two months ago had again developed signs of rusting, in some cases to the extent of cracking the cement. There would undoubtedly be considerable expenditure to face in repairs. The stability of the -wharf, however, was in no way endangered. Invariably where rusting occurred the steel approached too near the surface. One inch of concrete was too little, but Urn was absolutely safe, which was tho figure given in tho Board's specifications. In future work there should not be less than 2in. Rust marks were also due to othor reasons— nails and ironstones. Aβ to repairs, it was not sufficient to merely break away the affected concrete, and re-plaster, and it was very undesirable to have too great a thickness of un-reinforced concrete on the outside of any part, particularly in the piles.

The harbourmaster also reported suggesting that spring piles be placed for 40O£fc on **c eastern aide of the wharf.

Mr. Bradney congratulated Mr. Powell upon his report, and said he had no intention to attack ferro-concrete. He considered that the wharves when being built should be most carefully inspected. Seeing the Board had made a mistake, why not admit it? Damage was done to vessels and the wharf at each gale. He thought it might be possible to put tees on the wharves and shelter the basin. The idea of berthing vessels across the tide was a mistake. He need not speak about the' ferro-concrete, for it had spoken " for itself. He questioned very much if ferro-concrete would stand for a long period. Mr Bradney said that on one occasion he went to the engineer's office and saw that buffer piles were specified, then he found the clerk of works had no specifications. He considered it wrong that enormous works should be carried out without the clerk of works having copies of the specifications. He wanted the whole matter referred to a special committee of inquiry. He moved, accordingly. Mr G. W. Basley seconded the motion pro forma, as the statements were so grave that the matter should be inquired into. Mr T. B. Macfarlane said it was questionable taste to bring this up while the Engineer was away. It would be most disgraceful- of the Board to alter the scheme while the Enginer was away. He moved as an amendment that this he adjourned Until Mr Hamer returned. Mr Keyes seconded the amendment. Mr Hutchison said he had examined the wharf shortly after Mr Bradney did. The deck and beams through the whole structure were perfectly sound. Mr Bradney: "Quite right." Mr Hutchison said he also found that all the piles that were cast and driven were perfectly sound, but in several instances where the piles were jointed there were signs of the effects of the rust, but full)' 90 per cent, were above high-water mark. He was satisfied that these dangers could be prevented in the future if greater care was taken. He was satisfied the rust was preventable. Mr Napier opposed the motion on the ground that it was irregular. Still he considered it would be well to have the supervision increased on the ferro-con-crete works. Mr Hutchison said the whole trouble was that they had not been particular enough at the joints. Mr Bradney said he believed that if Mr Kamer wished to shift Rangitoto, some of the members would try to finance the work. The 80-ton floating crane was another costly thing. All they wanted was a big crane on a punt that could be towed to where it was wanted, but Mr Hamer's suggestion was to have it on a boat with a whole staff of men. There were only about three others like it in the world. The amendment was then adopted, deferring the matter till. Mr Hamer's return. The Chairman intimated he would ask the Board on Tuesday to set up a special committee to inquire into some of the matters referred to in the reports.