NAPIER HARBOUR

Hawke's Bay Tribune, Volume XVII, Issue 213, 23 August 1927, Page 8

NAPIER HARBOUR

COMMISSION’S ENQUIRIES further evidence heard. COMMENTS ON REPORTS. Continuing his evidence yesterday afternoon, Mr. R. W. Holmes, consulting engineer to the Napier Harbour Board, read the reply of Mr. Cullen's to the chairman ot the Napier Harbour Board as to his experience of harbour channels. Mr. Cullen said that such a channel as that proposed lor the Inner Harbour would not be considered to be of any exceptional magnitude, and they would not have any hesitation in making such a cutting, as they had carried out cuttings on the Queensland coast over fifteen miles in length. , Mr. Holmes said in connection with the remarks made by Mr. Cullen, that the channels on the sea coast north of Brisbane were through bars and would be.more or less at right angles to the littoral drift, which must be fairly considerable owing to the trade winds and the seas flowing and breaking at an angle to the trough. At Napier the channel at the immediate foreshore would be only about 300 feet in length, while the outer channel would not, as had already been stated, be of the same character as an ordinary bar- It was not to be supposed that no silting would occur, as it was to be expected that the sides of the dredged channel would fritter down. The removal of such material from the channel as it accumulated would come under two headings, one being purely maintainance and the other construction. Every yard of spoil removed would:-- effect a permanent improvement to the channel, both in width and depth. As the year went by the channel would become stable and a great improvement upon the original effort. The point where constructional dredging would cease would be where navigators considered that they had a sufficiently wide and d ;eep channel. The flatter the slopes of the channel the less risk to navigation. because if a vessel were to ground on the steep side of the channel the risk of the vessel capsizing when the tide went out would become very groat, whereas on very easy sloping sides no such risk would exist. ADMISSION OF EVIDENCE. Mr. Holmes referred to the admission of evidence, as some exception was taken during the morning regarding remarks that he wished to make regarding Brisbane. His friends 01 the legal fraternity practically based the whole of thqir court practice upon previous decisions and precedent after precedent was quoted. Engineers in their works followed the same practice, being guided by text books. The chairman explained the law also had a text book and precedents, and a large written code as well. The practice among solicitors was similar to that stated by Mr. Holmes to exist among enginoci... if Mr. Cullen had written a text book on engineering it could he quoted, but a cable from him could not be allowed'. Similarly Mr. Lusk would not be allowed the Lord Chief Justice’s cabled opinion on a point of law, though he could quote his book opinion. Mr. Holmes: 1. have been eWairman of several Royal Commissions and we used to accept every particle of evidence. We often got on better when there weren't any solicitors appearing. Mr. Lusk: 1 would have liked to see your evidence. Mr. Holmes: Information, not evidence ,that’o what we wanted. Regarding Cullen ct Keele s reports Mr. Holmes said that they recommended the increase of the width between the moles to 500 f- It was anticipated that there would be no necessity to extend the moles any further than ,a short distance than the present contract now being carried out covered. They recominanded the dredging 'of a passage between the moles to a width of 300 ft and a depth of 31ft at iow water spring tides. With the moles 500 ft apart it might be quite possible to obtain a channel up to nearly 400 ft in width as the moles and the quay nearly up to the Iron i’ot would be faced witn rock which would stand at a slope of between 1J to 1 and 11 to 1; so that with a height of 4Vft from

the top of the mole down to the bottom of the channel only 60ft would be encroached upon on either side, leaving 380 ft between the toes. The width of basin recommended, I,oooft, was merely a first proposal to be extended to meet shipping requirement as they developeu. They then referred to dredging outside the training wail to facilitate the passage ot tidal water to and fro from the la. goon. Witness had allowed for a considerable quantity of material being removed in order to facilitate the flow of the tide into and out of the lagoon, it being desired to obtain an increase in the height of the high water mark by two inches, having the effect of increasing the volume of water for scouring purposes by twenty per cent. They then drew attention to the advisability of diverting the Tutaekuri river, which witness considered was a desirable work. THE OUTER HARBOUR. Coming to the outer harbour Cullen & Keele remarked that the Breakwater was the lowest that they had any knowledge of. Witness ' drew attention to their having recommended an increase in the height by 10ft above high water, but they did not include in their estimate any item setting out the cost of their recommendation. They then stated that the large concrete blocks on the seaward slope of the Breakwater were not sufficient to break up the heavy seas. Cullen & Keele further remarked that improvement works should admit of future enlargement of the harbour. Since their 1912 plan was submitted they had agreed to a proposal to reduce the size of the outer harbour which was not, said Mr. Holmes, in agreement with their opinion of 1912 They had said that the Breakwater should be extended to the Auckland Rock and the entrance placed to the westward. This, to an engineer, was quite obvious, as the Auckland Rock could not be left to the leeward. The proposed extension would pass over this rock to make it part of the structure. If that was ever done it would he necessary to deposit pell-melb blocks over all that part of the ’

seaward side of the rock which might extend above the sea bed and outside the Breakwater because the patching of a breakwater on the top of a rock or reef was bad practice and likely to lead to the destruction of the Breakwater during a heavy storm as had happened in many other harbours. The recognised practice was to place a breakwater along the lee side of a reef notwithstanding the fact that it might entail much heavier work. Cullen & Keele then referred to the clearance required by vessels while being navigated, stating that six feet clearance was sufficient in heavy seas experienced iu Moreton Bay. Mr. Holmes pointed out that neither the Breakwater nor the Inner Harbour would be worked when the seas were so heavy as to require as much clearance beneath their keels. Cullen A Keele appeared to be the first of those reporting on the harbour question who had realised and drawn attention to the complete destruction of shingle along the foreshore up to the Breakwater. They stated that the shingle was ground into mud and carried into deep water by the undertow. On Saturday and Sunday a stream of mud passing in a north-westerly direction from the Breakwater was quite noticeable, the tide being on the ebb at the time. Mr. McKenzie: The day we were on the flagstaff hill a discoloured stream was noticed to be deflecting out to sea towards a buoy some two or three miles out. That wa/ not quite as you saw it?—No. ~ EXCEPTIONALLY HIGH. Continuing, Mr, Holme's said that the tide on Saturday was exceptionally high and the effect of the mud in suspension was very marked. The remaining material, consisting of silt, followed a somewhat sinuous path ultimately reaching the lee of the Breakwater; as already indicated. Mr. Holmes, proceeding, said that Cullen and Keele had stated that they considered the Inner Harbour works less liable to delay, practically consisting of wharfing and dredging, 'his aspect of the question was one requiring very serious consideration, as works being constructed in the open sea were subject to long delays through bad weather and also by loss of material and concrete iu a green state formed part of them. The Breakwater now reached a considerable length and its continuation in the present style of construction entailed the tedious process of running the crane out to the end before work each day and returning it at the end. As an indication of the delays which occurred in connection with work carried out where wave action took place, Mr. Holmes mentioned the Beacon Tower on Karor' rock in Cook Strait which took two years to build, the average amount of concrete placed each day amount ing to one yard. While constructing a beacon on Canoe Hock, Auckland, three months were wasted and nothing was done. Mr. Chairman : How far is Karori rock from the shore?—About threequarters of a mile. The Canoe rock is off Kawau Island in comparatively sheltered water. Continuing. Mr Holmes said that he referred to these instances in order to draw attention to the largo increase in overhead expenses and loss of time of employees and loss oi interest on capital, it was quit" impossible to gauge the cost of such works jiy the cost of works carried out on shore. The next item was a statement to the effect that the Breakwater was smaller than the Inner Harbour, more limited in area, took longer to execute and was more liable to damage by storm. Cullen and Keele in 1925 furnished a further report accompanied by estimates alleged to be up to date. They stated that the area of the Inner Harbou'' was not now lim.-fed to what was proposed in 1912. this remark being made presumably through the con. struction of the railway jinx? and naw bridge. They also remarked that the interesting theory regarding sand drift must be given up, and in this witness said he concurred. Cullen and Keele then stated that the objection raised against the entrance to the Inner Harbour channel was not warranted, to which witness also expressed his approval. Notwithstanding their opinion as set out m their report they ultimately recommended the Breakwater Harbour, giving as their principal reason its lesser cost.

ESTIMATES FOR EACH HARBOUR. Mr. Holmes then drew attention to Cullen and Keele’s estimates of the cost of each harbour. In their list of items of plant they included £65.000 for a sea-going bar dredger. The board had now the opportunity of purchasing the Kaione for £35,000. Allowing for overhauling her. anil sundry costs of conveyance to Napier and overhaul and slipping before leaving from Wellington, the cost would he about £40,000. The two grab dredges costing £12.000 would not be required as the J.D.O. might be made capable of doing that portion of the work. The basin dredger would not be required as the Kaione would do all the dredging necessary. The total for these items of £142.000 was reduced to about £70,000. The item given lor the construction of a quay 2600 feet in length hact to be reduced to £114.000 as a comparison was now being made for additions for accommodation for two ocean liners in the Breakwater and the same number at the Inner Harbour

To the chairman. Mr. Holmes explained that the only way m which comparisons might be made was by providing equal accommodation at each harbour.

Mr. Barton said that the proposal for two berths at the Inner Harbour tor overseas vessels did not coincide with Cullen and Keele’s modified scheme or with the board’s policy. All through a difficulty had been presented in attempting to compare two things which were not compare. able.

.Mr. Holmes: The Glasgow Wharf Is not strong enough. I condemned it before it was built.

Mr. Lusk: You approved of it. Mr. Holmes: 1 never approved of it. I only gave a certificate as required bv the Harbours Act to the effect that it did not interfere with navigation.

Mr. Barton pointed out that the Marine Department asked the Commission to give a finding on the harbour proposed in the board's policy, and, so far, all the evidence for the Inner Harbour had not conformed with the policy of the board a s pronounced by Mr. Jull The Commission, in adjudging the evidence on the Inner Harbour side' so far, had been up against the comparison of two things that would not compare It had enormously increased the difficulties. He understood from Mr. .lull that the board's scheme was to provide berths lor four overseas vessels according to Cullen and Keele's modified scheme. Now they

were told nothing about that scheme, and the only figures they had before them dealt with a scheme for two ocean-going ships. Mr. Gray said that the position had arisen in the attempt to make comparisons. The Glasgow Whari was not being taken in consideration for overseas vessels as it would be required for coastal shipping. He said that the necessary estimates could be easily prepared and supplied.

Mr, Holmes said that in determining which of two or more schemes should be carried out it was necessary that they should be al] put on a common basis. Continuing. Mr. Holmes said that the cost of the Tuner Harbour would be reduced to £386,000. Four berths could be provided for an additional cost of £114.000. making a total of £500.000. item of £lO.OOO for additional dredging would be recouped in the land that would be reclaimed

The second trial of Robert Grant Bastion, aged 20. Harry Allen FellIngham. 22, and Walter James Alexander Mitchell, 29. charged with using an instrument for an illegal purpose, was concluded in Christchurch yesterday. There were two charges against Mitchell, and one each against Bastion and Fellingham At the first trial on Wednesday last the jury disagreed. Mitchell was found' guilty on both charges, and Bastion and Fellingham not guilty. Mitchell was remanded for sentence