HARBOUR PROPOSALS.

Hauraki Plains Gazette, Volume XXXIV, Issue 4525, 9 February 1923, Page 1

HARBOUR PROPOSALS.

A MODIFIED SCHEME. SIXTY THOUSAND WANTED. A modified scheme for improve' ments to the Thames Harbour, drawn up by Mr E. F.’ Adams, CE., was considered a.t Wednesday night’s Thames Harbour Board meeting. 1 The chairman (Mr C. W. Harris) said he had requested Mr Adams to / draw up plans and place before the meeting what he considered the Board could do in harbour improvement work for the £60,000 mentioned at the previous meeting. ENGINEER’S REPORT. Mr E. F. Adams, C.E., submitted th? following report, and illustrated his proposals on a plan specially prepar- ■ ed fcr that purpose :— “Following your instructions of December 19 last, I have the honour to submit herein my recommendations in the particular works and plant necessary to give effect to the~harbour improvement you have decided to undertake. “A loan of £60>,000 will amply provide for the recommendations, will also provide for 12 months’ interest and sinking fund on the .loan, and in addition will allow of a large margin for contingencies. “In order .to keep the broader issues clear of detail liable to confuse them, descriptive matter is attached and reference given to it in the report. “The site of the works is that adopted by your Board after mature consideration, and on the recommendation of Mr J. Blair Mason, M.I.C.E. “Accompanying this report are two drawings illustrating, the recommendations, which are briefly as follows : “(1) To exclude silt and modify wave action by enclosing withirp rubble walls an area of 114’ acres, this' area being a. portion of the foreshore and a portion seaward of same. “(2) To provide for navigation to the extent of 6ft in depth at low water spring tides by furnishing the following facilities: (a) Channel of 150 ft of bottom width; (b) swinging basin; (c) berthage dredges 9ft deeper than the channel and swinging basin. “(3) To provide new wharf facilities clear of the present works with storage provision, etc. 1 “(4) To provide reclamation of 12 acres of land with a. frontage to the harbour. (5) Provision for a further reclamation of four acres adjoining the new wharf and berthage, to be constructed when required. (6) To provide improved navigation facilities ,to the Shorfland wharf by dredging out the shingle in the seaward channel for use in the main works. "(7) To provide a small working plant, consisting of: (a) A bucket dredger (ladder type), with a capacity of 90 cubic yards per hour; (b) an gin centrifugal suction cutter with a capacity of 45 cubic yards per horn” on a 10 per cent, solids basis; (c) three hopper punt®, each 80 cubic yards capacity; (d) a 40h.p. oil launch. “(8) Minor works, such as lights, dolphins, etc. “The harbour works will be carried out in and on harbour mud composed of slime and grit. These are of sueli consistency that a ship’s anchor does hot sink. The works bf your Board , have clearly demonstrated that there

'is 1 no risk whatever in the construction of sea walls, and that such walls may be economically and permanently . constructed if the lessons o f past ex--1 perience are taken into consideration. I “In the attached estimates I have • allowed fpr 46 per cent, of the whole ■ quantities as lost stone, although by past experience less than half this 1 allowance is necessary to give a permanent, foundation. In works of this sort a good margin is very desirable. “As the drawing shows, the walls bounding the eastern side of the enclosed area are carried to a height of five feet above spring tides. They are eight feet wide on top, with a core and base of general fill, and f t aced up with first-class rock. The reason for making these full-height walls is to have them full height for reclamation purposes, and also by so doing they give tramming facilities for their own construction and for the conveyance of material for the seaward works. “The northern, southern, and western walls are of first-class rock, 10ft wide on top, standing on a base, and having a foreshore of general fill and shingle. These walls range from a three quarter-tide wall to a half-tide wall. “As already mentioned, it is intended ,to use the Shortland shingle in the works. There is no material for this purpose so suitable or so cheap as that obtainable by bucket dredging from this source. “Apart altogether from the improvement that extensive dredging will make ip the Shortland approach channel, is is the most economical method of obtaining 20,000 to 25,000' cubic yards of the random shingle required, in those of the outer walls which are reasonably approachable seawards. Tihs method would not be so suitable for the inner walls,, to which tides allow of a very limited time afloat. ,

"A most, important requirement in tliose portions of the walls subject to the action of the sea is an abundant purpose the unaltered andesite 'of this locality is most suitable. Some three years ago I recommended your Board to secure a quarry at Una Hill, more •with the object of obtaining a footing locally than of incurring the great | expense of quarry development and connections in the initial stages of your works. This quarry is still available to you. It contains an unlimited supply of what might be term- > ed second-class rock, with evidence , in places of first-class rock. Before ■ entering into the question of develop- j ing your own quarry, especially in i view of the limited capital available ! for your works, I would strongly re- ' commend a mutual arrangement, between your Board and Thames Borough Council for the development of the Waiotahi quarry, where an enormous mass of first .class rock is exposed some hundreds of feet high on a steep hillside. The present is an opportune time to make a mutual arrangement under which; the quarry can be worked and a tramway laid down to deal with the large rock m your requirement and the spawls of the council’s requirements. ( “The dimension rock most suitable , for your exposed work is of two feet ( diameter or cube and upwards, ana ■ you would have little use in your , works generally for anything muc i ■ smaller one foot diameter ar | cube. The Waiotahi quarry site is so ! situated that the stone can be deliver- i ed from it in one tramming direct to the waterfront, avoiding the main business streets of the town. A short j

branch line to deliver to the borough rock breaker. “The-Council has not yet commenced operations, and if a mutual arrangement is made between the Board and the Council I would recommend, for transport in bulk the construction of a type of tram of which I have designed several. These have proved successful and economical in operation. To put all the exposed work in first-class rock would be a most desirable procedure. THE ENCLOSING WALLS. These walls entirely exclude from the enclosed area the silt brought down in rainstorms by the streams and livers discharging in the vicinity. They restrict the distributing action by waves over the foreshore so enclosed during the ebb and flow of ■the tide. They cut off the seaward transport of foreshore silt, which is at present conveyed during each ebb tide by the ordinary flow of the streams and the town drainage. These processes when allowed free scope are destructive to unprotected foreshore dredging, an" unprotected excavation oh the foreshore having no chance. The low groyne constructed by your Board at Burke Street wharf demonstrated that an interruption Oi free tidal and wave movement, although quite incomplete, postponed for three years or so the filling of the dredged berthage, which in the ordinary course of events would hot remain open for three months. The complete enclosure of the foreshore by the walls, which may be described as plus half-tide walls, provides a protecting water cushion to wave action. At the tidal period when the waves are free to pass over the seaward walls .the foreshore within the bas'n is entirely covered by the tide. ' “In calculating the quantities to be removed by dredging side slopes of 5 to 1 have been allowed for up .to a depth of two feet below low 'water spring tides. From this level upwards the banks will at low water be exposed to wash action from the shipping. • It is my intention to protec: these banks by a facing of shingle and mime mullock. The quantities and cost of such protection are included in the estimated cost of the works attached hereto. “The approach channel from seaward to the enclosed area will require no artificial protection. The banks here are entirely covered at the lowest tide. dredging of the port will be a negligible quantity. DREDGING PLANT. “For the dredging plant, consisting of bucket dredger, three hopper punts,, and launch, the sum of £9300 is allowed in the estimates. It is l recommended that the whole of the plant, with the exception, perhaps, ’of the launch, be new plant and speciall.v adapted for your work. “In the matter of the dredger in particular it is essential to have a small, compact, well-desighed plant, strongly built, and having the principal wearing parts of the bucket chain, etc., in manganese steel. The plant must have - plenty of reserve engine power. The work is rough, heavy work, and spare parts are necessary ) to save delays. The working draught need not be greater than three feet. ]

“A properly designed plant of this description is operated by two men, a winchman and an engineer. The six winches are power-driven, and give the winchman absolute control of every movement of the boat to get the best work out of the buckets. The

spoil is dumped over the top tumbler and delivers by chute astern or on either s’de as fflay be required. A more detailed specification of this plant is attached hereto. It is recommended that the first procedure be to invite tenders from manufacturers here and abroad for the supply of the plant. British and American manufacturers are now turning out a high-grade job at a cost well within your means. In the event, of a tender cutside the Dominion being accepted, the parts would be assembled and the pontoon built locally. “In recommending this, type and capacity plant I have taken into consideration the fact that your works will require to be completed within two years ; that on the completion of your works the plant would be a suitable one for general use either in harbour or river work. “Allowing the sum of £2090 per annum for interest and sinking fund, depreciation, and repairs, and taking into consideration all running costs, the cost of dredging, working for twelve hours a day, is 4d per cubic yard. “it is recommended to use the small suction cutter plant independently on the berthage and channel in the earliest stage of the operations. Thin type of plant is successfully manufactured by Thompson and Company, Castlemaine, Victoria, and also bv many British firms. This little plant would subsequently be used in a permanent site as 1 a transporter for the dredgings of the bucket plant. In this way the cost of diedging and disposal would not exceed an average of 9d per cubic yard, and the suction cutter plant would pay for itself within the dredging estimated cost, which has been placed at Is per cubic yard. RECLAMATION. “The drawings show the 12 acre; to be reclaimed with .the dredgings. As a matter of fact a greater area than 12 acres will be so reclaimed, as’ it is not suggested to wall up the northern end of the area. “It will be noticed that the new eastern wall north of the wharf approach road will take the futiction of the old sea wall originally 500 ft inshore of the new wall. As a mattei of fact the old sea wall has now no existence as such, and the dredgings will therefore make good that portion of your endowment which has' suffered by the action of the sea. “In the matter of reclamation and general fill for all purposes the materia! of the old mine dumps (mullock) is the nearest for, the purpose in the landward works. This material, however, behaves very badly in exposure to the weather or sea, and is therefore quite unsuitable for use unless properly protected. Whe’i suitably placed it is’ better than any other, and has the advantage of being most cheaply obtainable. I propose to make a very considerable use of it.

BERTHING AND STORAGE. “A considerable amount of work lias been given to the question of berthage. The present timber wharf will give landing facilities during the progress of the works —at least during their initial stage. It is inadvisable to make this wharf good to stand dredging 18 feet in dqpth below mud level. When the port warrants a wharf in reinforced concrete the site of the jpresent one is the most suitable position for a permanent structure. In the meantime the new works will not interfere in any way with the present facilities for the landing and storage of goods. The sum of £7o'oo is allocated in the estimates to the construction of a new wharf in hardwood and a new shed with tram connection allowing of all goods being handled on the hard at cart level. “Dolphine are provided for mooring purposes. These would be very seldom used owing to the particularly sheltered position of the berthage. “The guiding lights and beacons to mark the channel need be of a very inexpensive description, and have been liberally allowed for. “Special arrangements have been made in locating the eastern wall south of the wharf approach channel to" enable a solid reclamation to be made immediately adjoining the «iew wharf immediately business warrants such a procedure.

PRESENT AND FUTURE. The present, layout has been specially arranged so that, the facilities of the port are maintained intact. The works form the initial stage of a deep sea harbour. Should your, Board on the completion of the works embodied in the present layout find it convenient to proceed with better port facilities, these works will automatically embody themselves in those giving greater water depths and more extensive wharfage. WORKING MARGIN. “After allowing reasonable safety margins in the quantity and cost in place of materials,Mind providing for everything hi the layout, there still remains a sum in contingencies of £5500 in round numbers.

“There is a*ifurther margin in the actual cost of the works in that it is necessary to provide plant to carry out the works economically. Looking at t'he proposition from the point of view of a going concern your Board, on the completion of the works of this layout, will be in possession of £15,000 invested suitably for carrying on improvement works, or in any event saleable for probably half that sum.”

The- chairman said he wanted every member to be conversant with all the details, and to be convinced themselves before the proposals were placed before the ratepayers. The plant

proposed would be suitable for dredg- i ing the rivers if required. QUESTIONS. i In answer to a question, Mr Adams j said the depth of water could always be increased without interfering with the rubbie walls. He had not provided fci; dredging up to the Burke Street wharf, as if that were done the wharf would collapse. T.he dredging could be done when new piles were put down at. the wharf, but that was not included in his scheme. If they did not do something they would presently have no berthage at all. BUSINESS WANTED. Mr Bruce : Where are you goi ; ng to increase the business for all this berthage ? After spending the £6OOO they would only be able to get the Wakatere in a little bit earlier. The proposal would only be throwing the money into the tide. NO SILTING UP. Mr Cooper said he understood the bottom down the coast had not altered for 4>_> years. Mr Adams : That is so. In answer to Mr Donaldson, M.” Adams said there would be no greater possibility o,f the proposed channel filling up than if there was no cut made. Nor was there a possibility that, the bed of the Waihou would extend and block the channel up. In the 40 years referred to there had been a rise in the bottom at the entrance to the channel of 3ft. FACILITIES MAINTAINED. , In answer to Mr Miller, Mr Adams said the same facilities would be maintained, and they would have an improved port, as well as 12 acres of reclaimed land—a very valuable asset to the port. A very substantial portion of the big scheme would be carried out in his proposals. A DOUBTFUL, POINT. Mr R. Coulter said-one doubtful feature of the proposed works was the possibility of the tide affecting the cut, or channel. To him that seemed a doubtful point. Mr Adams said a similar cut was made at Stanley Bay, Auckland, and it had been a success. Wherever there was a water cushion the cut would be safe. There was no structural difference in the cut shown in his plans and that outlined by Mr 'Blair Mason in his report. The .proposed ciV was no less sounds Mr Coulter said that according to evidence given there appeared to he so little tide effect there that the wall seemed to be unnecessary. Mr Adams said he had been speaking of what the effect would be after the work he proposed was carried out. In answer to Mr Dauby, Mr Adams said his idea was to dredge shingle from the Shortland channel, which would thus be opened up for a considerable time.

The chairm&n said the work would be good value for the money, as apart from the reclaimed land they would have the plant .available for future work THE DEPTH. Mr Adams said boats drawing 18ft would be able to come in at high tide. The secretary, in answer to Mr Danby ,said the first overseas boat that went into Wanganui drew 17ft, and the Lindstol, which berthed at Kopu, drew 15ft 6in. Mr Danby said on those figures there was no reason why a boat could not. bring in produce for distribution in the valley. Mr Adams said the scheme could be completed in two years. INTEREST ON LOAN. Mr Donaldson said the Board had an assured income from which they could pay interest on £40,0'00. Mr Miller: What, is our annual income ? The secretary: £5OOO. Mr Miller : Then we should have to increase that by £2OOO. SUBSTANCE WANTED. Mr Coulter said the ratepayers would want something more definite regarding the development of trade. They would want something substantial, and so far that was not in sight. That, to him, was an important part that sholud not be overlooked. Mr Laughlin : If the trade did not increase it would place the Board in' a bad position financially. Mr Donaldson said that when the commission came round it. had given all that data. He contended that the people had had as reasonable data and facts placed before them as they would expect to get before a road or railway was constructed. It. was necessary to show x an optimistic s'pirit. If people would do nothing before concrete facts were placed before them nothing would ever have been done. The Hauraki Plains won 1:1 never have existed. Mr Miller : You ■ could not give a better example. Mr Donaldson said only £2OOO would be required to meet the interest, on

the loan, and he did not think they heed have any fear in placing that before the ratepayers. Even the fact that the Wakatere would be able ’.p come in at all tides would, he thought, give the required increase of trade. A QUERY. Mr Laughlin said that at Turua an 800 ton vessel could be brought in, while a boat drawing 16ft could go into Kopu. Why, he asked, did not more boats come through ; And if the proposed scheme was carried put, would the boats come to Thames ? The chairman said that if the £60,000 loan was raised Te Arolia would be asked to pay £35. Mr Coulter said the amount was small, but would Thames be interested if Te Aroha proposed to build a harbour there. ADOPTION ASKED FOR. The chairman said that if the members favoured the scheme he would ask them to adopt it now. He would move “That the loan poll to be taken, on April 26 next shall be for the amount of £60,000.’’ Mr, Coulter said the tracings and copies of the engineer’s report should be available for consideration, and that the matter should be considered at a further meeting before anything definite was done. They would be pledged to a scheme that they Had not had'' a reasonable opportunity of going into. Mr Hetherington said the engineer’s report, showing that they could get a reasonable scheme for £60,000, justified them in going to the ratepayers. The scheme could be slightly altered if found necessary. NOTHING NEW. The chairman said Mr Adams’ scheme was Blair Mason’s scheme in a modified forni. Mr Laughlin said the people should have time to consider the scheme. It was proposed to take the poll on the day of the elections, but it might be regarded^as the dying kick of the Board. Mr Coulter said the details coul.l very well be left to a later meeting. He did not want to be a member, of a board that considered a thing like this for a few hours and then tried to rush it through. Mr Donaldson said the proposed scheme had been under consideration for two years. The principle of Mr Adams’ proposals was exactly the same as Mr Blair Mason’s scheme. He thought the proposition was one that an enterprising man like Mr Coultei would adopt. The chairman said he would ask the Board to adopt the engineer’s report. Mr Miller suggested that the chairman’s motion could be put, and the scheme discussed at another meeting. The chairman said he proposed co stump the district and give the ratepayers full details of what, they were being asked to vote for, ANOTHER MOTION. Mr Coulter moved, “That the report and estimates lie on the table until the next monthly meeting, and that ’each member be provided with copies of the report, tracings, and estimates.’- “Why I” ho said, “we have not even considered the whole of the report.” Mr Laughlin seconded the motion, and said it was to the advantage of the scheme’to do as Mr Coulter suggested. The chairnian said it had been decided at the previous meeting to take a poll on April 26, and that would be done. EXPENDITURE • APPROVED. Mr Miller moved, “That the Board approves of the expenditure of £60,009 on harbour improvements on the lines laid down in Mr Adams’ report.’’ The chairman said they had decided to take a poll, and he would go on with the propaganda, as it would be necessary to put something before the ratepayers.

Mr Donaldson seconded Mr Miller’s motion, which was carried, Messis Coulter and Laughlin voting against it. THE POLL. • The chairman moved ‘’That the loan poll to be held on April 26 shall be for £60,000.” The motion was carried, Messrs Coulter and Laughlin again recording their votes against the proposal. • Mr Coulter’s motion was then put to the meeting and carried unanimously.