OPUNAKE HARBOUR.

Hawera Star, Volume XLV, 18 December 1925, Page 8

OPUNAKE HARBOUR.

THE SCHEME REVIEWED. COST OF COMPJjEiI J ON. ENGINEER’S REPORT. At a special meeting of tlie Opunake Harbour Board hold yesterday yTliursday), there was presented the report of the consulting engineers (Messrs. Vickeinuau and Lancaster, Wellington), dealing with the progress of the harbour work and the estimated cost of the completion of the scheme authorised. The members present were Messrs T. P. Hughson (chairman), C. Ti. Hurst, 0. A. Trotter, H. Young J. A. Pettigrew, H. A. Moore and Y. H. Hi Sinclair. Tlie general opinion of the board concerning the report was expressed by the chairman, who intimated that it contained reliable advice, which, considered together with the result of the board’s recent experience, would warrant the continuance of the work to the extent permitted 'by the available finance. He thought that even among those who, in the light of recent controversy viewed the .scheme with a certain amount of disfavour, no objection would 'be raised if the harbour could, within a reasonable expenditure, be made to give a satisfactory service to the district. Though the completion of the work to the full extent of the original project might not be possible within the ibounds of the original estimate, it appealed that the loan would be sufficient ito allow the harbour, by the construction of the mole to 650 feet for the time being, to be utilised for shipping and thus make it of real benefit.

Referring to the report, tiie chairman said that the estimate given entailed expenditure which was considerably less ami .more reasonable than the amount the late engineer had Jed the board to believe would be incurred. The consulting engineers’ estimate, However, might be regarded as an outside figure. Whereas they had 'based the cost of the stone at per ton, the works committee, as the result of the improved method now being employed in handling the boulder .stone, had found it was being placed in the mole at As 2d a ton. This improved method —that of utilising an air compression for drilling and thus allowing 'steel spikes to be inserted in the boulders, \\diich could then be handled more readily—had not been in operation when the consulting engineers had inspected the work. Had they heen apprised of it their estimate would probably have 'been reduced. Allowing 3s a ton instead of 2s 2d, a saving of £3600 would 'be made on the engineers’ estimate for the 36,000 tons of stone required to complete the mole to tlie hoc leer length, and this might be expected to be reduced stall further if a compressor capable of operating three drills instead of one, as at present was made use of. Summing up the position, he said that there appeared t.o be every prospect of the breakwater being built to the 650 feet length with the funds which were available to the board for the work and of extending it to the 900 feet originally .provided for within a reasonable amount of the cost as at first estimated.

The text of the report, which was dated November 24, is as follows: PLANT AND WORK DONE. “The bulk of the plant was obtained from Westport and was previously used on the Westport Harbour Works, ft is, we consider, suitable for your purpose, is in. reasonably good order, and was acquired at a reasonable price. The work done to date includes the construction of the .approach road to the workshops; the erection and equipment of stores and workshop; the purchase and installation of .plant and service tramways; the erection of the breakwater staging to 650 feet; the completion of the breakwater to 200 feet and its partial completion of the greater part of the excavation necessary co give road access to and space for stores behind the wharf; the purchase of wharf timber and manufacture oi some concrete piles.

“The works done are very suitably laid out for carrying on the harbour scheme and have been efficiently constructed, but experience has stressed the following difficulties, viz: the .store available is not so plentiful as was at first thought; the tides only allow a very short period for gathering stone, calling for quick means of handling and effective organisation ; the original estimates of post are being exceeded; the construction' of the wharf cannot be undertaken till the mole has advanced considerably further. STONE AVAILABLE.

‘•We find (tliat about 10,000 tons d stone lias been placed, •that a further ,10.000 tons will!‘probably be required to complete tlie mole to 650 feet, and V.at. m additional 68,000 tons will be need -id to finish from there to 900 feet. “From a close inspection or the beach, we consider the quantity needed to complete the 650 feet can* be obtained from along the foreshore between the Opunake bay and Middleton bay, leaving the remainder of the board s area between the Otahi. and Waiau [livens to provide for completing the 300 feet at present authorised. Your board is already alive to the fact that the removal of stone from along the foreshore will result in some denudation of the cliff®. This will m itself furnish further bo hide ns for then uibsequeiiit protection, but we -would itlivise that, in addition, a- width or at Vast- HO feet of .stone at one foot of the uliff be left untouched. Ais tliusi denudation will also provide a considerable quantity of sand winch will settle in -he ha vs We recommend that the done should first be worked from the chore end towards the breakwater on he Opunake side and that there should be the minimum, of interference possible with the present conditions at the em of the point to the westward of the breakwater.

KFFECTIVKNESS OF MOT/F,. “It thus becomes'a question or whether the single mole will be of real service, of what its length should be, aud of what, wi’l be the cost of its completion. . . , , “We have, therefore, investigated the result likelv to be obtained from single moles of different lengths, basing cur calculations on information supplied from your office re the wave heights common'y experienced in the bay at the point off the end of the breakwater, and on the available weather statistics, which indicate that winds from a general westerly or north-west-erlv direction prevail for about 60 per cent, of the year, those more or i'ess off shore for about 15 per cent., and those from a southerly direction for about 25 per cent, of the time.

The relative results obtainable makin <r the above assumptions would be tabulated as follows: —

Proportion of year Conditions under which condiat wharf. tions wou'd hold.

Boats could work with . ease with a range up to lft3m, * J could carry on up tc 2tt, » ut Q 1 that range shipping would have to St ° P ' PROBABLE COST. The probable cost of completing is estimated as follows: To 6ooft. with wharf ... |g),000 To 900 ft. with wharf ... £bo,ooo “A wharf design has been approve bv the Marine Department havin a approach viaduct 320 feet long with a tee wharf at the end lying at an anole td it and 150 feet long, and nrovfdiug about 10ft. of water at T WS T If work on the mo] e is stopped at the 650 ft. mark without any turn in it. the approach should m called oV straight for 350 ft and its end should he made suitable tor handlmg caroo. the tee being omitted ti'l the breakwater advances, with the object of keeping; vessels end on to the sea. Spring piles should also be provided to protect vessels at the- wharf when the seas arc rough and substantial moorings should also be provided. CONTRACT SYSTEM. RECOMMENDED. “With the wider he'd to be covered in future in gathering stone, we consider that economy will result it further work is done by contract, and we accordingly recommend that this system should he adopted and tenders called for completing the nw'e and constructing the wharf. The figures of cost thus obtained will also be of service to you in your task of reviewing the Whole situation. “AVe would add that we have not /ouched on the commercial aspect of the venture, because your board, has already dealt comprehensively with this and is satisfied as to the amount of business and the financial results likely to follow the provision of shipping facilities.” TENDERS FOR. THE WORK.

With reference to the extension to the 15th inst. of the closing date for tenders for the completion of the mole to 650 feet, and the construction of the wharf, the chairman explained that on the original closing date (December 10) tlie consulting engineer had telegraphed advising that if the date was extended a tender would he forwarded by a firm which had not previously seen the advertisement. As up to that time only on e tender had been received, the chairman had decided to al ow the extension, and the meeting to tlea] with tenders and also to present the engineer’s report on the scheme in open meeting had been adjourned accordingly. On the motion of Mr Trotter, the action of the chairman was endorsed, Mr Moore being the only dissentient. Before the tenders were considered, Mr Moore emphasised the opinion .that with a mole of only 650 feet in length the wharf would not be afforded adequate protection. He moved that the tenders remain unopened, and that fresh tenders be invited, giving an alternative for the completion of the mole to 900 feet. The motion was not seconded Only** two tenders were received, liese were dealt with in committee, ■and on the hoard resuming in open meeting it was announced that the tenders would he held in abeyance pending further consideration in oonreienee with the consulting engineers. ho would then he given an opportumt> of investigating the results of the fo“?he o Sfote t,onß in the stone

650ft. 900ft. Range breakwater. breakwater 'jit i.o 1ft 3in 85% 48% 6ft to 2ft Oin 65% 75% Above 2ft Oin 35% 25% Maximum range 6ft Oin 4ft 6in