WAIKOKOPU HARBOR

Poverty Bay Herald, Volume LXI, Issue 18582, 17 December 1934, Page 5

WAIKOKOPU HARBOR

BREAKWATER EXTENSION ENGINEER'S SCHEME ESTIMATED AT £159,000 (Special to the Herald.) i WAIROA, this day. Recommendations for the development of the existing facilities at Waikokopu harbor have been received by the Wairoa Harbor, Board from Mr D. Holderness, M.1.C.E., consulting engineer, Auckland, whose services were sought by the board some months ago, as the outcome of a growing agitation fox the provision of better port facilities either at Waikokopu or Wairoa. Mr. Holderness, in his report, indicated that in his opinion the Wairoa River harbor could not be brought up to a satisfactory condition without an exorbitant expense, and he had no hesitation in advising! the board to con centrate on Waikokopu. .In respect to that harbor, ho recommended the extension of the existing breakwater for a distance of 900 ft., the extension partially enclosing a large area of water, of sulhcient depth and width to enable ships of the size of Horns liners to work inside the shelter of the breakwater; and the enlargement of the present wharf to increase the Scope of the port. JUSTIFICATION FOR EXPENDITURE In the' course of his report, which was a lengthy document covering many phases of the harbor problems oi Wairoa, Mr. Holderness stated: — , "Under the circumstances and except insofar as existing! disabilities at Wairoa and Waikokopu have encouraged shipment through Napier and Oisborne of goods which under more favorable circumstances, would have been handled locally, it is only to the development of the Wairoa Harbor Board's district and the increased exports and imports therefrom that one can look for justification for expenditure on harbor facilities at Waikokopu. "Many New Zealand ports to-day are feeling the' effect of road and railway competition which in a number of instances have so diminished the traffic of goods through the ports and the revenue therefrom, that loan moneys expended with confidence only a few years ago are already becoming a serious charge upon the ratepayers and threaten to become progressively worse. "Harbor works in any locality can only be justified 1 if after full consideration of all factors operating!, there is a reasonable prospect of their being able to save money or make money for the people who ultimately have to stand behind the loans raised for their prosecution. latter condition may be achieved when Ehe construction of a harbor opens up and renders' profitable land which for lack of,other means of access was formerly unable to be worked at a profit. OUTLETS FOR PRODUCE At the present time Wairoa has available as outlets for her produce and for the import .of goods:—(l) Transport by road south to Napier and north to Gisborne; (2) water communication suitable for lighters and shallow draft vessels only, via the Wairoa River: and, (31 water communication via the port of Waikokopu, connected by railway to the town of Wairoa. "In the case of item No. 3 the position is complicated by the fact that the Wairoa-Waikokopu branch railway has not ye.t been—nor does it appear likely to be—taken over by the Railway Board, and the successful operation of this service by a department of the Government whose' function fs. constructional only. "A further potential complication exists in respect of land transport competition in the partially constructed railway from Napier to Wairoa which the Government has expressed its willingness to dispose of for completion and operation by private enterprise. Should this railway be completed, ' its operators, whether Government or private individuals, must necessarily make a strong bid for as large a part of the trade of the district as possible. "Reverting to the justification for harbor works being the saving of money, this may either be direct, in the general reduction in transport costs, or indirect in the better condition in which produce may be brought to market or goods be delivered to the consumer. PRESENT HARBOR WORKS

"At present, apart from the trade conducted in the river, which is handicapped through the regrettable failure of the river training works and the consequent uncertainty, and draught limitations which must continue to bo a feature of this port, the bulk of the water-borne trade of the district is and must increasingly develop through the port of Waikokopu. Here the construction by the Public Works Department of a wharf with railway connections arid in about 18ft. of water at L.W.S.T., with a protecting breakwater already enables coastal vessels and lighters to take in and discharge their cargoes in reasonable safety. "It is natural that the Public Works Department in making provision for the purely temporary trade induced by its operations at Waikaremoana and on the railway and road construction works in the locality would not require to construct harbor works on a scale suitable for the operations of a Harbor Board, whose responsibility is to provide facilities for the permanent and growing trade of the district and even for the continued functioning of the port on its present basis it is desirable that considerable improvement should be made. LINES 0 4 F DEVELOPMENT "There are two general lines upon which development at Waikokopu may be proceeded with, viz.: (1) The provision of a deep-water port with berthage and other facilities for the accommodation of overseas vessels; (2) the consolidation and improvement of existing facilities to provide a convenient and safe coastal and lightering port. "In the latter case it is essential that capital expenditure should be restricted to absolute minimum necessary to provide for existing trade with reasonable capacity for extension as this develops and closer settlement of the land in-

creasas the traffic through the port. "As has-been pointed out by other harbor engineers when reporting upon the posffifeilities of harbor development at Waikokopu, the depth of water in ••the' bav and other natural advantages . make the construction of a deep-water port at this place a simple—if costlymatter, and even if at ithe present time , it is decided that only minor works can be justified, it is of the utmost importance that your board, as custodians of this waterway, should preserve it in such a form that it can be developed later should the necessity arise. -''Trie immediate justification for the construction of a deep-water port imi«t he determined mainly upon the Having to be effected by direct shipment if produce as compared with the enst of lightering and the better condition in which such produce would reach its final market as a consequence of the lesser handling involved.

ItEVKNUF, OF THE FORT "Figures supplied by the Wuiroa Meat Company estimate llio average :ost of lightering I'C! outward cargo through Waikokopu at £3733 per aunum. ' 'Tlii' provision of deep water berthago would in addition represent a material saving to shipping, in which it would l>c reasonable for the port authority to participate in the form of increased dues. Figures given of loading rates indicate that it should 1"' possible to save an average of approximately half a day per vessel, and' assuming 1:1 vessels per year at an average cos I of £3OO per day, which lis conservative, the saving on this account would be, say, £I.BOO per annum. Part of this saving should bo retained by the ship, and part would be availI able to the board in its standard ! berthage charge of 2d per ton not I register. "Assuming 12 vessels with an average of 7500 not register tons each occupying a berth, for one day only, the return from this source w.oulfl be i .£7.")(l per annum. "Berthage charges at present colileeted from lighters would' be lost, but I these would appear to amount to very J little. These two items, viz., £3733 ! saved from lighterage, and £750 col(lected for berthage, total £4483 per {annum. This represents the most | important amounts which would be available to meet the annual payments for interest and sinking fund on capital raised to construct a deep water port without increasing existing charges or levying additional rates. : "The extent to which increased production and consumption is likely to augment the above figures is a matter , upon which your own local knowledge is the best guide, but from general I appearances it would seem that; for some time a steady increase in both ' these directions is to be anticipated. II believe it would be reasonable to | base- consideration of justifiable •expenditure upon at least a 33 per cent. j increase, or, say, £6OOO per annum. ; DEEP-SEA POET "The additional expense involved jin maintaining and operating a deep ' water port would appreciably diminish the surplus available for meeting overi head' cliarges, and taking everything into consideration and assuming that ' money would be available at 4 per cent., I am of the opinion that such a port should only be proceeded with in the meantime provided the cost is not. ' likely to exceed by more than £IOO,OOO the cost of carrying-out necessary imj provements to enable the existing ! facilities i,o function satisfactorily as a coastal and lightering port." 1 With a view to reducing the capital cost of providing harbor facilities, various suggestions were placed before Mr*. Holderness for consideration, and after discussing them the engineer continues :

"From an engineering and standpoint it is unfortunate that so much capital was expended by the Public Works Department upon works which obviously have been limited in their conception to the accommodation of coastal shipping. In view of the department's limited requirements this was the natural course to pursue, but the inevitable result is that a deep water port constructed as aji extension of the existing works will not be the

best which otherwise could have been devised. Nevertheless, it is still possible to make good use of the works now in existence and in the accompanying plan i have shown what I consider the most suitable and economical manner of extending these works to provide a safe and satisfactory deep-water harbor to cope with the probable trade of the district for many years. SUGGESTED WORKS "The works shown on the plan comprise an extension of the existing breakwater for a distance oi 900lt. and the construction of a timber wharf bOOU. long by 31ft. wide equipped with two lines ol railway and two portable electric cranes.

"Tlie breakwater extension would have a top width of 20it. with seaward slope ol 'I to 1 down to L.W.S.T. and below this 1£ to 1. The inner or harbor slope would be IJ,- to 1 down toL.W.&T. and 1J to 1 from L.W.S.T. to the sea bed. For a thickness of 10ft. on the top and seaward side and ior Sit. on the harbor side, the breakwater would consist of concrete blocks tipped pellmell. The hearting of the breakwater would be of shell rock and boulders from the foreshore up to a level of 10ft. L.W.S.T. with a layer of larger rock Bft. thick on both slopes and l'llt. deep on top as indicated in the cross section. "The breakwater extension would be constructed for a distance of 160 ft., running N. 93 degrees E. from the end of the existing work which would require to be brought up to its full height and section. Thereafter it would sweep round on a curve of 400 ft. radius for a further 300 ft., thence running straight 440 ft. on a bearing N. 480 degrees K. to its end.

"The new wharf would be situated on a line bearing N. 430 degrees B. with a depth of water of 29ft. at L.W.S.T. Waikokopu would not be likely to become a lirst or last port of call and it is anticipated that this depth would be all that is likely to be required. Should it later be found necessary the berth and the approach can be deepened by dredging to 33ft. "The wharf would be served by two lines of railway with crossovers suitably placed for working trucks and would be equipped with two 3-ton electric level-lufling cargo cranes. Electric supply for both power and lighting, and water supply would be carried down the wharf. Even with the trade of the port increased to many times its existing volume, one deep-sea berth will be sufficient and the wharf would therefore be designed for berthing on the eastern side only and would have a width of 3.1 ft., but at the outer end and at intervals of 100 ft. along the western side it would bo widened out an additional 24ft. to stiffen it against the bumping of vessels. At a later date if a second deep-sea berth were required this could then be provided by filling in the spaces between the buttresses, thus making the wharf 55ft. wide, and laying two additional lines of railway. Spring fender piling would be required for the full length of the berth and in addition the wharf would require to be very strongly built with numerous raker piles well framed into the structure.

"The existing timber wharf would be retained for smaller shipping.

COST OF DEEP-WATER PORT "The estimated cost of the works described above is £158,900, and the layout is such that a practically unlimited extension of traffic through the port could thereafter be provided for with relatively small outlay of further capital. "For a considerable time the existing shed accommodation near the root

of the breakwater is likely to be stiifi ciont for requirements

"Analyses of the local .stone from the cliil's adjacent to the breakwater which were available to me togther with personal observation, indicate that this material is quite unsuitable for breakwater construction where il would be exposed to the onslaught of the sea and surface erosion. Where is has been broken down and left exposed on the foreshore it has been worn and eroded into smooth boulders and these could safely bo utilised as displacers in the construction of large concrete blocks. They can also bo used with safety in the central core of the breakwater extension, the (op of which is 10ft. below L.W.S.T. and protected from erosive influence, but on account, of their rounded shape they should be employed hero only when mixed with at least an equal quantity of shell rock. ''l inspected the quarry at Tahaenui. which is an excellent source of supply for shell rock and the appearance of this material after exposure* to the sea in the breakwater indicates that it is in way suitable for use in breakwater construction. However, the cost of quarrying so as to produce a sufficient quantity of the heavy blocks—up fo 20 ton's—which would be necessary on the seaward -side and top of the breakwater would be so great that it will be more economical to utilise concrete blocks for both the inner and outer slopes and the top of the breakwater.''

THE MOST PRESSING NEED After discussing other details of construction, Mr ' Jlolderness states that for working as a coastal shipping and lightering port the most pressing need is for an extension of the breakwater. While the layout of the wharf is not all that might be desired and lack of equipment retards the rate of working, these matters would be of relatively little moment provided shipping could lie quietly and without surge at the wharf. There is not likely 'to be any justification for the introduction of mechanical handling appliances or cranes or for any material expenditure on improving the lay-out of the wharf.

"If the major works are not to be proceeded with in the near future," proceeds Mr Holderness, "it is in the highest degree desirable that the breakwater should'be extended at least 300 ft. beyond the end of the existing work, and the latter be built up to its full height and section. The estimated cost of this work is £34,500. " Undoubtedly somewhat greater protection to the existing wharf would be available if the extension of the breakwater was carried in a more northerly direction, but I am -firmly of the opinion that you should adhere to the line proposed for the major work and do nothing to interfere with the future development of a deep water port. '"lt will be clear from the foregoing estimates of cost that in the present state of the district's development, the construction of a deep-water port cannot be economically justified.

"As stilted above, it is desirable that the existing breakwater should be built up to its full height and section and that it should be extended not less than 300 ft. seaward. Had the Public Works Department not; already constructed a wharf and built the breakwater, it might have been • desirable and more economical to 'have constructed a basin for lighters by dredging out part of the river flats and constructing breastworks, 'but this work would now be more costly and would

not have the same potential value for' further expansion at a later date as will the extension of the breakwater. ! "Your board has had a most unfortunate experience of harbor and river works and is now saddled with heavy interest and sinking fund commitments for which practically no tangible assets remain. Had the original plans for the river training work at Wairoa been carried out and suitable materials been used in their construction, the trade of

the district could have continued through the river port until its volume had increased sufficiently to justify development at Waikokopu, and your ratepayers would nut have been unnecessarily burdened. "The reinstatement of the river wqrks to-day iii found materials would probably cost, not less than the original contract price for the work, and in my opinion, the benefits therefrom would not now be commensurate with the outlay. Under the circumstances I would advise you to concentrate your efforts and resources upon Waikokopu, with I In; ultimate object of shipping your produce direct on to ocean-going vessels. OWNERSHIP (W PORT WORKS "I understand that certain negotiations are in tram regarding the transfer of the wharf and breakwater at Waikokopu from iho Public. Works Department to your board. "in framing this report and making my recommendations I have assumed the ultimate ownership and complete control of all harbor works at Waikokopu being vested in your board, and it is, of course, essential that this should be so. "It will be realised that the cost of any extensions carried out at the present time added to the price paid by the board for. the Public Works Le- \ partment property must in the meantime be met by increased charges or additional rating, but the urgent neces-. sity of preserving and improving export facilities for your produce provide justification for this il it can be assumed that a steady increase in production is likely to be experienced. ' "It is understood that the export of chilled beef from the district is contemplated, and it may well be that if this branch of the meat export industry develops satisfactorily, it may necessitate a review of the system of handling the trade at Waikokopu. ■ t "There is one very important matter to which I must refer before closing this report and one which has a most important bearing upon your board's affairs. I refer to the Wairoa-Waiko-, kopu branch railway and its method of i operation. Waikokopu is essentially • what may be termed a "railway" port' and is dependent upon continuity of, service and stabilised freight rates. ' The railway is to-day owned and oper- j atcd by a department whose function is essentially constructional, and it would not be prudent to enter into any agreement iov the purchase of harbor works or to entertain any further commitments for improvements unless \ and, until a clear and definite understanding i as to the basis of future operation and ;

a guarantee of continuity has been obtained."