THE HARBOR SCHEME.

Gisborne Times, Volume XXVI, Issue 2109, 7 February 1908, Page 1

THE HARBOR SCHEME.

A HUGE UNDERTAKING

BRITISH ENGINEERS’ REPORT.

The following report, has boon received hv the Harbor Hoard Irom Messrs Goode, Son, and Matthews, the English linn of engineers, who, through Mr. Wilson, a member ol the firm, were retained to report on the outer harbor proposals:— Sir.—When Mr. Wilson was in Auckland early in March this year, ho received from you a telegram asking whether lie was prepared to visit Gisborne for the purpose of reporting upon a scheme tor harbor improvement, which had been prepared bv Mr F. IV. Mnrehnnt, M. Inst. O.E. ‘Following this telegram, Mr. Wilson received a letter from you confirming the same, and stating that the Gisborne Harbor Board bad instructed you to ask him if ho “would be prepared to undertake the inspection of the site and report upon the feasibility of the _ proposed scheme, as to cost, reliability of estimates, and future probable success,, ; your letter further states that it 'would not be necessary for him to make any fresh survoys or soundings. ■ 2. As a result of the above and further correspondence, it was arranged that Air- Wilson should visit Gisborne, and he arrived there on March 6tli. \ careful examination of the eito of tho subsequently made, togothor with a genoral enquiry into the local conclitions of wind, sea, and weather as affecting . tho works. In this connection‘much useful information was received irom Mr. Darton, who had assisted Mr. Marchant in carrying out his survey, taking soundings, etc. Accompanied by Mr. Gibbons, Borough Engineer, an inspection .was made of lie quarry Waihiroro, whovo Mr. Merchant proposes “to obtain tho stone for tho breakwater, and subsequently Mr. Wilson had. the pleasure of meeting Mr. Sievwright, the deputy chairman, and the members of the Gisborne Harbor Board. 3. At this meeting tho general scope of tho enquiry was discussed, mid iT was decided that tho report should he limited to the consideration of Mr. Marehant’s scheme, and any modifications tlierof which might suggest, themselves, tho capabilities of further expansion in tho matter of quay space being specially kept in view. Mr. AA ilsou also bad interviews with Captain Cumming, Harbormaster, and Mr. McLeod, the Harbor Board Inspector, from whom ho received useful information with regard to local conditions as affecting the design and carrying out of tho works. Mr. Wilson subsequently returned to Auckland, where he had the advantage of meeting Mr. Marchant, and fully discussing with him the question in all its bearings 4. Wo wrote you on 22nd May last, and again on 24th September, explaining tho reasons which had caused us somo delay after Mr. Wilson's return from England in taking up the matter. Mo trust this slight delay, which was quite unavoidable, will have caused the Board no inconvenience. We have now, however. been able to took very carefully into the whole matter, and beg" to present the following rel>°s. The port of Gisborne lies at tlm bead of Poverty Bay, on the east coast of the North Island, on tho west bank of the Turanganui river. It is the capital and trade centre of tho Poverty Bay district, and is rapidly increasing in sizo and importance as tho surrounding country is opened up and becomes productive. The trade of the port is at present carried on in the inner harbor, which has been formed at the mouth of the Turanganui river, the latter having been considerably improved by dredging during recent years At present there is a channel having 7ft depth at low water spring tides leading to tho harbor, where there as about 2000 ft of wharfage accommodation of equal depth. Only small coasting craft can, however, uso this river ,whilst the larger class of vessels lie at anchor in the bay, and load or discharge into lighters alongside, the latter being towed into port by steam tugs. This system is liable to interruption during bad weather, although, it is seldom that communication is impossible, the cost and further, the risk of damage, to cargo caused by additional handling and exposure are very considerable. 6. Great advances have, in recent years been made in the size of vessels visiting New Zealand, more especially since the development of the export trade in frozen meat, and it is cloar that to cope with present requirements more extensive .accommodation and deoper water are required. ' OUTER HARBOR. 7. The only means of avoiding the transhipment of goods, between ships and lightors while lying at anchor in the open roadstead is by the provision of a deep water harbor in a suiable position in tho bay. Various designs for an outer harbor have ben put forward at different times, and although it is generally agreed that such a harbor is imperatively necessary the position and design remain unsettled. The question of site for the proposed harbor is exceedingly important, and requires most careful consideration. SEA AND EXPOSURE. 8. Poverty Bay is well sheltered, except from the south-east, but heavy gales and seas are experienced from this direction in tho winter time, and it is therefore from this quarter that protection is required. Very strong winds aro also experienced from the west am! north-west. These being off shore, do not raise much sea, but it is dcsireablc that any wharf or jetty accommodation should bo so arranged that vessels may lie as far as possible in the direction of these winds. SAND TRAVEL.

9. In the case of harbors projecting from a coast line, the question of sand travel and possible .accumulation resulting therefrom within the sheltered areas is one of great importance. Sir John Coode, basing his opinions on the best information at the time available, stated ill bis report of December, 1880, roleiied to in hereafter, that “he was unable to recommend any solid structure between the shore and the line of threo fathoms at low water, inasmuch as ho anticipated that a serious amount of sanding up on the inner or westorn side would inevitably follow. Since that date this matter has received much attention, and has boon the subject of several eloso investigations, to the results of some of which wc may refer. Mr. O. X. O’Gonnor, in his report, dated December, 1890, says:—“Tho evidence which I obtained, and the observations and measurements of currents, etc., which I made myseli, all go to show that the prepoiulering force ol Hie is distinctly Irom the soutliA " , This would point to a* tendency to sand travel Horn thf south-east, which, m faet, s the ease.” Mr. Napier Bell, who imported several times upon the Gisborne harbor, -dealt very fully w Hi the question of sand travel m M report, dated November loth, 1832, and came “to the conclusion that tu- sand of Hus beach all round Poverty I} ay shows no signs of permanent travel ’h dn'ec' ion In tho same report, novel Cl j he stances tho travel to tho from the mouth of the inei pieces of slag, which came under blown observation, and concludes that “whore slag travelled mtlnsMi U, sand of the beach travelled with it--10 Tho foreshoro to tho eastward of the river consists almost entnely

of bare rock, with the exception of a narrow strin ol sand between the harbor and Pali Hill, reaching from above high water mark down to übi out the level of tliree-quaiters tide. From a comparison of old plans, and from inquiries made upon ilte spot, it does not appear that there -lias been any appreciable change in tins foreshore for many years, thus clearly showing that there cm have been no material travel of sand or beach from the westward past the river mouth, and bearing out (in' opinions of Messrs O'Gonor and Napier ill'll above quoted. SIR JOHN COODE’S PROPOSAL. 11. As previously stated, Sir John Coode reported in JBBO upon the best men: s to bo adopted fur the construction if a harbor at Gisborne. The prop .sals then put forward comprised a small detached harbor, situated olf tho mouth and somewhat to the eastward of tho Turanganui River. The harbor, which was to be ronnecti d with the mainland by means of ii i open iron viaduct 1410 ft long and n solid approach 6601 t long, won 1 have had an area of about six acres, tho depth of water varying from about .18ft, to 80ft below low water of spring tides, berthings for I four vessels of from 800 to -100 feet I in length being provided. 12. Since the date of Sir John Goode’s report more accurate information with regard to the bn'• in the nature of soundings, etc., has been obtained, and what is known as •‘tho inul grounds,” consisting ol more or.less, shoal water with a number ...off dangerous pinnacle rocks, on which several vessels have been lost, hive been discovered. The joul grounds” lie off tho entrance to the river, at a distance of about nine cables from tho shore, extending lor about three-quarters of a mile in a northerly and Fouth-oustorly ilircction. Tho existence of these rocks would render it unsafe for large vessels to enter a harbor constructed between them and the shore, so that any extension of Sir John Goode s original design in order to adapt it to nresent requiremtiis would not ue practicable, and it is therefore clear that a do on water harbor any where adjacent to the river •mouth is not permissible. OTHER PROPOSALS. 13. It was suggested to Mr Wilson whilst at Gisborne that advantage might be taken of the projection of the coast line at Tuamotu Island in order to form a harbor under the shelter of that island. I'liis. however, would not be' practicable. The are i which could be sheltered at a moderate cost by the construction of a breakwater from the western end of the island would consist for the most part of shallow water, with rocky ’bottom, which could only be deepened at great cost. On the other hand, if a breakwater were formed which would shelter a sufficient area li n mg adequate depth of water, its cost would be excessive, owing to the rapid deepening of the water off the point greatly increasing the cross .section of the mound and, therefore, the quantity of material require.l tor its construction. Moreover, tlm AVnihora rocks would render the uppoaeh to any harbor in this locality dangerous. 14. After carefully examining the merits of each particular proposal, we are of oninion that the onlv satisfactory site for the required harboris in the neighborhood of that selected by Mr Marchant. 18.’ In February of this year Air Marchant reported on the provision of an outer harbor. Mr .Marchant s scheme contemplates the construction of a breakwater from Pah Hill Point, running in a soutlierly. direction until reaching a. depth of about five fathoms, when it would, he curved round to tho north and west, so as to run more or less nurillel with the shore, the total length being about 4700 ft. Cnder tho protection of this work a jetty of 100 ft in length would be built and railway connection established between it and the existing Government rail wav to the northward of the Turanganui river. A reclamation at the root of _ the jetty would be ine.ro.iced to 1350 ft. A further reclamation at the .root of the breakwater completed the scheme, which will be readily understood on reference to drawing No. 1. CONSTRUCTION OF BREAiv- \ VATKR. IC. Mr. Marchant proposes to construct the breakwater entirely of rubble stone, provided a plentiful supply of blocks of over 15 tons in weight cm be obtained. Upon tho cross section of the proposed work given on ‘Mr. Marchant’s drawing the outer blocks are.shown' to be from 15 to 25 tons in weight, the seaward face being formed to a shape of 2.) to 1, ‘reaching' to a depth of 10ft below low water, the slopo beyond that depth being If to 1. The top width of tho mound to be 2l)ft at a maximum height of 15 feet above high water of spring tides. It is very essential for the stability of a

breakwater of this description that the upper portion of the mound and the seaward side should be formed of largo and angular stones in order that they knit well together, and so be the less liable to disturbance, but it must be borne in mind that a certain amount of maintenance and replenishing in places wlioro stones have been disturbed is inevitable in this class of work, and must be provided for accordingly. The initial cost of a solid concrete breakwater of the length and dimensions required would, however, be prohibitive, and we therefore concur in the proposal of Mr. Marchant that rabble stone should he adopted. B e consider, however, that the breakwater should be widened out, landward of the jetty, to form a railway approach to the latter, so that- communication could be maintained as far as possible during lie ivy weather. AS TO MAINTENANCE OF DEPTH.

17. The proposed breakwater would consist of a rubble mound constructed continuously from the shore line. Mr. Marchant is of opinion, as stated in his report, that no drift of beach material, such as to cause an accumulation under the lee of, or' against, the breakwater, was likely to occur, with which opinion, l'or the reasons already given in paragraphs D and 10, wo are able to concur. 18. On comparing .Hie soundings given upon the Admiralty chart of i ( JO2 with those given upon the chart of 1895, and also with the soundings taken in 1879, it would appear that deposit has to some extent taken place off the mouth of tho river ami to some little distance to the eastward thereot. This is chiollly noticeable in- .the position of the three fathoms lino, which, off' tho river mouth, appears to have moved seaward some 250 ft or so since the date of iSir John Goode’s report, 19. We understina that during flood’s a very considerable quantity of silt is brought down t-lie river and carried some distance seaward of the river mouth. There would always be the possibility of -some of tins material being earned by the cunents within the shelter of the break water and there deposited- AA edo not. however, anticipate that this would amount to any large quantity, or move than could be readily dealt with hy occasional dredging. HARBOR ENTRANCE. 20 On tho occasion of Mr. \\ ilson’s visit the question of. Hie position of the entrance to the proposed harbor was raised by tne haiboimaster, Captain Gumming, who wa., - -minion that- vessels would find some’ difficulty in making the harbor during south-east gales owing to the proximity of the “foul grounds Wo 'understand from Mr Marchant that he has considered this point with the enntains of vessels accustomed to visit* the port, and they have expressed themselves as perfectly satisfied with tho position of the entrance as laid down by mm.

Mr. Merchant in bis report refers lo the question of anchorage within the harbor, and expresses tho opinion Hint “while the iniehnrago cannot be said to be first-class, it can bo said io be sufficiently good.” This is a poinl, however, upon which wo are not in n position to express an opinion, hiving no information upon tho subject. It is, however, a metier of importance that before any works are undertaken tho question of making provision by means of mooring buoys or otherwise for the safety iiiid convenience of vessels entering tho harbor should be fully considered. Tho width between the bead of Um breakwater as proposed by Mr. Marchant and the 80ft contour line is about 1200 ft, whilst tho distance from the head to the buoy marking the south-eastern end of tho “foul grounds” is- about 8000 ft; these widths should be amply sufficient. T t would no doubt lie considered advisable to indicate by means of sonic suitable mark flic posit ion of tho 80ft contour line at iho entrance. SUGGESTED MODIFICATIONS OF MR. MARCH ANT'S DESIGN. 22. It will be. seen that the breakwater ns proposed by ourselves would commence at the same point ns Mr. Marchant’s, and follow practically tho same Jim; seawards, but would turn somewhat sooner and would have the outside cant running in a rather more westerly direction. The bead of the breakwater would be formed in almost the same position as tinit^,sel-^ctcd -.hy- Mr. Marchant’.' ‘ AA’e are of opinion that a harbor on tho linos proposed by ns would bo sufficiently commodious for all purposes, whilst at the name time a considerable curtailment, in the length of the breakwater is effected. Should it, moreover, be at a ay tune considered advisable to extend tho latter, the line proposed by m would better suit such extension than that proposed bv Mr. Mnrehnnt. To this subject Vo shall allude again lierellftCl FUTURE EXTENSIONS. 24. We have further shown by green color the lines upon which future extension could bo carried out should such be required. It will be noticed that we propose ultimately to form a reclamation about 300 ft wide connecting the roots of the jetties. This won id give valuable space for Customs ami other sheds, and also for railway hidings, which would be very necessary with increasing trade. ' Tho depth of water alongside the jetty to be first constructed would lie from 29ft to 37ft- at low water of ordinary spring tides, which would be sufficient ior all requirements. At ilte outer jetty, the depth alongside would be from 3014 to mt, whilst at I lie inner jetty the depth would be from 17ft to 33it. ■BREAKWATER. 25. There can be no question blit that heavy sea:- from tho south-east are experienc'd at Gisborne. Mr. Marchant states in his report that flic sea bottom consists of bare papa rock up to a depth of 24ft. Ibis would indicate considerable sea disturbance. Moreover, deep water is found in the immediate vicinity seaward of the proposed harbor. Wc should therefore anticipate that the break water mound would in heavy south-easterly gales experience a rery considerable wave stroke. For this reason we consider that- it would be advisable to provide for a sea slope of 3 to 1, extending to a depth of 15ft below low water of spring tides. Blocks oi from 15 to 25 tons should be used exclusively upon (he top of the mound and upon the se i slope, as shown upon the cross section given upon drawing No. 3 accompanying this report. We should not advise filling in tho interstices between the stones forming the top with concrete as proposed by Mr. Marchant. MODE OF CONSTRUCTION. 26. We do not consider that it would bo possible to construct a mound of the cross section required by direct lipping from waggons; nor, owing to the nature of tho bottom, do wo consider it would be possible to erect a staging at any reasonable cost. We propose, therefore, tint tho stone for the breakwater should bo deposited by means of. a powerful travelling crane of wide gaugo running along the toi> of the completed mound. The crane should bo capable of depositing stones up to 25 tons weight at a radius of, say. •lot. Single large stones would bo lifted and deposited by means of nippers, tin; smaller stones being brought down from the. qiurrv in trucks having removable bodies. The bodies containing tho stone would bo lifted from the under-cargviages by tho crane, and tho stone deposited therefrom by means of suitamo tipping arrangements. The cost of such a crane would no doubt bo considorablo, but without some such means of depositing large stono well out upon the sea slopo we are cer-tain-that it would not he possiblo to obtain satisfactory results. ROOK PATCHES. 27. An inspection of the Admiralty chart shows that numerous isolated rocks with deep water all round exist in the vicinity. These are exceedingly dangerous, and even with close sounding small rocks might he passed by without. being discovered. Should it be decided to proceed with tho proposed work's, wo would recommend that the site of the harbor and its approaches should be carofnllv “swept” by means of a horizontal rail passed over the area and kept at a given depth below lowest water level of spring tides, or by some other means, so as to ensure that no pinnacle rocks exist projecting above the sea bed to an extent likely to be a source of danger to vessels making use of the harbor. ALTEKNAiIVE SCHEME. 28. \\:ifi regaul to t) V question oi Aie proximity of Hie entrance oi the proposed harbor to the “foui ranot l-y the Harbourmaster, and hereinbefore alluded to, we have shown on drawing No. 3 a possiblo alternative position for tho mubor somewhat further to the eastward. The points in favor of this site are: (1) The on trance would be well removed from the 30ft contour line and also from the foul grounds.” and no apprehension could be entertained with regard to either of these points. (2) Advantage is taken of a considerable extension seaward of the 011 and. lSit contour lines, thus diminishing the quantity of material required for the breakwater, (o) The depth of water within the sheltered area is, subject to qualification now to be mentioned, more suitable for deep water jetle|p. Unon tho Admiralty chart, near the middle of tho proposed harbor, is shown a patch of rocks covered by only 18ft oi water. 1 Ins patch we have shown on drawing No. 3, Inn nob on drawings Nos. 1 and A - hoimh Mr. Marchant’s soundings, which cover tho position of tins natch, are taken comparatively cose together, they did not detect such a rock, but it would not be sate to jsuimo on that account that the shallow spot does not exist. Gaiefu! sweeping, as before described, mmlit orove the existence of this oi rather shallow patches, which would be serious and costly obstacles to removfc. It would bp for the Harbor Board to determine whether thej would be prepared to have tin., alternative site thoroughly survejtd, but such a survey would bo indispensable before definitely . considering the possibility and advisability m selecting that site for the proposed harbor. The position is sonnvwha■ further removed from the town time the site selected Iff Mr. Marchant and this aspect of the question shou.c •vl-o receive full consideration. quarry. 30 As already mentioned, Mr. AVilson visited the site of the pro

posed qtiarrv at AVailiirere, where it is intended *to obtain the stone for tho works. Tho stone consists oi a hard shell limestono, and judging from Hie results of some quarrying which liad already taken place, there should be no difficulty in obtaining in nmole supply of large stone. MR, MARCHANT’,S ESTIMATES. 31. AVitli reference to. the cost of carrying out the works, tho main item in the construe,tion of tho proposed harbor is the rubble stone tor the breakwater. Air. Marchant. estimates that tliis can lie quarried, delivered, and deposited in the breakwater, exclusive of Hie cost of tho railway and of plant, for 3s per ton of 18 cubic feet. There appears to be every probability that tho quarry will turn out satisfactory and oas” to work. There should be no difficulty in obtaining a large working faeo, and it would no doubt be possible, as pointed out by Mr. Marchant, to firing down considerable masses of stone at one time by mining. In this connection, however, we would again point out that it would bo essential to oiisuro a sufficiency of largo stones for the top and sea faces of the breakwater; this is a most important matter, and should lie carefully kept in view during ‘mining and quarrying operations, as the success and stability of the work will depend upon an ample supply of such large stone being available. The proposed quarry is situated up a narrow valley, so that the loaded waggons would be taken awav upon a down grade, which would be favorable to the work from tho point of view of economy. Having regard to the foregoing, and also to inquiries made locally, and as to tho cost of obtaining material at Timarii and elsewhere for similar purposes, we are of oniniou that the price adopted by Mr. Ala reliant is fair and reasonable, and we have accordingly based our own estimate upon this figure. 32. AVitli regard to plant, the quantity required will depend largely upon the time required to complete the works. AA’e understood from Afr. Mnrehnnt. that he estimated the time for completion at seven ■■• ears, and had provided for one 25-ton and two 10-ton cranes for the quarry, two locomotives and 48 block trucks, at a cost of £13,000. AA’e have carefully looked into the matter, and consider that the plant proposed would be inadequate to complete the work in seven years as contemplated. Neglecting Sundays, the quantity of rubble only to be handled amounts to an average of over 700 tons per day throughout this period, and basing our opinion upon the experience gained in carrying out somewhat similar works with which we have been connected elsewhere, we consider that the smallest amount of_ plant necessary would be one 25-ton quarry crane, two 10-ton quarry cranes, one 5-t-on quarry crane, eight trucks, a proportion to have movable tops for stone up to say 10 tons, and the remainder to be suitable for carrying lirge single stones up to say 25 tons, and the remainder. to be suit;b!e for carrying large single stones up to say 25 tons; five powerful six-wi-cel tank locomotives, one 25-ton crane for breakwater, 40 tipping waggons for reclamation. AA'e estimate the cost of the above plant delivered in New Zealand at £IB,OOO, uiioii the assumption that the freightage. colonial duties, erection, etc., would add about 50 per cent, to the cost of the plant in England. ..I his estimate contemplates the provision of new plant and machinery throughout. and wo do not consider that it 'S excessive for dealing with such heavy material such as will be required for these works. Should it he found possible to obtain any portion of the required plant locally at second-hand, this estimate would, of course, lie proportionately reduced. 33. AVitli regard to tho proposed railway connection with the quarry •and between the harbor and the Government railway, wo have no means of going properly into these questions, and have consequently adopted for the purpose of our estimate the sums of £22,900 and £BOOO respectively provided by Air. Marchant. AA’o .understand these sums do not include any provision for the purchase of land other than that or two •sections of private property adjoinin<r the river where crossed by the quarry .railway, and that ior the icmninder of tho distanco it is not anticipated that any payments on account of land purchase or compensation will be required. As to this we aro of course not in a position to express any opinion. 34. Seeing, however, that the Government railway passes within a short distance of the quarry and that tho traffic is, we understand, exceedingly' small, it might be desirable (assuming the permanent way to bo suitable for carrying the. weights required) before constructing an entirely new and independent railway, to ascertain whether the Government, would bo willing to enter into some satisfactory arrangement with the Harbor Board whereby the material should be carried over the existing lino. If such an arrangement could bo made, a. large saving m the length of new line required would be effected. It would then only be necessary to construct a branch from the quarry to tho nearest point on the main line, and a further branch from near tho’Gisborne terminus to the harbor. This latter portion of railway would bo on tho line of that described by Air. Marchant in his report under the heading “Connection with Government Railway,” and included as such in his estimate. JETTIES.

35. For the purpose of this report we have adopted the same dimensions for the jetties as suggested hy Air Marchant, the width being suffiee'ut for live lines of railway is required. Should it he ultimately considered. as is probable, that this width should bo increased, the estimated cost would bo correspondingly raised. Air. Alarchant proposes to use jarrah timber for the. piles and bracing with iron bark and guip .superstructure. A structure of this nature would no doubt ho the clioapei at first cost, but we fear that owing to the attacks of the marine worm it would not be durable. At AA ollington, to the south, and at Auckland, to the north, the life of unprotected timber is exceedingly short, and wc have no reason for supposing that tiio worm will bo less active at Gisborne than at tho two places above-men-tioned. At AVellington tho timber used is protected by metal sheathing, which is costly and not in all cases entirely satisfactory. At Auckland timber has been discarded m Hie new jetties and wharves now m piogress. ami ferro-concrote in being used in lieu thereof. Air. Alarchant <nvcs an .alternative proposal ior a jetty of the hitter type. 3(3. The difficulty with regard to the construction of jetties at Gisborne for largo vessels is the question of obtaining sufficient stability: the hard nature of the bottom rendering it impossible to drive piles in the ordinary way. AAo lear that the

j I method proposed for concreting the foot of tiio piles into a shallow trench excavated under water would bo difficult l:> carry out, and would not give satisfactory results. AVo believe that tho only means hy which a structure of timber or ferro-eonoreto piles could bo satisfactorily executed would bo by boring holes into the papa rock, to a distance of say 10 foot boloiv tho surface, into which tho piles could be driven. It would, of course, bo essential that tho point of tho pile should ho driven firmly into tho bottom of tho hole, and it would bo necessary to determine by experiment tiio proper diameter for tho hole relative to tho diameter of tho pile to ho driven therein, so that tho lattor should be thoroughly secure. AA’e may mention that the piles carrying the timber portion at tho inner end of the present eastern mole at the river entrance wore inserted into holes previously bored in Hie papa rock. AVo. have shown ill Drawing No. 2 a typical cross-section of such a jetty if constructed of timber and . tho manner in which wo should propose to arrange the bracing. 87. AAitli regard to tho cost of the jetty or wharf, judging from information gained in the Dominion with reference to somewhat similar work, wo consider that the price estimated lay Air. Alarchant for the timber structure shown upon his drawing, is a fair one. In order that our estimate my compare with that of Air. Alarchant, we have assumed that the jetty would fie carried out in timber, but have mado provision for the additional underwater bracing which we consider necessary, and also for boring boles in the rock prior to driving the piles. 38. For tlic reasons hereinbefore given, however, we cannot advise the uso of timber for these jetties, but strongly recommend that ferroconcrete construction lie adopted. Should it bo decided to carry out the work in this material there would bo no difficulty in obtaining a tender from some competent firm of contractors experienced in this class of work; and we believe that in this case, also, satisfactory results would ho obtained by driving the piles into holes previously bored in the rock. AA’e fear the system of fendering as shewn on ALr. Alarcliant’s drawing would not prove snisfactory, and we would recommend that tho more usual practice of attaching the timber fenders direct to the piles be adopted, as at Auckland and elsewhere. 39. AA'e have very carefully looked into the probable cost i the work if carried out in accordance with the design ns shown in red upon Drawing No. 2, and, subject to the various considerations previously set forth in this report ,estimate as follows :—• £ Railway to Quarry ... ... 22,900 Railway and Quarry Plant ... 48,000 Limestone and Rubble Breakwater ... ... ... 212,200 Timber Jetty ... ... ... 40,000 Reclamation at root of Jetty 15,000 Railway Connection with Go- ■ vernment Line 8,000 Moorings, and Lights ... 5,000 Reclamation at root of Breakwater ... ... 18,900 £370,700 Engineering and Contingencies 10 per cent ... ... 37,070 £407.770 Say £408,000. This figure compares with the £330,890 given by Air. Alarchant, tho additional sum being necessary, in our opinion, for the satisfactory completion of the works. 40 Should it he desired in the future to extend the accommodation in the manner shown by green color upon the same drawing, we estimate the cost as follows: £ Two Timber Jetties ... ... 80.000 Reclamations at roots thereof 35,000 £115,300 Engineering and Contingencies 10 per cent ... ... 11,530 V 126.530 Say £127,000. 41. AA'e have not included any estimate' for a harbor is constructed on the alternative site to the eastward, of Pah Hill shown upon drawing No. 3, and to which reference lias been previously made, seeing that sufficient information with regard to depth of water, etc., is not available to enable this to he done. GENERAL REAI ARKS. 42. Referring again to the instructions which we received as set forth in the opening paragraph in this report, it will be seen that we consider the scheme as proposed by Air Alarchant to have been generally well conceived and adapted to meet the requirements of the place and to the local conditions as effecting its construction. AA'e have suggested some slight modifications which we consider advisable, more especially with regard to the construction of tho proposed jetty, which in the matter of plant we have added considerably to tho sum allowed by Air Alarehant, and have framed our'estimate accordingly. 43. It was also desired that we should report upon “the future probable success of the scheme.” So far as concerns the actual carrying out of the work and its ultimate utility as a harbor wo have every reason to believe that it would prove a success and be of great value to the district and convenience to shipping making uso of the port. AVhethor it would prove financially successful we are not in a position to judge. From the figures given in the annual report of Gisborne Harbor Board for the year 1905 it would appear that the harbor receipts have been advancing steadily in the past and the trade of the port increasing. Gisborne is the natural outlet for a large 'and rich district, which wo understand. is beginning to develop rapidly, and there can he no doubt that with improved facilities the development of trade may ho expected to continue in the future, but with the scanty information at our disposal relating to this question wo arc not- in a position to express a definite opinion thereon. AA’o trust, however, that we have dealt generaly with the engineering aspect oi tho ijiiostioii in a manner satisfactory to the board and have afforded t-heui tho information desired. 44. In conclusion we have to express our thanks to those gentlemen members of the Harbor Board and others, who so kindly rendered assistance in collecting local data in connection v.itli his report, anil in particular Air. Alarchant ior the icis full information afforded us, together with the drawings so courteously placed at our disposal.—AA e have the honor to be. .Sirs, your obedient servants, COODE, SON, and AIATTIIEAA S.