E.—2

1880. NEW ZEALAND.

TIMARU HARBOUR WORKS. (REPORT OF THE COLONIAL MARINE ENGINEER AS TO THE DAMAGE CAUSED BY BUILDING A BREAKWATER AT TIMARU, AND THE FURTHER DAMAGE THAT MAY ACCRUE THEREFROM.)

Presented to both Houses of the General Assembly by command of His Excellency.

No. 1. The Colonial Marine Engineer to the Hon. the Minister having Charge of the Marine Department. Memorandum re Timaru Harbour Works. Public Works Office, Wellington, 2nd February, 18S0. My last report on the Timaru Harbour works was on 3rd July, 1579, and was intended to reply to certain questions asked by the Hon. the Minister for Public Works—viz.: What amount of damage was inflicted on the railway ? How much of this was due to the Harbour Board's operations ? What action is necessary, and its probable cost, in order to prevent further encroachments, and to arrange that the Harbour Board, if thought responsible, should undertake repairs? The reply to the above was given in qualified terms —namely, that there could be no doubt that the damage to the railway line north of Timaru Harbour works was due largely to the erection of the breakwater; but until further evidence was obtained, it was difficult to state how much of the damage was due to the breakwater, and how much to the violence of the storms. Since this the action of the sea has been closely watched by Mr. J. H. Lowe, the Resident Engineer for Railways, who has twice reported on the subject. A perusal of these reports shows the prejudicial action of the breakwater in so clear and strong a light, that there need now be no uncertainty in the mind of any one who is capable of justly estimating the importance of the facts therein recorded. The facts are briefly these: Before any breakwater was erected, the sea-beach was covered with a coating of shingle of such a breadth, depth, and quantity as to act as a protection to the softer parts of which the beach on which it lay was composed. This shingle, or the upper layer of it, was in an almost constant state of motion along the beach northwards, due to the action of the sea. When the breakwater was erected, it acted as a stop to the flow of shingle, which became banked up on its southern face, while the shingle which had already passed the line of the breakwater still continued its motion, gradually as it moved, laying bare the beach beneath. As the beach was laid bare and deprived of its natural protection or cJothing of shingle, its denudation and destruction by the sea became rapid, as described in Mr. Lowe's second report. This action, if the building of the breakwater is proceeded with, will go on ; the shingle will be moved northward; and, no further supply following, the spits or beaches across the mouths of the lagoons will disappear, and the railway embankment across these lagoons will be laid open to the attacks of the sea. This action will not be confined to the locality of Timaru ; it will be felt in due course of time (shorter or Jonger, according to circumstances) along the whole stretch of coast-line to Lake Ellesmere, working changes, the nature, but not the full extent, of which can readily be foreseen. It may, then, be asked why this effect of the building of a solid breakwater at Timaru was not pointed out, and its promoters and the Government not warned that disastrous effects would follow. An answer to this question may be found by perusing a report, dated 1871, made to the Timaru and Gladstone Board of Works by Mr. Carruthers, the late Engineer-in-Chief, wherein he describes, in terms most precise and almost to the letter, what would be the result of building a solid breakwater. His words are: " The shingle being thus stopped, it would collect on the south side " of the breakwater, until in the course of time it had pushed out to the end of the latter, when " the northerly motion would begin again. In the meantime the shingle to the north, beyond the " protecting influence of the breakwater, would have been still moving northwards. As no new " shingle could come to supply the place of that which had moved on, the coast would soon be bare, " and the sea would begin to cut down the sub-beach." Again, " The first effect of the above works would be the degradation of the coast to the north." Again, " The detached shingle beach across Washdyke Lagoon would next begin to disappear." Again, " I strongly recommend the Board not to undertake the work, notwithstanding the great " benefit which a harbour at Timaru would cause to the rich surrounding country." Mr. Carruthers, and, later, Sir John Coode, have been emphatic in the expression of their views as to the bad effects of stopping the flow of shingle. Mr. Balfour, in making his first design for a breakwater, fully appreciated the difficulty of dealing with the moving shingle, and showed that a portion of it should be built open to allow shingle to pass. Mr. Carruthers

E.—2

2

doubted that any moderate amount of open work would have the desired effect. Sir John Coode, taught by a life-long experience, provided no less an opening than 900 feet before he proposed to begin the solid work of the breakwater, thinking (although lie had not seen the place) that this was sufficient. But, on this fact being questioned by Mr. Carruthers, 24th October, 1876, and his criticism being brought to the notice of Sir John Coode, the latter felt that the objection might be just, and begged that all the facts of the case should be referred to the consideration of a third party, of high engineering celebrity, before any rash steps were taken. It might be supposed that such warning would have been attended to, but it was not. The promoters, anxious apparently to have a harbour of some sort as quickly as possible, and also to avoid the large expense and delay of building such a breakwater as designed by Sir John Coode, sought the special aid of the Legislature to assist them in building a less costly structure —a solid breakwater, in fact, attached to the shore. Accordingly a clause was inserted in " The Timaru Harbour Board Act, 1876," by which any proposal for such a work, instead of being submitted to the scrutiny of the ordinary Government Engineers, who were known to be averse to such a structure being erected, should be approved by a Commission appointed by the Governor ; and this legislation was confirmed by "The Harbours Act, 1878," which specially provided for such a Commission, although all other harbour works would be dealt with in the ordinary way by the officers of the Government. The result is now a matter of history. The Commission was appointed, and plans for a solid breakwater were laid before those composing it. The Commission, composed of gentlemen having no special experience in marine engineering, affecting to ignore or undervalue the importance attached to the movement and quantity of shingle so strongly insisted on by engineers, approved of certain plans submitted; and here is the result* —a solid breakwater in course of erection, attended with all the bad results anticipated. Little more need be said in explanation, but it is clear that, if the breakwater be proceeded with, some person or body of persons must be made responsible for the protection of the beach and railway works north of it. Naturally the Harbour Board is the body to look to for such protection, as the damage is the result of their work : but the magnitude of the cost of this no one can estimate; it will reach thousands of pounds, and may reach hundreds of thousands, but under any circumstances it will be far beyond the power of such a body as the Timaru Harbour Board to cope with. The Harbour Board may urge with truth that they are working to plans recommended and approved by a Commission appointed under special legislation by the Governor in Council. Until, therefore, further legislative action is taken in the matter it may be difficult to restrain the progress of the works ; but should other means fail, the Minister for Public Works might meanwhile apply to the Supreme Court for an injunction to stop the works. This being done, the shingle would in course of time find its way round the end of the breakwater, destroying the so-called harbour in its passage, and eventually gain the northern beach, where, after a while, the normal state of affairs would again be restored, the beach would be again clothed with its natural protection, and further damage would be arrested. This desirable result would be hastened if the breakwater were wholly or partially removed or broken up. My recommendation, therefore, is this : to stop the building of the breakwater at once, and afterwards to remove or break it up so as to lessen its prejudicial effect on the beach, the adjoiuiug lands, and railway works to the north. The Hon. the Minister having Charge of the John Blackett, Marine Department. Marine Engineer. P.S. —Attached are the instructions and reports on which this present report is based, viz.: — 26th June, 1879: Hon. Minister for Public Works, instructing Marine Engineer to proceed to Timaru. 3rd July, 1879: Marine Engineer's Report on encroachment of sea on railway line, and Reports of Eesident Engineer, Railways Department, attached thereto. 4th October, 1879, and sth January, 1880: Eeports, Eesident Engineer, W. R. Also, for the sake of showing the history of the breakwater in a connected and intelligible form the following papers are attached, viz.: —■ Plan of Mr. Balfour's proposed jetty at Timaru. (See plan attached, No. 1.) 29th October, 1871: Mr. Carruthers's Eeport to Timaru and Gladstone Board of Works (see Enclosure 3 to No. 7). 10th August, 1875 : Sir John Coode's Eeport. 1876 : Legislative Council Papers, Enclosures, Reports, &c. sth July, 1877 : Sir John Coode's Letter remarking on evidence taken before the Legislative Council of New Zealand (sec Enclosure to No. 8). Ist October, 1877 : Mr. Carruthers's last Memorandum (No. 4). 13th December, 1577: Commissioners' Report on Timaru Harbour Works (Messrs. Heale and Henderson). —J. B.

No. 2. The Hon. the MiNtsiisS foi- Public Works to the Colonial Marine Engineer. Sir,— Public "Works Office, Wellington, 26th June, 1879. It having been reported that serious damage is being sustained by the railway line at Timaru, arising out of encroachments by the sea, I have to request that you will be good enough to examine the spot, and report at your earliest possible convenience as to the extent of the damage, as to how far it is attributable to the Harbour Board's operations, as to what action may be necessary, and at what probable cost, in order to prevent further encroachment.

E.-2.

3

If it should appear that the damage to the railway is the result of the Harbour Board's operations, it would be well for you to communicate personally with the Chairman, with a view to the Board taking such steps as may be necessary to protect the line from being washed away. The Engineer in Charge of the Middle Island has been directed to meet you at Timaru, and the Chairman of the Harbour Board has been apprised that you will probably be there on Saturday. 1 have, Sec., The Colonial Marine Engineer. J. Macandbew.

No. 3. The Colonial Maeine Engineer to the Hon. the Minister for Public Woeks. Sib,,— Marine Office, Wellington, 3rd July, 1879. In accordance with the instructions contained in your memorandum of the 26th ultimo, I proceeded to Timaru, accompanied from Christchurch by Mr. ,T. 11. Lowe, Resident Engineer, Working Railways, and there met by appointment Mr. W. N. Blair, Engineer in Charge of Middle Island. We made a careful examination of the coast to the north and south of the Timaru Breakwater, and collected evidence on facts requiring elucidation ; then, after due consideration, arrived at an agreement as to the terms of a report which I now beg to lay before you, and in which, I may state, Mr. Blair fully concurs. The report deals with the heads laid down in your memorandum, in their order of succession, viz. :— 1. The damage consists of encroachments on the shore by the sea at four different points, all to the north of the breakwater. The first affects land held by the Harbour Board, and the buildings connected with their boat service, but does not at present affect the railway station. The Harbour Board are taking steps to prevent further encroachment, by sheet-piling and other works. The second and third points are in the cliffs between the railway and the sea, and the fourth is at Whale's Creek Viaduct, in Caroline Bay. The cliffs consist chiefly of clay, with a thin bed of basaltic rock about midway up the face, and another forming a floor or causeway on the foreshore at the foot. The second and third encroachments are at points where there are gaps in the rock, each of them about two chains long. The fourth encroachment —that at Whale's Creek—is about four chains long. It occurs in a gully or sharp depression between two bluffs, where the shore had formerly an easy slope, the ground being clay, with a thick layer of shingle covering it. The railway crosses this gully on a viaduct which originally stood about a chain from high-water mark ; the sea has now* washed away the shingle completely, and cut into the slope close up to the piers of the viaduct, leaving a steep face of clay. It is from the encroachment at this place that immediate danger to the railway is to bo apprehended. 2. There is no doubt whatever that the encroachments are to a very considerable extent attribut- . able to the operations of the Timaru Harbour Board; but I am not prepared to apportion exactly the damage between these operations and the action of the very severe storms that have lately swept the coast. The breakwater certainly is the cause of the almost entire removal of the shingle from the shore immediately to the north of it, as exactly the same thing occurred on two previous occasions when an obstruction to the passage of the shingle took place at the site of the breakwater. One occasion was on the erection of an experimental concrete groin by the late Mr. Balfour, and the other the wreck of tl}e " Princess Alice." The groin and the wreck stopped the passage of fresh shingle from the south, and so allowed the sea to denude the shore on the northern side of the obstruction. Serious damage was done to the landing service on both occasions. Relief came in the first instance by the sea carrying away the groin in a storm ; but the wreck had to be blasted and otherwise broken and burnt to pieces for removal before the encroachment ceased the second time. On the other hand the late storms, which were unusually severe, have to some extent denuded the beach of shingle in places south of the breakwater; so it is clear that a share of the encroachments on the northern side may be attributable to the same cause. Until a period of ordinary weather has restored matters to thennormal condition, it is impossible to say how far north the action of the breakwater extends. The vicinity of Whale's Creek should be watched, with a view of ascertaining whether the shingle there is ever replaced to its former thickness and quantity; and the result will determine, to a certain extent, the share the breakwater may have had in causing the damage. 3. It will be necessary to stop the encroachments at Whale's Creek at once—the viaduct is already in danger ; and the first thing to be done is to drive additional piles in the end piers (south), and protect them with large masses of rock. For a permanent protection, I recommend that two rows of hardwood piles be driven into the foreshore about a chain from the viaduct, also two transverse rows reaching from them to the cliff, and that the intervening space be filled in with masses of rock ; this will cost about £3,500. Also, that the southern abutment of the bridge be reconstructed in solid rubble masonry in cement; the foundation of this to be laid at once, and built up as the filling-in with rock proceeds. The cost of this and the necessary alteration to the superstructure, with the filling-in behind the abutment, will be about £1,000. As this matter is urgent, Mr. Lowe has arranged for a supply of rock, and is placing it in position. The protection of the two encroachments in the cliffs, executed in the same manner, will probably cost at each place about £1,750 ; and if piles cannot be driven their place must be taken by heavy concrete blocks. The work at the one nearest the station should be proceeded with at ouce, and arrangements should be made for carrying out the whole of the works described with as little delay as possible. Eor your information, I append a copy of a report addressed by Mr. Lowe to the Commissioner of Railways, Middle Island, on this subject, which contains an estimate for works of a different character amounting to £12,000: but this sum would not bo sufficient to provide for a length of protective works of the character described equal in length to those estimated for above ; it would probably be increased by £2,000 to £3,ooo—say, total, £14,500. The contingency of being obliged to protect th§

E.—2.

4

line further north than Whale's Creek may, I think, be left for future consideration, as the damage, if any occurs, will probably be of a gradual character, and will give time for arranging* means to avert it, I have, See., The Hon. the Minister for Public Works, John Beackett, Wellington. Marine Engineer. P.S.—Mr. Lowe has been supplied with sketches and particulars of the proposed works, so that he can proceed with them at once. —J. B. Note.—For sketoli showing position of onoroaclimonts, see plan attached, Wo. 3.

Enclosure in No. 3. Memorandum from the Resident Engineer, Christchurch, to the Commissioner of Railways, Middle Island, re Encroachment of the Sea near Timaru. Resident Engineer's Office, W. R., Christchurch, 26th June, 1879. During the south-east gales that were experienced on the 21st and 22nd instant, the shingle beach was entirely swept awaj r, from the Timaru Breakwater northwards to a point beyond Whale's Creek. The principal part of the distance named is more or less protected by rock, solid in places, loose in others; but wherever the clay bluffs are exposed the sea is making rapid inroads. There are three points within three-fourths of a mile of the breakwater where the railway is seriously threatened. The most immediate danger is at Whale's Creek Bridge. At this point the rock terminates ; the foot of the perpendicular clay bluff is exposed to the full force of the waves. The bluffs are rapidly undermined, and fall in.* The south end of the Whale's Creek Bridge rests on this clay bluff; ordinary tides are now continually wearing it away. To retard this work of destruction, lam putting a facework of heavy stone. Should, however, another gale come on from the east, north-east, or southeast, our temporary protection will bo swept away, the viaduct will give way, and the traffic will be stopped. We shall then divert the railway on to the public road alongside, and by that means got the traffic through for a few weeks longer ; but it can only be a short time when the diversion of the railway and public road will likewise succumb to the sea. Permanent repairs will be of enormous cost. The best and most complete means of repairing the line will be by a sea-wall. To repair present breaches, this must be between 300 feet to 350 feet long, and 21 feet in height. It must be strong enough to bear the full brunt of the sea broadside on. It will cost at a rough estimate £10,000. The filling-up of the embankment inside the wall, and securing the ends, will bring this estimate to about £12,000. A plan that may perhaps be somewhat less costly, will be to rebuild the bridge in masonry, piers sunk below low water. These piers will have to be forty feet high. The clay approaches at each end will require strong groins to protect them, and the slope of the road will require facing with stone. This cannot be reckoned at much under £8,000 ; but Ido not give this as a definite estimate, as it will require more time to consider fully how it would answer. It is to be borne in mind that this is but the beginning. Two other points will soon suffer between this and the breakwater. There is abundant evidence, too, that other places further north will be affected later on. Such disastrous results from the first gale that has taken place since the breakwater commenced, give rise to the gravest apprehension. I have no doubt whatever that the whole of these damages arise from the stoppage of the shingle at the breakwater. An enormous accumulation of shingle has taken place to the southward. Had this shingle been allowed to travel along in its natural course, the present damages would not have occurred. If it should be allowed to travel again, the damages could bo repaired at a comparatively trifling cost by erecting small groins just northward of the breach, and thus bank up the shingle again, which would be as good a protection as the costly sea-wrall. J. Henry Lowe, The Commissioner of Railways, Middle Island. Resident Engineer,

No. 4. The Commissioner of Railways, Middle Island, to the Colonial Marine Engineer. Sir, — Christchurch, 11th January, 1880. I have the honor to hand you the Resident Engineer's report JNo. 1 (which you already have in the shape of a letter from that officer) upon the encroachment of the sea at Whale's Creek, Timaru. I have, Sec, W. Conyers, The Colonial Marine Engineer, Wellington. Commissioner of Railways, Middle Island.

Enclosure in No. 4. Memorandum for the Colonial Marine Engineer re Sea Encroachment at Whale's Creek, and Protective Works, Timaru.—(Report No. 1.) Christchurch, 4th October, 1879. The abutment and wing wall is just finished, and is a substantial work. A. quantity of rock has been sloped out on the beach, and does not give any signs of travelling. Unless it does, Ido not think we need go into the piling. All the charges for the masonry work are not yet in, so I cannot state the actual cost, but it will be well under the estimate. We have thrown about 2,000 cubic yards on the

* §cc plan attached, No. 4.

E.— 2

5

beach, at a cost of about £900. The work is now complete so far as the reparation of immediate damage goes. The clay bluff immediately to the northward of our work at Whale's Creek, between it and the next viaduct, is being steadily undermined. It is sufficiently far off not to hurt at present ; but if the process continues more rock will have to be put down, extending northward. With regard to the travel of the shingle, and the observation you made that there was encroachment by the sea southward of the breakwater, I have noticed that this is clearly the case, but feel satisfied by frequent observation that it is accounted for thus : The sea is continually surging the shingle northward. It is interrupted in its progress at the breakwater and accumulates there. The deposit of shingle does not take place to any great distance back —in fact, very little additional beach is made further south than the point immediately south of the southern boat-landing stages. The action of the sea in sweeping the shingle northward is comparatively regular in calm weather, and the beach presents an even and regular appearance; but in heavy gales the action is violent and irregular, and, while the general tendency of the shingle is northward, in doing the work the sea scoops the shingle out in some places and piles it up in others. This leaves the beach irregular after gales, and there is the appearance of encroachment in the places where the shingle happened to be rushed out at a more than ordinary rate. This irregularity is by slow degrees toned clown afterwards until another gale makes more encroachment. The second series of encroachments are, however, not likely to be in continuation of the last, but more power will be bestowed on the lumps. There is, however, no great nicety observed by the sea; and, considering the force it can exert, and the lively nature of the shingle, it seems remarkable that the alterations or temporary encroachments made along the beach are not more extensive. The main fact remains as clear as ever that the breakwater intercepts the general progress of the shingle, and the beach to the northward remains denuded. A small quantity of the shingle occasionally gathers along the shore from the Government Landing Service to Whale's Creek, but it as often disappears again. After you were at Timaru, and a recommencement was made at the breakwater, great difficulty was experienced from the quantity of shingle that was found at the end. The shingle had filled up the bight caused by the mole, and was forming a beach round the end, and no doubt before long there would have been a fine beach beyond the mole, the end of which would have been buried in the debris at high-water mark. The blocks consequently did not find a bottom, and the delays entailed made it apparent that the shingle could pile up as fast as the breakwater could be built. They then tumbled blocks in roughly, and so got to the end of the shingle, and from that point began again the permanent structure with the foundation blocks on the bottom. It is therefore evident that any delay of four or five weeks will be sufficient to allow the shingle to overtake the work again. The idea of the Harbour Board was that the shingle would be deposited in layers somewhat parallel with the beach, as in sketch A,* so that the quantity stopped by equal lengths added to the mole would increase in a great ratio. This does not appear to be realized, but, on the contrary, the accumulation seems to be forming as in sketch B.f In this event the chance of ever keeping permanently ahead of the shingle seems greatly reduced. The Engineer to the Harbour Board, in a recently-published report, states that he has computed that the accumulation of shingle on the south side of the breakwater for twelve months could be carted across to the north side for£l,ooo. A question arises whether this (if continued where the breakwater has been extended sufficiently to give still water on the north side) would not block up the harbour. J. Henry Lowe, The Colonial Marine Engineer. Resident Engineer.

No. 5. The Commissioner of Railways, Middle Island, to the Colonial Marine Engineer, Wellington. Sir,— Christchurch, Bth January, 1880. The Resident Engineer has handed me the enclosed report (No. 2) upon the encroachments at Whale's Creek, Timaru. I can fully indorse the statements of the Resident Engineer, and need hardly point out to you the serious urgency of the case, so far as the safety of the railway is concerned. I beg you will do me the favour to submit the report at your very early convenience to the Hon. the Minister for Public Works. I have, Sec, Wm. Conyers, The Colonial Marine Engineer, Commissioner of Railways, Middle Island. Wellington.

Enclosure in No. 5. Memorandum for the Commissioner of Railways, Middle Island, Christchurch, re Encroachment at Whale's Creek, Sec, Timaru. Resident Engineer's Office, Christchurch, 6th January, 1880. In accordance with your instructions of the 15th ultimo, on your M. 79-388, I forward attached hereto my report (No. 2) on Whale's Creek encroachments for the Colonial Marine Engineer. J. Henry Lowe, The Commissioner of Railways, Middle Island. Resident Engineer.

* See plan attached, No, 8. t See plan attached, No. 9,

E.—2

6

Sub-Enclosure to Enclosure in No. 5. Memorandum for the Colonial Marine Engineer, New Zealand, re Encroachment of Sea at Whale's Creek, &o, Timaru.—(Report No. 2.) Christchurch, oth January, 1880. The encroachment of the sea on the clay bluffs to the north of Whale's Creek has continued since my last report without intermission. The shingle beach which disappeared about the end of June has never formed again. A light covering of shingle has occasionally been spread over the clay, which has assisted the sea in the abrading of the clay. I attach a tracing* which shows the extent of the encroachments on the bluffs between the two viaducts between July and December, 1879. The south end of the Whale's Creek Viaduct has been permanently secured by the stone abutment and wing wall that was completed about three months since. The rubble breastwork that has been laid along the shore to replace the shingle beach and break the sea from the foot of the clay, is proving to be only a partial protection. The quantity we have placed so far is insufficient to completely stop the inroads of the sea, although it has checked it to a very great extent. In rough south-east weather the sea breaks heavily on the stonework. This causes the stones to grind upon and cut away the clay, both below and behind them; and the sea, running in and out between the stones, washes out the loosened clay. As the clay is thus gradually worn away, the stonework settles backward. The sketchf will give an idea of this process. This effect is proceeding all along the shore where stone has been laid, and indicates that the work is only an amelioration and not a cure. A far larger mass of stone might perhaps remedy this. Again, it is obvious from careful examination that the large blocks of volcanic rock from Timaru quarries that were thrown in are rapidly wearing down into comparatively small, round boulders, and will last no great length of time. A small portion of stone brought from Lyttelton stands far better. As the stones from the north extremity of the breastwork commenced to travel northward, I put in a groin of piles and whalings to stop them, and also with a view of retaining any shingle that might be travelling along the beach. This has been finished, and it holds the stonework, but, unfortunately, there is now no shingle travelling at all. A coarse sand, which is passing in small quantities, is banked up at times, but it is so light that the sea easily washes it out again. It will only take from six to twelve months for the sea to break into the line of railway at the present rate of encroachment. Another very serious event is threatening the railway. The shingle bank that separates the Waimataitai Lagoon from the ocean is gradually, but surely, dwindling away. This is due to the same cause as the other damages suffered along this shore—viz., the stoppage of the travelling shingle at the Timaru Breakwater. The action of the sea is working this shingle beach away to the north, and the supply that should come up from the south to maintain the bank is cut off, so it is gradually disappearing. As soon as it becomes too weak to oppose the breakers the sea will wash into the lagoon and break direct on the railway embankment and bridge, which cannot possibly resist any such attack. These disastrous results are, in my opinion, impending at no very distant period. Of course, should this apprehension be realized, it is only a question of a little longer time when the same effect will be produced on the shingle bank that closes in the Washdyke Lagoon, and another and greater length of railway will be exposed to destruction. J The action of the sea is comparatively gradual; but the certainty of the ultimate results I have described is, I believe, beyond all question. It will take several thousands of pounds to make any effective resistance to the encroachments, and also a considerable time, so that the steps to be taken should be decided upon with the least possible delay. J. Henry Lowe, The Colonial Marino Engineer. Resident Engineer, W. R.

No. 6. TIMARU HARBOUR. Sir John Coode to His Honor the Superintendent of Canterbury. Westminster Chambers, Victoria Street, Westminster, Sir,— 10th August, 1875. In accordance with telegraphic instructions received from the colony, I arranged with an assistant, Mr. Whately Eliot, C.E., to proceed to Timaru in order to make a proper engineering survey, take soundings, and obtain in the locality such data and special information as I found to be necessary to enable me to form a definite opinion and to report upon the question of harbour accommodation for that place. Mr. Eliot arrived in Timaru on the Ist of September of last year, and was engaged there until the 4th of November. Since his return to England he has completed the plotting of his survey and sections, which, together with his notes and other data, he handed over to me about two months since. I refer to these facts in order to account for the time which has elapsed since I received instructions to report upon this subject. I should here remark that, subsequent to Mr. Eliot's return, and after receiving his verbal description of the general results of his examination of the locality, I obtained from Captain Gibson farther information, in reply to various queries which thereupon suggested them-

* See plan attached, No. 5. t See plan attached, No. 6, J See Han B, attached, No. 7.

E.—2.

7

selves to me, in reference to some of the local conditions: this information has been useful to me in the course of my study of the subject. Captain Gibson has also supplied important facts with reference to Port Lyttelton. Having now given the question of harbour accommodation for Timaru my most careful and prolonged consideration, I have the honor to submit the following report, accompanied by two drawings, upon each of which the works I shall hereafter recommend are shown in red colour : — Drawings. —Drawing No. 1 is a general chart of the coast from Patiti Point to the Washdyko Lagoon. Drawing No. 2 is a plan, to a scale of 80 feet to the inch, showing in detail the sea frontage of the Town of Timaru, with the existing landing-places, and the railway line and station which were in course of construction at the time of Mr. Eliot's visit. Present Mode of carrying on Trade.- —The landing and embarking of merchandise and goods at Timaru are at present carried on under peculiarly difficult and dangerous conditions. There is no shelter of any kind for shipping, vessels having to lie in the open roadstead, and there to discharge and take in cargoes by means of surf-boats, which ply between them and the shore. Goods sent to and from England are therefore, for the most part, conveyed between Timaru and Port Chalmers or Lyttelton by small craft, and then transhipped into or from such vessels as are capable of making the voyage to Europe. The freight from Port Chalmers or Lyttelton to Timaru is about the same as from England to Port Chalmers, in addition to which there are heavy charges consequent upon the surf-boat service. The expenses connected with the conveyance of goods to and from England and Timaru are therefore more than double those between England and Port Chalmers or Lyttelton. If safe and convenient harbourage were provided at Timaru, 1 know of no reason why the charges there should not be practically the same, so far as freights and landing expenses are concerned, as at Port Chalmers or Lyttelton; and the special losses from damage to goods through being wetted in the surfboats, which I understand is now a subject of complaint by the underwriters, would be avoided. With respect to the present entire absence of shelter for shipping at Timaru, Mr. Eliot has brought under my notice the important fact that formerly, during the wool season, large vessels of about 1,200 tons burden, and drawing from 16 feet to 18 feet of water, called to take in cargoes of wool direct for England. Since the year 1871, however, vessels of this class have ceased to come to Timaru, as the insurance companies refuse to undertake the risk attendant upon their lying in the open roadstead. It will, I think, be readily conceded that under present conditions the trade of Timaru, and the vast, rich producing-district surrounding it, is held in check through the absence of adequate means of landing and embarking sea-borne goods and produce. Proposals tvldch have been made. —Various proposals have been made from time to time with a view to provide for, or at all events to mitigate, the evils which I have referred to —notably the designs which were prepared by the late Mr. Balfour, C.E., and the suggestions in the able report by Mr. Carruthers, C.E. Mr. Balfour's designs did not, however, provide for the berthage of deep-draughted ships, but were mainly intended to increase the facilities for working the surf-boats. Mr. Carruthers, after carefully reviewing the whole question, came to the conclusion that, in consequence of the rapid northward travel of the shingle' along the shore, it would be injudicious to construct either a solid work at right angles to the coast-line, or a wave-screen in the same direction (the latter of which had been suggested by Mr. Balfour), inasmuch as he apprehended that either of these works would obstruct the passage of the shingle northward to such an extent as would eventually render it useless. In the soundness of this opinion I entirely concur. Mr. Carruthers, as I read his report, was of opinion that, taking into consideration the travel of the shingle, the wants of Timaru would on the whole be best met by constructing an open iron jetty, at a cost of about £10,000, with the view of facilitating the working of the surf-boats. No doubt a jetty of this description would be of great assistance in the performance of the surf-boat service, inasmuch as it would obviate the necessity for beaching the boats on all occasions in order to discharge their cargoes : in my view, however, nothing short of deep-water berthage for vessels, and the abolition of the surf-boat system, are compatible with the proper carrying-on of trade at Timaru. Travel of Shingle. —From the River Waitaki, about forty miles south of Timaru, to Banks Peninsula northwards, being a length of 130 miles, there is an uninterrupted beach of shingle extend-* ing along the coast. The heaviest seas come from the south-east, and break obliquely upon the shore, causing a rapid movement of the shingle northward. It is agreed by all who have investigated this question that the balance of the travel of the shingle is unmistakably towards the north. The late Mr. Balfour made some experiments with a view to determine the rate of this travel; he found that in ordinary weather his experimental blocks, which were thrown in at Patiti Point, travelled towards Caroline Bay at rates varying from one mile to one-seventh of a mile per diem. A further confirmation of this rapid northward travel is also to be found in the short experimental breakwater which was carried out from Mr. Balfour's design. The construction of this work occupied about three months, and although within three months after its completion it was carried away, yet in this short period it exercised such an effect in curtailing the passage of the shingle northwards as almost to cover up the work. The waves, curling around the end of the structure, heaped up the shingle on the inside, and scoured away the material from the beach to the northward to such an extent as to endanger the safety of the large boat-shed of the landing service. This action continued until the breakwater was demolished, when the shingle resumed its normal travel northwards. Mr. Carruthers states that the effect of this breakwater in curtailing the supply of shingle to leeward was perceptible at the foot of Caroline Bay, half a mile from the work, and would have been felt even farther than this had it not been for the basaltic rock which forms the subbeach over this part of the bay. The quantity of shingle on the foreshore in front of the Town of Timaru and along the southern margin of Caroline Bay is not very great, if regard be had to the breadth and thickness of the shingle-band : at the time Mr. Eliot's survey was made its average breadth did not exceed 100 feet. Erorn Patiti Point to Caroline Bay the shingle nowhere extends further seawards than to about low-water mark, outside which the rock is bare, and runs in reefs sea

E.—2,

8

ward to a depth varying from five fathoms off Patiti Point to two fathoms in Caroline Bay. Beyond the reefs the bottom is sandy, deepening very gradually, and affords, I am told, excellent holdingground for shipping. I have already stated that the heaviest seas come from the south-east: Mr. Eliot, however, informs me that gales from the north-east are of frequent occurrence, and produce a short, broken sea, dangerous to vessels lying at anchor in the roadstead; he also says that gales from the east but seldom occur. Conditions to be fulfilled. —I take it that harbour works at Timaru, in order to be successful, must fulfil the following conditions: Eirst, that the travel of the shingle northward must not be interfered with; second, that shelter must be provided from north-east around to south-east, to enable vessels to lie afloat at all times in perfect safety, with quay to facilitate the landing and embarking of cargoes; third, that the available sheltered depth at low water of the lowest tides should not be less than 20 feet, so as to accommodate vessels of carrying capacity adequate to the wants of the over-sea trade; fourth, that means should be afforded for connecting the quay with the railway system of the province ; and fifth, that, in order to insure a fair rate of progress, the works should be of such a character that they can be carried out practically independent of divers, since the exposed situation and the prevalence of surf would render diving operations possible only at rare intervals. I am fully aware of the difficulties which would have to be overcome in carrying out harbour works of this character at Timaru ; but, after giving the matter my best consideration, I do not hesitate to say that it is practicable to construct such works, although their accomplishment can only be effected by a heavy expenditure. In considering this question, and the character of the works to be executed, I have kept prominently in view that Timaru is only at present a small though rising town, and I have therefore endeavoured to confine the extent and first cost of the works to the narrowest limits compatible with the fulfilment of the conditions which I hold to be essential for their success, and to provide means for extension hereafter if required. The design which lam about to describe may therefore be considered as the least in extent which ought to be constructed ; and if money be not forthcoming for its execution, then I see no alternative but to continue the surf-boat service, as at present, with perhaps the addition of steam tuggage, and vessels to lie in roadstead. Any work of the character of an open jetty only may be so constructed as not to interfere with the travel of the shingle; but vessels could not lie alongside of it, and it would not thus be of any use except as a means for facilitating the discharge of the surf-boats in fine weather, as has been suggested by Mr. Carruthers. Proposals. —The works which I have to recommend may be carried out in two stages—namely, in the first place, those which are the least that can be constructed to afford the accommodation necessary at the present time; and, secondly, those which may be executed at a subsequent date, should it be proved that an extension would be desirable. Works to be executed in Eirst Instance. —The works should be commenced by constructing an artificial reef from A to B (drawing No. 2), formed of blocks of concrete, each of forty tons weight, deposited in a " pell-mell " form from barges, and carried up to 4 feet above high water of spring tides, This reef would be nearly parallel to the coast-line, at a distance of 1,300 feet from low-water mark, and end-on to the south-east sea. It is evident that such a work as this would not of itself afford any obstruction to the free travel of the shingle northward. Mr. Carruthers states in his report that it is not necessary that the breakwater should be attached to the shore. " Still water is as effectual a barrier as a masonry wall." This would doubtless be the effect of a structure which curtailed to any extent the action of the south-east seas upon the shingle, but could not result from a work placed, as that which I propose would be, " end-on " to the sea. Upon the completion of the mound of blocks from A to B, the " return " ends from A to C, and from B in the direction of D, would be carried out. The latter arm maj**, in my opinion, be safely extended to the point D without in any way interfering with the northward travel of the shingle ; the exact point, however, for the landward termination of this arm would be determined by observation and experience. The blocks for the formation of the mound would be made upon the waste piece of land near the railway viaduct at the south-west angle of Caroline Bay, and transported from thence, and deposited in the work, by properly-constructed barges. Upon the completion of the block-mound from C to D in the manner I have indicated, being a length of 1,240 feet in all, I would recommend that a quay or harbour-wall should be formed parallel to the mound, and under the lee or sheltered side, between the points E and E, being a length of 400 feet. Simultaneously with the formation of this wall, the inner end of the mound should bo connected with the shore by an open iron viaduct extending from G, near the present Government boat-shed, to D, being a length of 900 feet. The top of this viaduct would be 2L feet 6 inches above high water of spring tides, and the top of the new quay, from EtoE, 8 feet above high-water mark of spring tides. These works should be connected by a temporary timber stage, extending in a straight line from D to E, and gradually falling from the level of the viaduct to that of the quay. The mound of blocks, with the 400 feet of quay-wall, the viaduct, and the staging, constitute the works that should be constructed in the first instance, and are the least in extent that can be relied upon to afford accommodation for the present trade of Timaru. By means of these works large vessels could be afloat with perfect safety in all states of wind and weather within the sheltered area afforded by the arm from C to D, and discharge and take in cargo directly in connection with the railway system of the province. Extension and Accommodation. —-Should the trade of Timaru outgrow the accommodation that would be afforded by the works I have indicated, as it would in all probability do at an early date, the design thereon upon the drawings* should be completed by continuing the harbour-wall from the point E to D, and from Eto C, under the lee of the block-mound.. Erom Cto D would thus become a breakwater

* See plan attached, "So. 2.

9

E.—2,

pier, 1,240 feet in length, with a depth of water of not less than 20 feet at the lowest tides; it would be sheltered throughout by a high parapet runniug along the sea face, and furnished with a capacious shed for the reception of wool and other goods ; it would also be adapted for laying the lines of railway arranged in the manner indicated upon drawing No. 2. Erom D to H a jetty 350 feet in length, extending in about a south-east direction, should also be constructed. This jetty would prevent any undulation within the harbour from south-east seas, and at the same time provide an extra length of 350 feet of quay-berthing for ships along its eastern face; moreover, it would act as a training wall to guide the seas passing through the viaduct on to the beach, where they would have to do their work in propelling the shingle northward. Upon the completion of the permanent incline to connect the viaduct with the quay level, the temporary staging from D across to E, being no longer required, would be removed to afford access for ships to the new quays between these points. The works just described, with those to be constructed in the first instance, would comprise the whole of the design shown upon the drawings, and I apprehend that the scheme, if carried to the full extent proposed, would be amply sufficient for the wants of Timaru. I do not apprehend that these works, either in whole or in part, would exercise any prejudicial effect upon the travel of the shingle; they may, however, possibly cause some little accretion at first in the bight of Caroline Bay, which accretion, if it occur at all, would cease as the shore-line might be brought under the more direct action of the south-east seas. The proposed harbour would be easy of access, but during north-east winds it would be necessary for vessels leaving, either to be warped out a sufficient distance to get an offing, or to be towed out, as it is absolutely necessary that shelter shall be provided from the north-east, and at the same time that the main arm shall be in a south-easterly direction. This cannot be avoided, having regard to the configuration of the coast. I estimate the cost of the works as follows":— Eor the works recommended to be constructed in the first instance—viz,, the mound of blocks, 400 feet of quayage, the viaduct complete, and the temporary staging ... ... ... ... ... £240,000 Eor the works to be undertaken when the trade requirements render more extended quayage necessary—viz., completing the harbour and parapet walls, forming permanent incline, and constructing the jetty, so as to complete the designs to the full extent shown upon the drawings ... £79,000 These figures are based upon the supposition that the works are executed without the intervention of a contractor, as in the case of harbour improvements of a similar character now being constructed under my direction by the Colonial Governments of the Cape of Good Hope and Ceylon. Sufficient allowance has been made for contingencies, and for the provision of special plant adapted for the economical, and speedy execution of the works. The purchase of land, should the same be required, and the formation of the lines of railway upon and in connection with the quays and viaduct, are not included. It would have been much more agreeable to myself to have been able to recommend works involving a less expenditure than that named above, but, having regard to the peculiar conditions of the site, I regret to say that has not been practicable. I have now in conclusion the pleasing duty of acknowledging my obligations to the Agent for Canterbury, Mr. A. 0. Ottywell, for the many facilities which he has afforded to me since I have been engaged upon this investigation. I have, &c, His Honor the Superintendent of Canterbury. John Coode.

No. 7. REPORTS AND PAPERS RELATIVE TO OAMARU AND TIMARU HARBOUR WORKS, AS LAID BEFORE THE LEGISLATIVE COUNCIL. The Engineer-in-Chiee to the Hon. the Chairman of the Waste Lands Committee. Sir,— Wellington, 24th October, 187(3. I have the honor to submit the following answers to the questions asked by the Committee :— Ist Question.— Are you aware of the present condition of the Oamaru Harbour works ? Answer. —I have not seen them for some months, and do not know exactly the state in which they are at present. Whenever I visit Oamaru I examine the works, and have therefore a fair general knowledge of the state in which they are. 2nd Question. —If now stopped for a time, would there be any risk of injury to the works ? Answer. —There would be some risk of injury to the seaward end of the breakwater if a substantial pier-head were not built. 3rd Question. —-If resumed hereafter, would there be a waste of money through the stoppage ? Answer. —There would be a loss of money, as a pier-head would have to be built, the cost of which would be considerable. If the breakwater is carried on to completion, only one pier-head would be required at the end of the finished work. The plant now on the works would also have to lie idle, subject to deterioration, as long as the works were suspended. It is likely that compensation would have to be paid to the contractors for stoppage of the works; and, in any case, the interest on the money already expended in work and plant would be nearly all loss, as the incomplete works would be of comparatively little value. 4<t% Question. —What is your opinion of the harbour works now being undertaken at Oamaru ? Answer. —I am of opinion that they will be quite successful if completed with a north pier as well as the south pier now under construction. Should the north pier not be built, there is some risk of 2

E.—2

10

shingle being heaped up in the corner of the bay where the boat service now stands. Ido not think the fear of this happening should induce the authorities in charge of the harbour to undertake the construction of the north pior at once, as the shingle may not heap up to an injurious extent inside the harbour; and, in any case, the evil will increase gradually, so that time will be given to build the north pier after it is found necessary to do so. The north pier would, however, much improve the harbour by giving shelter from northerly seas, to which the harbour will be otherwise quite open. I may mention that I reported on this harbour to the Hon. the Minister i'or Public Works on the 30th October, 1871, and again on the 14th July, 1874. I append copies of my reports. sth Question. —Have not these works been somewhat prematurely undertaken, and will not the effect of what has been clone prevent this harbour being so useful as would otherwise have been the case ? Answer. —l have no doubt it would have been better had the Oamaru Harbour been so designed as to have included water of sufficient depth for the largest class of ships. This was out of the question, on the score of cost, at the time the works were begun. If a beginning were now to be made, I have little doubt the works would be designed on a larger scale, and would be more serviceable to the Town of Oamaru. The work already done would be of very little use if the scale of the harbour were now increased. My reply to both sections of the question under reply is therefore in the affirmative. 6th Question. —Do you believe that any harbour could be successfully constructed between the Waitaki and Lake Ellesmere ? Answer. —l do not think so. The large Canterbury rivers bring down so much shingle that any harbour works would be rendered useless by it. 7th Question. —What is the effect of moving shingle on permanent harbour works ? Answer. —The shingle heaps up on the windward side of the harbour, until the corner between the pier and the beach is filled up, when the shingle begins to travel across the harbour mouth. If there is not sufficient tidal scour in and out of the harbour to keep open a channel, a shingle beach would be formed completely across it, and a detached beach would form to leeward. If there were sufficient scour to keep open the channel, a bar only would be formed across the harbour mouth, the depth of water on which would depend on the quantity of shingle travelling, the amount of scour, and the direction and force of the waves. Bth Question. —Are there any harbour works, within your knowledge or experience, the conditions of which are at all analogous to those of Timaru ? Answer. —There are many harbours which have been successfully built where a small travel of shingle takes place, but I know of no beach where a tithe of the quantity of shingle travels that does on the beach between the Waitaki and Lake Ellesmere; and I know of no harbour works having been undertaken under conditions so likely to lead to failure as occur there. 9th Question. —As regards the cost, are you of opinion that the figures of Sir J. Coode's estimate can be relied upon ? Answer. —The plans are not made in so detailed a manner that an estimate could be formed from them by any one but the designer, or at least without further information being furnished by him. Erbm a very rough calculation I have made, I am afraid the actual cost would be found to exceed the estimate. 10th Question. —Are you of opinion that, if the proposed works are constructed, there is any likelihood of any injury to the harbour as it now is ? Answer. —No, I do not think so. In the event of a complete failure, the only effect would be that the shingle beach would be widened seaward until it embraced the harbour works. 11th Question. —Has the plan proposed by Sir J. Coode been carried out elsewhere on a scale sufficient to test its efficiency for large harbour works, such as proposed at Timaru? Answer. —I have no knowledge of any large harbour at all similar in design to that proposed for Timaru. 12th Question. —Have you any objection to the proposed plan ? If so, upon what do you base your objection. Answer. —I am of opinion that the proposed plan is the only one on which there would be the least chance of success. I am, however, also of opinion that it would not be successful. I should have more hesitation in differing from the opinion of so eminent an engineer as Sir John Coode if he had any personal knowledge of the locality, and knew from his own observation how large a mass of shingle is brought down from the mountains by the Waitaki, Waihao, Otaio, and Pareora Eivers, all of which are to the south of Timaru. Erom the Waitaki to Timaru the coast-line bears somewhat west of north, while the average direction of the seas beating on the beach is from the south-east. The beach is thus not at right angles to the direction of the seas, and the obliquity causes the shingle to be carried northward. To the north of Timaru the beach tends to the north-eastward, thus being nearly at right angles to the average seas, and the shingle there travels less rapidly than it does between the Waitaki and Timaru, but the quantity is much greater, as several very large shingle-bearing rivers there fall into the sea. The quantity of shingle brought down by a river like the Waitaki is enormous. I know of no other country in which the geological, and topographical features so favour the formation of shingle. The mountains in which the Waitaki and other Canterbury rivers have their sources are formed of clay-slates, so fissured that they may be said to consist of ready-made shingle: indeed, Dr. Hector named them provisionally, before their geological value was known, the " shingle-forming rocks." It is by no means uncommon to see in these ranges long slopes from 500 to 1,000 feet high, as regular as the slopes of a railway embankment, and formed entirely of clay-slates, broken up to about the size of road metal; the stone lies at an exact angle of repose, and if a shovelful were taken from the foot the movement would extend to the top of the slope. It may readily be conceived that a mountain torrent rushing past the foot of such a slope would carry immense quantities of shingle into the main stream. Even where the rocks are not actually broken up, they are so easily disintegrated that every small

11

E.—2

stream forms a large fan of shingle where it reaches the valley. During floods the streams cut deep gulches through these fans, carrying the shingle away into the main river. Some idea may be formed of the quantity which is thus brought into the Waitaki, from the fact that the inclination of its bed is between 30 and 40 feet per mile, while that which the bed of a river of the same size would take if no new shingle were brought into it would not be greater than 3 or 4 feet per mile, for it is a large stream, fully three-quarters of a mile wide when in flood, with a depth of from 10 to 12 feet at its lowest stage of water. Although it would be impossible to estimate how many tons or cubic yards of shingle the Waitaki bears to the sea, I think the fact that its inclination is ten times greater than it would be if it carried none is sufficient to show that it brings down enough to bury any harbour works which impeded its progress northwards. As above stated, I believe the greater part of the shingle brought down by the rivers south of Timaru is driven northwards by the sea, and passes that roadstead, to be distributed over the beach between the Orari and Ellcsmere. Sir John Coode proposes to make his harbour, which would be of a horse-shoe form, about 900 feet from the beach. The inner limb would be parallel to the prevailing seas —that is, north-west and southeast. It is hoped that by this arrangement the shingle will pass harmlessly along the beach as at present. Sir John anticipates " some little accretion [of shingle] at first in the bight of Caroline Bay," but does not think it would be prejudicial. With great respect for his opinion, I, however, think' there is a very great chance of this accretion being sufficient to render the whole work useless. I think, also, it would take place, closer to Timaru than the bight of Caroline Bay. Sir John states that he is informed by Mr. Eliot that gales from the eastward seldom occur, and he does not appear to have been informed that heavy seas from the eastward without wind are by no means uncommon. Now, an easterly swell would drive the shingle northward, and a large part of the beach would be sheltered by the breakwater from such a swell; the shingle cannot pass still water, and would accumulate between the breakwater and the beach. With the immense quantity of shingle which I believe to be moving, a few days of easterly swell, if followed by northerly gales, miyht, I think, cause such an accumulation that a southerly wind following would be unable to clear it away. The accumulation would then increase rapidly, and in a few years the whole work would be buried in shingle. 13-7. Question. —Are the circumstances in connection with the harbour works at the Cape at all similar to those which exist at Timaru ? Answer.—l have no personal knowledge of the Cape, but I believe the circumstances to be quite different. 14<th Question. —Sir J. Coode's proposal is that the work should be done by labour under the superintendence of Government: are you of opinion that such a system is preferable to doing them by contract ? If so, state your reasons. Answer. —I believe work could be carried out very much cheaper by day labour than by contract if the Government would give their executive officers as much power as a contracting firm give their agents, especially the power to get rid of a useless man without giving a reason for doing so. The principal difference between a well and ill managed contract is generally that the subordinate officers in the one look to their immediate superiors for praise or blame; and in the other they trust to side influence for promotion. Under parliamentary government, where all the workmen have votes, there would be great danger of those officers being most successful who made themselves popular with the men by allowing " Government stroke;" but if members of Parliament loyally abstained from interference with the management of the works, and from 'recommending men for employment, I believe work could be done cheaper by day labour than by contract. The contract system may be described generally as a system by which the contractor cannot lose and may gain. If the contract is a losing one it is given up, or on one plea or another the losses have to be made good to the contractor. If, however, it is a paying contract, the contractor makes money which he does not share with the Government. Again, a great many contractors are men of no skill or judgment, who lose money even when the prices are good, simply by bad management. Here again the Government often lose by the blundering of a man who is practically an irremovable servant of their own. It would not be difficult for the Government to secure the services of the same men who under the contract system actually carry out the work, and these men would work just as well for the Government as for the contractors. The contractors' profits would be saved, and the cost of a double staff of engineers, who under the contract system are necessary. I have had some experience of carrying out extensive works by day labour, and the company who adopted the system got at least twice as much for their money as a neighbouring company did who adopted the " responsible contractor " system. 15th Question. —In the event of this work being decided upon, would it not be expedient, previous to the commencement of the works, to obtain further professional advice as to the feasibility of the proposed works, reference being had to the peculiar circumstances of Timaru ? Answer. —I consider the chances of failure so great that I think the works should not be begun without consulting some other engineer, and 1 think some one well acquainted with Timaru should be sent to give information to such engineer as to the peculiarities of the locality. I would even recommend that Sir John Coode be invited to visit Timaru. I have, &c, John Carritthers, The Hon. the Chairman, Waste Lands Committee. Engineer-in-Chief,

E.—2,

12

Enclosure 1 in No. 7. OAMARU HARBOUR WORKS. The Engineer-in-Chief to the Hon. the Minister for Public Works. Sir,— Wellington, 30th October, 1871. I have the honor, in accordance with your instructions, to submit the following report on the harbour works at Oamaru :— The works which it is proposed to carry out there are shown in the accompanying general plan and consist of—lst, A south concrete pier; 2nd, A north concrete pier; 3rd, A dock. It is proposed that the south pier only shall be constructed at present, the others being left for future consideration. I made, accompanied by Mr. McGregor, the Engineer in charge of the harbour works, a careful examination of the coast from the mouth of the Kakanui Biver to the North Cape of Oamaru Bay, and again at the mouth of the Waitaki Biver, with the viewr of finding out where the shingle which forms the beach at Oamaru comes from, and whether it is stationary or not. I feel pretty confident that the beach south of Cape Wanbrow is permanent, and that no shingle to speak of comes from the south into the harbour. To the north the shore consists of shingle cliffs from twenty to fifty feet high, which are being rapidly cut down by the sea, and there is little doubt that this is the cause of the Oamaru beach. There is also, I think, no doubt that on the whole the beach is stationary. With northerly seas the shingle is heaped up opposite the town, and with southerly seas it is driven away again to the north. The heaviest seas are from the south-east, and the harbour is partially protected from them by Cape Wanbrow. It is found, however, that the waves curl round the end of the Cape into the harbour, and it is to prevent this that the south pier is to be constructed. The pier is to consist of a concrete wall, 1,000 feet long, and raised to high-wrater level, and is estimated to cost £35,000. I have no doubt that it will much improve the harbour, and it appears to me to be designed of sufficient strength to resist the heaviest seas. It is not unlikely that the shingle will collect to a considerable extent inside the harbour when the pier is completed. At present the shingle brought in by the northerly winds is driven out again by the southerly ; the pier will offer no hindrance to its coming in, but by breaking the force of the southerly waves will prevent its being driven out again. Ido not think this will cause serious trouble for many years ; and, when it does, the erection of the proposed northern pier will stop it. The northern pier is to be of concrete, about 2,000 feet long, and will cost about £70,000. As it is not intended to go on with its construction at present, detailed plans have not been made; but there will be no difficulty in building it, and thus completing the protection of the harbour from all seas. It is not proposed to build the dock until both piers shall have been completed; so neither plans nor estimates have been made. I have, Sec, John Caerutiiers, The Hon. the Minister for Public Works, Wellington. Engineer-in-Chief. P.S, —The plan is in the Exhibition Boom, Public Works Office.

Enclosure 2 in No. 7. REPORT ON THE OAMARU BREAKWATER. The Engineer-in-Chief to the Hon. the Minister, for Public Works. Sir,— Public Works Office, Wellington, 14th July, 1874. In accordance with your request that I should report on the present state of the Oamaru Breakwater, I have the honor to state that, although I examined the works closely when I was there, I took no measurements, and am therefore unable to report on the amount of work which has been done. In October, 1871, before the work was begun, I had the honor to report to the Hon. the Minister for Public Works on the plans. It was at that time thought that enough shingle travelled round Cape Wanbrow from the south to render the breakwater unserviceable at a more or less distant date. I therefore carefully examined into this matter, and reported that I thought the beach to the south, was stationary, and that "no shingle to speak of came from the south." Experience shows this opinion to have been correct. The contractors cannot now get any shingle from the south side of the breakwater, and it may be taken for granted that the works are perfectly safe from failure from this cause. The breakwater is also designed of ample strength, and is being carried out in a manner highly creditable to the contractors and to all concerned in the supervision. As far as could be judged by what I saw, the work is being done as well as it is possible to do it. The cement used is of excellent quality. The concrete is well mixed, and the blocks are set in place in a very careful manner. 1 have not in any respect changed the opinions I expressed in my former report —viz., that the present breakwater will much improve the harbour, but that eventually the northern pier will have to be built as well as the present one, on account of shingle from the north heaping up under the shelter of the southern pier. When this is done, the harbour will be protected from all winds, and will be a safe and useful work. The rate of progress appears to me to have been slow ; but I am not acquainted with the causes of delay, which have probably been unavoidable. With the magnificent plant now on the work, I have no doubt future progress will be more rapid. I have, See., John Carrtttiiers, The Hon. the Minister for Public Works, Wellington, Engineer-in-Chief.

13

E.—2

Enclosure 3 in No. 7. TIMARU HARBOUR WORKS. Mr. Carrfthebs to the Chairman, Timaru and Gladstone Board of Works. Sir,— Timaru, 29th October, 1871. I have the honor, in accordance with instructions, to submit the following report on the .Roadstead of Timaru :—■ In November, 1865, and in September, 186S, the late Mr. Balfour wrote two valuable reports on the same subject: these, together with his plan of the roadstead and a very elaborate survey made by Lieutenant Woolcombe, have been placed at my disposal, so that I have had considerable facilities for acquiring information. I have also examined the beach for some miles on each side of the town, and have gathered by personal inquiry of persons acquainted with the roadstead such information as could be procured. Above all, I have carefully observed the experimental breakwater constructed by Mr. Balfour. It is agreed, by every one acquainted with the subject, that the prevailing seas come from the south-east, and this is fully corroborated by the trend of the coast at points where the beach does not seem to travel. The trend of the coast between the Waitaki and Timaru and for some miles to the north is somewhat east of north, so that the seas break on the beach, not at right angles, but obliquely, at an angle of about 50 degrees. It is to this obliquity that the motion of the shingle is due which makes Timaru so difficult a port to improve. When a wave coming from the south-east breaks on the beach, it carries the shingle forward with it in a north-west direction; the retreating wave does not, however, travel back on the same path, but runs down the slope of quickest descent, which is at right angles to the beach, or nearly east. Each piece of shingle, therefore, travels northwards in a series of zig-zags. It is evident, since the motion of the shingle is due entirely to the breaking of the waves on the shore, that any work, such as a breakwater, which would make still water, on the beach, would deprive the shingle of all northward motion. It is not necessary that the breakwater should be attached to the shore : still water is as effectual a barrier as a masonry wall. The shingle being thus stopped, it would collect on the south side of the breakwater, until in the course of time it had pushed out to the end of the latter, when the northerly motion would begin again. In the meantime the shingle to the north, beyond the protecting influence of the breakwater, would have been still moving northwards. As no new shingle could come to supply the place of that which had moved on, the coast would soon be bare, and the sea would begin to cut down the subbeach. These remarks apply as well to an imperfect as to a perfect breakwater. In the former the effects would be slower to show themselves, as, owing to the imperfect stoppage of the waves, a part of the shingle would continue to move along the beach ; but the final effect would be the same. The practical question to be solved is, at what rate does the shingle travel ? Mr. Balfour found that some blocks of wood loaded with lead, which he threw into the beach, travelled as much as a mile in a day, even in fine weather. This would indicate a very rapid rate of travel. The experimental breakwater consisted of a concrete wall thirty yards long, placed on a reef below low water, and detached from the shore. It was hoped that the shingle would continue to travel along the beach, as the landward end of the breakwater was further to seaward than the line to which the shingle was drawn back by the undertow of the receding waves, and the breakwater was also so small that it was not expected to offer any perceptible protection from the beat of the waves on the shore during rough weather. It was found, however, that the protection given by this small work was sufficient to prevent the shingle from passing across the stiller water behind it. It was heaped up between the breakwater and the shore, and then behind the breakwater. To leeward the shingle was all carried on to the north, and the sub-beach cut away sufficiently to endanger the large store at the landing-place. This effect was perceptible at the foot of Caroline Bay, half a mile from the breakwater, and would have been much greater than it was if it had not been for the basaltic rock which forms the sub-beach over a part of the bay. This was all done in one storm, and no more convincing proof could be desired that the shingle travels with very great rapidity. The breakwater was partially carried away, giving the shingle free vent, when the beach to leeward was at once restored nearly to its original shape. There are open to the Board three methods of improving the harbour accommodation—* 1. By erecting a breakwater on a large scale, completely stopping the shingle; 2. By endeavouring to give partial protection, and at the same time letting the shingle pass; 3. By improving the boat service. Plan No. I.— The first thing to be done on this plan would be to construct a breakwater straight into the sea. It would have to be nearly at right angles to the average direction of the waves; for, if it were made very oblique to it, the shingle would pass along it and cross the mouth of the harbour, turning the latter into a lagoon with a detached shingle beach. It would have to be carried out to deep water, which would require a length of about 1,000 feet, and would have to be constructed in the most substantial manner, as it would have to resist the direct force of the very heavy seas which occur at Timaru. This part of the work would somewhat improve the boat service. A comparison with the Port of Oamaru shows that it would not do much more. At that port Cape Wanbrow takes the place of this first breakwater. It projects in the best direction for a distance of about 2,500 feet from the shore, but gives very little protection in heavy weather to any point behind it, of which the destruction of the Oamaru Jetty is a proof. The Timaru Breakwater would give still less, as it would be much shorter, and would not be carried above high-water mark; but, as the holding-ground is better, small vessels might perhaps ride out a storm behind it: they would, however, probably prefer getting to sea.

E.—2

14

A second breakwater would then have to be built generally parallel to the shore, which, if of a good length, say 300 yards, would give shelter in which vessels drawing 12 feet to 14 feet of water could lie. Landing and shipping of goods could be carried on here during somewhat rough weather, unless the sea was from the north-east, to which the harbour would be quite open. The first effect of the above works would be the degradation of the coast to the north. Caroline Bay would bo deepened, unless the bottom is rock, and would extend somewhat further inland at Mr. Henry John Le Cren's ; but it is so well protected by the rooky capes on both sides, that no great change would take place there. The detached shingle beach across Washdyke Lagoon would next begin to disappear, and it would take very many years before this supply was exhausted, so that there could be no effect on the coast further northward. In the meantime the shingle from the south would have been heaping up behind the breakwater. It is quite impossible to say how long it would be before it would reach the end; but eventually it would certainly do so. A new breakwater seawards would then be required. I consider it so probable that this would happen within a few years, that I strongly recommend the Board not to undertake the work, notwithstanding the great benefit which a harbour at Timaru would cause to the rich surrounding country. The cost of such a work as I have above described would be about £100,000 if of coucrete, or about £80,000 if timber were used for part of the work, and its value, when completed, would not be great, as but a small part of the roadstead would be sheltered, and that only indifferently. Plan No. 2.—The chances of failure with this plan are very great. Mr. Balfour's experimental breakwater had this object in view, but completely failed, although it was very well selected for the purpose. It has been suggested that, if a long jetty were constructed, with a short, solid breakwater at the end, the object would be gained ; but a short breakwater detached from the shore would give no shelter, the waves would simply curl around it, and a long one would stop the shingle, with the further disadvantage that it would be difficult to predict exactly where the shingle would be deposited, and more harm than good would probably be done. I consider this plan.even less advantageous than the first. Plan No. 3.—lt is to the improvement of the boat service that I think the Board should look. An iron jetty would, by shortening the distance to be gone over by the boats, help considerably to make the landing and shipping of goods less tedious. It would be only on a very few days in the year that a ship could lie along it, so goods would have to be carried from the pier-head to the ship in boats, as at present; and, as the jetty would be very high, there would be considerable inconvenience in raising and lowering : still, there would be a balance in favour of the jetty, especially if steam cranes w rere used. A jetty extending into 16 feet of water, supplied with two steam cranes, would cost about £10,000, and I think the expenditure of this sum would give a good return. The use of a couple of small steam-launches to towr the boats out and in would perhaps be nearly as good as a jetty. They would cost about £750 each. I have, Sec, The Chairman of the Timaru and Gladstone John Carruthers. Board of Works. P.S. —A copy of this report is forwarded to the Hon. the Minister for Public Works.

No. 8. The Engineer-in-Chief to the Hon. the Minister for Public Works. Sir,— Ist October, 1877. I telegraphed to the Chairman of the Timaru Harbour Board for a copy of Sir John Coode's memorandum for my own information, and the Board have courteously sent it. Sir John recommends that a copy should be sent to me for any remarks ; but, as no tracings have been sent, and the enclosing letter does not ask for any remarks, Ido not think any action is required in the matter. The Board also appear to have given up Sir John's design, as they arc inviting competitive designs. I have, &c, The Hon. the Minister for Public Works. J. Carruthees.

Enclosure in No. 8. Sir John Coo.de to the Chairman, Timaru Harbour Board. 2, Westminster Chambers, Victoria Street, Westminster, S.W., Sii;,— _ sth July, 1877. I beg to acknowledge receipt of your letter of 10th March, transmitting for my information copy of report of evidence, taken before the Legislative Council of New Zealand, of the Engineer-in-Chief for the colony relative to the proposed harbour works at Timaru. The design which accompanied my report of 10th August, 1875, was the result of much careful study and consideration of the data and information laid before me by Mr. Eliot upon his return from the colony, but, notwithstanding the fact that the proposed works were thus based upon a special survey and examination, coupled with much local inquiry and investigation, I nevertheless feel bound to give due weight to the opinions of an engineer of the standing of Mr. Carruthers, who is well acquainted with the locality, and has watched the peculiarities of the shingle-travel; and the more so as I have not myself had the advantage of personally examining the site. I was therefore glad of the opportunity of perusing the evidence which had been given by that gentleman, and have since well considered how far the objections which he has raised can be held to affect the principles of my design.

E.— 2

15

Before entering upon a consideration of the subject here, I think it well to point out that the gravity of the interests involved, as bearing upon the well-being of Timaru and the surrounding districts, demands that the most searching inquiry should be instituted into the prospects of success or otherwise of the proposed works, before the Board commit themselves to the large expenditure which will be requisite for their construction. Endue haste in precipitating matters in either direction would probably result in disappointment hereafter. Mr. Carruthers considers that my plan is the only one which offers the least chance of success ; but that, having regard to the travel of the shingle along the coast, he does not think, if carried out, it would prove successful, as he apprehends that, after a time, the proposed harbour would be blocked by shingle. He also says that I did not appear to have been informed that heavy seas from the eastward without wind are by no means uncommon at Timaru; and that, as the easterly swell would drive the shingle northward, and a large part of the beach would be sheltered by the breakwater from such a swell, the shingle could not pass along the bank of still water, but would accumulate between the breakwater and the beach. The question of the shingle-travel along the coast has a vital bearing upon the permanent utility and success of the proposed works, and was very fully considered by me before the design was laid down. I explained in my report of 10th August, 1875, the principles which guided me in forming the design, and the reasons which induced me to consider that the suggested works would not interfere with the passage of the shingle along the coast, otherwise than possibly to cause a slight accretion at* first in the bight of Caroline Bay, which would cease as the shore-line was brought more under the direct action of the south-east seas. Two points of great importance as bearing upon the effect of the works on the travel of the shingle must be kept well in view : first, the specially-favourable circumstance that, whereas very large quantities of shingle are incessantly travelling northwards in front of Timaru, the shingle-bank there is narrow in itself, and does not extend below low-water mark. The shingle, therefore, would still be readily acted upon by the sea, more especially in south-east winds, provided no great amount of shelter be afforded to the beach itself. The second point is also a favourable feature in the case: I refer to the fact that, as the south shore of Caroline Bay is almost east and west, whilst the general trend of the coast-line is north and south, it follows that with a given force of wave on the beach the shingle would travel more readily along the south shore of Caroline Bay (see annexed plan) than along the sea frontage on either side of it; and for this reason I determined upon starting the work from the south-east point of the bay, so that any slight obstruction to the waves which might be caused by the piles of the viaduct would be compensated for by the more favourable angle at which the waves would act upon the shingle. As a proof that the shingle travels more rapidly along the south shore of Caroline Bay than at any other part of the coast adjacent to it, I may mention that the belt of shingle is narrower there than elsewhere within the limits of the survey. It is admitted that the seas which mainly act in propelling the shingle travel in a south-east direction, and as the outer arm of the proposed breakwater pier from A to B (report drawing No. 2) is " endon " to the line of seas in that direction, it follows that the work from A to B, whilst it would afford no •shelter during south-east gales, would not affect the northward passage of the shingle. 1 propose to carry the sheltering arm from B shoreward in the direction of ~D only to such an extent as experience may show to be perfectly feasible without materially affecting the action of the waves upon the belt of shingle lying between the high- and low-water marks. Now, the measure of the shelter which these works would afford to the beach would depend upon the distance of the solid structures from the coastline—in other words, if there is a doubt as to the works permitting of the unobstructed passage of the shingle, that doubt, it appears to me, may be removed by increasing the length of the viaduct, and placing the solid works further from the shore. The accompanying trace, marked No. 1, shows the coast-line at Timaru, the direction of the rollers, as observed by the late Mr. Balfour and by Mr. Eliot, and the outlines of the proposed works. I have indicated upon this trace, by means of arrows, what would be the effect of the works upon the easterly swell, to which Mr. Carruthers has referred in his evidence. It will bo seen that with a length of viaduct of 900 feet, as recommended in my report, the sea might be expected to wheel around in the manner shown, so as to fall upon the beach and act upon the shingle throughout the length of the coast to almost as great an extent as is the case at present under similar conditions of sea—in fact, I have been from the first of opinion, and a reconsideration of the case since the receipt of Mr. Carruthors's evidence has only tended to confirm the view, that the proposed works will have but little effect upon the wave-stroke at the beach-line, and that any slight shelter which might be afforded to the shingle upon the beach would be compensated for by the more favourable angle of impact of the waves along that portion of the coast, which may be spoken of as being to the leeward of the works. Mr. Carruthers having a doubt, as to the sufficiency of my estimate, I have thought it desirable to enclose herewith a tracing, marked No. 2, showing a cross-section of the breakwater pier, from which the quantities of work to be executed were ascertained. I also enclose a statement of the principal rates upon which the estimate was based. Of course the details of the mode of construction provided for are open to modification in working out the complete and final set of drawings from which the worka would be executed. The line of action which I have to suggest for your consideration is,— 1. To forward this letter, with its enclosure (or a copy), to Mr. Carruthers for any comments which he may have to make thereon. 2. Should Mr. Carruthers's opinion still remain adverse to the success of the works, then I would suggest that the opinion of another engineer—say, Sir John Hawkshaw—should be solicited. If the Harbour Board are willing to adopt this course, should the necessity arise for doing so, I shall be prepared to hand over to Sir John Hawkshaw, or such other engineer as they may depute, the whole of the information which I have here, leaving the said engineer to draw his own conclusions therefrom, and report accordingly. 3. In the event of the further reasons and arguments which I have adduced in support of the

E.—2

16

works satisfying Mr. Carruthers's objections thereto, I. think the Board would then be fully justified in proceeding with their construction ; and if they desire that I should prepare the contract drawings and the specification, it will be necessary that particulars of the nature of the bottom along the line of the viaduct and pier should be obtained by borings or probings, and the results forwarded. It will not be practicable to decide upon the final details of the works until this information is at hand. I ought to mention that these particulars were not obtained by Mr. Eliot, because until he had returned and laid the information before me the nature and position of the works could not possibly be determined. 4. I have received your telegrams of 30th June. The first reads : " Please forward harbour specifications without delay." The second reads : " What will details and specifications cost? Reply." To which I answered on the 4th instant: "Contract drawings and specifications not exceed five hundred guineas." In the event of receiving a telegram from you authorizing the preparation of the drawings and specifications, I shall, nevertheless, feel it necessary to postpone any action thereon until all doubt as to the soundness or otherwise of the principles upon which the works are based have been set at rest by the adoption of the course herein suggested. 5. Should it be decided to proceed with the works, and if the Board are desirous of my being identified with their construction, it will be necessary for me to nominate a competent Resident Engineer. The salary of this officer would be from £800 to £1,000 per annum, and he would be required to enter into a formal agreement with the Harbour Board. 6. In the event of the works being proceeded with, I presume agreements with workmen, arrangements for plant, stores, See., would be conducted through the office of the Agent-General for New Zealand. I have, See., Eulbert Archer, Esq., Chairman Timaru Harbour Board. Jho. Coode. P.S. —After this letter had been written, your telegram requesting that the contract drawings and specifications may be proceeded with has come in. As it is quite impossible to explain the case by telegram, I have no alternative but to wait further instructions after your receipt of this letter, which I shall do, as it would, in my opinion, not be proper either for the Board or myself to incur the responsibility attaching to procedure with the work until every reasonable precaution had been taken to remove the doubts which have been expressed. —Jito. Coode. —6th July, 1877.

Sub-Enclosure to Enclosure in No, 8. Timaett Haebotte. Peincipal rates upon which the estimates given in Sir John Coode's report of the 10th of August, 1875, were based: Rubble in mound, per ton, 4s. 2d. ; concrete blocks in reef, per cubic yard, 305.; concrete in mass over blocks, per cubic yard, 405.; concrete in parapet of sea-wall, per cubic yard, 305.; concrete blocks in foundation course of harbour wall, including preparation of bottom, per cubic yard, 455. ; concrete blocks in harbour wall between foundation course and low-water course, per cubic yard, 375. 6d.; concrete blocks in harbour wall above low-water course, per cubic yard, 365. ; wrought iron in viaduct, exclusive of special price for fixing piles, per ton, £32; cast iron in viaduct, per ton, £26. In addition to the above prices, an allowance of 15 per cent, was made to provide for contingencies, sea risk, engineering, and superintendence, and also an additional sum of £36,000 to cover cost of special and floating plant. Having regard to the prospect of tenders being invited, the prices should be regarded as strictly private. Westminster, sth July, 1877. Jno. Coode.

No. 9. REPORT OF THE ROYAL COMMISSION ON THE TIMARU HARBOUR WORKS. To His Excellency the Most Noble the Marquis of Norman"by, P. 0., K.C.M.G., Governor of New Zealand. Mat it please Youe Exceli-ENcy,— The primary function which we conceive ourselves to be called on to perform is, in terms of the 28th section of " The Timaru Harbour Board Act, 1876," to approve or otherwise of the plans and estimates of work previously adopted and determined on by the Harbour Board. We find, however, that the Board has not finally determined on any plan. We are unable, therefore, to exercise the approval which the Act requires to be given before any work can be commenced. Instead of any adopted scheme, the Board laid before us eleven plans which had been submitted to them in response to an advertisement calling for competitive designs. Of two of these they had expressed an approval by awarding to them first and second premiums ; and a qualified acceptance, as a working plan, of that which received the first prize, was intimated to us, but with a request that we should examine the whole of the plans, and express an opinion as to the suitability of any of them or parts of them. This duty is far larger than that contemplated in the Timaru Harbour Act, but, since it appears to fall within the scope of your Excellency's commission, we devoted ourselves to the performance of it as well as the limited time at our disposal would admit. The one formidable consideration on which the practicability of making any breakwater at Timaru depends, is the asserted travelling of the shingle along the coast. It has been maintained that the whole of the shingle beaches which extend from Oamaru to Banks Peninsula are subjected to a powerful and continuous scour, which perpetually urges their material to the north, the shingle so removed being constantly replaced by fresh supplies discharged from the great rivers, and by an erosion of some shingle-bearing cliffs to the south of Timaru ; and that the quantity of shingle travelling is so vast that any work exposed to its action, which, by diminishing the motive force of the waves oa

17

E.—2

any pa.it of the line of coast, would afford a resting-place for the moving mass, would be speedily overwhelmed by it. To this subject, therefore, our inquiries were mainly directed. The weight of the oral evidence which we have taken, as well as our own observations, have led us to the conclusion that the impact of the waves on the shore is, an the average, in a direction very nearly perpendicular to it, and that the ordinary movement to which the shingle is subjected is to be carried outwards towards lowwater mark and a short distance beyond it, under the influence of the south-east seas, which are the heaviest which occur on the coast, and to be replaced near high-water mark during the fine weather, with winds from north-east, which prevail during the greater part of the year. It seems certain that the result of these excursions is a general movement to the north ; but we find nothing to convince us that the quantity so travelling is so large as seriously to endanger harbour works on a considerable scale, within such a period as it is necessary to look forward to in a colony. The plan proposed by Sir John Coode is to construct a solid breakwater, by means of barges, at a considerable distance out, which would only be connected with the shore after its completion, by an open viaduct. The adoption of this scheme would involve a cost far beyond the means likely to be available, since the breakwater would necessarily have to be of the great size designed by him to afford sufficient shelter; and the plan would be liable to the further objection, that it would afford no facilities to the commerce of Timaru during the long period which would be required for its construction. On the whole, then, we are led to conclude that a solid mole, carried out from the shore to a distance of about 900 feet, and terminating in a breakwater similar in character and direction to that proposed by Sir John Coode, but of smaller dimensions, would best meet the requirements of the port, would be the least expensive to construct, and that such a work would not be exposed to greater risk of failure from shingle or any other causes than necessarily attaches to any harbour works on an exposed coast; but in the course of executing such work, experience would be acquired such as we do not now possess. At least a year would be consumed in carrying out the mole to a distance of 300 feet: if, during that period, an accumulation of shingle should take place in the southern angle between it and the shore, such as should threaten injurious consequences, an opening might then be left, which we believe would be as efficacious as one commencing from the beach, while the portion already executed would shelter the present landingplace, and would afford considerable facility for carrying on the commerce of the port with appliances similar to those now in use. The two plans selected by the Harbour Board are both framed on the principle of starting with solid work from the shore. We are unable to approve absolutely of either of these, in terms of the 28th clause of " The Timaru Harbour Board Act, 1870." The one to which the first prize was awarded is inconvenient in form, provides insufficient wharfage accommodation, and the construction it proposes, of pierre perdu, would certainly not resist the transporting action of the sea. The other, with a better form and a safer mode of construction, is proposed to be placed in a position where the harbour would be inconvenienced by rocky ground, and the strength of the structure would have to be somewhat increased. The estimate of cost of both is certainly too low. One other plan, marked "A Mon Cre," is, in our opinion, a very superior one, an(i the report accompanying it shows that the difficulties have been carefully weighed ; but its extensive character— the outer breakwater being connected with the shore by a mole no less than 1,326 feet long—would make its construction so necessarily costly as to put the adoption of it quite out of the question. This plan would make use of the rocky ledges running off Patiti Point, both to lessen ihe cost of the mole carried out on them, and also as a sheltering breakwater for the work, since the heavy seas are broken on them and their power much lessened; the outer point of the reef would even give some protection to the finished work, such as the Cape does to the Oamaru Breakwater, though necessarily less efficiently, since the reef has a considerable depth of water on it, even at low water. Accepting, then, the general form of the work as shown in the plan, marked " Panagathos," we think the most suitable situation for it would be to project the mole in a nearly north-easterly direction from the point on which Mr. Balfour's breakwater was constructed, carrying it out with the greatest rapidity solid to the extremity of the rocky bottom, about 300 feet. If, by the time that was completed, the accumulation of shingle should be but small, the work could be proceeded with in the same manner; but if, contrary to expectation, the southern angle should be found to be extensively filling up, it would be prudent to construct a timber framing over the executed portion, to carry platform and rails at a height of 20 feet or 21 feet above high-water mark, to he continued by a work on the same level on piles over a space of 300 feet further, from which point again the solid work would recommence, formed as before from the shore end. We think that the curl of the sea round the end of the shore work would be certainly sufficient to cany inshore the shingle, should any pass it, and that the greater facility the shingle has in travelling in a westerly direction would prevent it from lodging till near the turn of Caroline Bay. It remains to consider the mode of construction ; and here, unfortunately, we are met by some uncertainties which preclude our giving any confident opinion. Wo have been unable to learn that any borings have been made to ascertain the substratum of the bottom outside the rocky ledge, which is marked on the map as " fine sand," but which several of the nautical men whom we examined called mud or clay. The shore in the neighbourhood of Timaru consists of sandy clay of moderate depth, lying on beds of what appear to be streams of basaltic lava. This flatlying rock forms the ledges which everywhere line the shore, and inland it is seen in some places that several beds of it occur, separated by moderate thicknesses of clay soil. It has been stated by several witnesses that the fine sand in the roadstead is only a shallow deposit on such rock ; but we have no certain evidence of the fact. Should a flat rock-bottom lie at accessible depth below the clay, it would render practicable a construction on the same principle as that on which the work is being carried on with such signal success at Oamaru ; and before any final plan can be resolved upon, it is absolutely necessary that the bottom should be tested by borings, carefully executed along the line of the proposed works. It* has been suggested that gravel may underlie the thin coating of sand. Should this really be the case, it would greatly increase the risk of constructing any work at all, as the supply of shingle would be inexhaustible. Should the sand or mud be of considerable depth, the only construction suitable would be random blocks. Very cenvenient quarries, at no great distance, would furnish an 3

E.—2

18

abundance of material of a high specific gravity, and of which a large proportion —probably one-half— could be got in blocks from five to ten tons weight. It is certain that a mound of stones of this weight would not long resist the transporting action of the sea, and it would have to be protected on the outer face by blocks of concrete, of not less than thirty or forty tons weight, thrown over the side of the work. But wherever a tolerably fair continuous foundation of rock can be obtained, a mode of construction like that in use at Oamaru would furnish so substantial a work, with the use of so much less materia], that there can be little doubt of its superiority. While this uncertainty as to the best mode of construction exists, it is impossible to form any accurate estimate of cost; but, after comparing the cost of the much more favourably situated works at Oamaru, we are convinced that a structure of the dimensions shown in the plan marked " Panagathos," which we consider are the smallest which would give the required accommodation, could not be completed under £250,000, and that it would not be prudent to undertake any work of this kind unless that sum could be definitely counted on. Given under our hands and seals this 13th day of December, 1877. Theoph. Heale. John Henderson,

Minutes op Proceedings. Commissioners : Theophilus Heale and John Henderson. We, the Commissioners, met in Wellington on the 20th November, 1877, and proceeded to Timaru on the 21st. On the 24th November we sat in the Harbour Board Office, at Timaru, and commenced to take evidence, and continued so to do day by day until the 29th November. On the 31st November we proceeded to Oamaru, and examined the breakwater and beach, and proceeded thence to observe the effect of the Kakanui Harbour works, returning to Wellington on the 6th December, since which time we have been discussing the evidence and drawing out the report which we now have the honor to present. Theoph. Heale. John Henderson.

By Authority : George Dibsbuby, Government Printer, Wellington.—lB79.

PROPOSED JETTY FOR TIMARU BY J.M. BALFOUR ESQR MARINE ENGINEER To accompany Mr Blacketts Report of 2nd February 1880.

CROSS SECTIONS at Whales Greek-Timaru 25th June 1879. Scale 20 feet=1inch.

To accompany Mr J.H. Lowe's report of January 5th 1880.

Plan illustrating Sir John. Coode's Report on TIMARU HARBOUR