REPORT ON THE NGAKAWHAU COALFIELDS.

Westport Times, Volume VII, Issue 1098, 15 August 1873, Page 2

REPORT ON THE NGAKAWHAU COALFIELDS.

Mr H. P. Higginson, C.E., has reported to the Eugineer-in-Chief the result of his visit to Westport and the Ngakawhau in June last. From a printed copy of his report we extract the following valuable information. Mr Higginson reports that having personally inspected the Ngakawhau in company with Mr A. I) Dobson, whose knowledge of the district was of essential service, as also the information obtained from Harbor Master Captain Leech, it was obvious that there were only three propositions to deal with, viz:— 1. To render the Ngakawhau river navigable for small steamers and barges drawing not more Wan eight, feet which would convey coal to larger vessels lying in the River Buller. 2. To construct works of such a nature as to give 1 2 feet or more in the •Ngakawhau at low water, with wharfage sufficient for vessels to carry the whole trade, and to make such excavations in the bed of the river as would allow those craft to swing clear of everything. 3. To connect the Ngakawhau coalfields with the River Buller at Westport by means of a railway, and there to construct wharfage at which Vessels could lie to take in cargo l with safety during floods. After describing the Ngakawhau as being a river with bar dry at low water, and the channel upwards to the pool opposite the mine as being nearly dry at low water, although navigable at high tide, and the pool being of an area only sufficient to allow certainly not more that two vessels with a few barges, representing a measurement of about 300 tons, to take in freight at one time; Mr Higginson records his opinion that proposition No. 1 will mt-do • for the following reasons, shortly stated. Twice handling the coal would be objectionable. The process of digging it out of barges to tranship would also do it harm. The transport from the mine to the Buller by sea would be most uncertain, depending on the state of the bar and weather ; the frequent formation of shingle banks on the bar rendering it often impossible for a vessel to go out seem on to sea. The limited supply to be thus obtained would prove insufficient The improvements required to work the mine in this manner would not be extensive. The channel and pool should be widened and cleared of boulders and snags and the jaws of the entrance pitched with large stones to prevent floods cutting away the shingle. Proposition No. 2.—Haying made careful observations of the beach north and south of the river, in order to ascer tain if it is to any extent affected by the current setting northward ; Mr Higginson came to the conclusion that this northerly t-et does not extend so far, or else that the Torea Rocks are a check upon the shiugle. The bank forming the bar of the Ngakawhau seeming to be a fixed quantity conducting itself in the following manner :—A heavy sea running, for some days drives it home into the mouth of the river, the channel forcing a straight central course, throwing* the shingle up on either jaw of the entrance. At such timos, the river being easily navigated, a vessel taking the bar end on. When (he river is flooded the shingle is swept off each jaw or bank and spread out fanwise across the entrance, and the current divides into two, making the course for vessels almost parallel with the coast line, and nearly broadside on to the surf, consequently when a heavy sea is running tlie bar becomes very dangerous

The necessary works to improve the channel would be two pier heads or breakwaters, extending outwards 25 chains into deep water, contracted to a distance apart of not more than three chains, to give proper Velocity to the stream to clear the channel. The river near the mine would also require exca vating to a depth of twelve feet at low water, an expensive undertaking, necessitating the use of machinery to remove the large and closely packed bon'lders. An approximate estimate of the cost of two piers of granite blocks or concrete, a stone or timber wharf for six vessels, excavation of the basin, construction of tramways, shoots, &e, and for contingencies, is stated at £119,853, of which £34,548 alone would be required for the excavation. Any less expensive construction, such as a timber structure loaded with stone, Mr Higginson does not consider would prove of any avail, nor does he' consider it advisable to recommend the plan stated for the following reasons : " Because of the difficulty that would be experienced in entering the port during weather, the piers being of necessity so close together, for it must be remembered, that this is an open roadstead, without any shelter from north to nearly south-west. Because that during floods in the Ngakawhau river, it is certain that to some extent stones and shingle are brought down, which, however small in quantity, would eventually refill the expensive excavation made alongside the wharf. Because of the large expenditure necessary, and which might be considerably increased before the completion of the works. Also because the time necessary for construction cannot be accurately defined. Proposition No. S. —Referring thereto, Mr Higginson says: " I have now arrived at the last proposition, and the one I can confidently recommend as being the quickest and the most efficient manner of opening up not only the Ngakawhau but the Waimangaroa coalfields as well Its adoption would not prevent the River Ngakawhau being

used for small craft to a much larger 1 exteut than it now is till the works are completed. A line of railway from Ngakawhau to Westport is favored by the natural features of the country—i the gradients would be nearly level, rendering traction cjieap, and only two 1 rivers of any importance need be crossed, Th>' harbor fur shipment on the River' Buller is, I believe, the best on the Const. On the 11 th June the Harbor Master sounded the bar and found H feet at high water, which is less than is usual, owing to recent floods having widened and consequently shallowed the channel. It is AVell protected from the S.W. winds by Cape 1 Foul wind and the Steeples Rocks, The river is capable of accommodating a large amount jf shipping,.with plenty,o? depth at low water for such as can cross the bar. In conveying the coal from the mine by railway they would be but once handled namely, when put into the trueka- at the mine, they would be from thence shot into the railway waggons, which, on arrival at Westport .would again shoot their contents into the vessel's-hold." After referring to the necessity for' river bank protection on the Buller, and that wharf accommodation would necessarily form part thereof, Mr Higginson indicates the proposed route for the railway as follows: "It would start from the coal reserve in Westport, (point marked on plan, somewhere about Brobam street) curving round till parallel with the beach road ; it would Cross the Orawaiti a little above the present road bridge, striking off there to the open Pahiki. Its* course for this length Would be over high sandy ground. For two and a half miles it would run through the open Pahiki, requiring very little formation, and ballast being plentiful within two feet of the surface. A mile of bush would then be passed, crossing Deadman's Creek by a small bridge. We then find another Pahiki,- through which the line can be taken for four' miles, crossing the Wariatea eri route by a small bridge'about 2 chains long. From here the line mßst strike through a mile of bush to the crossing, of the Waimangaroa, for Which a bridge of about four chains long would suffice.. From this point the line would run along; a high shingle terrace for eight and a half miles up to the coal mine. This ten ace appears formed by nature for a railway. It consists of clean shingle, and varies in width from one to three chains. It is well above high water' mark, and the line would be in a position safe from the heaviest seas. Neither ballast or drainage would be necessary, with the exception of two openings through which flood water flows from the lagoon to the sea." The estimated cost, including br'dges, £4,230, and cost of permanent way in England, £20,900, is stated at £35,35.>, or about £3OOO per mile without rolling, stock. This latter item is calculated at £SOO per mile. Mr Higginson concludes by saying that he considers the construction of the railway would answer the purpose best for nearly every reason. It would give' the means of opening up other coalfields and induce a timber export trade.