ALTERNATIVES TO PURAKANUI CLIFFS.

Otago Witness, Issue 1918, 24 August 1888, Page 21

ALTERNATIVES TO PURAKANUI CLIFFS.

A representative of this paper waited on one of our local engineers on Wednesday with the view of obtaining some information with regard to the d--uiger that existed on the northern line of railway, and also with regard to the relative merits of the alternative routes that have been proposed in order to avoid Pnrakanui cliffs. The gentleman in question was very willing to render what information he could, and in reply fco questions put to him he said the danger of Jhe existing- route round Purakanui cliffs was bfcat the -whole of the hillside was of very looseformation, and unless the top soil was taken down to the rock, and a long slope made, there would always be theriskof some loose stuff coming do«-n. People who knew the locality said thecliff was undermined, and the public would aiot be "atif fied until an exhaustive examination wa» m»'V aud the matter set at, rest. Bofcre proceeding with the tunnel as proponed, or any protective works, it would be necessary to makesura that the rocks at the cliffs were safe, and sufficient to carry the weight of the works. ' If no alternative line was to be made, a tunnel was probably the moat feasible scheme for making the present line sufficiently safe. The

tunnel, however, might be expected to cost a very great deal more than £10,000 The .formation of the- bill was Buch as would probably render tho lining of thu tunnel absolutely necessary, &n was'found in the case of the Deborah Bay tunnel, which was expected to be sufficiently solid to stand without lining, but it had afterwards to bo lined at a very considerable cost. He thought the line at Purakauui was &o dangerous that tne Government were bound in the interests of the public to make it thoroughly safe. The danger that existed afc present would be obviatad in one part of the route at least by a tunnel, provided the cliff was solid ; but to put a tunnel through tha whole length of the ground which was now dangerous would involve a very large expenditure. Supposing that ib would take £20,000 to make a tunnel and approaches at present afc Purakanui, he thought it would ho advisable to do this, although an altogether different line wore made ultimately, because it would take, two or three years before a new line would ba available for tratfic. It therefore Seemed necessary that there bhould be an outlay of m ney at the cliffs at the present time, so us to secure the safely of the travelling public with as little dtl-iyas possible. The y'ac<j could not pos-iibly be made safe without some sort of covering being provided for the highway. He did not look upon the line this Mdc of Deborah Bay as being very dangerous. There was a very big embankment there, but its firmness had been pretty well tested now. A slip m|ghfc possibly occur, but he did not consider the line there was really dangerous. | With regard to the Leibh Valley route as an alternative to the present line, he said the primary fact of the natural fall of the valley at j Woodhaugh being as steep as 1 in 40 was sufficient of itself to show that we nce'l not look for a line being made up the valley. He did not think .Dr Coughtrey'd route was at all practicable, as the hill which would have to be encountered was too forbidding, being very solid. The route would also involve a tunnel of some miles in length, as the hill was very wide and the distance in which a grade could be run up to the tunnel very short. The route at Sawyers' Bay appeared to be open to the objection that a tuunel of more than two miles in length would b« required. The tunnel would certainly be through solid ground the greater part of the way, and the route would be a shorter one to Blueskin than that which had been adopted. Then it would have the same advantages that all inland lines had, of serving the country on each side of it. In referring to , the Mount Oargill route— i.c, from Ravensbourne up the slope— he said if it could be shown that it was a superior route to all others, and that the only objection that could be urged against it was that it rose to an altitude of 500 ,feet more than the present line, ifc would ceriainly have been better to have taken the line by Mount Cargili than to run the risks which were run at present at Purakanui. He was persuaded that if things had to be commenced denovo, the route starting from the south end of the Lookout Point tunnel, and going via Balmacowen Saddle, thence into the Kaikorai and Leith Valleys, and rising up and piercing the Faddle between the Leith Valley and the Wa'tafci by a tunnel a mile and a-half in leugth, would, on the whole be the best loute to be adopted. Throughout its whole length ifc would go through country of good firm formation. At the Duo&fiHti end ib would develop a payable suburban traffic. Further up ifc would have good timber traffic; ultimately a good dairy traffic; and, most important of ail, it would aid in deveb ping the workings of shale deposits which were situated on the Waitati watershed. It might be urged, of course; against this route that it went a little higher, and would also be longer than the route from Sawyers' Bay, via Purakanui, as already constructed, but the larger amount of traffic which might reasonably be expectfd from its adoption would compensate for the length. The distance from JDunedin by the Kaikorai Valley route and by th>i present route to the north of Blueekin Bay, would be about the same. The objection "with reference to carrying the goods traffic over a higher altitude than ifc was carried at present wa3 after all not so important as ifc afc first sight appeared, considering that any goods that had to go coastwise— north, say of Otspopo— would go by sea. The goods intended for the interior would ultimately goby -the Ofcago Central, so that the principal part of the goods traffic that would go over the Kaikojai Valley line would be for the district more, immediately adjoining it, as> far north perhaps as Otepopo. As regards the passenger traffic, passengers would not iv the least object to being carried a higher altitnd?, but if the matter were put to them they would certainly prefer that to encountering the risk at Purakanui cliffs. As regards the question of the carriage of goods, the matter, so far as the line now adopted and the Kaikorai Valley line were concerned, resolved itself into whether a comparatively low-level line would be taken along a country which was not likely to -iurnish traffic to any considerable extent or along a slightly higher altitude through a country of remarkably valuable natural resources. If any one were asked to decide upon commercial principles he would have no hesitation in giving the preference to the line which traversed the more valuable country. Another thing in favour of the Kaikorai Valley line was that if ifc were adopted ifc would serve the woollen mills and pther factories in tha Kaikorai Valley, Ofeher tfastories would alsostarfc.no doubt, soon if there -were a railway in the valley. The construction of a line from Look-out Point tunnel to the north part of Blueskin Bay would probably .cost something like £130,000 The Government, rhowever, would never think of making this line 'at present for the sake of avoiding the present .difficulty at Purakanui.; .but the features of the \ country by the KaikoritUValley route were suffi,'jciently favourable to make it worth while to make a closer examination of •the.rqute if any calternntive to Purakanui was proposoji to be .-adopted.