TAWA FLAT DEVIATION

Dominion, Volume 21, Issue 15, 12 October 1927, Page 12

TAWA FLAT DEVIATION

FURTHER CRITICISM (To the Editor.) Sir, —I have held the view for a considerable time that our new Tawa Flat tunnel was going to be constructed in the wrong place, but I have abstained from paper criticism, principally on account of the fact that I am not a railway engineer, and have left a more qualified man to open the criticism of the Government scheme. 1 am glad tliat Mr. Fulton has criticised the scheme, and I feel that I am at liberty to amplify his statements by my knowledge, gained through twenty-five years’ experience as a licensed surveyor and engineer, in and around Wellington. f have been over this part of the country hundreds of times, and would like to enter my protest before it is too late.

I would like to outline what 1 conceive to be a better scheme than Mr. Fulton’s or the Government one.

Starting from Ngahauranga and going north along the present Hutt line, about a mile, the Hutt road could be crossed either by a ramp or by an elevated line as Mr. Fulton suggests. This would bring you to a point just north of a place known as I’aparangi Point, where the tunnel would start to pierce the hill, taking as its alignment a point close to the Tekapu overhead bridge for the northern exit. This would give practically the same results as Mr. Fulton's, only with the difference that the grade would not be quite as easy as one in 300, but would pan out somewhere between one in 260 or one in 280, according as to whether the Hutt Road was crossed by a ramp or an elevated line. The grade could be made easier by lowering the present track ac the Tekapu bridge. Haulage up, to haul down again, is quite contrary to the best rules of engineering, and is cut out m my scheme, as well as in Mr. Fulton's, and both schemes are infinitely belter than the Government one. Now the Government schenio is faced with costly construction at its northern exit near Piebald Corner, right along to where the old track is picked up near the Ranui golf course. This will entail heavy cutting, numerous curves (also quite contrary to the best rules of engineering), the destruction of the farms and homesteads, outhouses, fences, hedges, etc., the construction of numerous culverts, the concreting in of the Porirua Stream, the mutilation of the Main Highway now in the course ot construction; the beauty of the landscape would giv° place to day banks, to say nothing about compensation for destruction wrought, and all could bo avoided. Tho advantages of my scheme aro obvious. . The lino is direct, with a climb of 90 feet, as against 195 in the Government The grade imperceptible for heavy haulage. . , The smoke nuisance is reduced to a minimum, and the comfort of the passengers considered. No costly viaducts.. ' No costly construction at the northern exit. Here the Government scheme fails badly. . No compensation for destroyed farm houses, severences. etc. . ... No extra funnelling worth mentioning. No clay embankments along our mam highway. ~ , . ... No destruction of the beauty of the countrv-side— everything will be underground. . . , No curves worth mentioning and the utmost speed can he obtained, a thing badly wanted, in these days of hustle. A straight line could he had practically right to the Tawa Flat railway station. No haul up to haul down again. The cost of the work entailed in pushing out the sea 24ft. is saved in other directions previously mentioned. It is well that practical and experienced men like Mr. Fulton should take matters like these up. He predicts that he will be abused, but I do not think so. Instead, if this scheme can be altered, I think he should bo thanked by the people of this Dominion, particularly those of us who use the railway everyday and who desire to see a fast service, with the maximum of comfort. I don’t see how we can have either of these with grades of 1 in 110 or 120 in a tunnel nearly three miles long.. I can just imagine what a second smoker will be like—phew! Any error in location and grade must be nailed down before the work proceeds further, and I am confident the Government aclieme ’8 wrong in both. ■The work should Hi done. properly now wo are at it. A little longer tunnel or a little more expense should not weigh one iota, as long as we get a job that we are proud of and one that cannot be bettered for grade and location. We see all over the Dominion badly located roads, with hairpin bonds end steep gradients, which in nine cases out of ten could have been avoided. The same applies to the railways. We see it on the Alam Trunk, Rimutaka. in fact, nearly every line in the Dominion. We see in manv places short radius curves put in ail lib. where straight and long easy curves could have been used with very little extra cost, if any. If we are going to have fast services with safety through the country (and the time has arrived), then scores of these short curves will have to be cut out, also grades will have to be flattened. Bi

the hard part is (hat the taxpayer has to pay twice over for bad engineering—he does not count in the picture at all. I do not think Mr. Fulton’s, criticism or mine will carry much weight with the Minister, who, being a layman, has to rely on his staff to supply him with all his d»ta and to prompt him as to what he should do. Ho has no alternative : but in matters like these, a competent engineer outside should be asked for a report. It was only the other day that some adverse criticism was levelled at the Arapuni scheme, but the critic may just as well have saved his time and ink, but if the thing is a "washout” he will have the satisfaction of saying, "I told you so." This will be about as far as we can expect to get. What I wish to avoid is a repetition of such monstrosities as .Mangahao, Paremata Road, Paekakariki Hill Road, etc., and it is only by getting tho best brains in the community that these calamities can be avoided. The sorry part about our Public Works is this—there is never an estimate nor a plan published until tho work is well under way—then it is too late for outsiders to offer suggestions.—l am, etc., 11. SMITH. Paekakariki.

P.S. —Since writing this letter, I have noted the reply of the Minister of Public Works to Mi-. Fulton’s. He certainly picked out a weak spot in Mr. Fulton’s scheme in the additional length, but this does not apply to my scheme, which is just as direct ns the Government one. The Minister’s reply regarding gradients is equally weak. Because there are gradients of 1 in 100 on the Paekakariki —Palmerston line in the open it does not say that we nre to suffer a similar one in'the second longest tunnel in New Zealand. It is not necessary. H. S.