BIG ROADING WORK

Chronicle (Levin), 29 November 1946, Page 2

BIG ROADING WORK

Haywards to the Coast Two remarkable cuts, almost on the scale of those made during the reconstruction of the Ngahauranga Gorge highway, are being driven through steep ridges to straighten the Hutt Valley end of the Haywards-Pahau-tunui Road, whieh in a few years tlnie will beeoine an important highway of full-scale four-lane standards, to givo direct access betAveen the growing population of the Hutt Valley and the eoastal motorway to the north. This is the tliird time m 15 years that this one-time hill cart road has been taken in hand. First it was tackled as a reliei job, but piek and shovel methods made littie impression upon the hairpin bends and the deep gullies round wliich the old road twisted; the country was too tough for relief work results. '

A fe.w years ago power plant was used and a considerable improvement was made in gradients, but the tearing out of uutcrops on the lengtli between the Western Hutt Road and the crest above Haywards, by substanfial lillings in some of the deeper gullies furtiier on, and in the proteetion of tlie sealed surface from storniwater damage. Though the road as so reconstructed was stiil below highway standards it would proi>ably have served for a good many years but for two factors: the decision of the Water Board that the pipcline from the Hutt Valley shouid cross over the Haywards Hiiis lustead of foliowing thc lower valley route, and the phenomenal growth of population in the Hutt, to be followed soon by housing and industrial expansion at Tawa Flat and Porirua. So much is involved iu widening the road formatiou in the, lirst hiJl length ubovc Haywards and through cuttings towards Judgeford tiiat the Water Board and the Main Highways Board talkcd it over and decided that the seusiblc thiug to do was to sharc the cost of layiug thc main aud bringing the road up to full highway rcsorvation standards riglit away. That is lo say, the work that is bciug doue today will uot Iransi'oriu this road iuto a moderu motorway, but the hill ciits, neeessary iu auy case to gel llie pipeline through, and the widenings and straightcnings further on, will provide the widths and foundations for the four-lune motorway, not so many years altead. Tlie work is being done partly by contract and partly by the BublieWorks Department. In its iirst climb from the Western Hutt Road the pipeline has a service road of its own, beginniUg from near the Silverstream bridge and joining the tratiic road up the hill, before thc lirst of the bad bends.- This was a contract job, ripped along the sidlings by bulldozer and ear ry-alls in quick time, for Ihe going was straight ahead. But it would have kept a big team of picks and shovcls busy for a long time, all the same. The 70ft deep cutting in hand now and the 100ft cutting that is to follow would have been impossible in the face of labour shortage today, but the power plant is shifting the rotten rock at the rate of about 500 cubie yards an hour and in really spectac-ular fashion. Some of the spoil is being * sliced from the bed of Ihe deepening cutting by carry-alls and hauled a few chains to forin a hvge lilling, and Imlldozers shove tons at a pusli over ihe edge of the cutting to the roadway below, and from there it is hauled back to the uphill fill by carry-alls. Just ahead of this bulldozer working is a very deeji gully, but it cannot be used as the dumji for the first cutting, for the 100-foot cut will use all the space tlnit that gully provides. Tliese bulldozer experts really know thcir job; they work to the last six inches, apparentiy, with a drop of 40 feet below, with absolutc eonfidence in tlie power of the diesels to take them to the brink and take them back again. Tlie second cut will be far more spectacular, for this plant must work downwards, aiul the lirst earth slicing vy i 1 1 be done on a bench at tlie very top of the batter, more than 100 feet above tlie roadway. The formatiou is not ncarlv as tough as through the Ngahauranga Gorge, and rock-rippcrs, witli bulldozer power have so far beeu able to tear hard

putclies apart without need to use explosives. Tliese two niajor cuts and lcsser cuts vfrom ridge ends will replacc 12 bends, sonie of them in tlie bad hair-pin class, to six easy Iransitionai curves on tlas first length between Lhe Western Hutt Jfoad aud Lhe crest of the hill, but over the wiiole of this length the uew roadway will be ou the solid, l'resh-cut country, aml not upon thc deep hills. Beyond the crest and towards Judgeford a good deal of work will be done in widening oi' euUiugs and straightening of Lhe bad bends iei't in the last road improvement, but there wiiJ be nothiug spectacular. The main requirement at the niouient will be to givo space for the layiug of the three-fool main outside the paved surface as it will be wlieu the four-lane divided motorway goes o\ er the hill from tlie iHuttiWalley to .>thej coast.- « )i i.u ti Six Miles of Service Road. Just past the site of the former American canip at Judgeford the pipeline will leave the road aud will follow a narrow vaJlev up Duck Creek. (Kabbits, and a hare or two, yes, but no ducks, not a featlier.) This is entailing the carving of six miles of service road through not very comfortablu oountry to the head of the creek, where a tunnel Avill slrikc through a narrow ridge, to bring the pipcline out at Takapua South. From that i>oi n t the main line will continue on through Johnsonville to Wellington, and a brancli wili turu olf to supply Tawa Flat, Porirua, aud Plimmerton. Six miles oi' service road through brokeu country is costing a lot of nionev, Imt so great a nnleage of watermain will be saved by the short cut that it is the economical thing to do. This again is a bulldozer and carryall job, manned by a Jughlv skilled team of operators aud ii.v the culvert builders who are safeguardiug the pipeliue route against storm damage by euelosing every creek and creeklet. Once this side. valley road has served its pupose for the haulage of the pipes, the heavy trench digging plant, and tunuelling geur, and as the bed of the watermain it will go oll' tlie main. JJuek creek is no tourist resort. The pipeliue will follow Ihe main road through the Hutt Valley from Silverstream bridge northwards through Maoribank, aud to givo working space for the digging of the five-foot trench the road formatiou is being wideued in several ieciious ot this length. The Ilutt bridge, just pu.st tlit Silverstream bridge, too, is lo be wideued, to eud the trafiic botlle-neck whi« h lias beeu a problem on every :ace dav. The Hutt bridge will b'e, wideued, temporarily, before the summer meeting by throw- i ing a short Bailey bridge across the streani on the northeru side

10,000 Tons of Steel. A contract has uot yet been let for : the manufacture of the pipes, but the lirst cousignment of steel is ou hand; i 10,000 tons will be required for the i'ull ; mileage between the Hutt Kiver and1 Wellington and the bratich mains to the! Porirua basm. It will be concrete-lined ! lo guard against iuterior eorrosion, and i further investigatious are being made ! iuto reeeut developments in Auslralia | and clsewlierc into methods of protect-j ing the exterior surface of the steel, for this, in spite of tlie huudrods of tliou- 1 saus of miles of steel pipe tiiat eiigiiieers have laid, is still a main probleiu. Givon thc peri'oel seal, stc'el mains are good for all timo, but uo oue has gol salisi'aetorily close to peri'ectioii. 1l is ! likely that lenders will be callod early in tlie New Year, aj.nl it is expeetod that, i'or a job oi this size, tlie conLrucLor will sel up a special factory. First and last the ucw water supply will cost well over £1,000,000, by far the greater part of whicli will be spenl in labour. The first estiiuate of time of completion was giveii as 1949, but there are doubts now . vvhether water Itoiu tlie Hutt Kiver wili reueh Wellington before 1950 or 1951 Uiroilgh ihe Upper Hutt Valley, Taita and way i points will have their new supply be--' fore then.