THE EAST COAST RAILWAY

Evening Post, Volume CXXIV, Issue 57, 4 September 1937, Page 14

THE EAST COAST RAILWAY

I Five faces of the three major tunnels on the East Coast Railway construction have been opened up, says the "Poverty Bay Herald," and the.sixth is about to be tackled. The three tunnels are the Waikura, Coast, and Tikiwhata jobs, 73, 46, and 126 chains long respectively. The Waikura tunnel has advanced 4J chains from the northern end, and three chains of cementing have been done." The southern end is in what is practically a cliff, and months have been consumed in making a deep cutting at the approach to the tunnel face. Only the 'bottom headings haye been opened up, each for eight chains, in the Coast tunnel, which will connect the Tikiwhata Valley with the open coastline sector north of it,

The biggest of the three tunnels, now known;as the Tikiwhata tunnel (formerly called the Coast.Rbad tunnel), also has been.'; tackled at either end, and at 4he'southern face, debouching.,into the top end of the Waiau Valley, the bottom heading has ■ been pushed ten chains into the hillside, while the top heading is being carried on at present, opening up the full section of the tunnel in preparation for concreting work. Air compressors for the operation of drills and ventilating fans have been established at each of the five faces on which work is proceeding, and preparations are in hand for the use of the, same type of machinery at the southern portal in the Waikura tunnel. MECHANICAL EQUIPMENT. Special concreting technique is being employed on all Ithree of the major funnelling jobs, Steel sheaths having been fabricated in sections so that they may be erected within the huge shafts to hold the concrete lining in place. Special machinery, also, is to be used in placing the concrete aggregate, in conjunction with the powerful pumps which will force the aggregate through hoses'to the-point at which work is /proceeding at a given time. , ' Substantial additions have been made to the mechanical equipment at Torrie's Camp, where from the earliest days of construction on this section of the line heavy engineering work in •connection with tunnelling preparations has been carried on. Recent additions to the plant there include four electric locomotives, for operation in the tunnels, these vehicles operating on batteries and being recharged after each shift of eight hours. |

Similar equipment.is being delivered at other points along the line where fumeless mechanical transport is necessary, while . a further shipment of

electric locomotives is to be delivered shortly. ; JIGWAYB FOR HEAVY PLANT. The lowering of heavy plant to formation level in the Wharekakaho and Tikiwhata Valleys presented a considerable problem in the first instance, but the solutiqn has been found in the construction of jigways, consisting of steeply-inclined, truck-lines upon which trolleys operate. In the cases of some items of plant, such as the large 250 h.p. transformer weighing three tons, required for the electrical station at. the northern portal of the Tikiwhata tunnel, trolleys were found to be out of the question, and the jigways were used merely as skids. The lowering of the transformer occupied two days, but was accomplished without the loss of a drop of the oil with which the big unit was filled as a preliminary measure. A much less arduous task was the lowering of an electrical air compressor for the same job. Almost on the same scale as at Torrie's Camp is the machine-shop installation at the southern portal of the Tikiwhata tunnel, at the head of the Waiau Valley.l, 'Here a number of special items of plant are established on a permanent basis, with a staff of engineers, 5 electricians, and fitters experienced in public works jobs, and well acquainted with the technical problems associated with tunnelling operations. PLATELAYING TO COMMENCE. So "far advanced is the formation work (filling and cutting) on the Wai-kokopu-Gisborne section of the East Coast line that a few months' work will see the greater part of this section ready .for platelaying. Already the number of men engaged on railway construction has been reduced substantially, and during the next two months a further series of reductions will take place as contracts rut! out and men are released for employment elsewhere. ■: Of material importance as this work will be to the line as a whole, it is merely superficial in character when compared, with the huge undertakings in the way of tunnels, cuttings, and I fillings necessitated in carrying the formation through the precipitous hill country from Torrie's Camp southwards to where.the,country opens out again into the Kopuawhara Valley. I Before the year 1938 is advanced very I

FORMATION WELL AHEAD

PROGRESS OF THE TUNNELS

far, work on the Waikokopu-Gisborne section will be concentrated on the major tunnelling operations, and on the provision of bridges to carry the line ov;» streams and rivers. Steelfor constr •■'•on purposes, has been exceedingly difficult to obtain in recent months; otherwise the bridgework would be well in hand by now, judging by the progress made in other, directions. '

Circumstances which have held updeliveries of steel also have affected progress in certain other features of railway construction, including the deliveries of special plant for tunnelling, but gradually the full establishment of plant is being assembled, and it is hoped that steel for the bridge jobs will be coming to hand in good quantities before long. , .