TRAFFIC TUNNEL

Evening Post, Volume CXI, Issue 71, 25 March 1931, Page 10

TRAFFIC TUNNEL

ALMOST FINISHED

AN EXCELLENT JOB

APPROACHES AND PAEK

Within a few days the contractors, Messrs. Hansford and Mills, will have completed their work on the traffic tunnel through Mount Victoria, and will hand over the job to the City Council to proceed with the paving of the tunnel bed and the laying of tram tracks.

Many complimentary remarks were passed by people competent to judge during tho progress of tho work, and now, when the- tunnel is receiving its "polishing,'' the comment is equally favourable. The lines are dead true, and the finish is remarkably smooth, the result of forcing the concrete Btix at considerable pressure behind polished steel moulds which formed the interior of the arch.

While the preliminary drives were being made wet patches were struck, and walls and roofs literally poured water at a dozen places, but this is common experience in tunnelling, and, a3 was forecasted at that time, the rock gradually dried out. The arch is now quite dry, but from low down on the walls and through tho tunnel floor small springs arc still leaking a failquantity (in the total) of water, and under the traffic of lorries running the last loads of spoil away the floor is churned into inches in yellow mud. Drainage and paving will attend to this and the whole job will rapidly dry out. The raised footpath, along the northcm wall of the tunnel, is completed for its full length, and the upper and lower air ducts are practically finished off.

The upper duct has been formed by building a false flat ceiling about threefeet below the centre of the arch and the lower duct is underneath the fobtway. Numerous openings in both, will take care of ventilation, and the upper duct ig also open to the air through two vertical shafts, spaced evenly along its length. Orders have been placed for special ventilating fans, which will be housed in the Electricity Department's sub-station buildings at the tunnel portals, and forced ventilation will be used when the natural draught through the tunnel fails. To what extent this forced draught will bo necessary is not at present known, but it is considered probable that on normal days there' will be no need of fan operation. At such times when traffic is exceptionally heavy, particularly if the weather should be calm, artificial ventilation will, however, be necessary to swoop the tunnel clear of dangerous exhaust gases from motor vehicles.

NO DECISION AS TO CITY APPROACH.

So far the -position in regard to the city approach to the tunnel is indefinite. The City Council wishes to avoid the expenditure of something like £42,000 on the diagonal approach suggested by the Access Commission by making shift by an approach up Ellice street, round the Brougham street corner, and so into Patterson street. The Public Works Department some time ago indicated that it did not consider the proposal satisfactory, and before the council can proceed the sanction of that Department must be obtained. Since the Public Works Department gave that indication circumstances have altered considerably, and, tight as finances were then, they are tighter now.

The Access Commission recommended that ultimately a new road should be constructed on the Hataitai side, parallel to Moxham avenue and nearer the hill, but that in the meantime the tram tracks should be laid to connect up with the present lines in Moxham avenue. Provision has been made for a connection to Moxham avenue to be made right away, and a start has been made also in the construction of the new road recommended, for though it may not be required for some years that work offered the most useful means for utilising spoil taken from the tunnel. This preliminary formation has been carried down almost to the line of Goa street.

A BIG PAPvK IN THE MAKING,

The greater quantity of spoil obtained was trucked round a toe of the hill and dumped into gullies and hollows, as tho beginning of a now recreation reserve for Hataitai. It did not go so very fa.r, and the park seemed to be a Jong way ahead. Recently, however, the council has been able to put 150 men on to that work with Unemployment Board finance, and the tunnel spoil and the removal of bumps and filling of hollows under this relief work are combining to form a splendid playground, of seven or eight acres. The ground will not be regular in shape, but will be of ample width for the setting out of cricket and football grounds, and being against the hillside is already provided with a grandstand. Several shallow gullies offer possibilities 'as sites for tennis courts or croquet lawns, but these are a few years ahead. The top soil has beeii carefully saved, and when tho levelling job is completed will be sufficient to cover the whole area, ready for sowing down in grass. When the work is done Hataitai will possess a playing area as good as anything about the city and one which will be readily capable of great improvement.