SPANNING THE HARBOUR

Sun (Auckland), Volume III, Issue 773, 20 September 1929, Page 11

SPANNING THE HARBOUR

BRIDGE CHEAPER THAN TUNNEL ELIMINATING THE FERRIES Assertions that any harbour bridge would eliminate the vehicular ferries and would take 75 per cent, of the passenger traffic from Birkenhead, Northcote and Takapuna, 50 per cent, of the Devonport passenger traffic, and that a harbour tunnel would cost £1,600,000 as against £BOO,OOO for the proposed bridge, were made by representatives of the Harbour Bridge Association, addressing the Waitemata Chamber of Commerce at Devonport last evening. Mr. R. H. Greville, president of the Harbour Bridge Association, outlined the reasons for selecting the Shoal Bay site, its advantages being that it would serve all the North Shore and save time in transport, lessen charges on vehicular transport, and open up the North Auckland Peninsula. The Harbour Board had no scheme for major harbour development' west of the western reclamation, and therefore a high level bridge was not essential. A clearance of 90 feet above high water was suggested and the possibility of a lifting span was also being considered. In other places the shipping companies had been refunded the cost of installing telescopic funnels and masts on ships that had to jtass under the bridges.

Mr. Greville also contradicted a statement, made by Mr. D. E. Harkness, C.E., in a lecture before the Chamber of Commerce, that average tolls in the United States of America were 50 cents on motor-cars and five cents on persons. The speaker quoted Vancouver figures to show that there the charges were 15 cents and five cents respectively, with reductions for concession tickets.

A tally last month showed that about 600 vehicles a day made single trijDs on the vehicular ferries, or 300 made return trips. This was 160 a day less than in February, 1928. However, the association was confident that when the bridge was opened it would carry at least 3,000 vehicles a day and 10,000 passengers; even if the Vancouver toll was doubled—the Vancouver bridge cost only £400,000, against the proposed expenditure of £BOO,OOO in Auckland —the cost for each vehicle would be less than the present ferry charge. His own opinion was that trackless trolleys would come to the North Shore. Cheltenhani would be five miles from the city via the bridge, but with trackless trolleys it would be only 20 minutes’ travel, though cost of transport might be slightly above the present scale. Devonport would not be side-tracked by the bridge. Mr. Stanley Jones, advisory engineer to the Bridge Association, examined the suggestion of a harbour tunnel. The harbour bed. being papa, was ideal for tunnelling, he said, but on the costs of a tunnel recently driven in Wellington he estimated that a tunnel 7,200 feet long, inclusive of approaches, would cost £1,600,000, which was about twice the cost of his bridge scheme for the same capacity. A bridge with 90 feet clearance and 50 to CO feet wide, rising from the level of the western reclamation, was proposed. People would sooner travel by a bridge. The ventilation of a tunnel was a big problem. Without a proper survey of the harbour bed it was not possible for anyone to say definitely that a bridge or tunnel was better, or where it could go. Mr. Greville stated that even if a bridge site was good from town-plan-ning and economic aspects, the engineering aspect had to be considered. In reply to a question' by Mr. S. E. Kennings, he admitted that it was essential that a bridge would have to monopolise the vehicular traffic and secure a substantial portion of the present passenger traffic to pay. The ferries would be seriously hurt, but in the course of years a surge of population to the North Shore would give the ferry, a chance to recover, at Devonport, at any rate. On the motion of the chairman. Mr. T. Walsh, a vote of thanks was accorded tli» speakers.