Good Progress On Road To Quarry For Port Extension

Press, Volume XCV, Issue 28178, 17 January 1957, Page 10

Good Progress On Road To Quarry For Port Extension

A tricky job which is the key to a £3,500,000 programme for the extension of the port of Lyttelton is the building of the access road to the rock quarry east of Sticking Point. “Excellent progress has been made by the contractors (Burnetts Motors, Ltd., Ashburton), who are well up to schedule,” said the engineer-in-chief of the Lyttelton Harbour Board (Mr J. A. Cashin) yesterday. A hitch in the building of the access road, which is scheduled to be completed in April, is, however, likely. To make the best progress on the biggest part of the job—the dumping of stone to form a causeway across a deep' bay—the contractors desire to work from the cliff face downwards. The only access is through a reserve owned by the Lyttelton Borough Council and used as a rubbish dump. Access was granted by the council to the board on condition that an alternative rubbish dump was provided. The board accepted the offer but advised that no alternative site would be available. The council retaliated by withdrawing its grant of access and placed a gate at the entrance to the reserve.

Conference To Be Held Some drilling was done from the reserve by the contractors, who then removed their gear. The probability is that unless they can work from the top of the cliff face the roading work will be held up. A representative of the contractor has approached the Borough Council for a renewal of access. The Mayor of Lyttelton (Mr F. G. Briggs), replying yesterday to a question by “The Press,” said that he had been unable to do anything in the matter, which was one of several to be discussed at a conference between the Harbour Board and the Borough Council. The road runs from the rough reclaimed ground east of the Gladstone Pier. It has been hewn out of the rock face at the western end and a ba v divides it from the cliff and outcrop from which the extension work rock will be quarried, and where another section of the road has been blasted and bulldozed. 36,000 Tons Of Rock

After the contractors complete the road, preliminary work will be required before the hard rock can be reached and quarried. Big plant for quarrying and transportation of the rock to the big breakwater has been ordered by the Harbour Board. About 18.000 yards will be quarried, the stone averaging one ton and threequarters to two tons in weight for each yard. The breakwater will run for 1400 feet from the western end of the new access road at Sticking Point. The inland half of the breakwater will also be a reclamation wall, behind which about 40 acres of the harbour will be reclaimed. Three sheds, each 600 feet long, will be built, as well as a new export wharf. Four bores to test the harbour foundations have been sunk. The last was the only one to reach solid rock, 137 feet below the v’ater. For two of the holes used, vane testers, which give an accurate idea of the strength of the shearing clay in situ,- were used and two drills were in situ to produce undisturbed samples Soft Foundations? The peculiar nature of the m terial at the bottom of Lyttelton harbour is similar to that

which has been found in marine work in Norway, and samples of the silty clay are being sent to the director of the Geo-Technical Institute, Norway, an expert of great experience. Tests of the harbour bed suggest that in one section sand may have to be deposited in volume as a foundation for the rock for the breakwater. Mr Cashin confirmed a report that this work might have to be done, but said further investigation would have to be made before a decision was reached. The existence of fresh water springs on the line o* the breakwater has not been determined. When one drill hole was collapsed water was forced up the tube; but there was no certainty it was wajer from a spring, said Mr Cashin.