HARBOUR DREDGING

New Zealand Times, Volume XLII, Issue 9614, 21 March 1917, Page 3

HARBOUR DREDGING

the PAST YEAR’S WOES^ “The Harbour Board’s reclamations having been completed, there was no occasion last year to do extensive dredging work to obtain material for pumping ashore," states Mr J. Marchbanks (engineer to the Wellington. Harbour Board) in his annual report, "The dredge (he adds) has been employed on various works in and about Lambton Harbour* none of which were of very great extent, and consequently the cost of the dredging executed last year is high. The principal work done includes dredging on the site of the proposed Lambton wharf, which was deepened to 36 feet below 0.L.W.5., involving the removal 'of 66.161 tons of material. Some 4652 tons were lifted in deepening the eastern berth at King’s wharf to 36 feet below low water. On the site of future wharves at Te Aro 19,605 tons were lifted. Dredging at the north end of Waterloo quay reclamation amounted to 22,386 tons, of which a considerable portion was because of the overflow from the Waterloo quay reclamation when pumping ashore. From No. 2 berth, Taranaki street, 9100 tons were lifted —principally detritus which had been allowed to be washed Into the harbour through the Polhill Gully culvert. Maintenance dredging to maintain the desired depth at Clyde quay and bertha Nos. 2 and 4. Queen’s wharf, amounted to 16,321 tons. For the past two months the dredge has been working on a patch of shoal ground opposite Point Dorset. TJp to September 30th some 9350 tons had been lifted. It ia proposed to continue on this work up to the end 'of the year 1917 so as, bo ascertain the nature of the material and the rate at which it can he removed, after which it can be determined whether it is advisable to continue working or to lay the dredge up. Owing to the intermittent and light work which was done in and about tho wharves the rate of dredging was low compared with previous years, being 202 tons per hour as against 234 tons in 1913, and 299 tons in 1914. Very little material wag pumped ashore last year, the total being only 37,700 tons. This was principally because the reclamations were so far advanced as to make it difficult to retain anything but heavy gravel. The dredge continued to work on one shift only during the whole of last year. This lessens the amount spent on dredging during the year; but materially increases the cost per ton lifted."