DREDGING THE HARBOUR.

New Zealand Herald, Volume XXXIII, Issue 10047, 6 February 1896, Page 4

DREDGING THE HARBOUR.

IT is likely now that matters connected with the harbour will be put upon a better footing. One of the most important subjects is that of dredging. Dredging to a considerable extent must be carried ou if the plan proposed is to

be completed of a series of 'short tea extending into a deepened basin fronting Quay-street. There is no possibility of shirking the question of dredging rimtniust be done, especially if w s e J .berth large vessels as'closely as po ! sible to the warehouses. At pr4>nr the dredging is a very slow andcostlv process. The big dredge loads itself u » with silt, and steams away on a | 0 | p voyage outside the Rangitoto ee f 2 discharge it. half the time beiiw C on suiaed in the sea trips. Rut a new and much more t-floctive system of dredging lias been discovered and put in practice in America by which as much work could bo done in six months as by the present system in six years. It is called "The von Schmidt Dredge." and is described by Mr. G. Higgius, Assoc. M. Inst C.E., in a paper in the Proceedings of the Institution of Civil Engineers for 1891. Sand-pump dredgers have ben used for some years, but the present is the only machine which will deal with clay as well as with loose materials. The dredge is floated into position, and placed so that its bow (or suction-pipe end) nearly touches the bank which is to be cut away. The two spuds are allowed to drop through their sockets and their iron-shod ends stick into or rest upon the material in the bottom of the channel. The bottom of the pipe is fitted with knives, which are made to revolve, cutting away the material which is carried up the pipe by th e rush of water, passing through the whirling pipe and the discharge pipe to the shore. The quantity of still which can be lifted is enormous. Mr, Higgins, who is a contractor as well as an engineer, has paid a visit to Auckland, and guarantees that with hi; plant he could reclaim Freeman's Baj in five months, and deepen tiie whole of the foreshore basin. The machine would work in the basin, and a pipe could be laid along the road to Freeman's Iky and Mechanic's Bay. The cost would be much less than in the present method, and the process would be far more speedy. Some of the mem" bers of the Harbour Board have already looked into the matter. It seems to us that the Board should carefully consider the plan. The present method is very slow and very costly.