DREDGING THE UPPER HARBOR.

Evening Star, Issue 4965, 31 January 1879, Page 4

DREDGING THE UPPER HARBOR.

jOn this subject Mr -Simpson, the Board's Jeilgineer, reports tha't'.' from tbe co'mmencein|;ut of pperations until the Ist October the total quantity dredged was cubic yards, at-a cost based upon the contract I schedule rate-df £12,250. ;The 'material arising therefrom was deposited in reclamation areas adjoining Rattray street wharf and Pelichet Bay, partly.-by the ordinary piutage methpdv.-and partly* by the crane-aijd-box method. ThisJatter, however, was financially a; non-success, and Avas discort-. j -tinued. On taking over the work from Mr Proudfootit was understood that the plant i :.wp not in such a condition as to justify its immediate use, and certain repairs' and overhauls had Job undertaken with the view of puttihg'it in proper order and equipment. ' Taking this into consideration, it [will naturally be assumed that the last thjree months "would not .give the returns which under, altered circumstances the Board-might have a right to expect, although •they boar .-favorable L comparison; -.with the w6rk 3)reviously performed, as the accompanying summary of dredging, etc., will show. _ The summary" alluded to 6ontains information which 'must hot be accepted as ex--.hibiting anything like a fair average of work anxl cost for the'three months. As already • stated, the circumstances . attending the acquisition of the contract works were exand the period- t over which, 1 , the summary extends ..should be .looked upon as having been to a great extent [occupied, in preparations for carrying on the work in a manner consistent with expedition and economy. The estimated .'quantity dredgod from October 1 to December 31,-asper summary, is 35,110 cubic yards. This added to ; 140,000 cubic yards completed under contract, gives 175,-110 cubic yards, leaving ,a balance of nearly S-15,000 cubic yards still tojdredgc to complete the 70ft'channel. The longitudinal section shows in pencil the relative positions assigned ;ta the; Vulcan'and 'New- Era ([dredges)- about-the end of the year. The-'<>b]ect-''fo be attained-by so placing them is to establish ] dt the earliest ■ pdbible date a, communication tlirough the j.sandbanks, having-'a'-channel depth of say Mftj—wliich, when.once effected, will be. the j mean's,rl' believe,-of .mducing, a'.-scour suffir cieut to, aid in'the. deepening process afterj. wards.. The new hull for the side dredge—j the contoract; fqr .Avhich was entered into : siiice the comniencement of the present year --—>vill be completed in about seven weeks, and the fitting-ih of tlie machinery will prc'bablypccnpy three, or four weeks additional, completion the dredge: ,'willbe transferred to the sandbanks, to pre- , cede the other dredges by operating upon those'parts the' depth of water on which'is' athpresen{;;ins^^•ffi'cie'nt. , ' ' , Mi'c cos't'of' dredging, lifting', and depositing in Duncdin amounts. to 2s 4-kl per cubic yai'd. The cost in Port Lyttelton, where a strain..dredge and hopper-barges are used, has years i'rom to s|d per yard. In!the fortnight from lst;to 15th January the. Vulcan raised 2,142 yards, and the New Era 3,99S yards. The Vulcan was working uponhard sand unmixed .with"clay, and which had to be shovelled out of the shoot and' punts ; fhe'New Era was working upon hard sand with a thin seam of clay at the bottom Ot'the'CUt; ' ' •'' -- : ' .'■:■•: