EXTENSION OF THE BREAKWATER

Gisborne Times, Volume XXX, Issue 3484, 26 March 1912, Page 2

EXTENSION OF THE BREAKWATER

PROCRESS OF THE WORK. REPORT OF ENGINEER. The work of extending the breakwater was reported on- by the Engineer to the Harbor Board at yesterday’s meeting of the Board. The report was as follows: This contract was signed on December IS, 1911, and the date for completion is December IS, 1912. Air- Langlands arrived in Gisborne on February 28, and ks personally (superintending the works under this contract. Sixty tons of AVi Ison’s Star brand cement lias been landed on the works and a mixed sample of this was forwarded to the Canterbury Engineering College for testing on March 2nd. ‘ Twenty-four briquettes have been moulded here with cement and local sand in varying pneportions and with fresh and (saltwater, and will be tested at the end of 23 day*. Four blocks of concrete (about 1 cubic foot- each) have- been mixed with fresh and salt- water respectively and when a- month old will be placed in the sen for observation. Experiments have been made with both sand and stone (gravel) to ascertain the weight per cubic, foot and t-ne value of the interstioial spaces. During the past month Mr. Langlands has had in employ three carpenters and six general laborers. Ho has erected a travelling gantry cn which is fixed the concrete mixer. He has levelled the site .for the concrete block yard, hucl the rails for the travelling gantry, and -erected the poles for carrying current for Iris electric motors. 1 have pointed cut to Air. Langlands that it will l:e nec-essnry to screen the whole fit the gravel to separate the sand, so that the correct proportions may b-o brought together for the mixing' of concrete. Ho'has under consideration the erection of a rotui\ screen motor driven. Messrs Langlands and Go-, contractors fur the extension of the breakwater, in a letter to the lioarfu chow attention to the quality of the concrete- specified, which was distinguished as No. 1 and No. 2.3 he former was to consist c.f one part cement 2$ parts of sand and 7 parts of stone. No. 2 was to consist- of one part of cement, three parts mind and nine parts ot stone. They though an error had been made in the specifications for such a large aggregate, niid. said they recognised that they had only to bring this under the notice of the Engineer to h-ave the proportions increased, and so make a better, quality of concrete. The contractors also wrote offering LTO for the use of the trucks and wheels cn the breakwater, together with- the iron rails stored near the workshops ■ until the completion of their contract. Alossrs Langlands and Co. further wrote stating that as the larger portion of tin* timber breastwork leading on to the breakwater was under their control during the term of their contract, they wished to point cut the dangerous condition of the same inasmuch as it was a recognised public walk, and tliev thought that thev would be liable for any accidents which, might- occur to anyone through the instability of the decking. The Engineer reported cn this matter as follows. —The decking of the viaduct leading to the breakwater is in a very bad state of repair and is dangerous for public traffic. Air. Langlands lias asked me for a decision as to his liability to his own workmen and t have ruled that as the area that lias, been h.ande dev-er t:r him for the purposes c«f his contract, is under lii» j control, the liability rests with bint as contractor- The general public, however, use this viaduct, and as far as they are concerned, tire Harbor Board cannot evade their responsibility, except bv closing it to the public. I have riot- had time tel get out an estimate for the renewal of tins decking in hardwood, but the cost would be anything from £550 to £BSO. - As this question is one of policy in regard to future developments, 1 would ask ■for the Board's instructions in the matter, as the expenditure would be large if the viaduct- were looked upon only as a public promenade. In the mean time I would recommend that a prominent notice be posted up piphiibiting traffic thereon. It was decided to put up a notice on the breakwater informing the public that the breakwater was dangerous, and t.o also- insert' advertisements in tiie papers to the same effect. The Engineer was instructed to report at the next meeting on the question of redecking. ) In a further -report, which -was considered in committee, the . -engineer ! stated that he Lad ascertained thatj there was a considerable discrepancy I between the contract plan and the work as: it would have to be carried out. The contract plan showed the sea- bottom as 12ft at low water spring tide, whereas the depths ascertained by him on March 6th last averaged ! 14ft lOin. to sea-bottom and ISft 10iuto rock. (His finding as to the relative liability of the Board and tire contractor was as follows:

(1) The discrepancy as to tho depth to the sea. bottom amounted to 2ft ilOin. Hie contract plan shewed this depth as 12ft. Tourteen feet ten inches could not bo held to be (approximiately twelve feet, and he therefore found that the .Harbor Board was liable foi the whole of this extra depth of 2ft 10in of breakwater, as an extra, on the contract at schedule .rutes ; , and for this an extension cf time of two months should be allowed. (2) dn regard' to settlement through tho sea bottom, no provision was made in the contract for dredging to a foundation, and no suggestion was given as to an eventual, rock bottom. It was clearly anticipated in the specifications that settlement would take place, and the contractor was clearly liable to make such (good at his own post. The actual depth from sea bottom to rock averaged 4ft, and there was a possibility—if not a probability—that, the breakwater would- settle to that extent. The total extias ip.ava.ble bv the Board were as follow:—Extra *onCrete at contract rates £.2218, extra cement in all concrete £603 14s 2d, alteration concrete “in situ” £27 Os 4d plus f> per cent, for .contingencies £3OOO. The . report was adopted.