HARBOR BOARD.

Evening Star, Issue 3684, 12 December 1874, Page 2

HARBOR BOARD.

The principal nutter dh cussed at yestev<iy s adjourned meeting of the Board, was the consider ition of the Engineer’s report ou the question of dredging, and to determine wbi' tx of the two ebaane s should be dredged to (Ford a minimum depth of 9ft. at low water. Mr him son, the Board’s engineer, thus staled his reisous for recommending ■ he dredging of the long channel as a pr°. iminary step in the work of harbor improvement : To admit of access at high water to the Upper Harbor fertile inter-provincial steamers ami vessels of ordinary draught at the earliest possible time. A reference to the accompanying statement will show that this cm be accomplished under favorable circumstances, as' far as the upper junction of the two channels, in a period of four months, and at an expend!- : ture not exceeding L2,30t), whereas the short channel could not be made available within j mouths, involving; an expenditure of L 7,500, * i

2. That, inasmuch as the long channel is generally of a greater width than the other, obstruction would be offered to traffic during the operation of dredging to the preliminary depth proposed. 3. That as the short channel may probably 1 be adopted as the permanent one, it would be left free to be operated upon by a system of cross-dredging, which is the least expensive mode ; and I have no doubt that this . eourity from interruption would considerably affect the cost of the work, certainly to an extent that would more than recoup the Board for the outlay upon the long channel. In addition to the statement furnished as required, I think it desirable to append, for the information of the Board and for comparison purposes, an approximate estimate of the extent of dredging required in both channels to admit of a depth of 17ft. at low water, from which it will he seen that the difference is not so very great, being only 125.000 cubic yards. If the depth were reduced to IGft. it will he apparent that a less difference would show. • • • Lie present dredge can excavate at an average rate of 10Q tons per hour, equal to 71 cubic yards, which for a working day of eight hours gives 502, or say 600 cubic yards per day. The relative time, therefore, required to dredge the short and long channels to a minimum depth for Oft at low water will be as follows : - Short Channel, 355 days, allowing 312 working days for the year, the time lequiied to open the channel will be 13 A mouths. Long Channel, 107 days. Allowing the same number of working days for the year as before the time required to open this channel will be about four months, or less thau one-third o : that necessary for the other. From the up .er junction of channels to the cross wharf now under construction between Rattray and Jetty streets, the distance is about 68 chains. The average depth to be dredged in this distance, to a width of 200 ft, is approximately 2ft. This will give a cubical content of about 33,000 yards. The time required to excavate this will be about two months; consequently, the several periods required to open up the short and long channels between Rattray street cross wharf and Kilgour’s Coint, or the lower junction, to a minimum depth of oft at low water, will be respectively fifteen and a-half and six months. . . . Should the Board decide upon proceeding with the preliminary work of deepening the long channel, I propose, as the first work, to place the dredge on the cross channel, the material arising therefrom to be deposited in one of the contiguous bays, as a matter of economy; subsequently, to deepen from “Grant’s Braes” to the cross wharf between Rattray and Jetty streets, the material to go towards the reclamation of the Board’s endowment.

After considerable discussion, it was agreed to op -n up the long channel, as recommended by t!ie engineer, Mr M Kinnon objecting to spending L2,0U0 fir six months’ use of this channel.