HARBOUR DREDGING

Hawke's Bay Tribune, Volume XXIV, Issue 235, 17 September 1934, Page 8

HARBOUR DREDGING

Operations For The Month

ENGINEER’S REPORT

Dredging was curried out during the past month by the dredge Whakarire at the Breakwater harbour, when 15,450 tons of spoil were lifted, making a total of 104,350 tons to date.

The engineer (Mr G. W. B. Lowson) in his report to the Napier Harbour Board to-day on the whole of the dredging operations, stated that innumerable boulders near the surface, although easily dealt with by the Whakarire, had retarded the working, Mr Lowson’s report was as follows:

Dredger Whakarire:— The bucket dredger Whakarire was engaged throughout the period on the cut. along the eastern side of the proposed smaller wharf, dredging to a low water depth of 26 feet, and excavating to a width of 100 feet. -The ground encountered is still the usual soft papa overlaid with sand, but innumerable boulders have lately been found near the surface. Although easily dealt with by the dredger, such boulders nevertheless retard operations through having to be lifted out of the buckets. Latterly they have been loaded on to a pontoon and tipped seaward of the breakwater foundation, the “Daylight Passage” now being closed to shipping for all time. During the period, 15,450 tons of spoil were lifted and taken out to sea, the face of the cut thus being advanced to a total distance of about "80 feet. To date, 104,350 tons of material have been removed therefrom.

The Whakarire commenced working two shifts daily on August 30th., prior to which two dredge buckets were replaced and the condenser overhauled. A third bucket has since been renewed.

Dredger Apiti:—The suction dredger Apiti worked double shifts throughout the period reducing the shoaling iu the upper reaches of the Inner Harbour entrance channel. Discharging over Westshore pier No. 4, and dredging downstream to 10ft. L.W.O.S.T. for widths varying from 100 feet to 135 feet, line 3 was reached on August 18th. Pier No. 1 was then re-conditioned, and dredging carried further down the channel at the same depth for a width of approximately 150 feet. This work has since been completed To line 5, and the dredger withdrawn for general overhaul.

Dredger J.D.O.:—The grab dredger J.D.O. resumed’ work, after reconditioning on August 13th., and was then transferred to harbour and roadstead buoy service. Since then, the vessel has’been engaged in dredging both the Breakwater and the Inner Harbours, concentrating particularly upon the latter when tides allowed of so doing. The J.D.O.’s dredging returns for the period are as follows, viz.:—Nelson Quay 1280 cub. yds; Breakwater wharf 960 cub. yds; East side, Glasgow wharf 90 cub. yds; total 2330 cub. yds.

Costs:—The following amounts were expended during the past month upon the works mentioned: —Dredger Whakarire £llO3/13/4, Dredger Apiti £573/7/2, Dredger J.D.O. (Balance of overhaul £1936/5/9, Dredging £5B/8/11, Harbour buovs £lll 10/-) £2106 4/8, Glasgow Wharf £67/9/6; total £3850/14/8.