THE KAIAPOI DREDGE.

Lyttelton Times, Volume XCVI, Issue 14498, 9 October 1907, Page 2

THE KAIAPOI DREDGE.

At Kaiapoi yesterday, th© Waimaka* riri Harbour Board’s new dredge wa» christened and set to work. The river, which forms the river-port of the town, has been silting up very much , for ■> yeans, until now it is too shallow to be of much use to shipping, which is, moreover, entirely dependent on- tha tides. The Harbour Board has previously had dredges, but the new dredge is larger, and is expected to clear a, deep- channel. The dredge is built on a rectangular pontoon fifty feet long, twenty feet wide and five feet deep, and having a loaded draught of 2ft 6in. The pontoon deck supports the machinery: A centrifugal pump is placed forward with a suction pip© projecting . fifteen feet beyond the bow, and controlled by elevating gear. The pipe may be lowered ten feet below the water-line, audit' is aided by a eteel-bladed rotary cutter for loosening the material. The centrifugal pump was specially designed with a > view to improved efficiency and reduction of.internal friction, and; the chief wearing parts are easily renewable. A small circulating pump i« attached to keep th© sand clear of the stuffing box. It is calculated that, when dredging, fre a material, tho pumj> will deliver nearly one cubic yard per minute of solid stuff. Theengine is a. 12 h.p., non-condensing, compound, built by Ruston and Proctor; th© boiler, of about 16 h.p., with 1401b.working pressure, is of the goldfields’ dredge type, by the same makers. The boiler and engine are placed well astern>on the port and starboard sides respectively, the power being transmitted from the engine to the pump by a 9in belt of ample length. Immediately th® pump in the central space is placed * powerful steam winch, having she barrels for manipulating the pipe and the various mooring lines. Ejectors are provided for draining the bilges, procuring water for the boiler and charging the pump. The water and spoil from tho pump pass under ■: the deck , to the stern, and thence through floating pipes to the river bank or to th* swift current as required-. The spoilpipes are fitted with steel ball and sooket joints, and tho sections are supported on each side by larger air-tight pipes, all strongly joined together with timber yokes and holts. _ ' _ . The machinery on deck is covered, ut with neat and substantial housing, kept low enough to allow the dredge to pass under the Kaiapoi bridge at low water. The plant was designed by air E. Roberts, of Dunedin, the Board’s consulting engineer, and he prepared the plans - and specifications from .which the dredge was built. The pontoon was built by Mr P. Sutherland, of Dunedin, and the centrifugal pump, cutting gear and floating IPS®** hy Mr-A. Hadecke, of Rangiora. The dredga was erected by Messrs Lucas Bros. There was a large gathering at _tha christening ceremony. - Mrs Doubleday, wife of the chairman of the Harbour Board, broke a bottle of champagne against the suction-pipe,, declaring the dredge christened ‘ chairman of the Beard (Mr W. Doubleday) said that He hoped that the machine would result in a great increase ■ of prosperity for the district. . Mr J. H. Blackwell, Mayor of Kaiapoi, presented Mrs Doubleday with a greenstone brooch as a souvenir of the event. ,» ■ ■ The dredge was set to work, but owing to the tide being exceptionally low shifted little more than water. Later in the dav, however, she did much hotter work.' A large number visited her and examined the method of working with interest. ' . In the afternoon a banquet was held, about a hundred guests sitting down. A large number of toasts were proposed, and the Harbour Board was congratulated on the advance marked by the purchase of the dredge. Speakers referred rto the fact that tho Harbour Board had no rating powers, and, being dependent upon its reserves, waa consequently much handicapped in its operations. It was stated, however, that the Board intended to improve tho reserves so as to obtain an increased income, and also, when th© shipping increased, to impose harbour dues. After tho banquet about fifty of tha miests were taken for a very pleasant excursion on th© river - in two 'largo launches. The trip was made to Kairaki the Sumner of Kaiapoi, and back, under tu© most delightful conditions. After tne trip another visit was paid to the dredge, and she was found to he working better on. the higher tide.