IMPROVEMENTS IN DREDGING PLANT.

Otago Witness, Issue 2171, 3 October 1895, Page 16

IMPROVEMENTS IN DREDGING PLANT.

Extensive alterations, resulting in a great saving ia workiag oxponoos, have recently bstn carried out in two dredges on the Alolyneux—viz, tho Ot»go Gold I>redgiug Company'a dredge (Ute Miller'B Creek) and the Uolden Treasure dredge, In the Ofci»go dre Igo the tumbler framing has been cut down 4ft 61n, and the height of water delivery about sft Gin, and all mintco-sarp bonds in the pin? dispensed \vjMi 'J'hc revolving screen bus Lcmi leng'hcned (md shifted further a*t?rn, and i>rovi<3ed with a new easing to collect the screened material, wlieuce it ia delivered to a set of tables 12ft by 12ft. An elevator has been erected which take? the rough stones and boppiugs direct from tha end of tho screen and stacks them at a height of 22ft übove the water line if necc-s-iry. The elevator i 3 adjustablo for height even wl;i'ii runnii.g. The framing of elevator is fo'iiiiil o.it of the old stone shoot which catcher xho lirijn and any ficer p»rtic>ea which m>iy h.ivo c cap^tl the Bcrce«, dcliroring them at tin* hotto;n oad to a small cro33 tablo. Tho elevator works very smoothly, and owing to the buckets bting carried back without any baguipg the tlevator may be worked close up to the pile of tailings without disturbing the piia. Through the lowering of the tumbler framing the ladder, which is 70ft in length, can now dredge deeper than any dredge on the river, and no water is required for stone shoot by reason of the elevator taking tho hoppings immediately ftt the end of screen. Tbe dredge ia now worked by two men, or one less than formerly, and the coal consumption has been reduced according to the manager's report by one ton per day. At the Golden Treasure dredge the pontoons have beea strengthened by a heavy crossbeam immediately behind the tumbler fraruihg, bolted to the tumbler framing and to both hulls, and diagonal bracing (itteJ between the tumbler framing. Longitudinal tubes have been fitted under tho winches, new hand rails fitted all round, and the top pides of hulls recsulfced. New copper steam pipes have been fixed between engiue and boifer, covered with felt and canvas. The boilers have been fitted with new sludge-hole doois aud blow-off oock, and covered with nonconducting composition. Both high and lowpressure cylinder havo bad the. liners drawn and new linero of smaller size provided and fitted, aho new pistons. Tbo valve faces bava been refitted and copper education pir>B provided. A pair of pumps— one feed and the other bilge— have been provided, driveu with eccontric from second motion shaft. The centrifugal pump has been shifted f om the poit pontoon to the Bt&rboard pontoon, and a wrought iron well fitted to tho bottom of die ves c el, from which tbe pump draws the water and saves necdles3 bends. Priming apparatus, consisUn? nf steam ejector, has beea fitted to pump, with hinge valve on top of delivery column. This ejector is alao arrauged with a three-way ccck to draw the bilge water from the starboard pontoon when u*t in use for priming

the purap.^The height of the delivery column of the centrifugal pump has been reduced by 14 inches. New top and bottom tumblers and shafts nave been fixed, and a considerable number of bow connecting links. The dredge started work on tire 27th, aud tho manager reports that tho coal con. sumption has been reduced from 10, anil sometimes 20 bags, per shift, to 10J b»cs (tne bag 3 being tie 4 at the mouth). Both of thj above dredges ara under the management of Mr Qoorge Bennett. The altorafcions in both instances were designed and superintended by Mr Edward Roberts, consulting eugineer, Moms Oossena and Black carrying on the contract on the Otogo dredge, and Messrs A. and T. Burt supplying tha necessary work for alterations to engines, &c, and Messrs II S. Sparrow and Co. the new tumblers and links on the Golden Treasure dredge.