GOLD DREDGING

Evening Star, Issue 17968, 15 May 1922, Page 6

GOLD DREDGING

THE RLMU AT WORK

The ‘ Inanuahua Times’ (Uoefton) describes a visit to the Kmm dredge, which is working on theißurm Flat, lour mi es south o£ Hokitika, and is» electrically driven From the pilot-house, the repoit says, can be seen how the dredge is controlled. One man is in charge o several levers, and these control the whole ot the work done by the dredge. Here you Imd the telephone, which enables those on board to communicate with tho outside workers. A most interesting machine is an automatic depth recorder, which _ records every minute of tie day or night where the dredge is working, the depth, and at what particular time, krom tno pilot-house can also be seen the clearing rranf at work, rooting out the bush, assisted by a steam hauler. A good view can also' be seen of the buckets and lines, and in a week the dredge turns over an acre of ground frprn a depth of 4oft. Each bucket weighs 22cwt, and brings up 22 cubic feet of dirt. The buckets are kept in position with a 6in manganese steel pm. The bucket ladder is very massive. It weighs 160 tons, and is driven by a 2UJ horse-power motor. Two hundred cubic feet of dirt, stones, and boulders per hour are raised from a depth of 45ft and oelivcrud to tho rotary screen, which is 40ft by Bft. A heavy pipe delivers a strong jet of water on the screen, forcing all the smaller material through the perforations into the gold-saving fables below', which comprise a spread of 4,000 ft. The tables arc cleaned up every eight hours. The rotary Fcreon delivers the stone nml grave! on to the stacker, which is 120 ft long by 3ft 6iu wide, and is made of strong canvas covered with rubber. This is driven by a 40 h.p. motor. The next thing looked at is entirely new, and does away with the numerous lines used on other dredges to keep them in position. The Himu dredge is kept in position by twm long steel bars 50ft long and weighing 18 tons each. These are called spuds. When one of these is let down the dredge is held firmly up to the working face, comim T x'ound as on a pivot, and so Hoiking forward as wanted by using one spud after the other.