QUEST FOR GOLD.

Taranaki Daily News, 5 January 1924, Page 9

QUEST FOR GOLD.

A- RESTLESS MAMMOTH-DREDGE. AMERICANS EXPLOIT WESTLAND. (Christchurch Sun.) Westland is still -the land of gold. Though no longer the tents and campfires of the gold-seekers line the ’banks of the creeks and rivers, the quest for the yellow, glittering metal goes on. Ihe quest has led to fresh fields, rich, perhaps richer than ever were conjured up in the visions of the oldtime prospectors. The brave and picturesque men who splashed through the mountain streams, sifting the sands for the golden grains, had not the key that would lay open to them the store hoarded by Nature in the new fields. The genius of a mechanical age has cast the key. Imagine acre upon acre covered by huge boulders, some of which Weigh tons, that have been scooped by °argantuan hands from 60 feet or more below the surface and flung into heap’s that are veritalble hills. Such is the trail made by the new, order of "oldwinnners, and it is being laid in° the Kimu Flats at Hokitika.

It is a trail of -a gold-mining dredge, but such a dredge that a decade or so ago would not have been dreamed of. The dredge is the largest in the Southern Hemisphere, 'and it is run by an American concern, the Rimu "Gold Dredging Co., Ltd. The company has ‘struck it rich.” In the 27 months it has operated it has won approximately 100,000 oz of gold. Gold being worth about £4 10/- an ounce, the compan.v’s are thus the half-million mark—this on an original outlay of about £200,000.

GORGING ON THE LAND. The dredge does not float on any river. It cats its way thixnfgh land which once was river-bed, but which now is covered with dense bush, and»it floats on a lake made by its own operations. As it bites and scoops its way forward, its spoil, all but the fine gold, is flung in great heaps. 50, 00, 70 feet high, immediately behind it- And as it moves forward’ so does the lake. Iti its progress it consumes and ejects two acres of land a month, gorging on boulders and sand to a depth of about 46 feet beneath the surface of the water. And the surface of the water is about 15 feet below that of the ground. There is something almost demoniac in the appetite of this monster of wood and steel. Day and night it feeds itself, yet in the 24 hours its hunger hardly ever slackens; its terrific energy, drawn from hydro-electric works miles away, but seldom slacks off. It sucks uealth from the land and tosses aside what it rejects- And in the act it cieates devastation irreparable. The writer stood on the drejoe the other day. It quivered and shook, as though in anger, as its big buckets—there are 72 of them on the linedug into the mass of huge stones and sand, and wrenched them to the surface. And’ the clatter, and rasping, forbade speech, unless one shouted. A great steel wedge, 56 feet long and 18 tons in weight, had been dropped through the centre of the dredge, into the bed of the lake, and it held the vessel close to the bank, thick cables stretching to the shore assisting. The bulky Oregon timbers of the dredge groaned under the strain. It seemed as though the dredge would tear itself apart.

SEPARATING THE SOIL. Amidships Is a big perforated cylinder, which revolves. Into this the buckets tip their spoil. Jt is whirled round, and in. the process water, sent through 11 nozzles, each of 2in diameter, by a 12in pump, plays upon it- The sand is washed and forced through the perforations in the cylinder on to goldsaving tables below. The tables, two tiers of them, have a ribble surface, and as the sand flows over them, the gold, being heavier, lodges in the hollows. The tables have a surface of 4COO square feet. Meanwhile, the gravel and boulders are whirled round until they are thrown on to a running rubber pathway. which carries them up and clear of the dredge, where they are dumped. They help to form the mountainous trail. This strip of rubber is very thick, and it is strengthened with canvas, being of much the same material ns an automobile tyre cover. It needs to be strong, for it has to bear a weight up to 16 tons, ft i 6 88in wide and 280 ft long.

The buckets are large enough and strong enough to lift out of the bed of the lake boulders weighing up to three tons. Often such massive chunks of granite or other hard stone are of a size and weight considered too much to be tipped into the revolving cylinder. When this ..is so, the machinery is stopped and the stone is grappled by an electric hoist and conveyed to a chute.

The monster stone plunges over the side, and hits the water with a great splash- Visitors wijl sit on the banka for hours watching such summary ejections.

Now for some statistics: Each bucket can hold 10 cubic feet of gravel, and 19 buckets are emptied a minute. The usual rate of dredging is 422 cubic yards an hour. The engines of the dredge work under 500 h.p., and the dredge itself draws seven feet of water. The power-house, situated eight or nine miles from Lake Kanieri. whence the necessary water for the turbines is drawn, has machines, which generate 2000 volts- Not all this power is used by the dredge, some of the surplus being supplied to Hokitika for lighting purposes, and a dairy factory and several other concerns being provided with some current for power puposes. But when the dedge digs up a boulder tons in weight, its engines demand more current, and then the lights in Hokitika record the fact by burning low. They do this many times a night—the dredge works i-* hours in the day. three shifts of men being employed. Since the dredge began to operate jt lias devoured 46 acres of bush land and hundreds of acres have yet to be dealt v ith. The trees are felled, of course, before the land is dredged, and the trunks dragged clear. Roots near the surface are also torn from the track of the approaching lake. No one in Hokitika grudges the company the good fortune which has come its way- It had the courage to sink £200.0b0 into a project 'which was a gamble. Others had tried the field, but they had merely scratched the ground, as it were. The company saw that any ’ operations to succeed must be on a big

scale, and it took the plunge. First it made borings. It found that the gold was of the sort known as “shot.” This is the gold that has been torn from the reefs in the moirntains and worn to a powder, possibly by glacial action. Once a fortnight are collected the. precious grains from the ribbed gold-saving tables of the dredge. By means of quicksilver the gold is amalgamated, and then it is smelted. The fortnightly average is over I'Boo ounces.

When the company decided to begin operations it regarded the dredge as an experimental one. It assembled the parts on the spot, and launched the vessel on a small pond. The experiment has proved so successful that the company is developing plans for the securing of another dredge, which will be all steel and larger than the present goldI winner. The cost of this will be enorI pious, and it is clear that a new hydroelectric system will have to be installed. 'i..e present one, which was constructed years before tlie_ war for .mining at Ross and purchased by the company, is overloaded in the present operations. The plans for extension involve such a huge outlay that the company is hesitating on the question. In the meantime, it is investigating many other mining propositions in different parts of the West Coast. Other companies, too, are getting to work on the new methods. Gold-mining is far from being a declining industry on the West Coast.