REMARKABLE SCHEME

Dominion, Volume 21, Issue 188, 11 May 1928, Page 8

REMARKABLE SCHEME

TO WORK THE KAWARAU

WELLINGTON MAN PLANS DAM OF ICE

Dominion Special Service.

Dunedin, May 10. How can the Kawarau River be worked for the gold in its bed? That question was asked in the “Evening Star bn March 29, and a sensational reply has been made bv a VV ellington inventor. His scheme is to cast an ice wall or walls across the Kawarau in the shape of wing dams with a plant forcing liquid air at 311.8 degrees below zero. Patents for the scheme were taken out on February 8, 1927, and the plans were submitted some months ago to the Kawarau Gold Mining Company, which requested the inventor, Mr. Herbert Montague Rosenberg, of Wellington, to place his scheme before the Consolidated Company, which is now working strenuously for the amalgamation of all claim holders.

While Mr. Rosenberg’s scheme appears fanciful, he has backed it up with practical plans. The whole cost would be less than £20,000, he estimates, and, unlike dredges, the plant would always be productive. The suggestion has been made to Mr. Rosenberg that he should give a test on a small portion of the Kawarau River, to convince claim-holders that the scheme is efficient, he being allowed to take all the gold, won from the bed. The nature of Mr. Rosenberg’s invention is to freeze a wall in the river in the form of wing dams, etc, by forcing liquid air through a system of pipes. < Liquid air registers 311.8 deg. below zero, and would freeze one or two feet into the bed of the river, forming a solid foundation, so the inventor claims, for the rest of the ice wall. Mr. Rosenberg believes that it will be possible to freeze a wall 300 metres long, two metres wide, at the base, and four metres high, with a liquid air plant producing 100 cubic .metres per hour in the short time of from three to four hours after the starting of the plant. In the case of a sudden rise in the river the ice wall could be sprayed on the top with a long hose to raise the wall above the increased height of the water. The wall of ice could be removed quickly when required by forcing boiling water through the pipes. For reclaiming land, the area could be enclosed by a wall of ice. and the water pumped out, a permanent concrete wall being placed inside the ice wall. “This invention has been submitted to several expert engineers, who are all of the same opinion that it is the only way to work the Kawarau River cheaply and effectively,” said Mr. Rosenberg. ‘.‘The plant can be made to produce oxygen for welding purposes, and nitrogen for fertilisers in the spare time when the plant is not required for the river work. The extra profits would warrant the additional expenditure for the necessary appliances.

“The difference between this method and dredging is very marked,” states Mr. Rosenberg. “There will be no repair bills, and the river can be cleaned right, down to bedrock. The whole cost of this scheme should be less than £20,000, and unlike dredges, the plant will always be productive.”