Vast Engineering Project in China

Waikato Independent, Volume XLIV, Issue 6106, 26 September 1947, Page 5

Vast Engineering Project in China

THE ICHANG DAM

KARAPIRO JUST A DWARF / f * Briefly mentioned in a recent issue Mr Neville Sanderson, Borough Engineer, when he spoke to the members of the Cambridge Rotary Club on “The Machine Age,” gave much interesting detail about the vast Ichang Dam on the Yangtse River in China. Another interesting project referred to was the dredging for tin in the Dutch. East Indies.

It will be readily seen from the following details that the Ichang Dam actually dwarfs the Karapiro Hydro Dam into insignificance when it is mentioned that the dam will be 750 feet high and its bulk mass will be 15,000,000 cubic yards. The Ichang Gorge, as described by Mr Sanderson, is 300 miles east of Chungking. The Ichang dam is the largest irrigation and power project ever planned and its planning is to the National Recourses Commission, of China. Its experts are aided by engineers of the United States Bureau of Reclamation.

Mr Sanderson stated that the Yangtse River is at present navigable as follows: ' (a) For ocean going ships to Hankow, 600 miles up the river, (b) For river freighters to Chungking, approximately 1600 miles; but at limited periods, (c) For junks and sampans to the Ichang Gorge j a further 300 miles.

As already mentioned tlife dam across the gorge is to be 750 feet high, whereas. the world’s highest to date—Boulder Dam—is 726 feet. The bulk mass of 15,000,000 cubic yards, compares with 12,000,000 cubic yards of the Grand, Coulee Dam. The Ichang Dam will create a lake 250 miles 'long. - P Associated with the dam will be. a huge generating plant with three times the combined capacity of the Boulder, Grand Coulee and Shasta plants. 96 Coulee type 108,000 k.w. turbo geperators will generate 10,368,000 k.w., and you know . that Karapiro when completed, will generate total of *90,000 odd k.w. But this is not all. It is intended that bigger ships shall utilise the lake so that its commercial value can be. exploited. To do this ships are going to be raised to the higher water level by. a dry lift. Actually on one side they will go into a kind of lock and will be lifted 550 feet with straddle cranes and multi-reeving cables, attached to the sljip’s hull. There'will be a 200 feet, high entrance 'tunnel from . down stream to the lock base. Sampans will be handled in metal tanks, while ship hulls will have to be specially strengthened to stand the strain of the lift when fully ladened. The lock gates, will of course be 200 feet high. This enormous dam will provide irrigation water and power to 10,000,000 acres' of flood and drought devastated lands with a population 120 times greater than New Zealand. It will control the river levels to allow 12 month navigation of the Yangtse between Hangkow and Chugking. Dredging for Tin 'lt is readily appreciated that tin ore or sand is one of the most important natural deposits in the world today and in the Dutch East Indies its production is a great industry, here again is a striking example, of the development of the machine age, as so interestingly described by Mr Sanderson last week. Mr Sanderson

stated that the Island of Banka, Billiton and Singkep'produced 51,000 of the-total world production of 246,000 tons of tin in 1941.

To, further exploit the tin-bearing sand in the islands, two huge dredges named “Stuyvesant” and “Roosevelt” are being built and the first was actually due to operate this year. They are known as placer dredges, each of 4150 tons and are being built for the Mining Equipment Corporation of New York by Bucryus Eerie Company, Wisconsin, for operation on the islands mentioned. They are the largest tin-mining placer dredges to have ever been designed in U.S.A. The “Stuyvesant’s- hull is to have a length of 246 feet; beam 76 feet and mean draught, 12 feet 9 inches. It is estimated that the;dredge will have an output of '300,000. to 400,000 tons of tin-bearing sand monthly. The digging ladder on the vast machine will be 216 feet long and will be equipped with 148 manganese steel buckets each weighing 2 tops. The total weight of the ladder, buckets, rollers, idlers and tumblers will be 650 tons.

Mr Sanderson further mentioned that sluicing and washing tin-bear-ing sand required 1,500,000 gallons of water an hour, or the equivalent of four days’ consumption of the whole of the Cambridge district. The foregoing details of two vast engineering projects are surely examples of the-remarkable development that has been made in the realm of mechanics over the couple of past decades. ■