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A NEW QUARRY FOR hong kong
There are four main requirements in the production of sound concrete, good cement, correct placing of the mix, correct proportioning of the mix and sound, properly graded aggregate. There is plenty of good cement in Hong Kong and it is gratifying to note the increasing number of contractors who are The correct using vibrators to assist in placing the mix. proportioning of the mix is still a source of worry to supervis- ing architects. It was a really pleasant experience recently to look over a newly opened quarry which is yet one more help towards good building practice.
This quarry is producing a really first-class, hard aggregate, properly screened and dust-free and is being operated by modern methods. The owners of the quarry are the China Supply Company Limited and the site is at Ngau Chi Wan on the Clear Water Bay Road above Kai Tak.
Work was started in November 1948 in clearing the site, building access roads, installing plant etc. and the quarry is already producing thirty five tons per day of crushed stone.
Mr. R. A. Webb, who is part owner and in charge of operations, has been engaged in construction work for sixteen years. He served during and after the war with the R.E. in Germany and Palestine, his last job in Palestine being the construction of emergency camps in Jerusalem for the evacuation scheme during the recent troubles in that country.
Work has not yet been started on the permanent quarry face, the production of thirty five tons per day coming from boulders and outcrops which must be cleared from the site of Mr. Webb the access road and tramway to the quarry face. is planning his quarry to take full advantage of gravity in moving rock from skips to crushers, crushers to screens, screens to bins and bins to customers' trucks. Georgraphical conditions did not permit an ideal layout, with the result that the bin capacity is not as great as desired, but otherwise the planning should lead to great economies in handling. The maximum distance from quarry face to the crushers is about two hundred and fifty yards.
The plant at present in use is one Schramm 310 c.f. compressor driven by a Buda engine, two Grundler single toggle jaw crushers of a capacity of seven tons per hour each and screening apparatus built up locally. Each crusher is driven by a 27 B.H.P, electric motor. The screening at present is arranged for the greatest demand, i.e. rejects, 14", 1", " and dust. If needed the dust can be screened to supply i”.
All soft and decomposed rock is discarded, nothing but sound and hard rock being fed to the crushers. Experts have examined the rock in this quarry and pronounced it to be first class for concrete aggregate, There is some very attractive pink and grey granite which Mr. Webb intends to cut for facing stone. It is apparently free from iron or other matter which spoils otherwise good facing stone by staining.
The production aimed at in the very near future is one hundred tons per day for a seven day week. The time taken to load a customer's truck with 3 cubic yards is seven minutes.
It is rather surprising to note that, at the prevailing rates for electric power and for petrol, the Buda petrol engine driving the compressor costs less to run than an electric motor, H.K.$9.00 per hour for petrol fuel as against over H.K.$11.00 per hour for electric power at the rate of sixteen cents per Kw. Diesel fuel would cost still less than petrol but the higher capital cost must be taken into consideration, also the difficulty in obtaining a really skilled diesel mechanic to maintain the engine.
It was really refreshing to see this quarry producing a high grade product on modern lines and we trust it will not be long before Mr. Webb will open several more, on the island of Hong Kong as well as on the mainland.
Whate
DESTRUCTIVE AMAGE
DESTRUC
IS CAUSED BY WHITE ANTS
ON NT
DECAT Phone
24
30722
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THOMAS COWAN & CO. (CHINA)
Room 320 Queen's Bldg., Hong Kong The original white ant exterminators of the Far East
Agents :- JARDINE MATHESON & CO., LTD. Telephone 22019
FOR
BUILDING SUPPLIES
CONTACT
DREYER & CO., LTD.
YORK BUILDING
TEL. 30452
HONG KONG
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