(6) Sounding surveys at Tai O, Tung Chung fairway, Deep Bay, Tsing Yi Bay, Sai Kung, Ap Lei Chau, Wan Chai, North Point, Shau Kei Wan, area around buoy No. A16 and Aberdeen Channel.
(7) Surveys of foreshore and high water mark at Yau Tong Bay, Repulse Bay and Ma Wan.
(8) Sounding surveys before and after dredging at all nullah outfalls inside the harbour.
(9) Progress surveys on public spoil dumps at Hung Hom, Cheung Sha Wan, Sandy Bay and Chai Wan, and the Gin Drinker's Bay city refuse dump.
(10) Echo sounding surveys for checking the depths depicted on Admiralty charts at Rambler Channel, western part of the harbour, Ma Wan, Sulphur Channel and Luk Keng.
MATERIALS TESTING LABORATORY
8.24. During the year no less than 2,782 tests were carried out on various types of materials and on soils for foundation design on behalf of private firms. This is over three times the number of tests carried out for private firms during the previous year, which indicates the increased interest in scientific design and in the quality of work being carried out in the Colony generally. These tests earned revenue of over $32,000. It is expected that the number of tests for private firms will continue to increase.
8.25. The total number of tests on soils and construction materials carried out during the year totalled 20,773 and were made up as follows:
(1) Concrete tests No. of Tests 8,080 (2) Cement tests 450 (3) Aggregate tests 2,611 (4) Metal tests 2,657 (5) Bitumen and bituminous mixture tests 1,065 (6) Soil tests 5,834 (7) Miscellaneous tests 768.26. An interesting feature is the considerable increase in the number of soil tests. These are complicated and lengthy and added considerably to the work of the Laboratory.
8.27. New equipment acquired during the year included a set of pore pressure apparatus, a mechanized portable concrete mixer, and one more triaxial cell for testing 11/2" diameter soil samples.
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