was laid as a 6" vibrated cement concrete slab on 12" of granite bottoming. Cast into and flush with the floor are sets of rails on which runs a 20 ton gantry crane for the handling of the precast units. For this to be fully mobile over the whole area of the blockyard, a turntable and traversing trolley platform have been provided to operate in a trench with the floor of the moving platform level with the blockyard. The frontage sea-wall was built to provide 10 ft. of water at L.W.S.T. and a basin with ramp for the convenient off-loading of heavy plant, was constructed with a 20-ton sheer legs over-hanging the basin for loading blocks or piles directly on to lighters. On the frontage to King's Road was built a modern two-storied building, the upper floor of which now houses the P.W.D. laboratory with Port Works stores and offices on the ground floor. During the year use was made of the new yard to cast some 20,000 tons of concrete units and this resulted in minor subsidences of the floor which had been laid on reclamation fill insufficiently consolidated.
156. The many and various types of precast concrete units made included mooring blocks for the Marine and other Government Departments. The largest of these were 90-ton blocks for typhoon moorings. On account of the excessive weight and difficulty of handling, these were built in two parts, male and female, of 40 and 50 tons each; the 40-ton block forming a collar to the lower block in which the mooring link was built.
Investigations & Miscellaneous Works.
157. Preliminary designs were prepared for the construction of two new passenger ferry terminals to replace those operated by the Star Ferry Co. Investigation of the foundations were commenced with the driving of test piles and the sinking of bores to a depth of 80 ft. to obtain soil samples.
158. Another interesting problem was the design of a small berth and mechanical handling equipment for the rapid off-loading of mail bags brought to the General Post Office by lighter from ships.
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