51
Loan Works
291. The overflow section of the dam consists of sixteen twelve feet bays, and the ten feet wide roadway, which traverses the dam, is carried over the overflow section by sixteen reinforced concrete arches twelve feet span and two feet rise. The overflow is collected in two flood water channels which discharge into a water cushion fifty feet wide at the toe of the dam and thence over a sill into the original stream bed. A valve well is constructed centrally in the dam and is surmounted by a rectangular Valve House containing the operating gear for the various control valves. There are four 18" dia. draw-off pipes each controlled by an 18" dia. penstock and a 15" dia. Sluice Valve at levels of 300, 320, 340, and 360 A.O.D. and each is connected to an 18" dia. stand pipe. The 18" dia. supply main from the stand pipe crosses the South-east flood water channel on a reinforced concrete skewed arch bridge of 42'-0" span. A total of 29,300 cubic yards of concrete were placed in the works, the total number of blocks made being approximately 14,100 of which 7,200 were rock faced and 6,900 smooth faced.
292. The contractors for the works were the Hong Kong Excavation Pile Driving and Construction Co. who introduced modern equipment for the construction of the dam. Materials, except stone which was found near the site of the dam, were transported by road to a loading station at the East end of the dam and carried over the valley by overhead cableway to the mixing station. The sand and cement were deposited from the cableway direct into storage bins constructed immediately above a concrete mixer of one cubic yard capacity. The mixed concrete was hoisted inside a steel tower and discharged into a chuting equipment suspended from a cable slung across the valley. The pre-cast facing blocks were cast in gang moulds on a specially prepared concrete floor adjacent to the mixing station, the faces of the rock faced blocks being formed by cast iron moulds.
1961 Expenditure.... $217,888.07
Expenditure to 31st Dec., 1931...... $518,623.89
293. Item Q, Hong Kong Gardens Service Reservoir.-This work was referred to in paragraph 248 Item (Q) of last year's Report. A Contract for the construction of the Reservoir was signed on the 15th September by Messrs. Yee Lee & Co. for the sum of $189,500.95 and by the end of the year very good progress had been made with the excavation, tipping to banks, piling, concreting of main walls and turfing. The steel work for the reinforced piers and roof arrived from England during December.
1931 Expenditure..... $32,390.38
Expenditure to 31st Dec., 1931...... $32,601.88