ENG-1971 — Page 219

PUBLIC WORKS AND UTILITIES

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long-term contracts. There are now six such quarries in full produc- tion, and the site for a seventh is being cleared. Only six private quarries are still operating under the old system of Crown land permits but these are on sites which are not suitable for large-scale digging. It is planned that most of these will cease operating before the end of 1972 as new quarries under government contracts replace them.

The rate of production of aggregate has been increased con- siderably and, while there was a shortage in the first quarter, supplies were adequate to meet demand for most of the year. Towards the end of 1971 there were signs that demand was again increasing, indicating a possible need for additional sources of supply. The two government quarries at Diamond Hill in Kowloon and Mount Butler on Hong Kong Island, which produce aggregate and road-surfacing materials for government projects, also increased production to meet growing demands from the expanding construction programmes. Preparations were being made at the end of the year for installation of new machinery to provide additional production capacity and to improve efficiency.

The materials-testing laboratories operated by the Civil Engineer- ing Office of the Public Works Department carried out 93,162 tests on building materials; of these 10,240 were for private firms.

Electricity

PUBLIC UTILITIES

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Three private power companies serve Hong Kong Island, Kowloon and the New Territories, in addition to minor enterprises such as that on Tap Mun and a few village co-operatives. These companies do not operate under any franchise, but the Government worked out a scheme of financial control with the Hongkong Electric Co Ltd and China Light and Power Co Ltd in 1964–5. Safety aspects are covered by the Electricity Supply Ordinance.

The voltage is normally 200 volts single-phase or 346 volts three- phase, four-wire, 50 cycle alternating current. For bulk consumers, supply is available at 11 kV and, in some locations, 6.6 kV.

The total generating capacity of the three main companies is 1,571.7 MW, of which China Light (Kowloon and the New Terri- tories) accounts for 1,114 MW, Hongkong Electric (Hong Kong Island) 455 MW and Cheung Chau Electric 2.7 MW. Electricity consumption increased considerably during the year and amounted to 4,891 GWh for the three companies. China Light sold a total