For discussion PWSC(96-97)29
on 1 July 1996

ITEM FOR PUBLIC WORKS SUBCOMMITTEE
OF FINANCE COMMITTEE

HEAD 703 - BUILDINGS
Support - Others
147GK - Weather Radar Station at Tai Mo Shan

Members are invited to recommend to Finance Committee the upgrading of 147GK to Category A at an estimated cost of $22.8 million in money-of-the-day prices for the construction of a weather radar station at Tai Mo Shan.

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PROBLEM
PROPOSAL
PROJECT SCOPE AND NATURE
JUSTIFICATION
FINANCIAL IMPLICATIONS
PUBLIC CONSULTATION
ENVIRONMENTAL IMPLICATIONS
LAND ACQUISITION
BACKGROUND INFORMATION

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PROBLEM

The Digital Radar System installed in 1983 at Tate’s Cairn will become obsolete by 1998. In addition, there has been undesirable mutual blockage between the two radar systems located at the same site at Tate’s Cairn. Power failures at Tate’s Cairn can put both radars out of action at the same time.

PROPOSAL

2. The Director of Architectural Services (D Arch S), with the support of the Secretary for Economic Services, proposes to upgrade 147GK to Category A at an estimated cost of $22.8 million in money-of-the-day (MOD) prices for the construction of a weather radar station at Tai Mo Shan.

PROJECT SCOPE AND NATURE

3. The project scope comprises -

1. the erection of a steel tower on top of a base structure to interface with a weather radar; and
2. the construction of a single-storey base structure to accommodate air-conditioning equipment, a computer room, a duty room, a toilet, a pantry, an equipment store, an emergency generator room, a meter room, an uninterrupted power supply room and other necessary service installations.

JUSTIFICATION

4. Weather radar is used to track tropical cyclones and heavy rain. It is the key piece of equipment in operating the Royal Observatory’s warning services in respect of tropical cyclones, rainstorms, thunderstorms, floods and landslides. The Royal Observatory operates two weather radars at Tate’s Cairn, a Digital Radar System installed in 1983, and a Doppler Radar System installed in 1994. They send data to both the Central Forecasting Office at Observatory Headquarters and the Airport Meteorological Office and act as a back up for each other so as to ensure that radar pictures are always available to weather forecasters. The Digital Radar system is becoming obsolete after 13 years of service. Its spare parts are no longer manufactured and are expected to be out of stock by 1998. We therefore need to replace it with a new weather radar.

5. The present arrangement of having two weather radars side by side at Tate’s Cairn is not ideal due to the problem of mutual blockage between the two radars. Besides, the radars being blocked by Tai Mo Shan in the northwest cannot detect accurately rainstorms approaching from that direction. Furthermore, power failures at Tate’s Cairn can put both radars out of action at the same time. To mitigate these problems, we propose to install the replacement radar at Tai Mo Shan, instead of Tate’s Cairn. We therefore need to build a new weather radar station at Tai Mo Shan.

6. If we do not replace the radar in time, the Royal Observatory will have to operate in the absence of a back-up system for the first time since 1966, thus undermining the reliability and effectiveness of the Royal Observatory’s weather warning services.

FINANCIAL IMPLICATIONS

7. We estimate the capital cost of the project to be $22.8 million in MOD prices, made up as follows -

8. The amount of “Contingencies” represents about 12.6% of total capital cost which is a little higher than the usual level of 10%. The reason is that we have to include a higher risk factor due to the remote location of the station, difficult site/weather conditions and the need to allow for the necessary interface work for the installation of the radar equipment which cannot be finalized at this stage.

9. Subject to approval, we will phase the expenditure as follows -

10. We have derived the MOD estimate on the basis of the Government's forecasts of trend labour and construction prices for the period 1996 to 2000 . We will tender the works under a lump-sum fixed price contract because we can clearly define the scope of works in advance, leaving little room for uncertainty.

11. We estimate the annually recurrent expenditure for this project to be $0.06 million.

PUBLIC CONSULTATION

12. District Officer (Tsuen Wan) considers that no public consultation is required as the location of the proposed project is remote and local activities will not be affected. We issued an information paper on the proposed weather radar station with both the building and equipment parts of the project to Members of the Legislative Council Panel on Economic Services in May 1996. We have not received any comments from Members.

ENVIRONMENTAL IMPLICATIONS

13. In June 1995, the Director of Environmental Protection vetted a Preliminary Environmental Review completed by the Director of Architectural Services which concluded that there would be no long term environmental impacts and an Environmental Impact Assessment would not be necessary. For short term impacts, we will include pollution control clauses in the contract to control noise, dust and site run-off nuisances during construction.

LAND ACQUISITION

14. This project does not require land acquisition.

BACKGROUND INFORMATION

15. 147GK was upgraded to Category B in January 1996.

16. We will seek funding approval of the estimated cost of $28 million for purchasing the weather radar equipment under Head 708 “Capital Subventions and Major Systems and Equipment” in October 1996. We estimate the annually recurrent expenditure for the equipment component to be $0.55 million.

17. We are finalising the working drawings and tender documents using in-house staff. We plan to start the proposed works in December 1996 for completion in February 1998.

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