LCQ13 : Major infrastructures' safety inspection measures
Following is a question by the Hon Leung Yiu-chung and a written reply by the Secretary for the Environment, Transport and Works, Dr Sarah Liao, at the Legislative Council meeting today (June 27) :
The serious incident on the 11th of this month in which a cabin of the Ngong Ping 360 cable car system crashed to the ground has aroused my concern about the safety of other major infrastructures in Hong Kong, such as the road tunnels, major bridges and mass transit carriers. In this connection, will the Government inform this Council whether it has:
(a) regularly inspected the safety of the above-mentioned infrastructures; if it has, of the inspection standards adopted and the facilities inspected;
(b) regularly updated the safety standards adopted for such infrastructures with the latest international standards; if it has, of the details; and
(c) conducted, on a regular or irregular basis, risk assessment on such infrastructures, and formulated contingency measures in the light of the assessment results; if it has, of the details; if not, the reasons for that?
The Government has all along attached great attention to the safety of transport infrastructures such as road tunnels, major bridges, as well as mass transit carriers. Apart from regular inspections and maintenance, the concerned departments have from time to time updated the inspection and maintenance standards. Relevant details are as follows:
The regular inspections and maintenance of major bridges can mainly be categorised into the following three types-
(1) Six-monthly inspection
The inspection mainly adopts the visual method to check the conditions of the bridge deck facilities, main structures and ancillary structures so as to ascertain whether there is any damage that will cause safety problems.
(2) Biennial inspection
In addition to visual inspection in a short distance, the biennial inspection includes some non-destructive tests, for example, tests on concrete carbonation, chloride content and the adequacy of reinforcement cover so as to assess the service conditions of the bridges, compile the basic data required for the management and maintenance plans, as well as conduct comprehensive inspection on the conditions of both the main and ancillary structures.
(3) Special inspection
Government departments will conduct special inspections on the bridges in the wake of traffic accidents and natural disasters (such as earthquakes and typhoons) to assess their load bearing capacities and health conditions.
As far as bridge inspection is concerned, the international development trend is to install bridge structural health monitoring systems on long span bridges. The system, which comprises various types of sensors, including anemometer, temperature sensor, accelerometer, strain gauge, displacement transducer, etc., provides real-time data on loads (such as wind, temperature, seismic and traffic) and structural reactions (such as displacement and stress) of the bridges to facilitate their structural health assessments. The concerned departments have installed/will install the system for all the existing long span bridges and those under construction. They will also continue to upgrade the functions of the system, for example, to upgrade the outdated level gauge with global positioning system to monitor any deformation of the bridges. In addition, the concerned departments have actively participated in international bridge conferences to ensure that our techniques in bridge inspection and maintenance can be maintained on par with the international standards, and be further updated and upgraded.
The inspections of major bridges have been jointly undertaken by government engineers and the contractors. During inspection, they carry out analyses and assessments on the conditions of the bridges in order to formulate appropriate maintenance strategies and initiatives to avoid structural problems and the associated risks.
Major tunnels in Hong Kong fall into two categories, namely government tunnels and "Build-Operate-Transfer" tunnels ("BOT Tunnels"). For government tunnels, a number of government departments and the tunnel operators jointly carry out the regular inspection and maintenance works. The concerned departments regularly inspect the tunnel units under their purview according to the relevant guidelines and draw up specific inspection requirements for different units according to their maintenance needs.
As for BOT tunnels, the tunnel franchisees are responsible for the inspection and maintenance works, while related government departments monitor their performance in accordance with relevant legislations.
Moreover, all the concerned departments meet regularly over the year to review the inspection and maintenance work under their purview, as well as formulate and revise the related standards and guidelines in the light of international standards.
The related government departments and tunnel franchisees will also assess the possible risks associated with the tunnels, including facilities failure, serious traffic accidents, fire, flooding, etc., and develop contingency measures against such risks.
Mass Transit Carriers
On mass transit carriers, both the Kowloon-Canton Railway Corporation and the MTR Corporation Limited have developed maintenance regimes with reference to suppliers' maintenance guidelines to maintain the safety and reliability of the railway systems. Inspection and maintenance schedules have been drawn up for every unit or component in the railway systems, including the rolling stock, permanent way, overhead lines, signalling systems, communication systems, station facilities, etc. All the equipment is replaced before aging or wearing out as far as possible so as to achieve the best performance in terms of safety, reliability, service delivery, durability and productivity. For example, each train is scheduled for an overhaul once every three to four years, in which components of an assembly or equipment in a train system will be inspected, replaced or renewed to maintain the function of the equipment and integrity of the system.
Apart from drawing reference from the suppliers' maintenance guidelines, the two railway corporations have set up ISO certified quality management systems to ensure that the safety and reliability of railway services are maintained at a high standard. Based on the industry's best practice, the corporations also review and improve their maintenance and inspection regimes regularly to enhance the reliability and safety of the railway systems.
Both railway corporations adopt safety management systems in considering the safety issues in the design and construction of railways. Risk assessments are carried out systematically to minimise risks identified as far as reasonably practicable. At the stage of railway operation, the corporations take a proactive and systematic approach in managing the safety of their assets, systems, people and the environment through regular quality and risk reviews.
In addition, the two railway corporations from time to time review the lessons learnt in railway accidents and incidents happened in overseas railways with a view to controlling and reducing similar risks in local railway systems. Both corporations also engage independent experts to review their safety management systems at least once every three years.
Ends/Wednesday, June 27, 2007
Issued at HKT 14:30