Design for Safety and Constructability (DSC) refers to the overall process of proactive design and construction planning, and the selection of design options and construction methods with due care in order to reduce construction safety and constructability risks. MTR has been implementing the “Design for Safety” strategy in all its new projects, particularly the design activities of the built assets, throughout the process from the initial stage to final delivery.

DSC begins at an early stage of the project. To identify risks in a design activity, preliminary hazard analysis workshops will be conducted to review all the significant and unusual construction processes, operation and maintenance work activities for design mitigations. The DSC risk register acts as a live summary record of the hazard identification and control process to be reviewed throughout the design stage. Whereas there is more than one potential design mitigation measures, the optioneering recommendations will be recorded along the process. All relevant information documented at the design stage should be collated to the stakeholders in subsequent stages. Hence at the tender stage, a pre-tender health and safety plan will be issued to the tenderer for further development.

In addition, the designer will provide the necessary safety information of a design element with the aid of a health and safety file. It enables the future owner to manage residual risks during handover to end-user. In particular, the design assumptions, structural parameters or any restrictions should be clearly stated so that the contractor can process it throughout the construction process. Upon completion of the project, the maintenance supervisor will uphold the health and safety file and make it accessible for future use. Furthermore, the effectiveness of the safety in design should be evaluated, by MTR’s lesson learnt exercise, so as to ensure that good design practice and innovative measures should be applied in future projects.

A good and safe design cannot be achieved without effective communication between all parties involved in the life cycle of a project. As far as reasonably practical, the design mitigations shall follow the hierarchy of control to eliminate risks and hazards at source. Proper documentation by relevant safety management tools is of prime importance in DSC to accommodate the complexity of risk and uncertainties.

This article is contributed by Ir Lesly Leung with the coordination of the Safety Specialist Committee.