Accident at Worksite at Bugis Station, Downtown Line

Mr Gerald Giam Yean Song asked the Minister for Transport whether the lessons learnt from the Nicoll Highway collapse during the construction of the Circle Line in 2004 had been implemented in the Downtown Line construction project, and if these could have prevented the accident on 18 July 2012 that claimed the lives of two workers.

Mr Lui Tuck Yew: I thank the Member for his question. First, let me emphasise that the nature and scale of the two incidents are different. The Nicoll Highway collapse resulted from the failure of the temporary Earth Retaining or Stabilising System (ERSS) for deep excavation works. This led to the collapse of reinforced concrete walls within an excavated area. The Downtown Line (DTL) incident on 18 July, while no less unfortunate, resulted from a temporary scaffolding structure giving way. The incident was localised within the DTL Bugis station site and did not involve deep excavation works.

Following the Nicoll Highway incident, the following key recommendations were adopted for all LTA projects involving underground construction, including the DTL project:

(i) As the developer, LTA would engage an independent Qualified Person(QP) (Supervision) to supervise the construction work;

(ii) LTA would engage an independent checking engineer to check and endorse the ERSS design for deep excavation works; and

(iii) LTA would engage an independent instrumentation specialist firm to supply, install and monitor the instrumentation during the construction work for excavation that exceeds six metres in depth.

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Of the above, the recommendation that would be relevant to the Bugis incident is the appointment of the independent QP(Supervision) to supervise the construction work. This was fulfilled.

For temporary scaffolding structures, such as those involved in the Bugis incident, the Contractor is required under the Workplace Safety and Health Act, to engage a Professional Engineer (PE) to design and supervise such works. The legislation also places responsibility on the Contractor and his appointed PE to ensure that the temporary scaffolding structures are safely constructed according to the approved design.

While it is not a statutory requirement for the appointed independent QP(Supervision) to check temporary scaffolding works, LTA had earlier further strengthened its safety framework by imposing a contractual obligation on the QP(Supervision) to also review the design of temporary scaffolding structures by the Contractor's PE. This was implemented for the DTL Bugis station project.

As MOM's formal investigation into the incident is ongoing, it would not be right for me to comment at this juncture, on whether the incident was preventable.