Rail operators' duty to maintain rail assets

We thank Mr Shawn Lee Chieh Loong and Mr Chin Neep Hing for their letters (What's LTA's role in equipment maintenance?, Oct 18; and Maintenance won't help if design is flawed, Oct 21).

Under the New Rail Financing Framework arrangement, SMRT remains responsible for providing reliable and well-maintained rail services, which include ensuring that rail operating assets are in good working condition, replacing faulty components and establishing a comprehensive maintenance regime.

As owner of the rail operating assets, the Land Transport Authority carries out regular audits of the rail operators' maintenance records and on-site inspections, and has flagged maintenance lapses to SMRT for rectification.

The LTA also regularly meets SMRT to assess its maintenance plans, and has highlighted components due for replacement.

To provide stronger oversight, the LTA set up a dedicated "Rail Assets, Operations and Maintenance Group" last year to oversee condition assurance and stewardship of our rail operating assets.

However, primary responsibility ultimately remains with the rail operators, which must ensure that the assets are in a condition befitting their age or else compensate the LTA for them.

The MRT tunnel flooding on Oct 7 was caused by the multiple failure of redundancies and buffers built into the storm water pump system.

First, the malfunction of the "stop" float switch prevented pumps in the storm water pit from activating to discharge water collected.

Second, a separate and independent "alarm" float switch also failed to alert SMRT of high water levels accumulating in the storm water pit.

Third, the storm water pit, which is sized to contain six hours of continuous rainfall, was already full and, therefore, unable to cater to the further rainwater that afternoon. It should have been empty if it had been properly maintained.

From a design perspective, it is very unlikely that both the "stop" and "alarm" float switches would have failed concurrently, which underscores the importance of regular maintenance and checks. The design of the float switches is also not unique to the Singapore rail system, and is widely utilised in many other submerged pump applications.

The LTA has always been committed to working closely with all our rail operators to improve their maintenance processes.

Chua Chong Kheng

Deputy Chief Executive (Infrastructure and Development)

Land Transport Authority

A version of this article appeared in the print edition of The Straits Times on October 26, 2017, with the headline 'Rail operators' duty to maintain rail assets'. Print Edition | Subscribe