Circle Line trains could get electromagnetic shields to minimise signal disruption: LTA, SMRT
SINGAPORE: Authorities will explore the use of electromagnetic shields on trains to minimise the impact of interfering signals that have caused repeated delays on the Circle Line, the Land Transport Authority (LTA) and public transport operator SMRT said on Wednesday (Sep 21).
The possibility was mooted as part of feasibility studies that LTA and SMRT said they would undertake to strengthen the existing signalling communications network.
In a joint news release, LTA and SMRT said that they would also explore the possibility of changing the signal system frequency and/or modifying the system to provide redundancy in the event of signal interference.
They added they would continue to closely monitor the performance of the Circle Line.
SPECTRUM ANALYSERS TO PICK UP INTERFERENCE IN CIRCLE LINE TUNNELS
LTA and SMRT said that following a series of tests, they and train manufacturer Alstom assessed that an interfering signal could have disrupted the trains’ signalling systems and led to the loss of communications. This had caused the automatic activation of the trains' emergency brakes.
"Over the past two weeks, engineers have tried to establish the source of the interfering signals. However, as the incidents had ceased by the afternoon of Sep 2, they were unable to determine the source," the joint statement said.
"Notwithstanding this, LTA and SMRT will install spectrum analysers within the Circle Line tunnels to detect the presence of any interfering signal. This measure will be extended to the North East Line, which has the same signalling system."
LTA and SMRT added that signalling systems on newer rail lines such as the Downtown Line and current lines undergoing upgrading such as the North-South and East-West lines are already equipped with new features that provide redundancy in the event of signal interference.