Saturday, June 03, 2017

Problem with MRT signalling system

James Lim said:
The real shocker is that there's actually no need for such signalling system for use on SMRT's NSL and EWL because both lines are driven by humans.

From an engineer perspective, the "Moving block" signalling system used by SMRT in its current "upgrade" uses sensors to create a bubble of safety region for the train to travel. If the train exceed the bubble, electricity is automatically cut off and the train can't move causing a jam. Such system relies heavily on sensor and all the train speed on the railway. Since it's man driven, some trains travel faster / slower than what the computer required unlike unmanned trains like CCL/NEL/DTL which computer dictates the speed. Sensors can fail easily (e.g. bird fly pass / something blocking the sensor and it think it's a train)

The fact is we don't need such a system for NSL / EWL and it's a giant waste of money. If SMRT had implemented a timetable system (use in Sydney trains / Japan trains) and each train follow the timetable to arrive at the destination with drivers PHYSICALLY looking ahead for safety, there is no trouble / signalling / track fault at all.

Sadly SMRT don't want to implement this system.

I sometimes wonder if we are spending a lot of money unnecessarily. However, we do not have sufficient information to make a judgment. The information is not shared with the public. This is governance, Singapore style. The elites knows all the answers. They also knows all the excuses when something goes wrong.

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