3-line MRT Disruption that Affected 15 Trains and 123k Commuters Was Caused by a Rusty Plunger and a Short Circuit

When you hear the followings words, you will most likely groan in anger.

Some say that these groans can be heard from station to station.

And those words are MRT breakdown or delay.

So you may remember the massive 3-line MRT disruption last year, affecting 15 trains and around 123,000 people.

But on 17 March, Wednesday, Transport Minister Ong Ye Kung announced the Land Transport Authority’s findings on the case.

Namely, a rusty plunger and a short circuit.

What Happened

But it’s been a few months since the incident, so let’s look back a bit.

As mentioned, three MRT lines were seriously affected by the said disruption.

Specifically, services from Woodlands to Jurong East on the North-South Line, Queenstown to Gul Circle on the East-West Line, as well as HarbourFront to Serangoon on the Circle Line.

It also lasted extremely long. The first two mentioned lines were disrupted for three hours and 36 minutes, from 6:58pm to 10:34pm.

Meanwhile, services on the Circle Line were disrupted for an hour, from 7:34pm to 8:34pm.

All of this resulted in passengers having to walk on tracks in order to get to some stations. This in turn led to crowded bus stops as passengers all had to continue their trips by bus.

While the problem was later revealed to be the cause of a faulty circuit breaker, more details were revealed by Mr Ong recently.

Trip Coils and a Plunger

No, not the kind that you see in the restroom, but we’ll get to that in a second.

At the Integrated Train Testing Centre, Mr Ong said that some power cable failures and trip coils along the Tuas West extension had caused the disruption.

An inherent manufacturing defect or mishandling during installation then caused a cut in the insulation layer, which resulted in a short circuit.

The trip coils didn’t work also because a plunger had rusted.

Normally, the plunger would move to activate the circuit breaker in such a case, isolating the cable fault.

But the rust on it obstructed movement and malfunctioned the circuit breaker.

As a result, power got cut off power to some stations on the North-South and East-West lines.

Bruh Boon Lay also wth pic.twitter.com/PTJuKKTBbn

— CIpherLovesDonuts (@CipherDonuts) October 14, 2020

Further investigations showed that inadequate protective coating likely caused the plunger to rust.

Improving From The Incident

Since then, there hasn’t been an incident on this massive scale.

This is because, since Dec 2020, the older power cables along Tuas West Extension were replaced with better specifications.

For those who frequent the stations along Tuas West Extension, you may have noticed the full Sunday closures from 14 Mar to 23 May.

All trip coils have also been changed.

However, Mr Ong said they’ll change again with an enhanced design made of stainless steel by the third quarter of 2022.

LTA has also adjusted space heaters to reduce the humidity level within circuit breakers, to reduce rusting by humidity.

Meanwhile, SMRT has increased the frequency of the maintenance regime to every three months.

Mr Ong said that improvements can only happen by taking responsibility and working together while figuring out weak points to do better.

Featured Image: Adwo / Shutterstock.com