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SINGAPORE: The “inadvertent” disabling of a software protection feature has been identified by the authorities as the reason for an SMRT train hitting another, stalled train at Joo Koon station on Wednesday morning (Nov 15).

Twenty-nine people were injured after a train “moved forward unexpectedly” and “came into contact” with another stationary one in front of it, according to earlier statements from the Land Transport Authority (LTA) and SMRT.

At a joint press conference held later Wednesday, LTA deputy chief executive of infrastructure and development Chua Chong Kheng said preliminary findings indicated that the first train - in front - departed Ulu Pandan with a software protection feature which was “inadvertently removed” when it passed a faulty signaling circuit.

“This train then arrived at Joo Koon station without the feature,” said Mr Chua. “This resulted in it giving off a train profile on the new signaling system of a three-car train instead of a six-car train.”

“As a result, the second train (behind) detected the first train as a three-car train and misjudged the distance between the two, causing a collision.”

Mr Chua said that as a precaution, operations from Joo Koon to Tuas Link will be suspended for the entire day on Nov 16 while assurance checks are conducted with signaling contractor Thales.
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“SITUATION UNSATISFACTORY”

Expanding on his use of the word “inadvertent”, Mr Chua said there was no indication that the removal of the software protection feature was due to human action.

"The new trackside signaling circuit is still a work-in-progress and as the train passed by, we observed this (software protection) feature got removed,” he said, adding that a thorough investigation was being conducted to get to the root cause.

Mr Chua said that when the first train stalled at the station - due to an anomaly in the train signalling system - station staff boarded the train to run checks, and safety protocol at the station closed down the track to “physically protect” another train from coming in.

When the second train arrived, it “observed this stopping point” by halting 10.7m behind the first - a safe stopping distance, said Mr Chua.

Authorities were asked if the rear train driver - subsequently injured in the collision - could have overrode the signalling system and prevented his train from moving forward at an estimated speed of 16kmh.

Said Mr Kek: “10.7 metres away is relatively close, the movement before coming into contact with the first train took only 10 seconds.”

“The driver can override the system, and apply the manual brake, but he didn’t. It is now subject to the investigation.”

Meanwhile, Thales representative Peter Tawn said this was the first incident of such a nature.

“We are very confident our system is safe,” he reiterated. “The Thales system is on record one of the safest there is ... We’ve never had a collision.”

Said Mr Chua: “Obviously the situation is not satisfactory, we are concerned and will work closely with SMRT on this.

“There’s also a technical bit here and we must be clear about responsibilities. This incident involve technical aspects and we need to iron those out with Thales.”

“But ensuring the safety of our commuters remains our priority,” he insisted.

Thales is the French company which supplied the new signalling system.

Read more at http://www.channelnewsasia.com/news/singapore/smrt-train-collision-at-joo-koon-cause-lta-9408766

But somehow it's always been a bit scarier that it's "only" code, produced by some metaphorically spotty lad in an office, that keeps you safe.

I'm probably mis-remembering it, but I have in mind a story from Tom Rolt's Red for Danger in which a metaphorically spotty lad despatched a train with a cheery 'Right away, Jack'; sadly he was heard by the other train in the passing loop, and Jack was a common name back in those days... It seems that no amount of vigilance will ever entirely preserve us from the curse of the PFY, of whatever age or pimpliness...

.....But somehow it's always been a bit scarier that it's "only" code, produced by some metaphorically spotty lad in an office, that keeps you safe.

Oi do you mind. We are not all 'young spotty' signal engineers you know.... ::) :P

Seriously though, this sounds more like an operating incident than a software/hardware coding error.  Be an interesting read when the report gets issued (if it ever does).

...sfotware...

...there you go!  ;)

Tuas West stations to reopen only on Monday
(https://static.straitstimes.com.sg/sites/default/files/styles/x_large/public/articles/2017/11/16/jookoon.jpg?itok=xj2ac34n)
Train services between Joo Koon and Tuas Link stations were halted on Nov 16, 2017, for the authorities to investigate Nov 15's collision between two SMRT trains.ST PHOTO: LIM YAOHUI
SINGAPORE - Train commuters heading to the western end of Singapore will not be able to use the four stations on the Tuas West Extension (TWE) till Monday (Nov 20).

While the four stations on this extension – Gul Circle, Tuas Crescent, Tuas West Road and Tuas Link – will reopen after the weekend, the authorities will keep service between Joo Koon and Gul Circle stations suspended for up to a month.

The move comes as the authorities continue investigations into Wednesday’s SMRT train collision at Joo Koon following a signalling glitch, which left 36 people injured.
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Signalling system firm Thales apologises for Joo Koon train collision; assures commuters that its system is safe
Published  Nov 21, 2017, 11:29 pm SGT  Adrian Lim  Transport Correspondent

SINGAPORE - French company Thales has taken "full responsibility" for its part in the Nov 15 train collision at Joo Koon MRT station.

It said an "unexpected" problem occurred in the interface between the old and new signalling systems of the East-West Line (EWL).

Thales, which is supplying the new system for the EWL, has also apologised to commuters who were inconvenienced, and the 38 people injured by the accident.
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After the CBTC problem was detected, the train was switched to be driven in manual mode to Joo Koon MRT by design, at a speed of up to 18kmh.

This meant the platform screen doors had to be manually opened by the train captain at Joo Koon MRT station.

When the doors are opened manually, a "closed track" protection system is imposed, meaning that another train will not be able to enter the station.

After the captain manually opened the platform screen doors, all passengers alighted from the affected train. Waiting 36m behind was a second train carrying 517 passengers.

When the platform screen doors were manually closed to allow the affected train to move off, the "closed track" protection was lifted.

As a result, the second train, which was running in automatic mode, moved forward as it could not detect any protective bubbles around the first train. The two trains then collided.

Mr Alvin Kek, senior vice-president for rail operations at SMRT, said the 10 seconds before the collision was "insufficient" for the train driver onboard the second train to react.

Joo Koon-Gul Circle link to remain closed till mid-2018
Minister for Transport Khaw Boon Wan giving a door stop on the Joo Koon train incident which occurred on Nov 15, 2017.
Published  Nov 22, 2017, 5:00 am SGT Christopher Tan  Senior Transport Correspondent

The fallout from last week’s train collision at Joo Koon station will echo for several more months. It will mean the end of seamless journeys for commuters travelling between Tuas and Pasir Ris on the East-West Line for at least up to June next year.

There will also be early closures along stretches of the East-West Line on Fridays and Saturdays, and late openings on Sundays from Dec 8 to 31 as resignalling works get speeded up to finish by June instead of the end of next year.

This will affect 17 stations from Tiong Bahru to Tuas Link, as well as Bukit Batok and Bukit Gombak stations on the North-South Line.

On Dec 10 and 17, which are Sundays, these stretches will also close for the whole day.

The changes were flagged after it was revealed that the collision was caused by compatibility issues between an old and a new signalling system. To avoid the risk of a repeat incident, the two systems will remain separated till next June.