Tuesday, November 21, 2017

Lightning struck trackside equipment, not train that stalled at Bedok station: SMRT



An ambulance was dispatched to Tanah Merah MRT station after the train driver reported that he was feeling unwell on 20 November 2017.
PHOTO: An ambulance was dispatched to Tanah Merah MRT station after the train driver reported that he was feeling unwell on 20 November 2017
PHOTO: ST FILE
Picture posted by Lester Hio, The Straits Times, 21 November 2017 at 15:20 pm

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http://www.straitstimes.com/singapore/transport/smrt-lightning-struck-trackside-equipment-not-train-that-stalled-at-bedok?xtor=CS11-86



SINGAPORE - Transport operator SMRT has refuted claims that a lightning strike hit a train as it approached Bedok station on Monday (Nov 20), which caused the westbound train to stall.

Instead, trackside equipment was affected by lightning, causing the disruption, SMRT said on Tuesday.



A file photo of a train leaving Bedok MRT station.
PHOTO: A file photo of a train leaving Bedok MRT station. A train stalled near the station on Monday afternoon after being struck by lightning.
PHOTO: BERITA HARIAN
Picture posted by Lester Hio, The Straits Times, 21 November 2017 at 12:20 pm [2]

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http://www.straitstimes.com/singapore/mrt-train-struck-by-lightning-driver-in-stable-condition-says-changi-general-hospital



It added that the train driver who was admitted to hospital after the supposed “lightning incident” had also been on medical leave for two days over the weekend.

Following the incident, he was admitted for observation as a precautionary measure after reporting that he was feeling unwell.

He has been assessed to be well and remains under observation,” said SMRT spokesman Patrick Nathan.

After investigations, “our engineers... confirmed that the train was not hit by lightning. Instead, lightning affected trackside equipment”, SMRT said in its statement.

After the lightning incident, the train was immediately able to recover and move on its own power, moving passengers safely to Bedok station. At Bedok station, passengers alighted and the train was promptly withdrawn from service to allow for a thorough inspection by our engineers,” said Mr Nathan.

He added that it is safe for passengers to travel in trains during a lightning storm as trains are protected by a Faraday Cage.



It is safe for passengers to travel in trains during a lightning storm as trains are protected by a Faraday Cage.
PHOTO: It is safe for passengers to travel in trains during a lightning storm as trains are protected by a Faraday Cage.
PHOTO: ST FILE
Picture posted by Lester Hio, The Straits Times, 21 November 2017 at 15:20 pm

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https://static.straitstimes.com.sg/sites/default/files/articles/2017/11/21/st_20171121_vnlight_3573565-page-001_0.jpg
http://www.straitstimes.com/singapore/transport/smrt-lightning-struck-trackside-equipment-not-train-that-stalled-at-bedok?xtor=CS11-86



This is an enclosure formed by conductive material that blocks electric fields and electric currents, such as lightning strikes, from entering the trains. During lightning, the electric current will travel through the outside shell of the train and not into the cabin. It then travels through the wheels to the track.



Each train is protected by a 'Faraday Cage', an enclosure formed by conductive material that blocks electric fields and electric currents such as lightning strikes.
PHOTO: Each train is protected by a “Faraday Cage”, an enclosure formed by conductive material that blocks electric fields and electric currents such as lightning strikes.

"The cage conducts current around the outside of the enclosed space with none passing through the interior. If lightning strikes, the electric current will travel through the outside shell of the train, not through the cabin, and pass through the wheels to the track. The train is grounded to the track,"
Mr Nathan said. [3]

"Because the wall is electrically conducting, there is very little voltage difference generated," Professor Liew Ah Choy, a lightning expert, told The Straits Times previously. A significant voltage difference is what causes electrocution.

Even if a commuter was holding on to a metallic pole in the train when lightning hits, he would be unaffected. [4]
Picture posted by Christopher Tan, Senior Transport Correspondent, Audrey Tan, Adrian Lim, Transport Correspondent, Lydia Lam, The Straits Times on 20 November 2017 at 5:04 pm SGT
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https://static.straitstimes.com.sg/sites/default/files/articles/2017/11/20/171121-lightning-mrt-graphic-online.jpg
http://www.straitstimes.com/singapore/transport/lightning-strikes-mrt-train-injury-suspected

 
By Lester Hio, The Straits Times, 21 November 2017 at 15:20 pm



Reference
[1] Lester Hio, The Straits Times, Lightning struck trackside equipment, not train that stalled at Bedok station: SMRT, posted on 21 November 2017 at 3:20 pm, http://www.straitstimes.com/singapore/transport/smrt-lightning-struck-trackside-equipment-not-train-that-stalled-at-bedok?xtor=CS11-86

[2] Lester Hio, The Straits Times, MRT train struck by lightning: Driver in stable condition, says Changi General Hospital, posted on 21 November 2017 at 12:20 pm, http://www.straitstimes.com/singapore/mrt-train-struck-by-lightning-driver-in-stable-condition-says-changi-general-hospital

[3] Christopher Tan, Senior Transport Correspondent, Audrey Tan, Adrian Lim, Transport Correspondent, Lydia Lam, The Straits Times, Lightning strikes MRT train; train captain receiving medical attention, posted on 20 November 2017 at 5:04 pm SGT, http://www.straitstimes.com/singapore/transport/lightning-strikes-mrt-train-injury-suspected

[4] Adrian Lim, Transport Correspondent, The Straits Times, askST: Are commuters in an MRT train protected from lightning strikes?, posted on 23 March 2017 at 2:10 pm SGT, http://www.straitstimes.com/askst/askst-are-commuters-in-an-mrt-train-protected-from-lightning-strikes

Links
trackside equipment was affected by lightning, causing the disruption - http://www.straitstimes.com/singapore/mrt-train-struck-by-lightning-driver-in-stable-condition-says-changi-general-hospital