Dawn Fire at Daechi Station Also Caused by Lithium Battery... 'Thermal Runaway' Difficult to Extinguish with Water

Smoke Emission from Track Maintenance Motorcar Between Dogok Station and Daechi Station
Train Service Temporarily Suspended and Resumed Between Apgujeong Station and Suseo Station
Thermal Runaway of Lithium Battery, Difficult to Extinguish with Water

The smoke incident that occurred at Daechi Station on Seoul Subway Line 3 was identified to have started from the lithium-ion battery of a special vehicle.

[Image source=Yonhap News]

According to Seoul Metro, around 3:42 a.m. on the 1st, smoke was detected from the engine parts of a track maintenance motorcar located on the down line track between Dogok Station and Daechi Station. Due to the fire, train operations on both up and down lines between Apgujeong Station and Suseo Station were temporarily suspended, but the situation was resolved by 5:41 a.m., and train services resumed.

The fire department deployed 140 personnel and 70 pieces of equipment to extinguish the fire by 6:39 a.m. There were no casualties from this fire.

The fire authorities removed the motorcar from the track to lower the temperature of the lithium battery, then separated the lithium battery and submerged it in a water tank to extinguish the fire. A fire department official stated, "The smoke was difficult to extinguish, making firefighting challenging." The fire authorities are currently investigating the exact cause of the fire and the extent of the damage.

Lithium batteries consist of anode, cathode, separator, and electrolyte. If the separator is damaged, the anode and cathode collide, triggering a chemical reaction that generates heat. This phenomenon is called thermal runaway, and water is not effective in extinguishing such fires, requiring special firefighting methods.