A Tokyu Toyoko Line train emitted smoke from an under-floor battery at Nakameguro Station on Saturday, leading to a temporary service suspension [1, 2].
The incident disrupted one of Tokyo's primary transit arteries, highlighting the safety risks associated with mobile battery systems used in modern rolling stock.
The event occurred July 18, 2026, shortly after 3 p.m. in Meguro Ward, Tokyo [1, 2]. Smoke began emanating from a battery located beneath the floor of the train carriage, prompting immediate safety protocols and the suspension of rail services [1, 2].
Service was halted for approximately three hours [1]. The suspension primarily affected the stretch of track between Shibuya and Jiyugaoka stations, leaving thousands of commuters to find alternative transportation during the peak afternoon period [1].
Emergency responders and transit officials addressed the smoke at Nakameguro Station to ensure the area was safe for passengers and staff [1, 2]. Despite the fire risk and the resulting smoke, officials said there were zero injuries [1].
Tokyu Corporation officials monitored the situation as the train was secured. The under-floor battery system is designed to provide power and stability, but this specific failure led to the emission of smoke that necessitated the line's closure [1, 2].
“A Tokyu Toyoko Line train emitted smoke from an under-floor battery at Nakameguro Station”
This incident underscores the critical importance of battery thermal management in urban rail systems. As transit agencies shift toward more battery-dependent power sources for efficiency and redundancy, the risk of thermal runaway or electrical failure in under-floor components remains a primary safety concern for high-density networks like Tokyo's.
