Case study: improving air quality
27 October 2026
Changes follow concerns about air quality at a train maintenance depot.
A safety report highlighted concerns about poor air quality inside Hitachi’s North Pole train maintenance depot. Staff reported headaches and eye irritation caused by diesel fumes when several train engines were running at the same time.
The reporter questioned whether existing ventilation systems were doing enough to protect people's health and wellbeing.
The depot has air extraction equipment designed to remove exhaust fumes and a shore supply system that can power trains without running their engines. However, the reporter believed the extraction system was not removing fumes effectively and said the shore supply was rarely used—so there was unnecessary engine idling.
Hitachi investigated the concerns and confirmed both systems are operational. It is now reviewing working practices, increasing the use of shore supply where possible, monitoring air quality, and introducing automatic alerts to reduce engine idling.
Early results show engine running times are already falling.