Clearing the air beneath our cities.
SubClear is a clean-tech startup developing a track-mounted air filtration system designed specifically for underground rail networks. The system attaches to existing engineering trains and is passively towed through the tunnels, cleaning polluted air directly at track level — where air pollution is densest and most toxic.
Air pollution in subway systems is dangerously high — in some areas, particulate matter (especially PM2.5 and metallic dust) exceeds above-ground limits by 10x or more. These pollutants come primarily from:
Prolonged exposure poses serious health risks to commuters, staff, and maintenance crews.
SubClear introduces a modular, retrofittable filtration system that's mounted on the chassis of engineering trains or dedicated rolling stock. As the train moves through the tunnels during non-passenger hours, the system sucks in contaminated air, filters it, and discharges cleaned air back into the tunnel environment.
Captures tunnel air at high flow rate
Ionises and traps ultrafine dust
Extracts metallic particles using embedded magnets
Removes residual PM2.5 and PM10 particles
Battery, onboard generator, or regenerative power
Embedded PLC to monitor flow rates, filter condition, and diagnostics
Designed to integrate with existing underground rail rolling stock and loading gauges