Scope of work

We appointed Imperial College London to build on the success of T1188. The project team has developed a transportable monitoring system to use inside train carriages. It measures live PM concentrations and collects samples for laboratory analysis.

Six types of diesel train on six different routes were chosen for the trial, as high PM levels were measured on them in the previous project. 

After overcoming some technical challenges, the team successfully completed the sampling. A sophisticated mathematical model was used to determine the PM sources. The results were used to find ways to reduce their health effects on passengers and staff. 

Key findings 

The levels of metals recorded in the air were below relevant limits. However, they were also likely to be higher than roadside levels. Metals in the air are likely to come from wear of wheels, rails, brakes, and electric train power supply. 

The project significantly improved our understanding of PMs onboard trains. We know more about levels and sources which helps us to improve air quality in carriages. For example, we could reduce engine use and fuel combustion, use different materials for brake pads, improve ventilation, and improve filtration systems.