Global warming, new technology & new knowledge on the effects of air pollution are set to send fossil fuel diesel trains into the sidings
CO2 from diesel fuel
Replacing dirty diesel trains with emission free travel is vital to achieve climate change goals by cutting CO2 emissions and the use of fossil fuels on the railways. Using electricity produced from renewable sources like offshore wind will cut the carbon impact of rail travel, eventually enabling zero carbon operation.
Diesels cause toxic air pollution around railways and in stations
Diesel also has a major impact on air pollution. Diesel trains do not have the same requirements to use particulate filters or adblue SCR systems. This affects people near railways and in stations especially covered terminus stations like London Paddington which combines idling diesel trains with a still largely diesel cab rank all under a covered roof.
Diesel locomotives produce dangerous levels of toxic pollution inside passenger train carriages.
New research has also highlighted why diesel trains expose passengers to dangerous levels of particulate and NOx.
Most diesel passenger trains put the locomative or engine at the front of the train, or both front and back or in the middle. The diesel exhausts are on the roof. The passenger cars aircon systems suck air from the roof and pump it round the carriages.
Even diesel cars have their exhaust at the back of the car. With trains the usual arrangements means each a train is effectively pumping a portion of the diesel exhaust into its own passenger carriages.
A few trains run with the diesel locomotive at the back of the train pushing. This unusual configuration reduces pollution in the passenger cars massively.
Looking at this 76 page document from ATOC detailing the requirements for all UK rolling stock the sole requirement is this line
3.1.3 On diesel multiple units the HVAC fresh air intake shall have a good separation from exhausts.
The future without diesel?
The link below runs through the main contenders