The amount of diesel pollution on some new trains is 13 times higher than on one of the busiest roads in central London, the researchers found.
Passengers aboard a London to Bristol Great Western Railway carriage, purchased by the government as part of a £ 5.7 billion scheme, are subject to huge spikes in nitrogen dioxide (NO2) pollution. when they switched to diesel for electricity.
NO2 levels on two-year-old Hitachi bi-mode trains peaked at more than 13 times the average recorded on the jammed Marylebone Road in central London, according to a study by the Rail Safety and Standards Board ( RSSB).
The Department of Transportation (DfT) said ministers had commissioned further investigation after the “troubling findings” as well as an immediate review of air quality standards and regulations for trains.
The bi-modes built by Hitachi were part of a £ 5.7 billion government acquisition of trains to operate on the Great Western Main Line and the East Coast, with a controversial design combining diesel and electric power. The trains were also abruptly withdrawn from service recently after cracks were discovered in the carriages.
GWR trains run on electricity from London to Cardiff, but services further west and south-west run on diesel. The planned electrification of part of the line to South Wales, as well as the branch from Chippenham to Bath and Bristol Temple Meads, was scrapped by then-Transport Secretary Chris Grayling in 2017 after huge budget overruns.
Pollution increases significantly when trains are in tunnels or idle at stations, the RSSB said. Passengers on trains pulled by diesel locomotives are more exposed to fumes when they sit in the rear carriages than in the front carriages, the researchers found, possibly due to the way exhaust gases enter the train’s windows or into the air conditioning system.
The RSSB examined six types of diesel trains and found high levels of particulate pollution in the older diesel trains operated by Avanti West Coast, the Super Voyager class 221 models built by Alstom.
However, the RSSB concluded: “Newer types of trains do not necessarily have better air quality on board compared to older trains.” The worst NO2 pollution was found on the GWR dual-mode trains, which were only two years old.
The DfT said the RSSB report had independently concluded that air quality in services remained within legal workplace limits. He said cross-industry research was already underway to understand problems and identify solutions, while he had commissioned more studies to measure air quality on eight other types of trains used in Britain.
Railroad Minister Chris Heaton-Harris said: “The safety of personnel and passengers is our top priority. While these findings are within limits, I don’t think people should accept anything less than the highest levels of air quality.
“I have asked the industry to immediately conduct more research and explore all engineering modifications and options to rapidly improve air quality in trains and stations.
He added: “If necessary, we will not hesitate to strengthen legislation to ensure that the highest air quality standards are met and maintained.”
A spokesperson for the industry body Rail Delivery Group said: “Rail is one of the greenest forms of transport … We welcome government action to improve air quality on board trains, but it is also needed the government’s investment to electrify more railways and eliminate more polluting trains altogether. “
GWR said it was working with manufacturers to help develop possible solutions. A spokesperson said: “In the long term, this is why the government’s ambition to electrify the grid and reduce the number of trains running on diesel is so important.”
An Avanti West Coast spokesperson said most of its fleet was completely electric and that it would replace diesel Voyager trains with electric and bimodal trains in the coming years.
George is Digismak’s reported cum editor with 13 years of experience in Journalism