The new bi-mode trains will be cleaner than the diesel trains that they replace. In addition, when running on the electrified part of the network the engines can be switched off completely and therefore will not produce any diesel particulates.
The table below shows the emissions standards met by Intercity Express Train (Class 800) rolling stock. From 2017, Class 800 trains will progressively replace Class 43 rolling stock on the network (also shown below):
Engine emissions standard
Particulate Matter emissions standard
Nitrogen oxides (NOx) emissions standard
Class 800 – Intercity Express Train
0.025 g/kWh (grams per kilowatt hour)
Class 43 – High Speed Train
1975-1982 (re-engined in 2005-2010)
The standards shown above are maximum emission levels, shown in grams per unit of energy (kilowatt hours). Class 800 trains can operate under diesel or overhead electrical power; the above data relates to diesel operation only.