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Railways: Exhaust Emissions

Question for Department for Transport

UIN 118503, tabled on 11 December 2017

To ask the Secretary of State for Transport, what assessment has he made of the potential effect of diesel particulates from bi-mode trains on the health of (a) passengers, (b) railway workers and (c) people who live near to railway lines.

Answered on

19 December 2017

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):

Train class

Year manufactured

Engine emissions standard

Particulate Matter emissions standard

Nitrogen oxides (NOx) emissions standard

Class 800 – Intercity Express Train

2015 onwards


0.025 g/kWh (grams per kilowatt hour)

4.0 g/kWh

Class 43 – High Speed Train

1975-1982 (re-engined in 2005-2010)

UIC II (following engine overhaul in 2000s)

0.250 g/kWh

9.5 g/kWh

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.

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