There is some info on rail emission factors in this report by the UK government. - Defra (Department for Environment Food and Rural Affairs) and DECC (2013) [2013 Government GHG Conversion Factors for Company Reporting: Methodology Paper for Emission Factors]( https://assets.publishing.service.gov.uk/media/5a80dec840f0b62302695f77/Emission_Factor_Methodology_Paper_-_2013.pdf). Defra and DECC, London, UK They also have a [more recent version of the report for 2021](https://assets.publishing.service.gov.uk/media/61ee7e198fa8f5058d5a7771/2021-ghg-conversion-factors-methodology.pdf ).
There is some info on rail emission factors in this report by the UK government.
They also have a more recent version of the report for 2021.