like you can read the complete HS2 train specification yourself, if you've a taste for incredibly dry 'this is what we want the train to do' documents:
>https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/794108/HS2-HS2-RR-SPE-000-000007_P11_TTS_Main_Body__External_.pdfSection 7.9 is the 'gauging' detail. I also fouund this from the Rail Standards and Safety Board while investigating:
>https://www.thepwi.org/technical_hub/technical_hub_files/section_meeting_presentations/gauging_historic_infrastructure_for_the_21st_century_-_23_april_2020...goes into the reason there's a mish-mash of gauges, and what's being done about it. This made me Sensible Chuckle though
