Delays at London Paddington train station have now been cleared, following two days of disruption.
Services to Heathrow Airport were suspended and other services were cancelled on Thursday after two fires caused signalling problems.
Trains are now running normally to and from the station.
More top news
The 24-year-old was unarmed and the incident is not being treated as terror-related.
Some platforms have been taken out of service with disruption expected to continue until the end of the day.
The Met Office has extended its weather warnings for snow and ice to cover vast swathes of the country, including London and the South East.