The timing when "tubes start running" depends on the context:
- If referring to the London Underground (the Tube), the trains typically start running around 5:00 AM on weekdays and Saturdays, with slightly later start times around 6:30-7:00 AM on Sundays. The Tube then runs until midnight or shortly after, with some lines offering Night Tube service from midnight to 5:00 AM on Fridays and Saturdays.
- If referring to plumbing pipes or water tubes "running," this typically means when water starts flowing through them, usually when a fixture or valve is opened or when a toilet tank refills after being flushed. Pipes might run continuously if there is a leak or faulty valve causing continuous water flow even when everything is supposed to be off.
Please specify if the question was about transportation (London Tube) or plumbing pipes for more focused information.
