Britain's train services will continue to be disrupted on Wednesday due to the knock-on effects of Tuesday's strike. Here the PA news agency answers 10 key questions about what passengers should expect.
How many trains will run on Wednesday?
Only around 60% of the 20,000 normal weekday services will be able to operate.
Why are timetables not returning to normal if there is no strike on Wednesday?
Walkouts by signallers and control room staff who would usually work overnight from Tuesday night into Wednesday morning means trains will leave depots later than normal, delaying the start of services.
What time do trains normally leave depots?
Between around 3am and 4am.
What time do passengers services usually begin?
Between around 5am and 6am.
How will that change on Wednesday?
The process of taking trains out of depots will only begin when signallers on daytime shifts start work at 6-6.30am. No passenger services will run before 6.30am.
How long will the start of services be delayed?
It is expected to take up to four hours in some locations.
How quickly will services ramp up?
In London, services will increase quickly as trains do not have to travel long distances from depots to stations. It will take several hours in remote locations.
Will services eventually return to normal on Wednesday?
Network Rail said that "even during the day the service will stay thinner" than usual.
What about Thursday?
It will be a similar picture to Tuesday, with a second day of strike action planned. Around 20% of services will run and just half of lines will be open, only between 7.30am and 6.30pm.
Is there any chance strikes planned for Thursday and Saturday will be called off?
No negotiations are taking place so passengers are being urged to check with train operators for updates to services.
