The 10.17am Elizabeth line train from London Paddington departed on time for Heathrow Terminal 4 – the first train to leave the station for 28 hours.
But to the dismay of airline passengers anxious about catching flights from the UK’s busiest airport, the train came to a halt between Hanwell and Southall stations while an engineering train cleared the line.
The train arrived at Heathrow Terminal 2 and 3 half-an-hour behind schedule, and the final stop was abandoned.
The first eastbound service, from West Drayton, ran 40 minutes late. The first intercity arrival at Paddington, the 5.34am from Plymouth, arrived one hour and 40 minutes late.
Heathrow Express trains are currently running only hourly.
Paddington station, which serves the West of England and South Wales, was out of action for most of Monday because of overhead wire damage.
The closure wrecked the travel plans for tens of thousands of people hoping to be in the capital for the Queen’s state funeral.
Initially Network Rail, which runs the infrastructure, hoped to have services running by 10am on Monday. But the “substantial dewirement” involved around two miles of fallen overhead wiring – which became entangled in no fewer than six early morning passenger trains.
A Network Rail spokesperson said: “Engineers worked throughout the night and into this morning to repair the damaged overhead power cables.
“Overnight, more extensive damage was found meaning that two of the four railway lines into London Paddington will not reopen to electric power today.
“The Elizabeth line will be operating fully from Reading to London Paddington, with GWR services expected to offer a full timetable in operation by midday.”
Until then, passengers on long-distance links to and from Cardiff, Swansea, Bristol, Devon and Cornwall are advised to transfer at Reading, which has become a temporary hub for GWR.
Passengers then use the South Western Railway link to and from London Waterloo, though this is a slow commuter route with frequent stops.
Network Rail said: “We are very sorry that there will continue to be considerable disruption to services this morning and passengers are strongly advised to only travel if necessary and check before they travel.”
Later trains will be cancelled from 10pm on Tuesday due to a further closure to allow the two remaining lines to be fully repaired.
Tickets for GWR services valid for Tuesday will be accepted on Wednesday.
