Passengers travelling on the East Coast mainline face disruption throughout Wednesday after a lorry struck a railway bridge in County Durham.
A beam fell onto the lorry after it collided with the bridge
The vehicle hit the bridge at Plawsworth on Wednesday morning, limiting services in both directions.
No-one was injured in the incident but a beam from the bridge was dislodged and fell onto the lorry.
GNER is running two services and Virgin one cross country service per hour in each direction.
Transpennine Express trains are terminating at Durham, with buses laid on to take passengers on to Newcastle.
Northern Rail have introduced a similar operation, said Network Rail.
The crash forced the closure of one of the bridge's two tracks, meaning all services have been diverted onto a single stretch of rails.
Trains are also travelling at reduced speeds over the bridge, adding further time to journeys.
Engineers have inspected the damage and will make full repairs overnight, said Network Rail.
A company spokeswoman said: "A beam from the bridge fell onto the lorry, but there is no debris on the track.
"There are services running in both directions, but they are extremely limited while the bridge is assessed.
"This is likely to be the situation throughout the day and we apologise for the inconvenience, but passenger safety is a priority."
Passengers are advised to allow extra time for their journeys, she added.