Knock-on delays

How a delay to services in one area can affect trains elsewhere in the country

Most problems on the rail network are fixed quickly and without disruption, but sometimes a problem on one part of the railway can have a knock-on effect on another, depending on where it is, what happened and how busy train services are.

Every day, thousands of passenger trains and freight trains use the rail network. At peak times, critical parts of the network now run at close to 100 per cent capacity.

We resolve the majority of problems quickly, avoiding delays for passengers. However, particularly on busy routes, where trains need to run to a very tight schedule, even something as simple as a blown fuse can cause knock-on delays that continue for hours afterwards. As you can imagine, damage to overhead lines or a road vehicle hitting and damaging a bridge can take considerably longer.

If congestion builds, these knock-on delays can affect both the route with the issue and any connecting routes as trains slow down to wait for other trains. This in turn can mean that trains, drivers and crews aren’t in the right place at the right time to run other services in the day’s timetable. Late arriving trains are also more difficult to get cleaned, checked and ready in time for their next journey.

How one local incident can affect the national rail network

Here’s how one small incident, such as a vehicle hitting a bridge, can have a knock-on effect nationally nearly a day later.

Map of the UK showing a red dot where an incident near Cheltenham closes the line
Map of the Uk with red dots showing where train services are continuing to be affected six hours after the initial incident
Map of the UK showing spots of congestion and trains affected by the incident in Cheltenham - areas across the network are all affected
Map of the UK showing even more affected areas. Coloured dots highlight trains directly affected, congestion and late starting trains 20 hours on from the initial incident

How we’re reducing the effect of knock-on delays

No one wants to sit on a train that’s not moving or wait on a platform for one that’s had to be delayed or cancelled. But even though we do as much as we can to avoid and reduce disruption, knock-on delays do happen. The rail industry works together to achieve the best balance between getting trains back on schedule as safely and quickly as possible and minimising inconvenience for passengers.

We have contingency plans in place with all the train companies so we can quickly alter timetables to get trains running back on time as soon as possible. Here are some of the actions we take:

  • We may cancel trains with fewer passengers so that there is space on the tracks for delayed trains to complete their journey quickly.
  • We may miss out stops to make up time, or add stops to keep services moving and make sure we get everyone where they need to be – even if they are a little late getting there.
  • If a line closes, we may have to divert trains onto different routes or lines.
  • We may even stop short of a train’s final destination so we can carry out checks and cleaning faster to avoid further delay.
  • Sometimes, we may have to cancel all trains in the affected area for an hour. This is the quickest way to get trains running on time again.

It’s important that we take these actions, particularly on busy routes where it would take many hours before all trains were back on schedule otherwise.

We’re sorry when delays happen and we always avoid cancelling services if we can. We’ll do everything we can to keep you informed, minimise disruption and keep you moving.

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