The engineering train has broken down near Carnforth and the disruption is expected to continue until 12pm.
The break down means services are unable to run between Lancaster and Carlisle and buses are running between the stations to replace any cancelled services.
Northern services may be delayed by up to 30 minutes.
Virgin Trains services are being delayed by up to 60 minutes between Preston and Carlisle and trains are currently unable to call at stations between Preston and Carlisle, meaning a bus replacement service will run between the stations to replace any cancelled services.
Virgin Trains are advising passengers to not travel between Lancaster and Carlisle until approximately 12pm and advance tickets for journeys before then will be accepted on later services.
You can follow this incident using the hashtag #Carnforth on Twitter.