Every Thameslink service has been affected by the delays
Severe delays are affecting all Thameslink trains into and out of London this morning.
A signal box failure at West Hampstead at 8.15am has led to trains running up to 50 minutes late.
All Thameslink services pass by the signal box, causing delays on all services, including through St Albans City, Elstree and Borehamwood, Mill Hill Broadway and Hendon.
Thameslink spokesperson Roger Perkins said: “The power failure to the main signalling box has led to further problems which have caused the delays.
“It’s hard to tell how many services will be affected and for how long at this time.”
Other trains have been cancelled or replaced as problems continue.
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