An electricity supply failure at Welwyn Garden City caused significant disruption to rail services between London’s Finsbury Park and Stevenage on 18 September 2026. Operators affected included Great Northern, Grand Central, Hull Trains, LNER, Lumo, and Thameslink, leading to cancellations and delays at London King’s Cross.
Service Disruptions and Ticket Acceptance
The problems began early morning on 18 September, with reports starting between 05:30 and 06:14 GMT and disruption expected to continue until at least midday or 15:00 BST. Trains running between King’s Lynn and London King’s Cross were cut back to operate only between King’s Lynn and Cambridge according to National Rail. Great Northern
ran a reduced peak-time service from Peterborough to London, while services between Hertford North and Moorgate also faced reductions.
Passengers holding tickets from Cambridge were allowed to travel on Thameslink services to London St Pancras International, Great Northern to London King’s Cross, and Greater Anglia to London Liverpool Street during the disruption. LNER advised customers to verify ticket validity for alternate routes on their website.
Freight Train Breakdown and Overground Suspension
In addition to the electricity failure, a freight train breakdown caused delays on Thameslink routes and led to a temporary suspension of a London Overground line. Network Rail and related electricity suppliers worked to resolve
the fault at Welwyn Garden City, while operators managed the cascading effects on train services across the network.
Passengers were advised to check journey times before travel due to cancellations and altered routes. The combined faults on several major rail lines servicing London resulted in a complex disruption situation affecting multiple operators.
