Thousands of passengers were left stranded at Gatwick Airport after sinkholes opened up near a railway bridge in Purley, south London, closing all train lines between Purley and East Croydon and suspending the Gatwick Express until repairs could be carried out. Sinkholes on railway tracks are not common, but when they occur they can cause major disruption because the ground beneath the rails becomes unstable, forcing an immediate halt to services for safety reasons.
A sinkhole is a hole in the ground that forms when surface rock or soil collapses into a cavity below. In railway settings, sinkholes can appear when the ballast – the stones that support the track – falls through gaps in the underlying structure, as Network Rail explained happened at Purley Bridge. Engineers discovered a ‘number of sinkholes’ during planned engineering work, and described the track as ‘unstable’. The line was closed while structural engineers carried out thorough inspections and plugged the gaps to allow trains to run safely again.
“Why sinkholes form on UK railways, how they cause travel chaos, and what it means for passengers.”
Sinkholes can form for many reasons, including natural processes like the dissolution of limestone or chalk, or human activity such as mining, leaking pipes, or construction work. On railway infrastructure, ageing bridges and drainage issues can increase the risk. In this case, the sinkholes were spotted on a bridge, meaning the ballast was falling through, making the track unsafe. Network Rail apologised for the disruption, stating that safety was the priority.
For UK rail passengers, sinkhole incidents can lead to sudden cancellations, long delays, and overcrowded alternative transport. At Gatwick, Southern Railway advised people ‘not to travel’, and some passengers reported queuing for over two hours for replacement buses, while taxi fares soared – one Uber quoted £250 for a trip from Gatwick to Croydon. Highways also saw extra traffic on the M23. The disruption came at a particularly bad time for holidaymakers, with many trying to reach or leave the airport.
Sinkholes are rare but can affect any part of the network where ground conditions are poor or infrastructure is old. They are not limited to London: similar events have occurred elsewhere in the UK. While engineers can repair them relatively quickly – in this case lines reopened within hours – residual delays can last through the evening as fewer trains run. The incident highlights the vulnerability of the UK’s ageing rail infrastructure to sudden geological events.
Q: What exactly is a sinkhole? A sinkhole is a depression or hole in the ground caused by the collapse of a surface layer. They are often saucer-shaped and can form naturally or due to human activity, such as leaking water mains or mining.
Q: How do sinkholes affect railway tracks? Sinkholes can cause the ballast (the stones supporting the rails) to fall into cavities, making the track unstable and unsafe for trains. Network Rail must close the line, inspect the area, and plug the gaps before trains can run again.
Q: What should passengers do if a sinkhole disrupts their journey? Passengers should check National Rail or their train operator for real-time updates, allow extra time, and consider alternative routes. Replacement bus services may be provided, but these can be very busy. Operators may advise not to travel if disruption is severe.
What happens next: Network Rail completed urgent repairs and reopened the lines, but warned of continued disruption. The incident may prompt wider inspections of bridges and drainage systems in the area. No further sinkhole-related closures were reported in the immediate aftermath.