Train line closed indefinitely after massive sinkhole appears under tracks in Scotland

The 1m-deep fault was initially discovered on Sunday under tracks on the line between Caldercruix and Drumgelloch in North Lanarkshire.

Network Rail is working alongside contractors to establish the size and depth of the sinkhole, with the potential cause thought to be an underground spring.

An expected date for the line's reopening will be given after investigations are complete and a repair plan formulated. The Airdrie and Bathgate route is expected to remain closed until at least April 29.

Ross Moran, interim route director for Network Rail Scotland, said: "Sinkholes like this are very unusual on the railway and our specialist geotechnical engineers are working tirelessly to identify the cause, as well as planning the repairs, so we can reopen the railway.

"We understand the inconvenience this incident will cause for passengers, and I'd like to thank those who travel on this route for their patience and understanding while work continues."

A replacement bus service will run every 30 minutes between Helensburgh and Airdrie during peak times, and hourly outside of peak times. The Edinburgh to Bathgate route will also run every half an hour during peak times and every hour outwith.

Phil Campbell, ScotRail customer operations director, said: "We are doing everything we can to keep our customers moving while this issue is resolved, with replacement buses between Airdrie and Bathgate. Customers should plan their journey in advance and allow some extra time, as the bus service will take longer."