The sinkhole was discovered by track engineers on 21 April and the line has been closed to allow investigation work to be undertaken.
The line between Airdrie and Bathgate is expected to remain closed until Monday 29 April, due to the potentially complex nature of the repairs needed to the railway.
Network Rail and its contractors are working to establish the sinkhole’s size and depth, and the presence of an underground spring is being looked at as a potential cause. Once investigations are complete, engineers will be able to put together a repair plan, as well as give a clearer indication of when the line can reopen.
In the meantime, ScotRail services between Helensburgh Central and Edinburgh Waverley will terminate at Airdrie. A replacement bus service will connect Airdrie and Bathgate, calling at all intermediate stations, with a train shuttle service running between Bathgate and Edinburgh Waverley.
Trains between Airdrie and Balloch are not affected.
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.”
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.”
