Train services between Glasgow and ferry services for Barra and South Uist face disruption until next Wednesday due to a landslide.
Train services between Glasgow Queen Street and Oban and Mallaig are affected.
For the next seven days, buses will run from Glasgow Queen Street to Crianlarich where passengers will transfer onto trains for the rest of the route to the ferry ports.
The bus replacement service will depart up to 20 minutes earlier than the scheduled train time.
Tonnes of stone and mud washed onto the track near Lambhill in the north of Glasgow.
The foundations of a footbridge over the railway have also been significantly weakened following the landslip on Tuesday morning.
Engineers are working to stabilise the slope and assess the damage to the footbridge, which may need to be temporarily removed and then reconstructed before the line can be safely reopened.
The line is expected to be closed until Wednesday morning at least.
A ScotRail Alliance spokesman said: “We will be working around the clock to get the railway open as soon as possible, but extensive structural repairs will be needed to fix the significant damage caused to the footbridge.”
Scotrail is looking at the best way to help holiday-
“We ask everyone to plan ahead and arrive at the station in plenty of time for their journeys.”
Affected customers can use ScotRail’s Delay Repay compensation scheme, which kicks in for services that are delayed for 30 minutes or longer.
The cause of the landslip is being investigated.
Train link for ferry cancelled for a week after landslip
5 April 2017
