text: ScotRail said the Glasgow Queen Street Station tunnel would be closed from 20 March until 8 August.
  Services will divert to low-level platforms or Glasgow Central, bringing timetable changes and in some cases, longer journey times.
  The work is part of a Â£60m upgrade project that will allow faster and longer trains to use the station.
  Passengers on ScotRail's main Edinburgh to Glasgow service, via Falkirk High, are being advised to travel via Bathgate and Airdrie.
  That journey will take around 70 minutes.
  Phil Verster, managing director of the ScotRail Alliance, said: "Upgrading the tunnel will allow us to run faster, longer, greener trains in the future.
  "This will mean more seats, shorter journey times and less impact on our environment.
  "The long-term benefits of this investment will be considerable, not just for our railway, but also for the country."
  ScotRail said the closure was necessary to enable major engineering work to renew 1,800m of existing concrete slab track formation, which carries the rails through the 918m tunnel.
  The firm said this was the largest engineering project undertaken on the Edinburgh to Glasgow, via Falkirk High, railway, since it was built.
  The project will involve 140 days of continuous round-the-clock working, the removal of 10,000 tonnes of existing concrete slab and the installation of 4,000m of new rails.
  ScotRail has now launched a dedicated webpage to give passengers more information about the impact of the project.
  Transport Minister Derek Mackay said: "This is a once in a generation project and one of the most ambitious ever planned on the Edinburgh-Glasgow route.
  "The works will support the introduction of a new generation of faster, quieter and greener electric trains on routes across the Central Belt next year.
  "Although I understand that this work will cause some inconvenience to passengers, the ScotRail Alliance is working to ensure that services are maintained where possible, disruption is kept to a minimum and that passengers are kept well informed throughout the work."
target: The main tunnel serving Scotland's third busiest rail station is to close for 20 weeks, causing major disruption.