Invitations to tender for the £400m project, which is part of the Scottish government’s £650m Edinburgh-Glasgow Improvement Programme (EGIP), have now been issued for return by September.
The project will include156 single track kilometres of electrification works and remodelling and platform extension work at Waverley, Queen St, Croy, Falkirk High, Polmont and Linlithgow.
A new Edinburgh Gateway interchange station will also be constructed at Gogar as part of the project and a new depot created at Millerhill in Edinburgh.
Contracts will be awarded in early 2014 with construction expected to during summer 2014. Network Rail is committed to completing the main E-G electrification works in 2016.
Once complete, EGIP will cut journey times and increase capacity on the route between Glasgow Queen Street and Edinburgh Waverley.
David Simpson, Network Rail route managing director for Scotland, said: “The EGIP programme is a unique chance to modernise and enhance our railway and transform rail services across the central belt.”
Roger Dickinson, regional director for Network Rail Infrastructure Projects in Scotland and northeast England, added: “The tendering process currently underway also offers us an opportunity to continue to develop our new alliancing approach to infrastructure projects – which was recently successfully applied to the Paisley Canal line’s electrification – to work more closely with contractors and stakeholders to deliver in the most efficient, cost-effective way for passengers.”