Network Rail is now over 50 days into its 140-day closure of Glasgow Queen Street, carrying out essential work for the £742 million Edinburgh-Glasgow Improvement Programme (EGIP).
To accommodate the arrival of new Class 385 electric trains next year, longer platforms are needed with overhead wires erected.
In Queen Street Tunnel 10,000 tonnes of concrete slab-track is being replaced and new drainage and track installed, plus a conductor bar to deliver electric current (RAIL 795). NR reports the project is progressing on time and to plan.
During the first three weeks of the blockade (that started on March 20), five point ends were renewed at Cowlairs South and West junctions, four point ends were refurbished at West Junction, and 3km (1.8 miles) of plain line track was renewed between Cowlairs Junction and the north end of Queen Street Tunnel.
NR also began the demolition and rebuilding of platforms, while taking up track to begin preparatory and drainage work both within and to the north of the tunnel.
In mid-April work started to break up and remove the old slab-track on the Up (Edinburgh-bound) line within the tunnel, in a process that was due to end in early May. The new concrete bases are currently being poured for the Up line and new PORR slab-track units will be laid over the course of May.
NR says it will complete the new Up line before starting on the Down.