Major tunnelling on the Line 2 extension of Athens metro took a penultimate step to completion last month with breakthrough of the 9.46m diameter TBM at Ilioupoli station.
Following intermediate breakthroughs at Elliniko, Argyroupoli and Alimos stations, there only remains a short drive to tie-in the single tube, double-track extension to the existing line, the last station of which is Aghios Dimitrios. Excavation of the 5.5km long extension being developed by Attiko Metro began in February last year, and involves 4,655m of tunnel excavation.
The TBM is a refurbished and adapted Herrenknecht machine that has been erecting segmental (7+1) rings that are 350mm thick, 1.5m long and 9.18m o.d.
The shield is being operated by Seli, a member of the JV subcontractor for the tunnelling work. Other members of the JV are Aegek, Aktor and J&P-Aax. The main contractor is a JV of Aktor, Vinci and Siemens.
Line 2 extension was to have been completed in December 2009, but archaeological finds have led to this being put back by some months to early 2010. More than 80,000 passengers per day are expected to use the link.
At the opposite, north west end of Line 2, developments for further extension to the metro network include works to build links to Haidari, Peristeri and Anthoupoli.
The tender procedure for the link to Piraeus, which will have six stations, is underway. In addition, progress is being made on the design and procurement for Line 4, which will be 20km long and run in a major U-shaped loop in the north east of the city.
The line will have 20 stations and extend from the area of Galatsi to the centre of the city and back out to Maroussi.
