Sub-fluvial extension of Lyon metro delivered by Egis

On Wednesday 11 December, the Lyon metropolitan public transport authority SYTRAL inaugurated the extension of the city’s B line running under the River Rhone to Oullins in the south west of the conurbation. Egis has been a loyal partner to the project owner ever since the inception of Lyon’s first metro line. This new development is a confirmation of its know-how in the exemplary management of projects and in major underground engineering structures.

An exceptional project, delivered ahead of time

Line B of the Lyon metro dissects France’s third largest city from north to south, starting in neighbouring Villeurbanne and now terminating in Oullins, thanks to this new 1.8 km stretch of line and the addition of a new station.

This huge project required a new tunnel to be bored under the river, a quite exceptional project which drew on a range of rare expertise and techniques. The use of a single-bore slurry shield tunnel boring machine (TBM) was considered the most appropriate solution to deal with Lyon’s complex soil structure and cause the least disruption, whilst incidentally being the cheapest option to implement.

The work of the TBM – among other tasks – was successfully commanded by teams from Egis, well-versed in this type of construction. The tunnel boring was completed four months ahead of schedule in the initially allotted 11 month timeframe. The TBM arrived at its destination of the Gare d’Oullins station on 2 March 2011, completing the river crossing alone 41 days ahead of schedule. The stabling area and the station bored out of the granite were also delivered early, allowing compliance with all the deadlines that had been set by Egis when it first carried out preliminary studies in 2006.

Project management assignments

As the engineering, procurement and construction manager for both design studies and the construction work, Egis planned the entire project and supervised its technical and financial execution, including the issue of 25 separate works tenders. Egis was involved upstream in the definition of the construction method used to cross the Rhone, from preliminary studies to assistance for the principal tender for civil engineering and associated equipment, in keeping with the negotiated procedure chosen by the client. SYTRAL was thus able to rely on Egis’ competencies and expertise and on its experience acquired both in France and internationally. Egis deployed around fifty of its people on this remarkable project.

Key to the accomplishment of the project was the mobilisation of a tight-knit multidisciplinary infrastructure and systems team totally focussed on this objective. Another notable achievement was in the area of safety: not a single serious accident was reported on the project which started up in summer 2009.

Construction timeline:

• June 2009 Civil engineering works start
• September 2010 Tunnelling work starts
• 2 March 2011 TBM reaches Gare d’Oullins station
• April 2011 Tunnelling work completed
• July 2011 Track laying starts
• February 2012 Trackside equipment installation starts
• March 2012 Fixtures and fittings works start in Gare d’Oullins station
• July 2012 Track laying completed
• January 2013 Tunnel equipment installation completed and final civil engineering works
• February 2013 First train uses line extension, first system tests
• October 2013 Final fittings works completed in station
• October 2013 Ghost running starts (handover to operator)
• 11 December 2013 Start of revenue service