Press

Cleopatra is gnawing her way through the soil beneath Cairo. Cleopatra was of course Egypt's last queen, but is also the name given to the tunnel-boring machine (TBM) working 30 metres underground, advancing at a rate of 14 rings of precast-concrete segmental tunnel lining per day, on average, between the future stations of Abbasiya, Abdu Pasha, El Geish, Bab El Sharia, and Attaba. The new line will help alleviate the capital's chronic traffic congestion that is asphyxiating the city and its 20 million people. The project's office staff and 1500 siteworkers-2600 including subcontractors-have been burrowing beneath the city streets since 2007 to deliver the project on time at the end of 2011.

"It's an emblematic project", declares Site Boss Rémy Roussel. "Project financing was set up with the help of France, through the ‘RPE'¹ procedure. In this project under a consortium with Vinci Construction Grands Projets, Arab Contractors, and Orascom, Bouygues Travaux Publics is doing the tunnel and civils work and fitout for the stations." The contract was signed on 29 April 2007 and notice to proceed was given the following July. Handover is scheduled for October 2011, after 51 months of work. By early March 2009 the project had reached the 50% mark: the special foundations are all but finished and station fitout has started. The TBM driving the single-tube twin-track tunnel is currently between the Abbasiya and Abdu Pasha stations. It all seems quite simple, yet...

The tunnel is routed beneath roads as much as possible: 80% of the alignment is under a road, only the last section plunging beneath buildings and the existing line No. 2. All the apartments within a radius of 30 m of the stations and 50 m of the TBM were surveyed. A short distance from city offices, the steel fixing yard and a concrete batching plant have been set up at a former tram depot. The adjacent intersection is particularly congested, and the difficulties associated with the shortage of space, utilities (electricity, water, sewers, etc.), and transport infrastructure (the route passes beneath a railway line and a large number of roads) are severe. On top of the complexity of the works in this urban environment lies another challenge: finding the requisite technical skills and supervising the ambitious project with just 40 expatriates.

There were three times more expatriates engaged in construction of Line 2 when it was built by the Group in the 1990s... "The challenge is to achieve the same rate of work with fewer expats", states Yves Lazerges, the head of works services who is managing construction of the stations. "We're working as much as possible with Egyptian personnel and are succeeding in tightening construction times". Experienced local hands who worked on the previous metro line were re-hired whenever possible, but new recruits also had to be trained. In terms of safety and working standards, a different attitude to the value of life sometimes makes it extremely difficult to enforce safety requirements. "We're succeeding in introducing evolution, but hardly a revolution", says Rémy Roussel. And there has been evolution in the tunnel too...

Methods Manager Olivier Jorus recounts: "We proposed a project variant to the Client, NAT²: a bored tunnel instead of the 650-m-long section of cut-and-cover tunnel initially proposed. So the starter shaft we sank, from which the TBM could start its drive, also leads to the future maintenance depot". The TBM Manager, Alexandre Pellarin, explains more: "The 4,200 metres of the tunnel drive started in October 2007. The first hurdle was refurbishing Nefertiti, the TBM used for line No. 2. She'd been in storage in Marseilles for close to 6 years and needed a lot of new parts and a general overhaul". The 9.48-m-diameter, 74-m-long Herrenknecht slurry TBM is working around the clock in 12-hour shifts, stopping only on Friday mornings (the equivalent of the Christian Sunday). Fridays and Saturdays are devoted to maintenance, and tunnelling resumes on Saturday evening. Peak advance rates can attain 26 rings per day. The machine will break through in the spring of 2010. In the mean time she is steadily moving away from Abbasiya, the first station.

A steady pace of work; efficient coordination with other members of the consortium; "a fantastic country with hard-working and competent people", says a delighted Yves Lazerges... At all events, Imhotep, who engineered the pyramids, would certainly be astounded by the size of the project.

Line No. 3 will run a total length of about 30 km. Of its 29 stations, 27 will be underground.


The work done

• 5 underground stations built top-down inside diaphragm-wall boxes
• Bored tunnel about 3.5 km long with internal diameter of 8.4 m
• Access to maintenance depot by means of 1.15-km-long cut-and-cover tunnel
• Pedestrian connection to line No.2