Mireille: a TBM gets a female welcome as it marks its first breakthrough for a Paris metro line

Tunnel-boring machine (TBM) “Mireille” has completed the first leg of her journey.

After 2.2 kilometres of excavation, the TBM arrived on March 29 at the site of the future station of Clichy-Montfermeil, located on Lot 2, a section of Line 16 being built by Webuild and its French partner NGE. The future metro line north of Paris is part of Grand Paris Express, the most ambitious project in Europe for sustainable mobility.

Mireille had started off at a site called Bel-Air at the southern end of Lot 2 in the municipality of Chelles. Its arrival at the station box was received with applause from a large crowd including the mayors of Clichy-sous-Bois and Montfermeil, and representatives of the client, Société du Grand Paris.

In addition to Lot 2, which includes the excavation of 11 kilometres of tunnels and the construction of four stations, Webuild and NGE worked together on Lot 4 of Line 14 South, an extension more than four kilometres long completed more than a year ago to connect Orly Airport with the centre of Paris.

Lot 2 of Line 16 and Lot 4 of Line 14 South stand to help reduce daily traffic by 385,000 vehicles and annual CO₂ emissions by 81,000 tonnes.

Line 16 is one of the strategic lines of the Grand Paris Express. It will transport an estimated 200,000 people a day. As its trains cross Lot 2, it will stop at four stations, namely Clicy-Montfermeil, Aulnay, Sevran-Beaudottes e Sevran-Livry.

“Just like the other lines, Line 16 is part of a big project to improve transport services in the periphery of Paris,” says Guglielmina Fontana, construction manager for Webuild at the site of the Clichy-Montfermeil station. “It will obviously include many municipalities that are poorly served today by public transport. So it is a way to improve these areas and to make it possible to create quicker and more modern connections with Paris.”

Fontana arrived on the project after having worked on the Cityringen metro line in Copenhagen, another sustainable mobility project by Webuild.

“Of the more than 850 people who work on Lot 2, 55 are women who hold important positions. It is a record for the construction sites on the Grand Paris Express. These are women who have roles such as construction manager, planning manager, monitoring manager… We then have women who are responsible for costs as well as quality control and environment control. So we are talking about a line that is fairly ‘feminine’ so to speak. The fact that there are so many women is definitely a positive signal – also for the management of this project that does not look at gender but at a person’s skills, which is what should always be done in any sector.”

“The Clichy-Montfermeil station is a so-called emblematic station. It is emblematic for the people living in this area. It is also emblematic because its construction is complex at an architectural and geotechnical level. For instance, the soil is made of gypsum, which can cause problems as it dissolves when it comes into contact with water. This has been a challenge for us during the excavation for the diaphragm walls. We also have found what is called ‘green’ clay that can swell and change in size depending on how much water and air is inside it. This is a feature (of the site) that has forced us to solve a whole series of difficulties.”

With its successful arrival to the site of the station, TBM Mireille is being prepared for the next leg of its journey: 3.1 kilometres of excavation through the municipalities of Livry-Gargan and Sevran to reach Mare au Chanvre at Sevran, where it will meet another TBM called “Houda” that is coming from the other end of Lot 2.