The project for the northern and southern extensions of line 14 was a unique project with the digging of a 3 km long tunnel passing under an operating airport. A first in France! On this major project, NGE carried out, under RATP project management and in a consortium with the company Webuild, the last end of the southern extension of line 14 between the “Pont de Rungis” station and the maintenance site and Morangis storage facility. The project was completed on time despite an interruption of a month and a half during the Covid-19 pandemic in particular, thanks to efficient organization planned in close collaboration with the RATP.
“the NGE Group has particularly invested in the southern extension of line 14 by creating a lot with unique characteristics in a unique environment, under Orly international airport! This was the first operation to dig a railway tunnel in France under an operating airport. It mobilized 300 employees and required a little over 3 years of civil engineering and excavation work, with the highest quality standards, without any disruption to airport operations. With the successive commissioning of EOLE and the extension of line 11 in recent weeks, the NGE Group is proud to have supported SNCF Réseau, RATP and the Société des Grands Projets within the time allowed for commissioning of these strategic lines before the opening of the Olympic Games. Drawing on these experiences on these complex urban mobility projects and the ongoing projects on lines 16 and 17 of Grand Paris, our teams are already turning towards a new major challenge to take on: the design and construction of lot 2 of the line 15, western section » Jean Bernadet, general manager NGE.
Digging under an operating airport
It is thanks to the Koumba tunnel boring machine, named in honor of the French wrestler Koumba Larroque (qualified for the Paris 2024 Olympic Games), that the 4 km of tunnel in the section were built, including 3 km dug passing under the airport, the new terminal 3 and the Orlyval viaduct. Another specificity of this project was the descent of the tunnel boring machine into its starting shaft, 17 meters deep, in a single block. This is the first time in France that this type of lifting was carried out for a tunnel boring machine, whose weight was 880 tonnes for 11 meters long and 8.8 meters in diameter. This work, lasting three years, was carefully planned and executed to ensure the continued operation of the airport without any disruption. Teams installed targets to monitor structures at various locations throughout the airport, including the Terminal 3 building, duty free areas, baggage sorting areas and the tarmac. These places were constantly monitored to ensure the integrity of the structures. One of the major challenges was to carry out these operations under airport security and safety constraints for the teams. The complete success of this operation, essential to the commissioning of line 14 for the Olympic Games, served as a model for the following excavations: line 18 under Orly and line 17 under Charles-de-Gaulle.
Project figures
• 4 km the tunnel
• 3 service works (March 2018 – March 2021)
• 330 meters of covered trench
• 3 years of construction
• 300 people mobilized
• 69,200 hours of integration completed
