Eole Cnit La Défense

Eole Cnit La Défense
  • Transports
  • On going

In short

Developer: Paris La Défense
Project owner: SNCF and Ile-de-France Mobilités
Financers: State, IDF Region, Société du Grand Paris, City of Paris, Hauts-de-Seine Department, Yvelines Department, Ile-de-France Mobilités, SNCF Réseau
Project manager: Setec-Egis
Location: Arche Nord - Under the CNIT (Puteaux)
Commissioning: 2023

Arrival of RER line E at La Défense as early as 2023

Declared to be in the public interest on January 31, 2013, the RER E extension project aims to strengthen connections between the east and west of the Paris region by offering a new quality of service.

The Eole project consists of extending the current RER E line by 55 km to the west, from Haussmann Saint-Lazare station to Mantes-la-Jolie station, passing through the La Défense business district and Nanterre. 47 km of existing track between Mantes-la-Jolie (Line J Paris-Mantes via Poissy) and Nanterre will be upgraded and modernized. An 8 km tunnel will be dug between La Défense and Haussmann Saint-Lazare, the current terminus of the RER E.

The project will be accompanied by the creation of three stations (Porte Maillot, La Défense-CNIT and Nanterre La Folie) and will cross three departments (Paris, Hauts-de-Seine and Yvelines). In total, more than 620,000 passengers per day will benefit from this new line once it is fully operational in 2024.

Creation of the new line E station: La Défense-CNIT

Located in the heart of the La Défense business district, the future "CNIT-La Défense" line E station will make a major contribution to the development of the business district: a new-generation line, more trains, a new station with an impressive volume that will be able to accommodate large passenger flows. It will be the most interconnected line in the Paris region, particularly at La Défense, with the L and U lines of the Transilien, the RER A, the T2 tramway, line 1 of the metro and the future line 15 of the Grand Paris Express... A more direct and better connected link to the airports...

The future Eole station will be located underneath the CNIT, more than 30 meters below the ground, and links and connections with the neighborhood and other transportation lines will be facilitated. On level C of the CNIT, a new concourse will be created on the same level as the existing La Défense Grande Arche concourse and connected to it by the current passageway. This new hall will communicate with the upper levels of the CNIT, but also with the forecourt, Place Carpeaux and the extension of the forecourt on the Trinity side. Access to the RER E platforms will be from a mezzanine level overhanging the platforms, thanks to the various fixed staircases, escalators and elevators that will be installed there. This level will be an interchange hall where the main accesses and connections will converge: RER A, T2 tramway, Transilien L & U lines, exits to the outside and to the CNIT.

The new CNIT-La Défense line E station will open in 2023, providing access to eastern Paris and the future Nanterre-la-Folie station to the west. Then in 2024, the line will be fully operational as far as Mantes-la-Jolie.

**A technical challenge

The challenge for this project was to build an 18,000 m² underground station at a depth of 20 meters, and to create fast and fluid interconnections in the busiest multimodal station in France (connection to other transport lines) as well as direct access to the La Défense forecourt. The project will involve the redevelopment of the CNIT.

One of the challenges will be to implement solutions that limit noise pollution and the propagation of noise to the upper floors as much as possible. This is why an "acoustic sarcophagus" (floor, walls and ceiling) is enveloping the worksite under the CNIT. The project will involve several operations: reworking the foundations of the CNIT, which will be levitated with the underpinning of its 124 piles, the construction of the main body of the station, the creation of connection areas with public transport and the CNIT, the creation of the various exits from the RER E, while ensuring that the station is accessible to people with reduced mobility (elevators, platforms, ramps, anti-slip devices and warning strips).

Benefits for passengers

  • A new RER to serve La Défense from east to west
  • 2 exits to reach the various neighborhoods around CNIT, 2 connections with transport services and direct access to CNIT
  • More trains, faster, more comfortable and more modern
  • A new station to accommodate large flows of passengers and facilitate connections by providing new transit areas
  • A station and trains accessible to people with reduced mobility (elevators, escalators, trains at platform level, etc.)
  • A more important service:
  • Time savings on your journey: for example, from Mantes-la-Jolie to La Défense in 40 minutes instead of 52 minutes, from La Défense to Magenta in 10 minutes instead of 19 minutes today
  • Better coverage of the Ile-de-France network: more connections in Paris and, in particular, connections with the RER B and D lines at Magenta, easier access to airports
  • An RER that contributes to the improvement of other transport systems: desaturation of the RER A, B and D lines and the Saint-Lazare station
  • An interconnected station: RER A, metro line 1, Transilien L & U, T2 and the future line 15 of the Grand Paris
  • Looking back on 2020 and early 2021**

In less than a year, more than 120,000 m3 of earth have been excavated: the earthwork for the main body of the station is now fully completed.

At the same time, the underground work teams reached a major milestone on January 28, 2021, with the last of the bores in the two twin-tube tunnels, i.e. the last connection between the main body of the station and the parts of the station in tunnel (50 meters on either side of the main body of the station).

At the same time, civil engineering work is continuing actively on both the twin-tube tunnels and the parts of the station in tunnel or the main body of the station: the construction of the invert floors began in January.

The rest of the work will take place in the second half of 2021

In the station, work on track laying and fitting out the premises (secondary work) will begin in the summer of 2021. The civil engineering work on the station's transfer corridors and entrances will be completed by the end of 2021. The creation of the connection with the L, U and tramway 2 corridor will require a major operation under the tramway 2 tracks in the summer of 2021, which will result in a temporary interruption of traffic.

Project schedule

2016: Preparatory work for the tunnel towards La Défense: rerouting of networks, preparation for lowering the underground water table, preparation of the tunnel excavation shaft. 2017: Preparatory work, setting up the lowering of the water table, installation of the construction site, particularly under the CNIT, and modification of the CNIT foundations using the underpinning technique 2018 - 2020: creation of the new CNIT foundations ensuring the structure of the main body of the station, excavation and civil engineering of the station, and digging of the tunnels on either side of the station 2021 - mid-2022: finishing work on the station and rail infrastructure equipment Mid-2023: Commissioning

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  • Eole CNIT Défense
  • Eole CNIT Défense
  • Eole CNIT Défense

Did you know?

The station floor will be located 40 meters underground. In total, more than 140,000 m3 of earth must be excavated to create the volume of the future station, which is equivalent to 50 Olympic-sized swimming pools!