More than 6,000 watched as the third tunnelling boring machine (TBM) on the Grand Paris Express project was lowered into a shaft at the Bagneux site in Hauts-de-Seine.
The Cap joint venture, led by Vinci Construction, will use the TBM to drive a 4km tunnel on Line 15 to station Fort of Issy - Vanves – Clamart.
As well as watching the launch, the spectators also learned the name of the TBM, which was christened Ellen which was chosen by pupils from Henri Wallon B school in Bagneux.
Launch of the TBM marks a major milestone on this section of the new metro project and called for the project team to undertake considerable grouting work of former mines to create competent ground to tunnel through.
The section of tunnel is expected to be completed in summer 2020.