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SYSTRA France inaugurates the Donges bypass. The Nantes - Saint-Nazaire line has become safer

SYSTRA France inaugurates the Donges bypass. The Nantes - Saint-Nazaire line has become safer
photo: SYSTRA Group/SYSTRA France inaugurates the Donges bypass. The Nantes - Saint-Nazaire line has become safer
01 / 11 / 2022

The railway tracks no longer cross the Donges refinery, west of France, and passengers now have a new multimodal stopover. The inauguration of the Donges bypass, on the 24th of October, marks the culmination of a six-year SYSTRA France assignment to make the Nantes - Saint-Nazaire line safer and preserve the environment.

The completion of the bypass of the Donges industrial sites was necessary to secure a line used by 1.5 million passengers per year. The old route ran through a 350-hectare area dominated by the TotalEnergies refinery in Donges, the second largest in France, which is classified as a Seveso III ‘high threshold’ industrial site.

"The Donges rail bypass is a major project for SYSTRA France’s teams: it is a first insofar as SNCF Réseau has entrusted us with complete project management, including all professions, on a section of line in operation. We were the project manager for the studies starting in August 2016, and then for almost the entire project, with complex work methods and, in particular, continuous work, with traffic disruption and 24 hours a day. I would like to thank all the employees in Paris, Nantes, and Bordeaux who have taken part in the project since 2016: we can all be proud of the work accomplished!" says Didier Traube, CEO of SYSTRA France.

The railway line is now less exposed to industrial risks and the SNCF service to the town of Donges has been improved thanks to a multimodal stopover accessible to persons with reduced mobility (PRMs), five minutes from the town center, compared with 20 minutes previously. In addition, the freeing up of the former line’s rights-of-way will allow industrial sites to reorganize their locations.

Environmental protection at the heart of the project

The immediate proximity of numerous wetlands, marshes, and two Natura 2000 sites meant that a strong environmental dimension had to be incorporated into the project. In total, 17 hectares of land, spread over 17 sites, have been dedicated to environmental compensation, to reconstitute habitats favorable to these areas, with:

  • A new bat shelter with species transfer from the old building which is to be demolished,
  • Habitats for protected species (reptiles, birds, hedgehogs…),
  • The creation and/or rehabilitation of sanctuary wetlands, with the transfer of ponds.

In addition, the landscape integration of the project has been ensured by the creation of 7 merlons near the roads, dominated by tall trees (oak, ash, willow), which act as visual screens for residents and which act to re-establish the ecological network and encourage the development of local biodiversity.

A turnkey project for SNCF Réseau

From the very first stages of the studies, SYSTRA took into consideration all aspects of the project: land acquisition, rerouting of the numerous networks in the area, monitoring of the consultation and public inquiry process, and production of numerous visuals to help residents and the authorities to envisage the future line.

"This project, which is complex both in terms of its geographical specificity and the many interfaces it involves, represents a major step forward for all stakeholders in the region, both in terms of making passenger travel on the line linking Nantes to Saint-Nazaire safer and in terms of the economic development of the TotalEnergies refinery, as well as for the people of Donges, whose access to the new station has been greatly improved. It is, therefore, a project that serves everyone and illustrates the client’s confidence in our teams," says Antoine Cypierre, SYSTRA France Project Manager.

Launched in 2020, supervision of the works, carried out both day and night, proved to be particularly demanding, as the proximity of the refinery required constant vigilance. In addition to the requirements and accreditations specific to work on railways in operation, issued by our SYSTRA Académie training center in Poitiers, TotalEnergies also had to meet the requirements and accreditations of the project (training in petrochemical risks, specific personal protective equipment).

For two years, the construction of the new dedicated line took place at the same time as the overhaul of the facilities on the old line, particularly the track, electrical traction, and systems. This involved more than 400 nights, three lightning operations, and a 14-day shutdown to bring the new line into service. The project will be completed in the spring of 2023 with the end of the removal of the old track and the finalization of compensatory environmental measures.

Key features - Donges Rail Bypass

  • 4.5km of new, electrified double track, including the connections to the national rail network
  • 60 trains per day, of which 14 TER Pays-de-la-Loire (regional express trains)
  • 1 new multimodal railway stop accessible to PRMs with Park & Ride facilities
  • 6 years of project work of which 3 for construction
  • 2 road bridges
  • 4 railway bridges
  • 18 plant shelters
  • 450 trees planted, notably on 7 merlons
  • 13 drainage areas
  • 17 hectares of environmental compensation zone created


Source: SYSTRA Group Press Releases