Réseau Ferré de France – Modernisation of railway lines

Modernisation of railway lines : Siorac – Sarlat and Bergerac – Le Buisson

                                            1 RFF 2 RFF

The French rail network RFF wished to modernise 2 railway lines located in the department of the Dordogne:

– from Siorac to Sarlat: 25.23 km of track,

– from Bergerac to Le Buisson: 34.28 km of track.

 These lines are non-electrified single track, within UIC group 9 AV (with passengers) and used commercially by the SNCF (TER).

The 2 lines feature many structures of the following types:

  • Large, multi-span stone viaducts,
  • Stone walls and riprap,
  • Stone tunnels,
  • Metal structures of twin-beam bridge type,
  • Various single-span stone or concrete structures with modest apertures (of approximately 1 m to 20 m).

This was the first maintenance and modernisation project of an operational railway network to be carried out by a private engineering firm.

Client & Project Manager

Principal features

Pre-project, project, assistance in awarding contracts, project conformity assessment and approval of working plans, and supervision of works carried out in respect of the replacement of structures, restoration of impermeability, anti-corrosion protection and repair to metalwork, stonework and small civil engineering works on the engineering and hydraulic structures of 2 railways lines.

  • Impermeability of viaducts: 18 Engineering Structures (ES) including 4 large multi-span viaducts
  • Drainage of tunnels: 5 structures
  • Replacement: 4 ES
  • Total restoration of anti-corrosion protection: 21 ES
  • Masonry and small civil engineering works: approximately 200 ES

DIADES’ task

DIADES managed the project studies and the specialist maintenance works to engineering structures, which included replacing and modernising the engineering structures and hydraulic structures of the 2 railway lines.

The main works were of the following types:

  • Restoring the impermeability of the stone bridges and viaducts and draining the water from the tunnels having first used radar location,
  • Restoring the anti-corrosion protection with presence of lead, repairing metal structures, replacing or repainting safety railings,
  • Replacing 4 metal decks with 1 through-track structure (NTPJ-b) and 3 side-track structures (1 RaPUM and 2 RaDBA),
  • Masonry works (ground anchors, clasping ties, and so on) and small civil engineering works.



 Download the project sheet