Rossio Tunnel

The work consisted of the following specific tasks:

- Demolition of the existing floor slab;

- Excavation of the existing ground level and recesses;

- Primary support and definitive cladding of the threshold;

- Final cladding of the shafts and vault, including waterproofing;

- Cleaning and treatment of the exposed faces of the existing masonry cladding of the shafts and vault;

- Nailing, grouting and drainage;

- Electrical installations, ventilation, automation and fire network;

- Laying of 1668 mm gauge concrete track with direct fixing to a floating slab, continuous without fixing to a floating slab and continuous without fixing to a concrete slab;

- Laying concreted track units;

- Laying 1668 mm gauge ballasted track;

- Carrying out aluminothermic welding;

- Preventive grinding;

- Execution of glued insulating joints;

- Assembly of overhead contact line in 25 kV system;

- Installation of a feeder cable for power supply to the overhead contact line.

The process also included the construction of a concrete and ballasted track and the installation of a new electric traction system (overhead catenary) as part of the Rossio Tunnel rehabilitation. These works included laying 1668 mm gauge track in 6 different types:

- Track with direct fixing (Vossloh 336) on a floating slab - protruding rails. The system consists of laying a CDM DFMA H13 & 26 resilient mat (attenuation 40-125 Hz (dBV)≥ 20);

- Track with direct fixing (Vossloh 336) on a floating slab - embedded track. The system consists of laying CDM MTA-5 rail vibration insulation and a CDM DFMA H13 & 26 resilient mat (attenuation 40-125 Hz (dBV) ≥ 20);

- Continuous track without fixing on a floating slab - embedded rails. It consists of the CDM PREFARAIL CLASSIC system with a CDM DFMA H13 & 26 resilient mat (attenuation 40-125 Hz (dBV) ≥ 20);

- Continuous track without fixing on a concrete slab. It consists of the CDM PREFARAIL COMFORT system (attenuation 40-125 Hz (dBV) ≥ 10);

- Track on existing slab with direct fixing;

- Ballasted track with concrete monoblock sleepers.