The Borràs tunnel, with a length of 526 meters and a speed limit of 80km/h, is located in the Sarrià-Sant Gervasi District on the Ronda de Dalt in Barcelona, one of the main ring roads that surrounds the city and helps clear traffic around the urban area.

It consists of two tubes, one towards Besós and the other towards Llobregat, with three lanes in each direction accommodating the 157,000 vehicles that pass through the tunnel daily.

In the central section, there is an opening that allows natural light during the day and serves as a connection point to other roads such as the Ramal IJ and the Vía Augusta towards Besòs (where the tunnel expands to five lanes) and the entrance and exit to the Vallvidrera tunnels towards Llobregat.

DURABLE, SAFE AND LOW-MAINTENANCE TECHNOLOGY

In 1994, Carandini supplied the lighting system for the inauguration of the Borràs tunnel, using the PHR404 discharge solution. Thirty years later, the Barcelona Metropolitan Area (AMB) once again trusted Carandini to modernize the Borràs tunnel and the Ramal IJ, with the dual objective of reducing energy costs and optimizing light levels to ensure maximum safety.

The AMB needed a technologically robust and durable lighting solution that guaranteed a long service life with minimal maintenance and easy installation. Therefore, they opted for the modular tunnel lighting solution T-XTREME, characterized by excellent efficiency (up to 165lm/W) and prepared to withstand the most extreme conditions, including high-pressure washing (IP69K), a cleaning technique common in environments with high dust and dirt accumulation.

In the direction towards Besòs, 108 T-XTREME S size projectors, 16 size M units, and 182 size L units were installed. In the direction towards Llobregat, 96 T-XTREME S units were installed, along with 22 size M units and 159 size L units. For the Ramal IJ, Carandini provided 24 T-XTREME S units, 3 size M, and 27 of the largest size, totalling 637 luminaires with a colour temperature of 4000K.

In the opening central section, the VEKA road solution was installed to reinforce the lighting and prevent the “black hole effect”. With this additional lighting, we ensure that drivers entering the tunnel have a clear vision and do not experience discomfort due to the contrast between the light outside and inside the tunnel.

THE CALLENGE: A UNIQUE AND COMPLEX PROJECT

Each tunnel is unique and requires specific technical considerations, as well as a tailored lighting system. Different variables such as location, length, width, lanes per direction, usage, environment, or local regulations must be taken into account, and therefore, working closely with all project stakeholders is essential.

In the case of the Borràs tunnel, with a partially open area and up to five lanes in some sections, collaboration with UTE Rubatec-Urbalux, the installation company, and Miatec engineering has been essential to address the various challenges of the project. On one hand, we had to deal with height limitations set by the clearance gauge, and on the other hand, we had to achieve excellent uniformity in an area with sections of natural light and entrances from other traffic routes.

THE PROPOSED SOLUTION

After much collaborative work between Carandini and UTE Rubatec-Urbalux, it was decided to install flat projectors with frontal asymmetrical optics and zero inclination to address the clearance gauge limitations. Although inclination is a key factor in achieving good uniformity, choosing the most suitable optics for the project has been a fundamental element in achieving excellent uniformity. The installation was carried out bilaterally in both directions of travel and with reinforcement in the central area due to the existing opening.

Thanks to the fantastic work done and the great coordination between both parties, the new lighting has achieved exceptional results. The installed projectors emit bright white light that provides great visual comfort and perfect visibility for drivers, a fundamental aspect in areas with high traffic density such as this tunnel. Additionally, this new installation has allowed for significant energy savings, excellent uniformity, and increased safety.

MODERNISATION OF LIGHTING FINANCED BY EUROPEAN FUNDS

This action has been co-financed by the European Regional Development Fund (ERDF), included within the project to improve energy efficiency and reduce emissions through the replacement of conventional luminaires with LED technology in the area of the ring roads, according to the agreement signed between the Barcelona City Council and the Barcelona Metropolitan Area (AMB).