The air hums with the relentless rhythm of construction beneath Madrid’s A-5 highway. Trucks, excavators, cranes, and a myriad of mechanical marvels move ceaselessly through the tunnels, all working towards a singular goal: to open this vital artery to traffic by the end of the year. This ambitious project, a cornerstone of Mayor Almeida’s electoral promises, represents an investment of over 400 million euros, aiming to transform the city’s western entrance.
A City Transformed: The Vision Behind the Tunnel
For decades, the A-5, the main gateway to Madrid from Extremadura, has been a cacophony of traffic, a barrier separating neighborhoods from the Casa de Campo. Up to 80,000 vehicles daily contributed to the din, a far cry from the serene vision now taking shape. The 3.2-kilometer tunnel, currently extending from Avenida de los Poblados to its connection with Avenida de Portugal and the M-30, promises a radical transformation. Above ground, the future holds parks, plazas, bike lanes, and local access roads, turning a noisy thoroughfare into a vibrant green promenade. The mayor, Martínez-Almeida, recently quipped on television that the site resembled a “war zone,” but with a hint of irony, acknowledging the project’s smooth progress.
Overcoming Challenges: A Complex Underground World
Lola Ortiz, Director of Planning and Mobility Infrastructures at the Madrid City Council, is intimately familiar with every facet of this colossal undertaking. She explains that the southern tunnel, designed for vehicles entering Madrid, is 80% complete, while the northern tunnel stands at 50%. This means two-thirds of the excavation is already done, with the remaining work advancing on schedule despite heavy rains earlier in the year.
Digging beneath a bustling metropolis inevitably unearths surprises. Utility maps often fail to reflect the intricate reality of buried infrastructure. “A madness of cables everywhere,” Ortiz recounts, referring to the maze of pipes and wires for water, gas, electricity, internet, and even old postal and Ministry of Defense lines. While minor incidents like temporary power outages in Batán and water cuts in Aluche have occurred, the project has largely avoided major setbacks. One of the most complex technical challenges has been relocating a high-voltage power line, which will eventually be buried.
The ‘Zamorana Blanket’: A Game-Changer in Construction
The construction technique employed is ‘cut & cover,’ favored for its speed over traditional tunnel boring machines, which are reserved for longer, more extensive projects like the Metro Line 11. The city council prioritized rapid execution, acutely aware of the disruption such a massive undertaking would cause to commuters and residents.
A key innovation accelerating the work is the so-called ‘Zamorana Blanket.’ This term, far from its literal meaning of a traditional woolen blanket, refers to pre-assembled steel rebar mats used for the tunnel’s floor. Unlike smaller projects where rebar is laboriously assembled by hand, these large, pre-fabricated rolls are simply unrolled and adjusted, drastically reducing installation time and manpower. Manufactured by a company in Zamora, their distinctive shape earned them their unique name. This method, combined with working on multiple fronts simultaneously, has allowed up to 600 workers to be on-site at any given time, pushing forward at an impressive rate of 300 cubic meters of earth excavated daily from each of the five fronts.
Beyond the Tunnel: A New Horizon for Madrid
The excavated earth, totaling an estimated 600,000 cubic meters by project completion, is not simply discarded. It’s being used to create three new hills near the intersection with the Boadilla road, transforming the local topography. These hills will eventually form an elevated biodiversity zone and a viewpoint, further enhancing the new green corridor.
While the tunnel itself is slated to open to traffic by the end of 2026, the surface parks and pathways will follow. The final urbanisation contract, valued at 62 million euros, is currently open for bids. This will complement the 347 million euros already invested in the tunnel’s excavation, carried out by a consortium of Ferrovial, FCC Construcción, Dragados, and Acciona Construcción.
The upcoming months will see the critical phase of connecting the new tunnel with Madrid’s existing tunnel network and the Calle 30 access points. This complex integration is a delicate operation, but mobility officials are confident in their timeline. As residents peer from their windows, watching the daily progress, they can almost taste the future – a Madrid transformed, where the roar of traffic gives way to the tranquility of green spaces, and a once-divided city finds new connections beneath its bustling surface.
Source: https://www.eldiario.es/madrid/somos/secretos-gran-tunel-madrid-construye-5-excavacion-65-manta-zamorana-acorta-plazos_1_13070913.html
