Madrid Metro Line 11 Expansion: Mayrit TBM Assembly Begins in Spain

Madrid authorities have commenced the assembly of the Mayrit Tunnel Boring Machine (TBM), a critical step in the ambitious expansion of Metro Line 11. The technologically advanced machine, hailed as a “world benchmark in underground excavation technology” by Madrid regional president Isabel Díaz Ayuso, marks a significant investment in the Spanish capital’s urban infrastructure.

Main Body:

The Mayrit TBM, a colossal 98-meter-long, 1,500-ton machine, has undergone a meticulous 20-month assembly process in Germany. It is now being assembled at a depth of 27 meters, the precise location for the new tunnels of Metro Line 11. This significant piece of engineering, named after the Arabic origin of Madrid, is engineered to tackle the unique and challenging geotechnical conditions of the region, including hard rock, compact gravel, and black clay. Its construction and intricate transport, spanning over 2,000 km by road and sea, underscore the scale of this infrastructure undertaking.

Strategic Impact

The expansion of Metro Line 11 is poised to fundamentally reshape Madrid’s public transport network. This initial phase, extending between the Comillas and Conde de Casal stations, will introduce five new stations: two entirely new ones, Comillas and Madrid Río, and three crucial interchange hubs at Palos de la Frontera, Atocha, and Conde de Casal. With 43% of this initial work already completed, the project is progressing steadily. Upon completion of the full 33 km and 20-station network, Line 11 is envisioned by regional authorities to become the “backbone” of the Madrid Metro system, enhancing connectivity and efficiency across the metropolitan area.

Operational Details

The Mayrit TBM is engineered for relentless efficiency, designed to operate 24 hours a day, seven days a week, commencing operations in March 2025. It is projected to advance at an average speed of 15 meters per day. This advanced capability is largely attributed to its specialized cutting wheel, equipped with numerous milling discs and abrasive elements specifically designed to penetrate Madrid’s varied soil compositions. Excavated material will be continuously evacuated via an automated 6-kilometer conveyor belt system, minimizing operational stoppages. The TBM’s design allows for component replacement only once every 1,000 meters of excavation, a testament to its robust construction and planned durability.

Technical Specifications

• Length: 98 meters
• Weight: 1,500 tons
• Average daily advance speed: 15 meters
• Maintenance stop frequency: Approximately every 1,000 meters excavated
• Excavated material transport: 6-kilometer automated conveyor belt

Industry Context

The scale and technological sophistication of the Mayrit TBM project highlight a global trend in urban rail development, where significant investments are being made in advanced tunneling technologies to overcome complex geological challenges and expand vital public transport networks. For rail industry leaders, this initiative in Madrid serves as a compelling case study in project planning, TBM design tailored to specific site conditions, and the strategic importance of high-capacity metro lines in supporting urban growth and sustainability. The project’s commitment to 24/7 operation and impressive excavation rates demonstrates the industry’s ongoing drive for efficiency and innovation in delivering critical infrastructure.