Mayrit Tunnel Boring Machine Reaches Major Milestone
This Tuesday, the Mayrit tunnel boring machine crossed a vital checkpoint in its journey to facilitate the expansion of Line 11 of Metro Madrid. It burst into the gap of the future Madrid Río station, located on Paseo de Yeserías, completing a major geological section of the project that includes the crossing under the Manzanares River and the M-30 tunnels. The Minister of Housing, Transport and Infrastructure of the Community of Madrid, Jorge Rodrigo, was present to commemorate this significant event.
A Celebration of Progress
At approximately 5:30 p.m., Mayrit reached the “cale”—the technical term for the moment when two excavation fronts align, one towards Comillas and the other from the Madrid Río side. Initially, there was a dull noise from deep within the earth, followed by loose stones and finally the cutting head breaking through the station screen. This achievement was celebrated as a “moment of joy and pride” by Rodrigo, especially since it occurred eleven days ahead of schedule.
Excavation Results
Since its launch on March 26 from the future Comillas station in Carabanchel, Mayrit has excavated 1,116 meters of tunnel in just over two months, accounting for 21% of the total planned for this branch. The machine has installed 656 concrete rings, each composed of seven rhomboidal-shaped voussoirs that will serve as the definitive covering for the gallery.
Geological Challenges and Solutions
To successfully cross under the M-30 and the Manzanares, the machine had to descend and then ascend, adhering to the strict slope requirements typical for railway infrastructure. The average pace of excavation has been approximately 15 meters per day, with optimal conditions even allowing for peaks of 35 meters daily. Miguel Núñez, the General Director of Infrastructure for the Community of Madrid, attributed the rapid progress to the favorable geological conditions. The peñuelas clay, found underground in Madrid, has proven to be an ideal material for the tunnel boring machine.
Upcoming Tasks and Technical Review
For the next two weeks, Mayrit will remain stationed at the Madrid Río site where it will undergo a thorough review. Only the cutting head has currently emerged, and the remaining 98 meters of the machine will follow. Technicians will replace worn tools, check all computer systems, and prepare the machine for its next segment.
The Next Phase Awaits
Following the technical review, Mayrit will journey toward the Palos de la Frontera station, which lies 1,613 meters away and marks the longest stretch between any two stations in this expansion effort. Expectations indicate that it will arrive there before the end of the summer, subsequently proceeding to Atocha and finally to Conde de Casal, the endpoint of this branch. In total, over 4,100 meters remain to be excavated from the planned 5,227 meters between Comillas and Conde de Casal.
Project Scope and Financial Commitments
This section is part of a larger shift to modernize and expand the Metro network, with an investment exceeding €740 million dedicated to this phase alone. Line 11 is designed to serve as the major diagonal of the Madrid Metro, stretching 33.5 kilometers from Cuatro Vientos to Valdebebas, connecting important locations such as Atocha, the airport, and the forthcoming Formula 1 circuit in Ifema.
The overall project investment surpasses €2.5 billion, with work scheduled to continue in phases until 2031. The full excavation process is anticipated to take between 13 and 14 months, potentially concluding around May or June of 2027.
Cover image | Metro Madrid and Community of Madrid