ROME, 25 August 2026

SELI Overseas: New breakthrough on Line 4 of the Cairo Metro

The TBM, for which SELI Overseas provided technical assistance, entered the El Remaya station after completing 781 meters of tunneling in one of the most complex sections of the entire project.

Just a few kilometers from the Pyramids of Giza, deep beneath Cairo, a TBM has just completed one of the most challenging phases of Line 4 of the metro system. SELI Overseas, a Webuild Group company specializing in tunneling and mechanized excavation, provided the technical assistance that guided the machine to the finish line.

TBM 1 entered El Remaya Station (Station 5) after excavating 781 meters through highly complex terrain: sands and silts typical of the Nile’s alluvial system, running beneath one of Africa’s most densely populated urban areas. In this scenario, every meter traveled by the TBM requires a combination of geotechnical expertise, operational skills, and real-time monitoring of excavation conditions.

The most challenging moment occurred right near the station: the TBM passed within less than six meters of the wall of a 30-meter-deep excavation—a distance shorter than the machine’s own diameter. This situation required continuous monitoring of pressures at the excavation face, advance parameters, and potential deformations of the surrounding soil. To make the operation even more challenging, the entry into the station took place along a tight curve with a radius of 355 meters, completed inside a “steel bell”—the metal structure that allows for a safe breakthrough during the final stages of excavation.

This milestone marks another step forward for Line 4, the future east-west axis of Cairo’s metro network: once completed, it will serve approximately 1.5 million passengers per day, passing through areas of immense historical significance such as the Pyramids district and the Grand Egyptian Museum.

With approximately 850 kilometers of tunnels built in 32 countries and 75 years of experience, SELI Overseas is today one of the leading international operators in the tunneling sector. The company is committed to developing advanced and green technologies to make excavation increasingly efficient, safe, and sustainable, including the Dual Model TBM, Continuous Mining, and predictive digital solutions aimed at optimizing performance and reducing the environmental footprint of construction sites.