Published On: 20. September 2023|Categories: News, Sensing|

Fiber-optic Sensor Technology in the Heart of Munich: Monitoring the Subway Tunnel Ceiling


The concerned prestressed concrete structure dates back to the 1970s and has, over time, been subjected to substantial strains due to high traffic loads and temperature fluctuations. This led to alarming damages, particularly on the underside of the ceiling structure, compromising the tunnel’s safety and functionality. A renovation became imperative.

Our Solution:

As a leading manufacturer of fiber-optic cables and systems, we provided fiber-optic sensor cables that were installed within the tunnel ceiling. These cables are equipped with Brillouin technology, enabling precise and continuous measurements. With this technology in place, crack formations and deformations can be monitored in real-time, allowing for early detection of potential issues and ensuring a high level of safety for the subway system’s daily users.

The concept behind this installation encompasses both continuous monitoring of overall deformations and pinpoint measurements with respect to specific crack developments. With this dual monitoring strategy, we can assure that the renovated structure withstands the demands of modern urban transport while still respecting the historical legacy of the 1970s.


The initial results from the monitoring are promising, showcasing the potential of fiber-optic sensor technology in the realm of structural monitoring. As pioneers in this domain, we take pride in leading this technological revolution and supporting our clients with solutions that guarantee safety and longevity.

For those keen on diving deeper into the technical specifics and the initial outcomes of this project, we recommend the complete article, offering a comprehensive overview of the application and benefits of our fiber-optic sensor technology in this particular use case. You can find the full article here: Langzeitrissmonitoring an Spannbetonkonstruktionen mittels Distributed Strain Sensing

Source: Kindler, A., Schaller, M.-B., Nöther, N. and Breuer, S. (2023), Langzeitrissmonitoring an Spannbetonkonstruktionen mittels Distributed Strain Sensing. Bautechnik, 100: 383-395.