Fibre optic innovation: A new application in infrastructure monitoring

In a groundbreaking move, a European research initiative is uncovering the potential of fibre-optic cables to function as real-time structural sensors. This cutting-edge approach, part of the €5.1 million ECSTATIC project, aims to leverage the internet's carriers beneath our feet to safeguard infrastructure like bridges and tunnels.

Coordinated by Aston University in the UK, the project focuses on a heavily trafficked railway viaduct in a major UK city as its primary test site. Through this innovation, researchers aim to detect minute shifts, stress, and vibrations using light pulses traversing the existing fibre-optic system.

A key ambition, termed by Professor David Webb as creating a "global nervous system for critical infrastructure," seeks to convert ubiquitous cable networks into an advanced early-warning mechanism. The technique aims to identify subtle tremors and stress fractures, preventing potential disasters before they unfold.

Traditional methods of installing sensors across entire networks are prohibitively costly and disruptive. In contrast, the ECSTATIC project utilises existing infrastructure, potentially transforming a Victorian-era rail viaduct into a sophisticated monitoring system.

As part of the trials, finely tuned laser pulses travel through these fibre-optic lines. The passage of trains triggers minor flexes and vibrations, altering the light's phase and polarisation, painting a detailed optical picture of the structural loads.

By harnessing a dual-microcomb photonic chip and AI-driven signal processing, ECSTATIC intends to discover early signs of wear and tear. All this occurs without disrupting regular internet service or laying additional cables.

This forward-thinking method promises to revolutionise how ageing structures, including those dating back to the Victorian era, are monitored and maintained, effectively delaying the occurrence of tragic incidents similar to previous disasters in Europe.

The urgency of such systems is evident from past failures, like the Genoa Morandi Bridge collapse in Italy, which tragically claimed 43 lives. In Germany, the Carolabrücke incident highlighted the devastating impact of ageing infrastructure. These examples underscore the necessity for more reliable and non-invasive monitoring solutions.

ECSTATIC aims to provide early warnings based on better, real-time data collection, all while avoiding costly sensor installations. By tapping into the vast network of global optical fibres — exceeding five billion kilometres in length and spanning varied terrains — the project envisions an upgrade in infrastructure monitoring across Europe and potentially beyond.

Set to run until 2028, coordinated efforts by Aston University, alongside 13 European partners, hope to achieve a safer future where infrastructure monitoring combines innovation, collaboration, and technology to prevent unseen dangers.