Across the country, transport infrastructure is affected by subsidence and ground movement caused by both natural processes and legacy mining activity. The UK has over 172,000 recorded abandoned mine workings, with many more thought to remain undocumented. These voids can migrate towards the surface, creating potential collapse zones beneath railways and roads. Network Rail manages more than 1,500 mine sites in its Eastern region alone, many of which carry long-term stability risks. Equally between 20 and 60 per cent of infrastructure projects face delays from unforeseen ground conditions, and accidental strikes on buried assets cost around £2.4 billion each year. Current methods such as borehole drilling, geotechnical probing, and ground-penetrating radar are intrusive, slow, and often unreliable in conductive soils or under reinforced track beds. Existing gravimeters can provide valuable measurements, but they are highly sensitive to vibration and environmental noise, limiting their use in operational settings. Delta.g is developing a new approach using quantum sensing. The Delta.g quantum gravity gradiometer measures minute variations in the Earth's gravitational field caused by subsurface features. Unlike existing tools, our sensor cancels environmental noise at its source, making it possible to detect voids and subsurface anomalies quickly, safely, and without excavation. In ASIT, Delta.g will work with transport stakeholders, such as Network Rail, to define a practical use case for void and earthworks risk detection. Alongside this, we will develop a business case that explores the value of early detection compared with current methods. The outcomes will demonstrate how quantum sensing can reduce reliance on disruptive drilling, prevent costly interventions, improve safely for workers and passengers, and reduce delays all by identifying hazards before construction. Delta.g is a University of Birmingham spinout whose team delivered the world's first demonstration of quantum gravity gradiometer in the real-world (results published in Nature) as well as the first commercial quantum gravity gradiometer under commercial contract with the Department for Transport in 2024\. This work represents a critical step towards deploying a UK-led technology that strengthens resilience in rail, road, and broader transport infrastructure.

Detecting the world around us has long been a cornerstone of scientific research, with many sensing technologies developed for commercial use rather than purely scientific merit. The ability to view the subterranean environment was limited to destructive exploratory techniques, but in recent years commercial remote sensors have become more widespread. However, nondestructive methods can be severely hindered, ground features can be obscured and vibration or electromagnetic interference can prevent measurements altogether. These issues fundamentally limit the existing technologies for construction and infrastructure monitoring due to costly excavation and site closures which may not be possible. Quantum sensing techniques can overcome these barriers with precision measurements of gravity. Through cold-atom interferometry the quantum nature of a rubidium atom is compared to the phase of a laser beam, detecting very small changes in how the atoms fall freely in a vacuum. These changes can be used to determine the local gravitational acceleration, betraying the location of voids, pipes, tunnels or oil and gas reserves beneath your feet. Recent scientific achievements have proven atom interferometry is an invaluable tool for subsurface detection of features like buried tunnels or pipelines(doi.org/10.1038/s41586-021-04315-3). The technology to make the step to quantum sensors already exists, and has been proven in the field, however it needs commercial engineering techniques to bring it into everyday use by those without highly specialised training. Delta g Limited, a new quantum start-up in a unique position to take advantage of this second-generation quantum technology, will deliver the world's first commercial single button gravity gradiometer into the hands of end-users. Delta g brings world class expertise in quantum gravity gradiometry for field measurements, with direct links to the QT Hub for Sensors and Timing through the University of Birmingham to provide scientific support. Leaders from multiple industries will be involved as advisors or subcontractors to deliver key project capabilities. STL, an engineering consultancy with experience in bringing deep tech quantum to the commercial sphere, will deliver bespoke software, control and RF capabilities. NKT Photonics, a world leading laser system and component manufacturer, will provide a customised COTS laser engine for the GCC system. At an initial project workshop Delta g will present the results of previous trials, these will then be used as a benchmark and a panel of advisors, from across multiple industrial verticals, will use this to define a set of requirements and success criteria for the project.

Detecting the world around us has long been a cornerstone of scientific research, with many sensing technologies developed for commercial use rather than purely scientific merit.The ability to view the subterranean environment was limited to destructive exploratory techniques, but in recent years commercial remote sensors have become more widespread. However, nondestructive methods can be severely hindered, ground features can be obscured and vibration or electromagnetic interference can prevent measurements altogether. These issues fundamentally limit the existing technologies for construction and infrastructure monitoring due to costly excavation and site closures which may not be possible. Quantum sensing techniques can overcome these barriers with precision measurements of gravity. Through cold-atom interferometry the quantum nature of a rubidium atom is compared to the phase of a laser beam, detecting very small changes in how the atoms fall freely in a vacuum. These changes can be used to determine the local gravitational acceleration, betraying the location of voids, pipes, tunnels or oil and gas reserves beneath your feet. Recent scientific achievements have proven atom interferometry is an invaluable tool for subsurface detection of features like buried tunnels or pipelines (doi.org/10.1038/s41586-021-04315-3). The technology to make the step to quantum sensors already exists, and has been proven in the field, however it needs commercial engineering techniques to bring it into everyday use by those without highly specialised training. Delta g Limited, a new quantum start-up in a unique position to take advantage of this second-generation quantum technology, will deliver the world's first commercial single button gravity gradiometer into the hands of end-users. Delta g brings world class expertise in quantum gravity gradiometry for field measurements, with direct links to the University of Birmingham and the QT Hub for Sensors and Timing to provide scientific support. Leaders from multiple industries will be involved as advisors or subcontractors to deliver key project capabilities. STL, an engineering consultancy with experience in bringing deep tech quantum to the commercial sphere, will deliver bespoke software, control and RF capabilities. NKT Photonics, a world leading laser system and component manufacturer, will provide a customised COTS laser engine for the GCC system. At an initial project workshop Delta g will present the results of previous trials, these will then be used as a benchmark and a panel of advisors, from across multiple industrial verticals, will use this to define a set of requirements and success criteria for the project.

Detecting the world around us has long been a cornerstone of scientific research, with many sensing technologies developed for commercial use rather than purely scientific merit.The ability to view the subterranean environment was limited to destructive exploratory techniques, but in recent years commercial remote sensors have become more widespread. However, nondestructive methods can be severely hindered, ground features can be obscured and vibration or electromagnetic interference can prevent measurements altogether. These issues fundamentally limit the existing technologies for construction and infrastructure monitoring due to costly excavation and site closures which may not be possible. Quantum sensing techniques can overcome these barriers with precision measurements of gravity. Through cold-atom interferometry the quantum nature of a rubidium atom is compared to the phase of a laser beam, detecting very small changes in how the atoms fall freely in a vacuum. These changes can be used to determine the local gravitational acceleration, betraying the location of voids, pipes, tunnels or oil and gas reserves beneath your feet. Recent scientific achievements have proven atom interferometry is an invaluable tool for subsurface detection of features like buried tunnels or pipelines (doi.org/10.1038/s41586-021-04315-3). The technology to make the step to quantum sensors already exists, and has been proven in the field, however it needs commercial engineering techniques to bring it into everyday use by those without highly specialised training. Delta g Limited, a new quantum start-up in a unique position to take advantage of this second-generation quantum technology, will deliver the world's first commercial single button gravity gradiometer into the hands of end-users. Delta g brings world class expertise in quantum gravity gradiometry for field measurements, with direct links to the University of Birmingham and the QT Hub for Sensors and Timing to provide scientific support. Leaders from multiple industries will be involved as advisors or subcontractors to deliver key project capabilities. STL, an engineering consultancy with experience in bringing deep tech quantum to the commercial sphere, will deliver bespoke software, control and RF capabilities. NKT Photonics, a world leading laser system and component manufacturer, will provide a customised COTS laser engine for the GCC system. At an initial project workshop Delta g will present the results of previous trials, these will then be used as a benchmark and a panel of advisors, from across multiple industrial verticals, will use this to define a set of requirements and success criteria for the project.

Detecting the world around us has long been a cornerstone of scientific research, with many sensing technologies developed for commercial use rather than purely scientific merit. For a long time, the ability to view the subterranean environment was limited to destructive exploratory techniques, but in recent years commercial remote sensors have become more widespread. However, all these non-destructive methods can be severely hindered, ground features can be obscured and vibration or electromagnetic interference can completely prevent the generation of any useful data. These issues fundamentally limit the existing technologies for construction and infrastructure monitoring due to costly excavation and site closures, which in some cases may not be possible at all. Quantum sensing techniques offer the opportunity to overcome these barriers with precision measurements of gravity. Through cold-atom interferometry the quantum nature of a rubidium atom is compared to the phase of a laser beam in a way which can detect very small changes in how the atoms fall freely in a vacuum. Changes in this free-fall can be used to determine the local gravitational acceleration and the measurement can be used to tell whether there are voids, pipes, tunnels or oil and gas reserves beneath your feet. Significant strides have been made in the world of quantum sensing; recent scientific achievements have proven atom interferometry is an invaluable tool for subsurface detection of features like buried tunnels or pipelines (doi.org/10.1038/s41586-021-04315-3). The technology to make the step to quantum sensors already exists, and has been proven in the field, however it needs commercial engineering techniques to bring it into everyday use by those without highly specialised training. This project is led by Delta-g Limited; a new quantum start-up in a unique position to take advantage of this second-generation quantum technology, with a team experienced in construction and use of quantum gravity gradiometers for field measurements and direct links to the University of Birmingham, also partnered in the project to provide scientific support from their experienced Quantum Hub. They will partner with STL, who have a successful history of guiding quantum start-ups to commercial success and taking functional prototypes from the laboratory to field instruments and will provide the expertise to take the sensor closer to market readiness. End-user expertise within the project will be achieved through an advisory board formed by representatives from companies with a direct interest in the success of a commercially available quantum gravity gradiometer.