Pipeline Technology Conference 2026, Strain Relief Monitoring

Monitoring Land Subsidence on a German Natural Gas Pipeline: A Magnetic Inspection Case Study

In 2025, Skipper NDT was commissioned to monitor a 384-metre / 0.23 miles section of a 32-inch natural gas transmission pipeline in Germany, previously affected by land subsidence in a mining area. Using its proprietary Large Standoff Magnetometry (LSM) technology deployed on the ATLAS ground-based platform, Skipper NDT reconstructed the pipeline's 3D centerline and computed bending strain profiles through magnetic data inversion.

The results were validated against historical in-line inspection (ILI) data from 2019 and 2024, enabling a six-year temporal comparison. The analysis confirmed that mitigation works carried out between 2020 and 2024 had successfully relieved bending strain, and that no strain re-accumulation had occurred one year later, validating the long-term durability of the remediation.

This case study, published at the PTC Berlin 2026 conference, demonstrates the capability of Skipper NDT's magnetic inspection technology to deliver precise, non-intrusive strain assessment and to support cost-effective, continuous geohazard monitoring strategies as a complementary approach to conventional ILI.