The urban underground is a spider web of utility infrastructures competing for space, and the risk of accidental damage to existing infrastructures increases every day. Accurate digital As-built information is therefore becoming a vital element in asset management. My presentation focuses on the use of autonomous gyroscope based sensors to establish XYZ coordinates of existing pipelines. Recent developments by Reduct NV (Belgium) have resulted in an unique, easy-to-use, accurate pipeline mapping system that fills this growing need.

The DuctRunnerTM mapping unit is a self-use, lightweight all-in-one system able to map multi-diameter [ID 40mm (2,5 “) to 800mm+ (32”)] and multi-pipeline material underground utility infrastructures. The system produces accurately centerline coordinates of existing onshore or offshore pipelines.
The core system elements consist of an Orientation Measurement Unit (OMU) based on inertial sensor technology theories, two spacer wheel sets, and X-TractionTM data processing software that transforms the data logged by the OMU into an accurate three dimensional graphic image compatible with all known GIS platforms.

The OMU logs at 800Hz and samples are produced every few centimeters. The system has a tolerance of <0.25% of distance. The unique wheel system designs allow the DuctRunnerTM to pass welds, T-junctions, and other deformities in a pipeline without problems.
The DuctRunnerTM logs data autonomously, i.e. no walkover tracing or data wire is required. While many conventional steering, inspection and mapping tools stray near electromagnetic fields, the DuctRunnerTM technology is not affected by such external disturbances.