A free spanning pipeline has the potential to vibrate and subsequently fail. Pipeline owners and operators therefore have an interest in seabed changes that might affect the integrity of their asset.

A National Grid gas pipeline had become exposed. To improve the understanding of the ongoing sediment changes which had resulted in the pipeline exposure, ABPmer was commissioned to develop a conceptual understanding of the physical processes in the area concerned.

We reviewed the historical bathymetric data for the area, literature and related studies to develop an understanding of how the channel behaved.

Further investigations were also undertaken to establish the likely extent of erosion that would be required before vortex induced vibration could potentially become an issue in terms of the structural integrity of the pipeline.

The results of the work enabled National Grid to plan what maintenance work may be needed to ensure pipeline integrity.