Norske Shell needed to have a system to inspect butt and fillet welds on metalwork inside the concrete body of the Draugen offshore platform.

Safety restrictions meant that the inspection had to be carried out by underwater remotely operated vehicle (ROV).

The poor dexterity of subsea manipulators meant that it was not possible to deploy standard probes along the welds. TSC therefore developed special array probes containing compliant sensors that conformed to the surface while subsea motors drove the sensors along. The probes used suction to attach them to the structure during the scanning so that the ROV manipulator only had to place the probe on the surface before inspection and pick it up again afterwards.

TSC worked with Oceaneering A/S, experts in ROV's and subsea engineering, to develop the system and integrate it into a work-class ROV. The completed system underwent successful tank trials before being handed over to the client.