UnderWater Inspections in Lieu of Drydocking (UWILDs) are often required to ensure the structural and operational integrity of a marine asset. In current economic climates where saving cost is a key driver and safety and structural integrity are of critical importance, UWILD inspection programmes are becoming far more commonplace.

UWILD Inspection

Conducting these surveys in-situ with divers or with remotely operated vehicle (ROV)-deployed techniques saves the asset owners and their clients time and money by reducing downtime, reducing off-contract times and reducing or eliminating the need for expensive and limited drydock space.

Classification societies that issue guidelines on UWILD inspection, maintenance and certification for structures and vessels include the American Bureau of Shipping (ABS), Det Norske Veritas (DNV-GL), Bureau Veritas (BV) and Lloyds Register (LR).


In response to this and other environmental factors, TSC’s Engineering solutions team have developed the ACFM® MagCrawler™. This unit has been designed specifically to enable the ROV deployment of ACFM® Array Probe Technology underwater, and can inspect a wide variety of subsea geometries, including circumferential, fillet and full penetration welds in pipes and plates. Ideal for restricted-access areas, the MagCrawler is rated up to 150m (493ft) and is a robust, magnetic-tracked ROV equipped with cameras. Traction is achieved by two rubber caterpillar tracks that are easily maneuverable on horizontal and vertical planes, as well as inverted surfaces. Probes are mounted onto the crawler with a metal sprung arm for passive compliance with the surface and a 360° rotational head allows full weld coverage. An electronic rotary encoder also is on board to determine the position of the crawler and simultaneously collect distance measurements whilst scanning.

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Subsea Structures

Splash Zone

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