Marine Vessel NDT Inspections

Marine vessel inspection covers a wide range of NDT methods depending on the structure being assessed. Hull thickness measurement using ultrasonic testing identifies corrosion and wall loss without requiring dry docking. Weld inspection on hull plating, deck structures and pipework uses ultrasonic, eddy current and radiographic methods. Pulsed eddy current techniques can measure wall thickness through coatings and insulation, which is particularly useful for assessing areas of a vessel that are difficult to access. For composite superstructures and hull sections on modern vessels, matrix array ultrasonic testing provides imaging-grade data that conventional single-element UT cannot match.

In many cases yes, and the industry increasingly favours this approach for routine inspections to reduce downtime and cost. Underwater inspection in lieu of dry docking (UWILD) uses robotic crawlers, remotely operated vehicles and specialist diving teams to inspect hull welds, propeller shafts and keel areas while the vessel remains in service. Portable ultrasonic systems can assess internal structures, pipework and deck plating without the vessel being removed from water. Whether dry docking can be avoided depends on the scope of the inspection and the classification society requirements applicable to the vessel.

Ship inspection is overseen by classification societies such as Lloyd’s Register, Bureau Veritas and DNV, which set the standards and inspection intervals that vessels must comply with to maintain their class certification and insurance. Classification surveys define when and how structural components must be inspected, and NDT forms a core part of these requirements, particularly for welds, pressure-containing systems and structural integrity assessments. Vessels operating in regulated trades also need to comply with flag state requirements and international conventions such as SOLAS.