Subsea NDT for Maritime and Shipping

In-service Inspection of Hulls and Bilge Keels Welds

Through close collaboration with operators worldwide, TSC Subsea has harnessed its expertise to deliver underwater robotic solutions. Our primary objective is to assist our clients in ensuring the safety and integrity of their vessels and FPSO platforms. We are dedicated to providing comprehensive in-service or underwater inspections instead of drydock (UWILD), enabling our clients to conduct accurate asset integrity assessments while keeping their floating vessels in production.

Hull Surveys and Inspection

Wall Thickness Measurements and Corrosion Mapping

  • Non-contact method requires less surface preparation.
  • Exceptionally resilient to soft marine growth.
  • Quantitative wall thickness measurement with highly accurate depth sizing of +/- 0.2 mm.
  • Unmatched coating penetration, even when dealing with thick attenuative materials.
  • Corrosion mapping of external and internal surfaces.
  • Detect coating disbondment & degradation.
  • Geometry measurements for assessing dents and other anomalies.
Ship Hull Corrosion Survey

The HullScanner is deployed remotely using either work or inspection class ROVs. The ROV places the HullScanner onto the vessel, which is then securely held in place by strong magnets. Thanks to the integration of multiple sensors, the scanning time is significantly reduced, with a 1 m2 inspection taking only 30 minutes.

The HullScanner maintains direct communication with the top side, enabling data to be processed and accessed in real-time during the scanning operation, providing instant assessment capabilities.

By acquiring accurate data through direct wall thickness measurements while the floating vessel remains in-service. This capability facilitates the calculation of corrosion rates, allowing for more dependable asset integrity assessments without any disruption to production or service.

TSC Subsea’s proprietary Acoustic Resonance Technology (ART) has gained significant recognition within the subsea inspection field. Its exceptional capabilities for coating penetration and high accuracy in conducting through-wall inspections of ferrous materials make ART an excellent choice for conducting hull intregrity assessments.

At the heart of TSC Subsea’s ART lies its patented ultra-wideband acoustic inspection technology, surpassing existing inspection technologies in terms of penetration and measurement capabilities through coatings.

ART distinguishes itself from other NDT technologies due to its non-contact nature and remarkable tolerance to marine growth. When coupled with its coating penetration capability, it enables corrosion mapping of internal surfaces, even in regions with stiffening plates.

FPSO Ship Inspection Data

ART data detailing internal corrosion collected from the external surface

Weld Inspection

Bilge Keels and Hull Welds

  • Field proven Alternating Current Field Measurement (ACFM®) .
  • DNV and ABS approved.
  • Crack detection and sizing through coatings.
  • Accurate and auditable inspection data.
  • Deployed by ROV or via deck launch.
  • High Probability of Detection (PoD).
  • Array probe for greater coverage and efficiency.
NDT Hull Inspection
Bilge Keels weld inspection

The robotic MagCrawler™ is designed to perform diverless ACFM inspections of critical subsea welds, offering precise location and sizing data on surface-breaking cracks.

Equipped with array probes, the MagCrawler surpasses standard probes in speed and efficiency during weld inspections. Its rotating head enables seamless coverage of the entire weld and heat-affected zone (HAZ).

To navigate the subsea environment, the crawler employs two magnetic caterpillar tracks that adhere firmly to the hull. Onboard cameras play a crucial role by providing real-time visual feedback, ensuring comprehensive coverage and compliance with ACFM scan criteria.

Regular inspections of the structural hull and bilge welds are crucial to identify cracks and defects resulting from dynamic loading.

TSC Subsea’s ACFM electromagnetic inspection technology has been the method of choice for detecting and sizing subsea surface-breaking cracks in critical welds for over a decade.

Recognised and approved by many certification bodies, including DNV, ABS and Lloyds, the technique has been used successfully to supersede traditional non-computerised and more user-dependent methods, such as magnetic particle inspection (MPI) for subsea weld inspection.

ACFM Weld Data

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Subsea Structures

Splash Zone

Vessels and FPSOs

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