Advanced Subsea Structural Assessment: Jetties and River Walls

The appraisal of submerged infrastructure assets such as jetties, quay walls, and revetments in dynamic, high-flow environments necessitates a highly professional, engineering-led approach. Our specialist service combines expert commercial diving engineers with cutting-edge acoustic and remote inspection technologies to provide robust condition assessments where conventional methods are compromised by safety constraints, high current velocities, or zero visibility.

Operational Challenges in Hydrodynamically Active Zones

Assessing assets within fast-flowing rivers or tidal zones presents specific technical difficulties:

• Personnel Safety: Significant current velocities increase operational risks for divers, strictly limiting access to brief "slack water" intervals and demanding stringent safety protocols.

• Acoustic Turbidity: High flow rates often coincide with high sediment loads (turbidity), rendering standard optical or CCTV survey methods ineffective.

• Data Integrity: Maintaining survey equipment stability is critical for acquiring accurate, geo-referenced data; strong hydrodynamic forces inherently challenge this stability.

Integrated Survey Methodologies

To deliver comprehensive data for asset management, we employ an integrated, multi-disciplinary approach:

High-Resolution Acoustic Imaging (2D & 3D Sonar)

Acoustic surveying is the definitive method for detailed mapping in low-visibility, high-flow conditions.

• Principle of Operation: Sonar systems emit focused acoustic pulses and interpret the resultant echoes to generate highly detailed imagery and quantifiable 3D point cloud models of the subsea environment.

• Data Application: Engineers utilise this data to identify structural anomalies, quantify scour voids around foundations, and perform detailed structural integrity assessments.

• Deployment Versatility: Transducers are deployed via stable platforms:

  • Vessel-Mounted: Integrated into manned vessels or Unmanned Surface Vessels (USVs) for efficient linear survey transects parallel to the structure alignment.

  • Fixed Mounts: Rigidly deployed via frames or tripods lowered from the asset deck or seabed, providing stable data acquisition regardless of surface water movement.

Remote and Physical Assessment Techniques

These methods supplement acoustic data, providing verification and tactile information:

• Tactile Probing: Manual assessment using calibrated rods to determine the physical extent of foundation exposure or scour hole depth, verifying data gathered through non-contact methods.

• Direct Measurement: The application of engineering calipers and tapes by divers during brief operational windows to accurately quantify structural defects and material loss.

Hydrodynamic Camera/Sensor Systems

For acquiring visual data where strong currents inhibit diver or standard ROV operations, we deploy specialised towed systems:

• Towed Inspection Platforms: These streamlined, weighted "torpedo" or "sled" systems are deployed via a controlled winch system. Their hydrodynamic shape ensures stability and proximity to the vertical asset face, capturing continuous, geo-referenced High-Definition (HD) visual records essential for defect cataloguing.

Safety and Rescue: Specialist Marine Support

Safety is paramount in all marine engineering operations. Our company provides dedicated safety support services that can be integrated into any project:

Our specialist marine division offers fully coded and equipped rescue and safety boats for hire. These vessels are crewed by highly trained marine professionals and fast-rescue craft (FRC) operators. Services include:

• Diver Safety Support: Dedicated standby rescue coverage during all subsea operations in high-risk areas.

• Site-Specific Risk Mitigation: Deployment of vessels capable of rapid intervention in the event of an incident or personnel retrieval in swift currents.

• Environmental Monitoring: A stable platform for deploying monitoring equipment and ensuring compliance with environmental protection protocols during the project lifecycle.

By choosing our integrated services, asset owners ensure comprehensive, compliant, and safe data acquisition for managing critical infrastructure within challenging marine and fluvial environments.