3D Inspection of Mooring Chains


The collection of data to support FPSO mooring-chain fitness-for-purpose surveys is complicated by the dynamic motion of both the ROV platform and the chain target itself; the "moving platform-moving target" scenario.

The distance between the ROV and chain can vary significantly even in long-period and short heave conditions; making it difficult to safely deploy calliper-type tooling and reduces the efficiency of the data collection process.

Savante's subsea laser scanners combine SLAM (self-localisation and mapping) technologies with our enhanced 3D measurement system to enhance the speed and accuracy of mooring chain integrity assessments.  All that is required is for the ROV pilot to paint the mooring chain with the laser swath; the onboard electronics compensates for relative offsets and indexes each cross-section profile to a common datum.  It is no longer necessary to directly physically connect with the mooring chain to determine measurements. 

 

Significantly, the 3D output of the scanner enables improved accuracy in the monitoring of progressive wear compared to caliper measurements where inevitable mechanical deformation of the caliper blades generates inaccuracy and an inability to reference a constant datum results in poor repeatability.


 

Key Features:

  • 0.05mm 3D accuracy at six-sigma confidence level.

  • 3D texture mapped model combines structure with photographic-quality shading to provide highest performance rendering.

  • Chain length elongation measurements, butt welding failure detection

  • "Agile" laser scanning technology gathers structural data within the confines of the crown and capture points of each link.

  • Real time data collection.

  • GigE interface on ROV required for data handling.

 
 

Optional Extras:

Photogrammetry option (lower resolution) available in countries where laser importation laws precludes use.