Robotic inspection of mooring chains in air and water
Acronym: RIMCAW
Funding body: Innovate UK
Status: Project
Failure of mooring systems for offshore structures, primarily used by the oil and gas industry, represents a critical threat to the assets themselves, human life and the environment. Considerable effort is made to ensure that the integrity of the chains is kept to high standards, and a key part of this is a drive to increase the precision and reliability of inspection methods. TWI has recently been involved in the inspection of a critical chain link on an FPSO, developing a specific inspection tool for implementation by divers. This tool was able to detect critical fatigue cracking which had developed during service. The RIMCAW project takes this further by aiming to (1) size and map accurately fatigue cracks within the body of the chain, (2) replace the diver with robotic systems to meet evolving health and safety regulations and (3) address all links on a mooring chain system both subsea, at the splash zone and in the air.
• Develop a mechanised scanning trajectory and technique for critical areas of a mooring chain;
• Develop the ultrasonic transducers and instruments in a suitably marinised condition;
• Design, develop and demonstrate a robotic system to travel on a mooring chain and inspect critical areas of each link for fatigue cracking.
The RIMCAW project will deliver a robotic system for mooring chains that will operate in an autonomous fashion from the top side of a vessel to subsea. This will aid in systematic inspection schemes for critical mooring systems, with the ability to rapidly deploy the inspection system on demand and, importantly, maintain traceability on the condition of a mooring system for lifetime monitoring for the emergence of critical fatigue cracking.