Advanced inspection technologies for jetty piles inspection

Advanced inspection technologies for jetty piles inspection

#Jetty piles inspection #UAV/Drone #Pulsed eddy current #Remote operated vehicle #Topside inspection #Underwater inspection

AUTHOR: Savet Playchum / Puripong Klamdith

Background:

   Jetty piles are crucial components of a jetty's infrastructure. Their primary function is to support the weight of structures above water, withstand forces from mooring vessels, and endure the ever-changing marine environment.

 

   These piles are constantly exposed to the harsh marine environment, making their integrity vital for the safety and operation of the jetty. Corroded piles can lead to structural collapse, endangering people and causing damage to moored vessels, especially those involved in hazardous material handling, potentially leading to catastrophic consequences for life, property, and the environment. If plant machinery, pressure equipment, or pipes system are damaged due to structural failure, it can take a considerable amount of time to repair or maintain them for normal operation.

 

   Since steel piles are often obscured from view when looking down from the jetty, their deterioration and damage may occur beyond the inspector's line of sight. If not thoroughly inspected, steel piles remain vulnerable to degradation from the marine environment and damage from vessel berthing. Additionally, steel piles are designed in various forms, both vertical and angled to the seabed, creating potential limitations or blind spots for access.

Technical detail:

                                                                                                                                             

Steel Pile Inspection According to International Standards

   Steel pile inspection can employ various non-destructive testing (NDT) methods, with the results analyzed collectively to assess the current condition of each pile. SIGTTO / OCIMF  Jetty Maintenance and Inspection Guide (2008) mandates inspections of areas above the waterline every 3 years and underwater areas every 5 years.

 

The following preliminary inspections are specified:

• Overall visual inspection of the entire jetty.
• Close-up visual inspection of 10-20% of all steel piles.
• Thickness measurement inspection of 5-10% of all steel piles.

Conventional Inspection Technique:

   Traditionally, jetty pile inspections involved complex processes. Typically, experts were required to access the piles to assess their condition or initial damage through the protective wrapping. If damage was found, marine growth would be removed, the wrapping would be taken off, and the remaining pile thickness would be measured and repaired. This work environment was challenging due to its marine setting. Additionally, underwater piles required divers to assess their condition and the integrity of the cathodic protection system. This complex process not only resulted in high operational costs but also posed safety risks to the personnel involved. The process also required careful attention to ensure that repairs met standards and achieved their full design lifespan.

Advanced Inspection technologies:

   Recent advancements in inspection technologies have significantly improved the efficiency and effectiveness of jetty pile assessments. This article presents three key technologies that are transforming jetty piles inspection

 

Drone Inspection (Unmanned Aerial Vehicle/Drone): For areas above water, drones equipped with high-resolution cameras capture detailed images of the entire structure, highlighting corrosion and other damage. This method reduces the need for scaffolding, direct access by personnel, and boat trips to reach the piles.

Pulsed Eddy Current Inspection: This non-destructive testing technology can measure pile thickness through protective wrapping and marine growth without the need for removal and PEC can be done without need for contact with the surface of the material. Because of this, it can be useful in situations where an object’s surface is rough or inaccessible. The results enable operators to determine the remaining pile thickness and use this data for engineering calculations to assess the pile's remaining lifespan.

Examples of inspection results using the pulsed eddy current technique, which show the severity of corrosion
compared to the damage of the jetty pile when removing the protective wrapping.

Remotely Operated Vehicle (ROV) Inspection: For underwater inspections, ROVs equipped with high-resolution cameras record images of the pile structure at depths inaccessible to divers. They can also provide information on the condition of sacrificial anodes in the cathodic protection system, indicating whether they are functioning correctly or have corroded to the point of being unable to protect the piles. This method enhances safety and reduces costs associated with diver inspections.

Transitioning from Conventional Techniques to Advanced Techniques:

 

Enhanced Safety: By utilizing drones and ROVs, inspections can be conducted remotely, reducing the need for personnel to work in hazardous environments, both above and below water. This significantly minimizes the risk of accidents and injuries.

 

Increased Efficiency: Advanced technologies like drones, pulsed eddy current testing, and ROVs allow for faster and more comprehensive inspections compared to traditional methods. This results in reduced downtime and operational disruptions, leading to improved productivity.

 

Reduced Costs:  These technologies significantly reduce inspection costs by minimizing the need for scaffolding and diver deployment. They also eliminate the need for costly and time-consuming removal of marine growth and protective wrapping prior to inspection. This, combined with the ability to optimize maintenance activities based on accurate data, leads to significant maintenance cost savings in the long run.