Enhanced Rim Inspection with Eddy Current Array

Australian Standards require that all rims over 24 inches be tested and certified before use in the mining industry.   

Historically, this has been carried out with Magnetic Particle Inspection – but there are downsides to this method.  

MPI can be time-consuming, costly, and relies on visual inspection rather than hard data.   

Which is why Nexxis set out to test an alternative method.  

Introducing Eddy Current Array (ECA) technology.  

 

The Challenge 

MPI is one of the more common methods for testing rims.  

But it’s a lengthy process, requiring rims to be transported off-site for sandblasting and inspection (generally after 20, 000 hours of use). This results in increased downtime, logistical challenges, and higher operational costs. All that for a rim that may be in perfect working condition.   

Conventional approaches like this often lack defect sizing capability, limiting the ability to make informed maintenance decisions. 

 

The Solution 

To address these challenges, Nexxis introduced Eddy Current Array (ECA) technology, a proven method for detecting surface-breaking cracks through paint without the need for sandblasting. The solution included: 

• On-Site Inspection: The ECA system enables in-field assessments, significantly reducing downtime and eliminating the need for off-site transportation. 

• Defect Sizing Capability: Unlike MPI, which only detects the presence of cracks, ECA provides valuable data on defect size, allowing for proactive maintenance decisions. 

• Digital Record Keeping: Inspection results are digitally recorded, ensuring accurate data tracking for reliability-centred maintenance planning. 

• Reduced Carbon Footprint: Eliminating the need for sandblasting and off-site transport contributes to Fortescue’s sustainability initiatives. 

 

Implementation and Results 

Nexxis deployed the ECA system with a custom-designed probe specifically tailored for inspecting rims. The probe was engineered to detect cracks through paint, ensuring minimal disruption to existing workflows. The key outcomes included: 

• Early Crack Detection: ECA successfully identified crack progression in the EU Gutter section of rims, commonly found on many fleets.  

• Cost Savings: By implementing an in-house go/no-go inspection system and training teams in its use, mining companies can save millions in repair and replacement costs. 

• Proven Effectiveness: Sample defect images of EU 51”, 57”, and 63” rims confirmed the system’s accuracy, with detected defects later verified through sandblasting. 

 

 

 

 

Long-Term Impact 

The Nexxis engineering team has successfully implemented this program across multiple sites, ensuring long-term benefits such as: 

• Increased asset reliability through proactive maintenance strategies. 

• Reduced operational costs associated with rim inspections. 
• Enhanced sustainability by reducing waste and unnecessary logistics. 

Contact us to find out more about how to enhance your inspection processes with Eddy Current Array Technology or any of our other NDT products, or request a quote online.

You can read more about Eddy Current Array in Case Study: The Use Of Eddy Current Array in Reformer Tubes and 10 Things You Need to Know When Choosing an Eddy Current Array Surface Probe.