Illuminating the Future: The Cost-Saving and Safety Advantages of Upgrading to LED Tower Lighting Systems

Executive Summary

Aging transmission infrastructure is vulnerable to progressive corrosion, which can compromise structural integrity and threaten grid reliability. While the need for corrosion mitigation is well recognized, the success of any intervention depends on a clear and accurate understanding of current asset condition. This white paper highlights the essential role of comprehensive corrosion inspections in supporting informed asset management decisions. Advanced inspection methods generate the detailed data needed to evaluate degradation, assess risk, and select the most appropriate mitigation approach—whether through localized repair, protective coating application, or full replacement. By incorporating thorough inspections into the overall lifecycle strategy, utilities can strengthen operational safety, improve investment efficiency, and support the long-term resilience of their power delivery systems.

1. Introduction: The Hidden Threat Beneath the Surface
Steel lattice towers form the backbone of high-voltage transmission systems. Designed for long service lives, these towers face continual exposure to aggressive environmental factors such as pollution, salt-laden air, freeze-thaw cycles, and UV degradation. Even with protective galvanization, prolonged exposure eventually compromises coatings and exposes the underlying steel.

Corrosion is often difficult to detect visually, especially in concealed or inaccessible areas. Utilities that rely on superficial or irregular inspection risk missing critical deterioration until it's too late. Instead, a proactive, data-driven inspection approach is required to safeguard grid reliability and manage assets effectively.

2. The Imperative of Inspections: Beyond Visual Assessment
Visual inspections alone are insufficient for identifying the scope and severity of corrosion. Effective corrosion assessment must consider:

• Localized vs. Widespread Degradation: Corrosion tends to be highly site-specific, affecting crevices, base plates, joints, and water trap areas.
  
  
• Progressive Nature: Corrosion rates can vary drastically over time and with changing conditions, requiring periodic inspection.
  
  
• Impact on Structural Integrity: Superficial rust may hide more serious wall loss or pitting, which reduces load-bearing capacity.
  
  
• Need for Specification-Grade Data: Detailed findings support precise surface prep requirements, repair scoping, and coating design.
  
  

• Galvanization loss and zinc depletion.
  
  
• Rust classification (light surface, pitting, delamination).
  
  
• Structural deformations or misalignments.
  
  
• Connection integrity (bolts, welds, splice plates).
  
  
• Coating failure (blistering, chalking, disbonding).
  
  

• High-resolution visual and drone imaging.
  
  
• Surface profile measurement.
  
  
• Ultrasonic thickness gauging (UT).
  
  
• Environmental condition logging.
  
  
• Geographic corrosion mapping.
  
  

• Coating: When steel integrity is sound, coatings can restore long-term performance.
  
  
• Repair: Localized section loss or member deterioration may warrant reinforcement.
  
  
• Replacement: In cases of severe degradation, complete tower replacement is justified.
  
  

• Surface prep level (e.g., SSPC standards).
  
  
• Coating chemistry selection based on environment.
  
  
• Application strategy (localized vs. full system).
  
  

• Precise scoping based on UT and visual results.
  
  
• Material compatibility and specification.
  
  
• Work prioritization using risk and criticality scores.
  
  

• Multidisciplinary field inspectors with specialized corrosion training.
  
  
• Use of drones and digital inspection tools for safety and access.
  
  
• Repeatable inspection protocols and reporting formats.
  
  
• Integration of findings with utility asset management systems.
  
  

• Prevent unplanned outages.
  
  
• Prioritize maintenance effectively.
  
  
• Extend asset life and defer costly rebuilds.
  
  
• Support safe operations and compliance.