Lightning strikes and buried gas pipelines: Mechanisms, risk assessment, mitigation, and case insights from the hellenic gas transmission system

• Provides case studies demonstrating how lightning strikes can cause severe damage, including deep metal loss and metal wall fusion. • Uses the first documented incident to identify contributing factors and emphasize the need for improved risk assessment. • Describes a dedicated risk assessment tool to guide inspections and mitigation strategies. • Validates the tool’s predictive accuracy with a subsequent real-world incident showing damage matching the model’s forecasts. • Highlights the importance of input parameters and analytical models for assessing lightning-induced pipeline risk. Lightning strikes pose significant challenges to buried pipelines, especially with modern coating layers, as recent incidents illustrate. While factors like buried depth and distance from lightning sources influence the impact on pipelines, precise predictions are complex due to interacting variables. Understanding the mechanisms behind lightning-induced failures remains limited. Increased driving voltage and available current during lightning strikes elevate the risk of pipeline damage, challenging assumptions about coating defense. Recent incidents on the Hellenic Gas Transmission System, involving severe pipeline damage from lightning strikes, highlight the urgent need for improved risk assessment and mitigation. This work explores the mechanisms of lightning-induced damage, the role of corrosion and coating defects, and effective protection strategies. Emphasis is placed on comprehensive cathodic protection upgrades, continuous monitoring, and key mitigation technologies such as earthing and spark gap devices.