Container Stack Collapses: New Study Examines Weather Impact And Industry Implications


  • A recent in-depth study delves into the influence of adverse weather on container stack collapses, revealing insights into the increasing risk associated with high waves.
  • The study combines claims data from Gard’s P&I portfolio with meteorological data, providing valuable information on weather exposure differences among operators.
  • The findings prompt critical questions about mitigating adverse weather impacts on container safety and advocate for a broader industry dialogue.

The escalating volume of containerized trade in line with global economic growth raises concerns about the corresponding increase in the risk of casualties, particularly incidents such as stack collapses and containers lost at sea. This comprehensive study analyzes the impact of weather, especially wave height, on container stack collapses and aims to foster a more profound dialogue within the industry about strategies to enhance container safety.

Weather and Container Losses

As containerized trade continues to grow globally, incidents like stack collapses pose a heightened risk. To contribute to industry understanding and loss prevention, a study has been conducted, focusing on stack collapses involving Gard as a P&I insurer between 2016-2021. The analysis includes weather data from Windward, incorporating estimated wave height and wind strength on an hourly basis.

Incident Analysis Across Vessel Sizes

Container stack collapses, which can be severe incidents, occur across various vessel size segments. The study analyzes the incident numbers relative to the number of vessels in Gard’s portfolio, providing insights into claims frequency across different size segments. Despite more incidents on smaller vessels, there is a clear correlation between incident likelihood and vessel size, highlighting the risk associated with larger vessels.

Progressively Increasing Wave Height and Duration

Examining a 7-day period leading up to the incidents reveals a progressively increasing wave height. On Day 1, vessels experience an average wave height of 2.5m, escalating to 6.5m (gale force winds) on Day 7. The study underscores the duration of exposure to adverse weather, with vessels spending 72 hours in sea conditions with wave heights of 4m and above. Notably, incidents often occur after the weather starts to subside.

Higher Waves, Higher Risks

A focus on vessels exposed to wave heights of 7m or above reveals that although they spend only 5% of their time in such conditions, half of all incidents occur during these adverse weather periods. The study suggests that the relatively small percentage of time spent in adverse conditions significantly amplifies the risk of incidents, potentially up to 20 times higher.

Vessel Exposure Disparities and Operator Risk Profiles

The study identifies variations in exposure to adverse weather not only among different vessel sizes but also among container operators. The differences in exposure are attributed to variations in operators’ risk tolerance and internally defined weather thresholds for vessels.

Key Questions and Recommendations

Based on the study findings, several key questions arise for the industry, touching on conflicting priorities on weather thresholds, suitable tools for complex rolling phenomena, slackening of lashings in heavy weather, routeing considerations for vessels with deteriorated securing equipment, impact of weather on cargo securing inside containers, and the inclusion of safe weather routeing in key performance indicators (KPIs).

Did you subscribe to our daily Newsletter?

It’s Free! Click here to Subscribe

Source: Gard