What happens to shipping containers that fall overboard?
Around 90% of the goods you use daily, from the clothes you wear to the food you eat, were transported across the seas in large metal containers. These containers can range from 10 to 40 feet long in size and are stacked on enormous cargo ships that brave rough and unpredictable seas to get it to its destination. Though it may be a rare occurrence, what happens when one of these containers falls off the ship?
Hundreds of containers are lost at sea every year. In 2021, two significant incidents occurred in which a large number of containers were lost at sea. The first incident involved the ONE Apus, which lost 1,800 containers overboard, and the second incident involved the Maersk Essen, which lost approximately 750 containers. Both incidents were attributed to severe weather. The World Shipping Council (WSC) has noted a considerable surge in the number of lost containers during the pandemic, with an average of 3,113 containers lost compared to 779 in the previous period (2017-2019).
But how do containers fall overboard?
The obvious reason is the bad weather, however, the International Maritime Organization’s (IMO) Maritime Safety Committee (MSC 103) believes that there could be several causes for containers to fall off a vessel. Other possible factors they agreed on include propulsion issues, ship design, and how containers are lashed together. The degradation of containers resulting in metal fatigue could also be a possibility, as well as accidents.
In bad weather conditions, container arrangement unsuitable for rough seas could also lead to containers falling overboard. The higher the stack of containers, the larger the forces they are subjected to in rough seas, increasing the likelihood of containers being lost. The effects of climate change are expected to contribute to rougher seas in the days to come, adding to the challenge of transporting cargo safely.
Parametric rolling
Ships carrying larger and heavier loads in containers may also be prone to what is called parametric rolling, a phenomenon that can occur when waves hit the front of a ship at an angle, rather than head-on. This causes the ship to enter a rolling motion synchronised with the waves, which, combined with the ship’s normal pitching as it moves forward, can lead to containers breaking free from their lashings and falling overboard.
So what really happens to the lost containers?
Some containers sink into the ocean. Some float, especially containers laden with lighter materials such as plastic. Refrigerated containers with installed buoyant may float for days or even for weeks.
Although sunken containers pose a significant threat to marine ecosystems, floating containers could be even more perilous. These containers are a potential danger to vessels as the containers can remain partially or almost entirely submerged in the water, making them difficult to spot. Smaller vessels colliding with such containers could cause terrible accidents. Some may even wash up on beaches, requiring extensive clean up efforts.
The environmental impact of lost containers reaches far beyond the physical destruction of ecosystems. Depending on the contents of the containers, they can also pose a significant pollution threat. For example, containers that contain hazardous items or items that break down into hazardous chemicals over time can contaminate the ocean, posing direct danger to marine life and public health.
Who takes responsibility?
As with most regulations in the global maritime industry, the IMO leads the charge. To mitigate the risk of ecological disaster resulting from containers falling overboard, member states are required to report any lost containers containing hazardous materials to the relevant authorities.
IMO has also established a framework of liability and compensation conventions aiming to ensure prompt and cost-effective resolution of valid claims arising from lost containers. These claims may be in relation to pollution and other damage, costs associated with recovering containers, and damage to the container and their contents. However, proper regulations are needed to ensure liabilities are in place and parties are held accountable for losses resulting from reasons such as negligence or subpar standards.
