Why do ships still lose containers?

January 10, 2022 IMO

In the winter of 2020-2021, five vessels lost nearly 3,000 containers into the stormy Pacific. In just two months, those post-Panamax vessels accounted for more than twice number of lost containers in the previous year. Across widespread media coverage, a kneejerk reaction was to blame supersized vessels or increasingly unpredictable weather. But environmental conditions and vessel design are only part of the picture. Understanding this complex issue, and why losses are incredibly challenging to wholly avoid, holds the key to reducing losses not just from container vessels but across all cargo shipping sectors.
First, some context. According to the Word Shipping Council, international liners transported around 226 million containers in 2019, the last year for which figures are available. From 2008-2019, total container losses averaged 1,382 a year, representing around a thousandth of a percent of containers moved. And until the recent spate, the number of incidents has stayed relatively stable year-on-year, undermining the view that bigger ships and worsening weather are key factors.
Why spend time and resources analyzing such an infrequent occurrence? Because, according to Holger Jefferies, Head of DNV’s Container Ship Excellence Centre, even these few incidences can have a big impact. While the value of goods lost each year is difficult to calculate, there are much more damaging and wide-ranging consequences than the direct financial considerations on ship operators and cargo owners. Rogue containers can put lives, vessels, shoreside infrastructure and the environment at risk.
“Every incident has the potential to cause a lot of damage. Then there is a huge cost in finding the containers, cleaning them up, cleaning the beaches where they land and the extra measures that need to be taken when a dangerous cargo is lost.” says Holger Jefferies, Head of DNV’s Container Ship Excellence Centre.
Those consequences and clean-up costs typically spread much further than the ship owner, contributing to another reason for addressing the issue: reputational damage. In a consolidated market with just a handful of recognizable companies, maintaining a high safety record is a competitive advantage for container liners. And that perception can be easily negated by images of a broken container washed up on a once pristine beach.
As class rules and IMO regulations seeking to minimize container loss show, there is a motivation to tackle the problem on an industry level.
Design dilemma 
Incorrect stowage is one basic factor contributing to container loss. The lashing systems used to hold stacks of containers in place are complex. On a large vessel they can comprise ten thousand of locks, rods and other components that all need to be used in an exact way. If they are not, container stacks can collapse and boxes can be lost overboard.
Lashing systems are designed to consider the weather that container vessels might encounter.  The key factors are probability and risk. No ship or lashing system can be designed such that it will not lose containers in any weather scenario. Arne Schulz-Heimbeck, Programme Manager for Containership Development at DNV, draws a parallel with grounding.
“Ships are not usually designed to withstand grounding without damages. Of course, they could be, but it would lead to extremely heavy and expensive ships. The cost of transport would be so high that society worldwide would not accept them.”
Source: xindemarinenews