As any experienced export manager will tell you, the safe loading of containers aboard a vessel is no guarantee of their safe arrival. Violent events like rough seas, ship groundings, and collisions can all cause containers to tumble off crowded decks and sink below the waves. And with an estimated 6,000 containerships active on the world's seas and waterways at any given time, the numbers add up, according to the World Shipping Council (WSC), a trade group for the liner shipping industry.
But exactly how many containers are lost? In 2011, WSC started conducting triennial surveys of ocean carriers, asking how many containers had fallen overboard. The results of the study's latest edition show that over the nine-year period from 2008-2016, an average 568 containers were lost at sea each year during normal operating conditions. When the researchers factored in catastrophic events (defined as incidents in which 50 or more containers were lost in a single blow), that number rose to an average 1,582 containers lost at sea each year.
Looking at trends over the years, the average annual losses in normal conditions were fairly stable, ranging from 350 containers lost in the 2008-2011 survey to 733 containers in 2011-2014 and 612 in 2014-2017. Adding the figures from catastrophic events pushed those numbers to averages of 675, 2,683, and 1,390 for the three periods.
Although WSC points out that those totals represent a small fraction of the 130 million containers shipped in 2016, the group is now working with its member companies to drive the losses down. The shipping lines are trying initiatives such as verifying container weights before packed containers may be loaded aboard ships, adopting a code of practice for safely packing cargo on ships, and requiring standards for container lashing equipment and corner castings.