"The tendency is to assume that the weight on the booking form is the actual weight -- this must account for a large proportion of misdeclarations," said Richard Marks, director of the International Cargo Handling Coordination Association. "There's human error as well."
The degree of "variation", as he described it - error ratios of 22 percent in the case of the Napoli and 42 percent for the Deneb - were no surprise. The question for Marks was what the industry is going to do about it.
The issue is becoming more urgent because shippers could be required by law within three years to verify weight before containers are loaded onboard ship.
Parties to the Safety of Life at Sea convention agreed an amendment in September 2012 stipulating that a container should either be weighed in its entirety, or its contents weighed separately and added to the tare weight of the box.
Marks said the International Maritime Organization would consider the amendment in September this year and would probably adopt it in December 2014, leading to an entry into force in July 2016.
