Incorrect Cargo Weight Data Causes Containers to fall off Ship near California

The input of incorrect container cargo weight data when developing the cargo loading plan led to shipping containers falling off a cargo ship and others becoming damaged while the vessel was drifting off the coast of California, the National Transportation Safety Board said Tuesday.(25 Feb ’25)

On Feb. 6, 2024, the U.S.-flagged containership President Eisenhower lost 23 shipping containers overboard and another 10 were damaged as the vessel was drifting about 94 miles south of Oakland, California, while awaiting a berthing assignment. None of the lost containers contained hazardous materials. The value of the lost cargo and damage to the containership was estimated at over $735,000.

​Longshoreman at the Port of Los Angeles began loading the vessel on Jan. 31 in accordance with a cargo loading plan. The cargo loading plan was developed by the ship planners using the verified gross mass, or VGM, of each container, which was provided by the booking agen

The VGM was determined by combining the empty weight of the container plus the weight of the cargo loaded into it. Before the plan was developed, the booking agent had to manually enter the cargo weight of 40 containers due to an error in the booking system. During the manual entry, 39 container cargo weights were entered incorrectly and the VGM for those containers was significantly underreported. ​The actual VGMs for the 39 containers was 18.3 to 22.2 metric tons greater than the VGMs used to develop the cargo loading plan. Because the cargo loading plan included inaccurate VGMs, the container stack weights exceeded the maximum weight limit and the containers were loaded in reverse-stratified stacks, which caused the cargo-securing equipment to fail while the vessel drifted south of Oakland.

The booking agent has since modified their procedures and booking system to prevent this type of input error from occurring again.