Probable Causes of Losses of Containers from Container Ships

In May of 2020 a container ship sailing along the eastern coast of Australia encountered a storm and lost a number of containers. The loss of containers was not unusual, about 1400 containers are lost each year on average. What was unusual was the large number of containers on this one ship. Coincidentally, MARIN releasted a report in September 2020 investigating similar losses of large number of containers from container ships going to northern Europe. Then, between October 2020 and February 2021, seven ships on a northern Pacific route from China to the USA loss between 3,000 and 4,000 containers and had a large number of container stacks roll over. This paper is a independent generic assessment of a marine forensic investigation taking a systems engineering approach to look at the broad spectrum of possible causes of container stacks rolling over and lossing containers. The paper discusses weather effects on the stability and motions of the container ships and the securing of the cargo containers. The paper goes into detail about the underlying issue of the container stacks and their heights such that at decreasingly smaller angles of heel or rll, the line of action of the weight of the higher containers passes outside the base of the stack thereby causing a overturning moment on the corners of the containers.