How Shipping Containers End Up in the Ocean –
Hundreds of containers have fallen from container ships into ocean waters in recent months, in a flare-up of accidents that can destroy millions of dollars worth of goods, damage vessels and endanger lives and the environment.
Such accidents are rare among the millions of boxes that move across oceans each year, and maritime officials say they have been declining over the long term. But the recent spate of failures adds urgency to investigations of the losses.
Naval architects and engineers say a string of circumstances have to come together to create the catastrophic event known as parametric rolling. They say that as ships become bigger and containers are stacked as high as multistory buildings, the stability of vessels on the open waters is a growing concern.
“It is a big factor in container losses and it happens when waves hit the bow not head-on, but at an angle,” said Fotis Pagoulatos, an Athens-based naval architect. “Ships pitch up and down as they steam ahead but they can also go into a rolling motion from side to side. This can become uncontrollable and displace a lot of boxes that fall over.”