It’s no coincidence that the ship which blocked the Suez Canal for six days is longer than the canal is wide. Piled high with containers, it caught strong desert winds like a sail and jackstrawed into the bank. Stretching from bank to bank, and then some, it was firmly wedged in — and had to be dug and pulled out.
The debacle probably was bound to happen. If not this ship, then some other ship, because ships have gotten much bigger, while the canal has not.
The incident is leading to debates over ship size. A Singapore-based TV network says, “The largest container shipping vessels have quadrupled in size during the past 25 years. Stacking containers higher makes such ships more susceptible to high winds, while stacking them wider can increase hydrodynamic forces that make them harder to steer in tight spaces, such as ports and canals.” (Read story here.) That’s because when a lot of water is displaced in a confined space, the vessel squats at the stern and the bow is prone to waggle. For a scientific explanation of that, read this article.
Despite that, economics drives the shipping industry to ever-larger ships. In his book The Box, economist and author Marc Levinson wrote,
“Bigger ships lowered the cost of carrying each container. Bigger ports with bigger cranes lowered the cost of handling each ship. Bigger containers — the 20-foot box, shippers’ favorite in the early 1970s, was yielding to the 40-footer — cut down on crane movements and reduced the time needed to turn a vessel around in port, making more efficient use of capital. A virtuous circle had developed: lower costs per container permitted lower rates, which drew more freight, which supported yet more investments in order to lower unit costs even more. If ever there was a business in which economies of scale mattered, container shipping was it.”
(Quoted by the conservative-viewpoint magazine, National Review, here.)
Large ships may be more efficient, but greater size increases risks. About 12% of the world’s seaborne cargoes pass through the Suez Canal, and last week’s blockage is certain to disrupt supply chains all over the world. And insurers are certain to notice.