The limits of physics and economics prevent megaships from getting bigger
- Chris Baranuk
- Technology, BBC News
Ever Ace, one of the world’s largest container ships, embarked on an unprecedented voyage on August 14 last year when it left Yantian port and cautiously maneuvered towards the South China Sea.
To date, no other ship has carried such a large volume of containers: 6 meters 21,710 units.
the ship It is 399.9 meters long and 61.5 meters wide It is a true giant, but there are dozens of container ships of similar size sailing today.
Many more are under construction. Only two of them stacked vertically They are almost as tall as the world’s tallest building, the Burj Khalifa in Dubai.
The world’s largest cargo ships are 400 meters long and 60 meters wide. It is more or less Current upper limit There are many surprising reasons for these vessels and why they do not grow larger.
Larger container ships are unlikely to be found.
Vessels exceeding limits
are around 5,500 container ships in the world And they are capable of carrying 25 million TEUs (twenty foot equivalent unit) or the equivalent of about 25 million 6 meter containers if they are all fully loaded at the same time.
George Griffiths, Global Container Markets Editor at S&P Global Platts, explains. Thread Universal of orders The new cargo ships will increase the total combined capacity by 25% in a few years.
“We see them being built Many other large container ships“The rate of new ships moving more than 14,000 containers is staggering,” he says.
In the past decade alone, the ability The average container ship has increased from less than 3,000 TEU to around 4,500 TEU. And there are currently more than 50 vessels with a capacity of 21,000 TEU or more. Almost all were built in the last five years.
However, these Boats are out of bounds Even from the world’s largest ports, says Griffiths. To load and unload containers, cranes must cross the ships.
Container ships should also return Go through locks and canalsincluding the Suez and Panama Canals, which have size restrictions.
It is also important to avoid grounding ships. In some ports, there are huge ships So submerged in water In water they touch down And they slide through the sediment rather than float, says Stavros Karamperidis, director of the Ship Research Group at the University of Plymouth in England. Such maneuver should be handled with great care.
To accommodate ships much larger than today’s largest ships, that would be needed of A major overhaul of port infrastructure. That would be incredibly expensive.
“Why would you invest in big ships if you have to invest huge sums in ports as well?” Griffiths says.
Karamperidis says that even the largest ships controlled Given the routes they take, they are very vulnerable to bad weather. They may not cross the Pacific, for example, because of violent storms. Medium-sized container ships sometimes lose hundreds of containers in the Pacific.
“That’s why ships [ultragrandes] They don’t face big waves as they come closer to the coast. It is a question of stabilityMost U.S. ports are not large enough to accommodate the largest container ships, he adds. Only a handful of ships with a capacity approaching 20,000 TEUs have ever reached U.S. ports.
LIMITATIONS IN Boat size They have less to do with the engineering challenges of building really big ships, but more to do with the economics and logistics of operating such behemoths.
“Physically, there’s really no limit,” says Rosalind Blazczyk, managing partner and naval architect at Solis Marine Consultants.
Containers are built to hold them in place, and such systems have high limits on the number of boxes they can safely hold, says John Simpson, Blazejczyk’s colleague at Solis.
How these are done is another problem BoatsRide big and wide waves. When sailing directly in line with waves, boats can experience a phenomenon known as parametric roll.
As waves sweep the length of a very wide container ship, its bow and stern can sweep the water until the crest of the wave is amidships. This leaves the top of the bow unsupported by water. A variation in this support can cause the ship to rock oddly from side to side as the waves pass.
“They get it Roll angles A very large one without a very high wave height,” says Blazejczyk.
Larger ships are more at risk. And container ships have very large hatches in their decks, meaning their overall structure is weaker and more prone to twisting than other ships.
“They are like one A shoe box without a lidBlazejczyk adds that there is no problem in calm seas, but again, restricting when or where a ship goes limits its usefulness.
In addition to all the above reasons, a Economic environment Manage. Griffiths points out that oil prices are currently too high and the largest container ships require large amounts of fuel.
However, it is not possible to invest in large ships Financial will Smart in the future. Now these costs are offset by astronomical freight rates around the world. This is the current demand for inventory.
For container ships with capacities above 25,000 TEUs to be viable, the economics of operating them must change, Karamperidis says.
The Suez Canal It will always act as a bottleneck for ships traveling from Asia to Europe, but Karamperidis says it’s impossible to imagine a 30,000-TEU vessel or route from China to a growing African port.
“We can see those types of ships going from Asia to Mombasa,” he adds, referring to Kenya’s largest port.
24,000 TEU ceiling on capacity Container ships What we see globally today is a reflection of economic limitations such as port infrastructure, the shape and engineering of the world’s busiest waterways.
But under the right conditions, there is always the possibility of being with someone enough money One day commission a ship that will outshine today’s gigantic ships. It will surely be an amazing thing to watch.
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