Look around you right now. Chances are something within your reach came from another country and spent part of its journey to you in a standard shipping container on a specialized container ship. Your morning coffee, DVD player, vacuum cleaner, whiskey, beer, and TV probably all traveled over an ocean on the way to your home or office. Today intermodal containers transport about 90% of consumer goods cargo worldwide.
Ever since Noah received an order to build the mega ship of his time, shipbuilders have been discovering and overcoming the physical and economic limits to the size of a ship.
Over the last few decades a boom in world trade has driven a massive increase in shipping. Rather than just building more container ships, economies of scale drive shipping companies’ demand for ever larger container ships that deliver more goods for less cost per trip.
Container ship capacity is measured in container “twenty-foot equivalent units” (TEU). So the common 40 foot long container takes up 2 TEU spaces on a ship. Container ships are classified by several size categories defined by their TEU capacity from the “small feeder” that can carry up to 1,000 TEU’s, to the 5,100 TEU panamax, (fits through the Panama Canal), to Very-Large Container Vessels (VLCV) that can carry more than 10,000 TEU’s.
Ultra Class Large Container Vessels
The Maersk Triple E ships are now the standard for the Ultra Large Container Vessel (ULCV) class. In 2011, shipping giant Maersk spent nearly US$4 billion to build twenty of the Triple E ships. These giants can carry more than 18,000 TEU’s!
The three “E’s” stand for: economy of scale, energy efficient and environmentally improved” (isn’t that four E’s?) Nearly a quarter of a mile long (400 meters/1,312 ft.), these ships are not only among the longest ships on the sea but are the most efficient container ships per TEU.
As of December 2012, there were 161 container ships in the VLCS class but there are only 51 ports in the world large enough to handle these giants.
Is Bigger Better?
If ultra-large container ships deliver higher profits for operators through increased volume and reduced fuel consumed per freight unit, then bigger is better right?
Even on the seemingly limitless sea, there are physical and economic limits to the size of a ship. The Ultra Large Crude Carrier Seawise Giant supertanker was the longest and heaviest ship ever built. But it was too deep or wide to be able to navigate the English Channel, the Suez Canal or the Panama Canal.
The permissible maximum ship draft (depth) and beam (width) in some of the world’s main cargo sea routes currently present physical limits to vessel size.
Besides physical geographic restrictions, challenges to ultra large vessels include longer transit times, insurance loss limits per ship, ports ability to dock big ships and the speed they can be unloaded, and the ship’s inefficiency if the owner isn’t able to load it to full capacity.
Too Long, Wide, Deep, and High
Getting ultra large shipments into U.S. ports is another problem. West coast ports can handle ships as big as 10,000 TEUs, but even the average 8,000 TEU size ship is still too wide and long for the Panama Canal which is restricted to vessels of less than 5,500 TEUs.
The width (or beam) of ULCS’s is another limitation. Two ships passing in a channel require their combined width plus a safe separation zone between them. The 18,000- TEU Maersk Triple E ships have a beam of 59 meters (roughly 194 feet). Ships of this size are too wide for the Suez Canal or the Panama Canal.
At Hamburg, one of Europe’s most active and influential cargo hubs, shallow depths limit ships that “draw” less than 12.8 meters (about 42 feet) during low tide and less than 15.1 meters (about 50 feet) during high tide.
“Air draught” is the height of the ship and its antennae above the water also presents size limits. Many bridges along the U.S. East Coast that are high enough to allow most vessels to pass aren’t high enough for the new ultra large ships.
It was easy for Noah. He received divine guidance and the exact specifications to build a wooden mega ship 450 feet long by 75 feet wide by 45 feet high. Today’s ship builders have to consider a much wider variety of issues to decide how big to build their “arks” bringing you your coffee from Colombia.
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