+ Interview: Intermodal Shipping & Maersk Line - Part I

Intermodal Transport

Did you know that 90% of all non-bulk cargo worldwide is moved by container ships? Over 18 million containers are in use, traveling on an “Intermodal Transportation” system of ships, ports, trains, and trucks to move products and materials worldwide. The system was pioneered by Malcolm McLean who came up with containerized shipping in the ‘50’s, centered around standardized shipping containers that minimize human labor to load and unload cargo.

Maersk Line
The energy implications of this worldwide net are obviously important, and I was very lucky to be able talk to the Environmental Director for Maersk’s North American Operations, Dr. Lee Kindberg. MaerskLine is a division of A.P. Moller - Maersk Group, and is the world’s largest container shipping company, based in Copenhagen, Denmark. Maersk has a fleet of 500 ships, some 1,900,000 containers, and dock facilities. Dr. Kindberg has spent 3 years at Maersk and over 25 years in environmental health and safety management in the Chemical and Shipping industry. I had a lot of questions for her:

First off, what are you responsible for at Maersk?
“I handle environmental issues in North America and work closely with my colleagues in Copenhagen on environmental issues relating to our international ships.”

Dr. Kindberg had suggested I review the environment portions of MaerskLine’s website, http://www.maerskline.com/. Anyone interested in knowing more about this industry, and its energy and environmental issues should take a look.

Transportation & Energy Efficiency
Energy efficiency is a key issues for transportation, and Maerskline’s charts illustrate the greater fuel (and C02) efficiencies of ships and rail. Container ships have an especially large advantage over air transport for long distances. After checking this out, I wanted to know more:

Can you tell me any more about why ocean shipping looks so efficient?

“Let’s look at this from an engineering perspective. The hardest thing to do energy-wise is to go by air. You not only have to move the cargo horizontally, but you also have to lift it vertically, and stay in the air. When you’re talking trucks or rail, you have to deal with mountains and rolling terrain, and you have rolling friction and those kinds of things. In a marine environment, you don’t have that rolling friction. You have a little bit of drag on the ship, but no solid against solid.

The other thing to think about is scale. Only a small quantity of cargo can be moved in each airplane. Then if you move to trucks, you’re basically moving one or two containers. A stack train might carry several hundred containers. But our big ships might carry as many as 8,000 twenty foot containers. (Note that we quote capacity in twenty foot container equivalent units (“TEU’s”), although a lot of them now are actually forty foot units which count as two TEU’s. A Forty foot container is about the size of a city bus; it is 8 feet tall x 8 feet wide x 40 feet long. And in case you’re interested, it can hold about 54,000 Barbie dolls!)

The real advantage with containerized shipping is that instead of having to lift each piece of cargo on and off the ship, you have containers that are standardized sizes. That gives you standardization and economies of scale. Because of that, you’re able to load & unload the ships very quickly and get them back on the water.”

I’ve often wondered how long it took to unload one of the big ships:

“It depends on how many containers are booked to be unloaded at each port. Ship unloading and loading times range from a few hours to 2 or 3 days.”

And how are the ships scheduled?

“Typically a ship is on what’s called a string, which is a group of ships which follow each other on a given route. When you go to an airport to get on a plane, you don’t care exactly which plane it is, you just care that there’s a US Airways or Delta flight at 4pm heading from Columbus to Charlotte today.

With our strings of ships there’s usually a sailing on a weekly basis out of a given port. That might take seven to eleven ships on a given string so we can ensure you’ve got that regular sailing. Those ships don’t just go back & forth from Shanghai to LA either. They might go to Hong Kong, Shanghai, Yokohama, then across to LA, then back up the West Coast, and then back across to Hong Kong. You have a certain number of containers that will be unloaded at any given port, and also loaded back on.”

Balance of Trade & Maximum Efficiency

I’ve been curious about how the containers got back overseas, or wherever they came from. To me that would be a measure of system efficiency. Do a lot of them go back empty, or can you fill them?

“Right now the balance of trade is such that in some ports, you have more goods coming in that going out. A certain number of empties have to be repositioned or returned back to the point of origin. The better the balance of trade, the more cargo you’re moving for pretty much the same fuel. Some US ports have a slight shift towards exports, while others are dominated by imports.

US exports include chemicals, agricultural products, and all kinds of things you wouldn’t think of, like used cars that are not economical to repair in the US, but may be very economical to repair in another country. A surprising variety of goods are exported from the US, like scrap iron, scrap paper, and electronics. We also export a lot of forest and building products and agricultural products like wheat, soybeans, and so on.

Remember too that an Internationally-flagged vessel is not allowed to take cargo shipments between US ports -- from Los Angeles to Tacoma for example.”

That’s a quick look at what Maersk Lines does. In the next installment we’ll take a look at what they’ve done to be more efficient and environmentally friendly. You can check that out at:

http://www.thegreenergrass.org/2008/01/interview-intermodal-shipping-maersk_17.html