On a cold, blustery day at Port Elizabeth in New Jersey, one of several massive cranes whirs along a rail high above the pier, picks up a heavy container from a ship's deck and loads it on a waiting truck back on land. The truck drives away, another arrives and the whole process starts again.
It's a scene played out every day along America's coasts as massive container ships from across the globe pull into deep-water seaports, waiting to be unloaded. The ships are enormous — some 10 stories high and several football fields long.
Mark Hanafee, director for safety at the terminal, says no one on the pier knows for sure what's inside them.
"We know the contents of anything that's hazardous, but general cargo we don't know. It could be chicken, clothes, auto parts, anything, computers, televisions," Hanafee says. "We're an import society. We import everything."
Chris Koch, president of the World Shipping Council, says demand for cheaper goods over the past couple of decades has driven the shipping industry. He points to Walmart, which he says brings in more than 360,000 of the 40-foot cargo containers each year.
"If you add all that up, that's probably a line of trucks that is somewhere close to 4,000 miles long. That's a lot of cargo," he says.
“ We're an import society. We import everything.