Posted by news intern Marley Zeno

We've all seen the story that Washington State is reducing ferry capacity because Americans are getting fatter. But this story left us with some questions. If you can still drive heavy cars and trucks and SUVs onto a ferry, why would a few extra pounds from relatively light people make a difference? Is it about lifeboat capacity? I, your trusty unpaid intern, looked into it.

According to the US Coast Guard, which is setting the new rules, the issue is not with vehicles or lifeboats. It's a matter of ferryboat stability. Our ferries have wide hulls and a shallow draft, so they can be susceptible to tipping over if the load becomes too top heavy. US Coast Guard Lt. Eric Young explained that since the topside weight (people) has increased more than the bottom weight (cars), the number of people needed to be reduced to maintain stability. He told the Associated Press that with the new capacity, "the ferry wouldn't tip over even if everyone ran to the side at the same time to look at a pod of killer whales."

While the Coast Guard's stability requirements haven't changed since the 1960s, when the Center for Disease Control reported the average weight of an American was 160 pounds, the average American is now 25 pounds heavier. On ferries, those people hang out in the upper passenger decks.

A source familiar with the Washington State Ferries, who asked me to leave out his name, explains how this topside weight adds up: "Increasing the per passenger weight by 25 pounds for stability calculations on a 2,000-passenger capacity vessel can be 25 tons of additional topside weight."

But the new requirements only affect about one quarter of the fleet. The Washington State Department of Transportation reports that the Hyak, Kaleetan, and Yakima have reduced their capacities from 2,000 to 1,782 while The Evergreen State reduced capacity from 984 to 875 and the Tillikum reduced from 1192 to 1061. That's five ferries out of 22 total.

What does this mean for you? Not a lot, says Lt. Young. "Nobody is anticipating any type of impact on public transportation, or the normal traffic flow of the ferries." He went on to say that since the vessels are so large, "I haven't had any reports for any situations where vessels were approaching max capacity." In other words, even when a ferry is filled with cars it isn't necessarily carrying 2,000 people.