Safe Harbor?

Ships bringing liquefied natural gas from the Middle East pass regularly through Boston Harbor. Experts say there’s little chance of an LNG tanker going up in a fireball. Then why are city officials so worried? Should you be?

AT 2:30 A.M. ON A TUESDAY IN MAY, a 53-foot pilot boat called the Mystic motored out to just beyond Boston Harbor and came alongside the GDF Suez Neptune. Like all ships entering the harbor, the Neptune — 928 feet long and 141 feet wide — required a licensed Boston Harbor pilot on the bridge, and Frank Morton was on the job. Stepping to the edge of the Mystic’s bow, he reached for the rope ladder that dangled from the Neptune like something on a pirate ship, then clambered up the side and onto the state-of-the-art tanker.

[sidebar]As he directed the ship into the harbor, blue lights whirred in every direction: on law-enforcement escort boats, on police cruisers parked at the end of nearly every pier. A chopper hovered as the tanker sailed past the airport, past downtown, and up the Mystic River. The security detail was a spectacular acknowledgment of the ship’s cargo: 38 million gallons of liquefied natural gas, or LNG, enough fuel to power a region or, in the wrong hands and under the right conditions, incinerate half a city.

LNG tankers have been controversial ever since they started steaming through Boston Harbor to port in Everett in 1971, but became even more so after 9/11. If terrorists caused even 10 percent of the typical LNG tanker’s payload to spill and ignite, the resulting fire could be calamitous, according to a 2004 report by Sandia National Laboratories for the U.S. Department of Energy. The study didn’t publicly estimate casualties for Boston; in fact, no study has since 1977, when the Federal Energy Regulatory Commission estimated that up to 3,000 would die. Today, when the city’s population of 610,000 swells to more than one million on workdays, the number could be higher. It’s not hard to imagine why Boston remains the country’s only major city with an LNG terminal.

The tankers were such cause for concern after 9/11, Mayor Thomas Menino asked a federal judge to ban them from the city. The effort failed, and the LNG debate faded — until this past February, when shipments started arriving from Yemen, a known terrorist haven and site of the 2000 attack on the USS Cole. “This is serious stuff,” Menino says. “I take it very seriously, and my public-safety officials take it very seriously. We don’t have the equipment to put down an explosion of an LNG tank. They say, ‘Well, it will never happen.’ Well, 9/11 hadn’t happened either. We live in a different era.”

For nearly a decade, Menino has been urging the federal government to develop more natural-gas pipelines and offshore LNG terminals for New England — an expensive solution to what has been, so far, a hypothetical problem. Executives of Distrigas, a subsidiary of French conglomerate GDF Suez, which owns the Everett terminal, counter that security is better than ever, and point to their industry’s sterling safety record: There hasn’t been a serious incident since an LNG storage tank exploded in Cleveland in 1944, destroying 79 homes and two factories, and killing 130 people.

Still, even ships coming from countries more stable than Yemen are scrutinized. The Neptune, for instance, had sailed from Trinidad. Just before dawn it reached Everett safely, like the nearly 1,000 ships before it.

Yet some LNG experts, like University of Arkansas chemical engineering professor Jerry Havens, point out that something need go wrong only once. “Moving this much flammable fuel through a populated area should be considered…low risk, low probability, but high consequence,” he says.

  • Robert

    Skikda, Algeria, had a catastrophic LNG accident in 2004, that killed 26 workers and injured 74.

  • Robert

    LNG storage tanks contain vapor (called “boil off”) at the top, above the liquid. It does not require pouring onto land or water to vaporize — it simply needs a slight rise in heat.

    The statement about a lit cigarette and LNG vapor flammability give a false impression of safety. Liquid gasoline will not burn until it vaporizes, either.

    LNG vapor is 3.7% more flammable than gasoline vapor. Methane (LNG) has a fuel-to-air flammability range of 5% to 15% (a 10% range), while gasoline has a flammability range of 1.4% to 7.6% (a 6.2% range). Neither will burn or explode outside those ranges.

    The Federal Government has defined LNG ship Hazard Zones that extend 2.2-miles from the ship. The hazards within those zones include cryogenic burns, asphyxiation, fire, thermal-radiation burns, and explosion.