Ship anchor suspected in pipeline break that fouled beaches

LOS ANGELES (AP) — An anchored cargo ship in the Pacific is not a fixed point — it's different than parking a car. Even then, with a multi-ton anchor and brawny steel chains resting on the seabed, the massive vessels can move from shifting winds, ocean currents and tides.

A probe is continuing into what caused an offshore pipeline break that spilled tens of thousands of gallons of crude oil off Southern California, but one emerging possibility is that a cargo ship — inadvertently or not — dragged its anchor along the ocean floor, catching the steel, concrete-covered oil pipe and pulling it over 100 feet (30 meters) until it was pierced or cracked open the way pressure fractures an egg shell.

Federal transportation investigators said preliminary reports suggest the failure may have been “caused by an anchor that hooked the pipeline, causing a partial tear.”

“A ship at anchor will move around quite a bit as tides, winds change direction,” said Steven Browne, a professor of marine transportation at California State University Maritime Academy.

“One explanation would be they did not drop the anchor directly on the pipeline," Browne said. “The ship moved and dragged the anchor along the bottom if it wasn’t properly set. It could have potentially snagged on the pipe and dragged it.”

Many questions remain unanswered.

With the probe continuing, investigators have not yet said if a ship was directed by port managers to anchor in the vicinity of the pipeline break. Typically, a ship would be given specific instructions from port managers on where to drop anchor, and its position would be closely monitored.

Browne said he has never heard of a cargo ship dragging an oil pipeline, but is aware of cases in which phone cables have been lifted off the ocean floor. In such cases,...