Leaking pipeline likely was hit before

HUNTINGTON BEACH, Calif. — An underwater oil pipeline off the Southern California coast was likely damaged by a ship’s anchor several months to a year before it ruptured and sent oil spewing into the ocean and then onto some of the area’s best-known beaches, investigators said Friday.

Coast Guard Capt. Jason Neubauer, chief of the office of investigations and analysis, said after the first strike it’s possible other ships’ anchors subsequently struck the steel pipe that brings oil to shore from three platforms out at sea. Investigators previously said a large section of the pipe was bowed after being struck and dragged along the seabed.

It remains unknown when the slender, 13-inch crack began leaking oil, and investigators will pore over a year of data on ship movements near the area of the break. No ships have been identified as suspects at this point.

“We’re going to be looking at every vessel movement over that pipeline, and every close encroachment from the anchorages for the entire course of the year,” Neubauer said.

Neubauer said investigators have narrowed their search to large cargo vessels that would be powerful enough to move a 4,000-foot section of pipeline 105 feet across the ocean floor. He also said investigators have zeroed in on a windy storm Jan. 24-25 that could have caused problems for ships trying to anchor in the vicinity of the twin ports.

A crack suggests the pipe, which was installed in 1980, perhaps withstood an initial impact, but had been weakened over time by corrosion and became more prone to fail, said Ramanan Krishnamoorti, a petroleum engineering professor at the University of Houston.