Ship anchored near oil pipeline made unusual movements

The amount is unclear. Amplify has said publicly that no more than 126,000 gallons (98,421 liters) leaked but told federal investigators it may be only 29,400 gallons (11,129 liters).

AP first contacted Hapag-Lloyd on Tuesday evening, seeking an explanation for the ship’s movements on Sept. 22 and 23.

Nils Haupt, a spokesman at its headquarters in Hamburg, Germany, denied in an email Wednesday that the ship ever moved off anchor from spot SF-3 during that period. He said the transponder data displayed by MarineTraffic is erroneous.

“We have proof by the logbook, which is updated hourly, that the vessel did not move,” Haupt said. “MarineTraffic in this case is wrong and the position is indeed incorrect.”

Haupt said Hapag-Lloyd would cooperate with any investigation.

On Wednesday morning, AP sent an email that included a screenshot of the Rotterdam Express movements as indicated on MarineTraffic to the Unified Command Joint Information Center for state and federal agencies responding to the oil spill. Senior Chief Petty Officer Lauren Jorgensen said the command was unable to discuss matters involving an ongoing investigation.

Nikolas Xiros, a professor of marine engineering at the University of New Orleans, said it would be highly unlikely that the transponder data for a ship, which works through a global network called the Automatic Identification System, would be off by several thousand feet.

“AIS transporters are very accurate and the whole system is also very accurate,” Xiros said after reviewing the location track for Rotterdam Express. “I think probably the ship moved, that’s what I think. And with the anchor down, which was a big problem.”

Xiros, who has spent more than two decades teaching marine navigation and electronics to future ship captains and crew, said the only alternative explanation he could think of was that either someone had hacked the AIS system to make the Rotterdam Express appear to move or that the ship’s transmitter somehow became unfastened from its mast, fell in the water and drifted away before being retrieved by the crew, only to have it come unfastened two more times.

Xiros said he could provide no reasonable explanation for why the ship might have moved so far off its assigned station. Records show relatively calm weather and seas during the days in question.

“There is a series of peculiar things and all that need to be explained,” Xiros said. “It may very well be some kind of an accident, but not necessarily a human error. We will have to see. But … I think he most probable explanation is the ship with anchor down moved both back and forth and possibly caused damage to the pipeline.”

If a ship’s anchor were to become entangled with an underwater obstacle such as a communications cable or petroleum pipeline, the operator is required by federal law to notify the Coast Guard. The locations and movements of ships are also regularly monitored by both the AIS system and radar, according to the Coast Guard.

Xiros said if he were investigating the cause of the oil spill, he would seek to review the digital logs for both location and engine operations aboard the Rotterdam Express.

According to MarineTraffic data, the ship left Long Beach on Monday for the Port of Oakland, where it was moored at a dock Wednesday night.