ANCHORAGE, Alaska — Testimony in the grounding of a Royal Dutch Shell PLC drill barge off a remote Alaska island focused Thursday on why its towing vessel unexpectedly lost power in stormy conditions in the Gulf of Alaska.
The officer in charge of keeping the engines running said he has concluded a faulty fuel additive was likely to blame. Carl Broekhuis, chief engineer on the Aiviq, the vessel built to tow Shell’s floating drill rig Kulluk, told a Coast Guard investigation panel that something fouled the fuel injectors on the vessel’s main engines, and one by one they automatically shut down Dec. 27 and 28.
Each engine has a dozen fuel injectors and six to 12 of them failed on all four engines.
“I’ve never seen that many injectors go down at the same time before,” Broekhuis said. “Never.”
The engines’ troubles compounded problems that began earlier Dec. 27. The tow line between the Aiviq and the Kulluk broke and the tow vessel had to hook up to a backup tow system. Over four days, the Aiviq and relief vessels would fight a losing battle in increasingly stormy seas trying to maintain lines to the circular drilling barge.
It ran aground Dec. 31 off tiny Sitkalidak Island, just off Kodiak Island. All 18 people on board had been lifted off in baskets lowered by Coast Guard helicopter and the vessel was refloated six days later, but damage to the Kulluk cost Shell the chance to drill during the short open water season in 2013.
Broekhuis said he does not know for sure the cause of the fuel injector problems but said he settled on the fuel additive after eliminating other possibilities such as air or water in fuel lines.
The Kulluk last year drilled in the Beaufort Sea off Alaska’s north coast and seawater on the return trip had reached fuel tank vents. However, Broekhuis, said they functioned properly and no water was detected in tanks or lines.
An engine filter pulled from the malfunctioning engines, he said, was found covered with something slimy. A sample of the fuel indicated the presence of a clear, yellowish gel.
The 360-foot ship was carrying enough replacement injectors to swap them out of one engine and it was fired up after several hours. His employer, Edison Chouest, flew a company aircraft to a Caterpillar marine engine parts center to pick up additional fuel injectors and then to Kodiak. A Coast Guard helicopter crew relayed the injectors to the Aiviq on Dec. 29 and the other three engines were repaired.
The vessel eventually burned additional fuel that contained the additive but Coast Guard panel members did not ask why the fuel did not again foul the injectors.
Samples of the fuel were turned over to the Coast Guard, Broekhuis said, but he has not seen test results.
Also testifying Thursday was Capt. Bobby Newill, who served as third mate on the Aiviq and one of two officers at the vessel’s controls when the original tow line parted.
Newill said the speed of the vessel been reduced as the storm picked up Dec. 27 and was moving on automatic pilot at only about 2 knots, or about 2.4 mph.
A faulty alarm on the winch system, which earlier in the month had sounded even while the vessel was tied up, gave off multiple signals, he said. He relied instead, he said, on observations of the position of the wire between the vessels and tension readings that indicated the tow was within acceptable parameters.
“Everything seemed what I considered OK,” he said. “When that parted, it surprised me.”
The hearing will continue Friday and is scheduled to run through next week.