An employee for a Shell contractor testified Tuesday that a heavy chain -- which investigators indicated can be used to absorb the force of rough weather -- was eliminated from the towing setup for Shell's drilling rig, the Kulluk, because of concerns about handling the gear.
William Hebert works for Delmar, a Louisiana offshore oil field services company, and was sent to Alaska to serve as "rig move coordinator" for the Kulluk. He testified on Day 7 of a Coast Guard hearing investigating the Kulluk's Dec. 31 grounding in a fierce Gulf of Alaska storm.
The same tow setup was planned for the multiple legs of the Kulluk's transit, Hebert said, testifying by telephone from the company headquarters in Broussard. On Dec. 21, the Kulluk left Dutch Harbor under tow by a single vessel, the Aiviq.
Hebert said he oversaw the mooring system at the drilling site. He was not responsible for the tow plan, but helped Shell and its drilling contractor, Noble Drilling Corp., acquire the tow gear. A Delmar crew rode aboard the Aiviq and connected the tow gear, he said.
Unlike towing a car on land with a taut connection, at sea the line is mostly underwater and is curved to absorb movement. Often in Alaska, the tow gear includes heavy chain, called surge chain, which is pulled along to act like an undersea spring between the tow line and the bridle system that connects to the vessel under tow.
The Kulluk tow plan called for a 90-foot length of chain, Coast Guard investigator Keith Fawcett said in questioning Hebert.
"Was there any conversation about lengthening that surge chain to accommodate shock loading?" Fawcett asked.
"Not that I recall, sir," Hebert answered.
Then what, the investigator asked, was changed?
Hebert said the tow master for the trip north, Marc Dial, originally designed the system so that chain would be attached to the Kulluk, then connected to a wire, then to surge chain. To anchor for drilling, all that chain would have go up on the rig. The tow planning team talked about how the crew on the Kulluk would recover and deploy the tow gear.
"Noble personnel made mention that it just would just be kinda hard to handle, trying to be able to work, the way that was that designed," Hebert said.
So the surge chain was eliminated from the set up, he testified.
The Aiviq lost its tow connection to the Kulluk on Dec. 27 as the seas were picking up. As various boats came to help, they couldn't hold the Kulluk under tow either.
The Coast Guard appears to zeroing in on a shackle that came off and was lost at sea as the initial failure point. Fawcett also asked Hebert about the bending of a cotter pin intended to secure a bolt and keep the shackle intact.
In a photograph that is part of the evidence, the tips of the cotter pin are bent at 90-degree angles and extend beyond the edge of the bolt, Fawcett said, describing it for Hebert. The Coast Guard has not released any of the evidence. Could that protrusion have damaged the pin?
It could have, Hebert said.
"We've talked about the strain on the towing system that the equipment was subjected to at sea. Is it a possibility that the cotter pin might have failed, the bolt migrated or rotated off the shaft and the shackle simply fell apart at sea?" Fawcett asked.
"Yes, it's a possibility," Hebert said.
The hearing at Loussac Library continues Wednesday afternoon with testimony from the lone Coast Guard official testifying, Capt. Paul Mehler, commander of the Anchorage Coast Guard office. He led the federal response to the Kulluk situation.
The panel was supposed to hear this week from John Becker, the tow master on the trip south, but he's unable to testify because of a family emergency, the panel was told.
The hearing is set to wrap up Friday.
Reach Lisa Demer at firstname.lastname@example.org or 257-4390.