A vessel captain in charge of towing Shell's troubled oil drilling rig, the Kulluk, when it left a Seattle shipyard back in June said Tuesday that the gear was more than strong enough, the crews were qualified and that under the right conditions, a winter transit through the Gulf of Alaska could have been done safely.
Marc Dial, a tow master with Offshore Rig Movers International, testified by telephone from Veracruz, Mexico, on Day 2 of a Coast Guard hearing in Anchorage into the Dec. 31 grounding of the Kulluk.
For the June trip north and the December trip south, the saucer-shaped Kulluk was towed by a single ship custom built for Shell by Edison Chouest Offshore, a Louisiana-based company that also operated the tow boat.
Dial said the trip north was uneventful, with calm weather and favorable currents that allowed the vessels to move along at better than a 4 mph pace. While he didn't have experience in the far north before, he said he's overseen roughly 100 tows of jackup drilling rigs and maybe 40 tows of other drilling-related vessels.
Under questioning by Keith Fawcett, a Coast Guard investigator, Dial said he didn't like using a single tow vessel or tug. In the event of "catastrophic failure that could not be repaired at sea," the whole operation could be at risk.
But the tow planning team, some of whom spent months preparing for the transit, decided if the lead vessel or the main towing gear were lost "that meant we were in pretty heavy weather and there wasn't much a secondary towing vessel could do," he said. "So there was no point in putting any more lives or equipment at risk."
The tow vessel for the Kulluk, the Aiviq, was brand new, with four powerful engines, and designed for that purpose, Shell has said.
The team focused on the route, currents, weather, and the reach of rescue crews, Dial said.
Shell contracted with Noble Drilling Corp. to operate the Kulluk and Dial testified that Noble was concerned about a requirement that its crew ride on board during the transit. When the Kulluk was brought to Seattle, it was unmanned. The 30-year-old rig had been mothballed in Canada for a dozen years before Shell bought it in 2005 and Dial said no one was still around who knew about earlier tows.
Dial checked into the issue and learned that Shell's warranty surveyor, who examines the towing system for underwriters, insisted it travel with a crew.
Besides the Coast Guard, federal agencies and the Republic of the Marshall Islands, where the Kulluk is flagged, are helping in the investigation. And many of the players have lawyers, who also can ask questions.
Would using a single vessel to tow the Kulluk with a crew on board be too much risk in the winter? asked Barry Strauch, the National Transportation Safety Board's representative in the investigation.
"Not necessarily," Dial answered. Weather patterns, routing, and speed all would make a difference. "There are still a lot of things you can do to make it a safe tow."
He only worked for Shell the one time but said he would be willing to do so again.
The Kulluk was unique to tow. Because of its round shape, it didn't cut through swells but tended to oscillate, moving back and forth in a sort of elliptical orbit.
"That would slowly diminish as the train of swells diminished," Dial said.
The oscillation didn't strain the tow gear, Dial said.
Towing systems for ocean transits are complex engineered systems. They include what mariners call "jewelry" that connect heavy chains to a long tow line called a pendant wire. The Kulluk was attached by two bridle chains to shackles that hooked to a tow plate connected by another shackle to the pendant wire.
During the frantic December tows, one of the Kulluk shackles came off and was lost at sea during a storm, the first in a series of tow failures.
The Kulluk's shackles were super big, rated with a 120-ton working load strength, Dial said. The original plan called for smaller shackles but they were upgraded.
If the Aiviq, with a pulling force rated at 200 tons, ran at 50 to 70 percent of its power, a 120-ton working load shackle was plenty strong enough, Dial said. The shackle shouldn't have broken until it was hit with a force of five times that working load, though it would have begun to bend before that.
Old school skippers used to design towing systems with a weak link so that if a tow failed, they would know what part, Dial said. But that's not the modern way, he said.
"The shackle is one of the stronger pieces of this particular towing arrangement," Dial said.
Also on Tuesday, a Shell executive -- and recently retired Coast Guard officer -- returned to the witness chair.
Norman "Buddy Custard said he retired from a 30-year Coast Guard career in June 2012 and started working for Shell the same month. He was emergency response manager at the time of the grounding, and also filling in for the operations manager, who was on vacation over the holidays. And he was one of the rotating incident commanders during the Kulluk crisis.
Did he seek out the Shell job or did Shell approach him? Strauch asked.
"Shell approached me," Custard said. "They expressed an interest. They knew I was retiring."
Strauch asked him about reports that Shell shoved off from Dutch Harbor in late December to avoid a state tax bill that would have hit Jan. 1.
"There was a tax situation that was discussed but that was not the driving force," Custard said. Shell wanted to get the Kulluk to a shipyard in Seattle for maintenance work before the 2013 drilling season, he said. Shell now doesn't plan to drill this year.
The trip was supposed to take 18 to 24 days, Custard said.
How could Shell have known what weather it would encounter on such a long trip? Strauch asked.
Its experts analyzed the historical frequency and severity of storms, Custard answered. No one was forecasting 30-foot seas when the Aiviq and the Kulluk left, he said.
The Kulluk's 18-man crew was evacuated by the Coast Guard on Dec. 29. No one was hurt in the grounding. Only a few hundred gallons of diesel spill was spilled when life rafts crashed, Custard said.
The hearing, in the Assembly chambers of Loussac Library, continues Wednesday. It is expected to go until May 31.
Reach Lisa Demer at email@example.com or 257-4390.