Feds: Human, mechanical failures likely led to Line 5 anchor mishap

Human error and mechanical failure likely led last year to a wayward anchor damaging three transmission cables and denting Enbridge’s Line 5 in the Straits of Mackinac, according to a federal report released Wednesday.

An improperly adjusted anchor brake band and the failure of crew members on the Clyde S. VanEnkevort tug boat and the Erie Trader barge to secure a starboard anchor apparently resulted in the April 1, 2018 anchor strike, according to the National Transportation Safety Board. The tug boat was connected to the barge as they transported iron ore.

The resulting snarl at the bottom of the Great Lakes was so severe that when crew members discovered the barge’s 12,000-pound anchor had deployed two days later near Indiana they found it was missing both flukes on either side of the main anchor shaft, according to the report.

A second mate on board the barge had ordered both anchors be secured, according to the report, but the crew member responsible for doing so “stated he did not actually secure the starboard anchor despite communicating to the wheelhouse that all anchors were secured.”

The anchor strike released about 800 gallons of dielectric mineral oil from three American Transmission Company cables, resulted in more than $100 million in damage to the lines and caused minor dents to the 65’s Line 5 dual pipeline. 

Escanaba-based VanEnkevort Tug and Barge said it appreciated "the enormous investment" the NTSB made in its investigation and report on the strike. 

"However, with the Coast Guard investigation still ongoing and pending litigation, it would be inappropriate for us to comment on these matters at this time," the company said in a statement. 

The 2018 strike and resulting spill propelled negotiations over the future of Enbridge’s decades-old Line 5 oil pipeline in the Straits. It prompted former Michigan Attorney General Bill Schuette to file suit against VanEnkevort Tug and Barge Inc., alleging its tug was responsible for the alleged anchor strike.

The NTSB report comes during the same week Michigan Gov. Gretchen Whitmer told Enbridge she would like to reach an agreement by June 10 on the timeline for Line 5’s decommissioning beneath the Straits of Mackinac. 

Former Gov. Rick Snyder reached an agreement with Enbridge in December — roughly nine months after the anchor strike – to construct an underwater tunnel to house a new pipeline. But Whitmer halted state work on the project in March after Attorney General Dana Nessel ruled the plan approved by Snyder and the Republican-led Legislature was invalid. 

In May, Whitmer ordered state officials to issue rules requiring large vessels to verify that no anchors are dragging before passing through the Straits of Mackinac to prevent incidents like the one that unfurled on the Erie Trader. 

But environmental groups said the NTSB report shows the only way to eliminate risk in the straits is to eliminate Line 5.  

“Michigan must act on this new evidence,” said David Holtz, a spokesman for Oil & Water Don’t Mix. “Only shutting Line 5 down can prevent an oil pipeline rupture and it is urgent that the governor and attorney general immediately use their authority to protect Michigan and the Great Lakes.”

Nessel agreed, noting that the 2018 strike "was an accident that even the boat's captain was unaware of."

"All of the enforcement mechanisms in the world won’t prevent a tragedy from an unintended, accidental anchor strike," she said. "We are prepared to take legal action to decommission Line 5 as quickly as possible to protect the fresh water resources that are absolutely critical to our state.”

Whitmer acknowledged Wednesday that anchor strikes "remain a very real threat."

"While Gov. Whitmer has taken steps to reduce that risk, it cannot fully be eliminated, which is why the governor is seeking to close the pipeline that runs through the Straits as soon as possible," Whitmer's spokeswoman Tiffany Brown said. "An oil spill in the Great Lakes is unthinkable.”

The tug boat was connected to the 740-foot barge Erie Trader from Duluth, Minnesota, to Indiana Harbor with iron ore cargo and was headed west through the Straits of Mackinac with a crew of 14 when the strike happened. 

At the time of the strike on Easter Sunday, “most of the vessel crew had the day off,” the report said. Neither of the crew members on board responsible for ensuring the starboard anchor was secured did so and federal inspectors were unable to determine when the anchor had last been cleared, according to the report. 

The crew observed no unusual sounds or changes to the ship's operation while crossing the Straits in 6-foot to 8-foot waves, a captain told investigators. But he noticed the vessel was moving more slowly than it should have been on April 2.

It wasn't until April 3, as the ship neared Indiana Harbor, that a crew member noticed the anchor's chain was rubbing against the barge's hull and the crew realized the anchor had been inadvertently released. It was missing two flukes and the anchor crown when the crew pulled the anchor in. 

The U.S. Army Corps of Engineers was unable to locate the missing anchor pieces in the Straits. 

The captain notified his company and proceeded to the ship's next port. Because the U.S. Coast Guard only requires one anchor, officials felt no need to notify the agency of the damaged anchor, according to the report.

The Coast Guard determined the tug and barge were the likely source of the strike after boarding the vessel at the Soo Locks on April 6 and noting the damaged anchor.

“The captain told investigators that he was unable to determine the amount of time the anchor dragged and the location where the chain paid out,” the report said. “None of the crew members knew of any damage the anchor caused while out.”

At the time of the strike, VanEnkevort Tug & Barge had started implementing a safety management system, but “there were no policies and procedures related to anchor operations.”

“Had VanEnkevort Tug & Barge had procedures in place to regularly monitor these spaces, the unsecured anchor may have been detected earlier,” the report said.

In a December settlement with the Attorney General's Office, VanEnkevort and its parent company agreed to pay $200,000 in civil costs and fines, and implement new anchor monitoring technology and procedures. 

Enbridge and American Transmission Company also filed suit against VanEnkevort last year in federal district court alleging negligence and attempting to recoup the cost of repairs to their equipment.

The U.S. Coast Guard also has prepared a report on the incident, but is waiting to release the findings until a review at the Coast Guard’s Washington, D.C. headquarters is complete.