Report: Tug dragged 6-ton anchor for days after denting Line 5 pipeline

• Oct. 31, 2019: Michigan judge rules Enbridge Line 5 construction is constitutional
• ​Related: Michigan AG Dana Nessel files lawsuit to shut down Line 5 in Mackinac Straits

The crew of a barge and tugboat whose six-ton anchor struck Line 5 last year in the Straits of Mackinac had no clue it was being dragged on the lake bed until nearly two days later near Indiana.

The anchor dented Enbridge Energy’s dual Line 5 oil pipelines and sliced Wisconsin-based American Transmission Co.’s three underwater power cables, causing $100 million in damage to the cables and releasing 800 gallons of mineral oil into the Straits on April 1, 2018.

The details are among those in a new National Transportation Safety Board report on the anchor strike, which comes as Michigan officials negotiate with the owners of the 66-year-old pipeline about its future.

The report said human and mechanical errors led to the mishap, specifically “the failure of the anchor detail to secure the barge’s starboard anchor, and the improper adjustment of the anchor brake band.”

Michigan Attorney General Dana Nessel said the report “reinforces what we already know: It is incredibly dangerous for Line 5 to continue operating in the Straits.”

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

VanEnkevort Tug & Barge, the Escanaba-based company that owns the vessels, declined to comment, citing ongoing litigation and a U.S. Coast Guard investigation. Nessel’s Republican predecessor, Bill Schuette, sued the company over the incident last year. Enbridge sued as well. 

The National Transportation Safety Board, in its May 31 report, found several problems aboard the vessels as they carried iron ore through the Straits last April en route from Duluth, Minn., to Indiana Harbor.

Among the findings:

• The Erie Trader barge and Clyde S. VanEnkevort tugboat traveled through winds speeds above 30 knots and waves ranging from 6 to 8 feet on April 1, 2018;
• The captain told investigators he could not determine how long and where the anchor dragged, but underwater footage showed drag marks along the lake bottom just before the Line 5 pipeline about 230 feet below the surface. The anchor damaged three of the Wisconsin utility’s six transmission cables supplying power to the Upper Peninsula. Two were damaged so badly they had to be replaced. Three minor dents were found in Line 5, which was otherwise structurally sound.
• Because it was Easter, most of the 14 crew members had the day off, meaning no one was working the barge’s deck.
• Crew members on watch duty were ordered to clear and secure the barge’s two anchors as they traveled through the Gros Cap Reef in Ontario before approaching the Soo Locks in Sault Ste Marie. One crew member told investigators he did not secure the starboard anchor even though he told his superiors otherwise.
• A procedure used to test an anchor break that had been recently replaced “was inadequate for determining the brake’s full functionality.”

The report comes amid uncertainty over whether Gov. Gretchen Whitmer will greenlight Enbridge’s plan to replace the pipelines in the Straits and bury the new pipe in a $500 million bedrock tunnel — a plan Enbridge says would protect the pipeline from future anchor strikes but environmentalists oppose.

Enbridge last year signed a series of agreements with Whitmer’s predecessor, Republican Rick Snyder, about a tunnel for the pipeline,  which transports up to 23 million gallons of oil and natural gas liquids per day between Superior, Wisconsin, to Sarnia, Ontario.

In March, Whitmer ordered state agencies to stop work on the project amid questions surrounding the deal’s constitutionality.

Whitmer has set a June 10 target for a new agreement with Enbridge. Attorney General Dana Nessel, a fellow Democrat, has promised to take Enbridge to court if negotiations fall through.

In a text message on Wednesday, Tiffany Brown, Whitmer’s press secretary, said “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. An oil spill in the Great Lakes is unthinkable,” Brown added.

Ryan Duffy, an Enbridge spokesman, called a tunnel, which Enbridge would fund, “the best solution moving forward” to protect the pipeline and serve the Upper Peninsula’s energy needs.

“The concrete-walled tunnel is to be placed approximately 100 feet below the lake bed, reducing the risk of a spill in the Straits to virtually zero and eliminating the risk of an anchor strike,” he told Bridge in an email.

Enbridge said last week it could complete the tunnel by 2024, shaving years off previous estimates.

Whitmer has taken other steps to address anchor threats in the Straits.

Last month, she directed the Department of Natural Resources to file an emergency rule requiring large vessels to verify they aren't dragging anchors when passing through the Straits.

Snyder's administration last year barred ships from anchoring in the Straits, and the Coast Guard proposed similar rules. But in a letter to DNR Director Dan Eichinger last month, Whitmer called the previous efforts "an important first step" that "did not address the core threat" of the 2018 anchor strike.

Environmentalists called the federal report “shocking,” saying it suggests no anchor regulations could prevent such a series of mishaps.

“This report shows there is no regulation or law short of eliminating the pipeline that Michigan can pass to protect the Great Lakes from a catastrophic Line 5 pipeline rupture,” David Holtz, a spokesman for citizens group Oil & Water Don’t Mix, said in a statement.

“Michigan must act on this new evidence. 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 echoed those concerns on Wednesday.

“Even though Gov. Whitmer has taken action to prevent anchor drops in the Straits, the 2018 incident was an accident that even the boat’s captain was unaware of,” she said.