Coast Guard inspected ship before Line 5 anchor dragging
Less than three weeks before a barge’s 12,000-pound anchor was dragged across Line 5, the barge and its newly installed anchor brake system were inspected by the U.S. Coast Guard and the American Bureau of Shipping.
Both inspections on March 12 and March 18, 2018, found the system to be satisfactory.
But on April 1, 2018, the improper installment of the anchor brake pad, the unexplained disengagement of two backup brakes, a series of communication errors and icy, rough waters caused the starboard anchor to pay out over the Straits of Mackinac, where it was dragged over dual oil pipeline and severed three transmission cables, according to a U.S. Coast Guard report.
In the Coast Guard report, released July 15, the investigating officer recommended the suspension and revocation of the mariner credentials of a crew member on board the Erie Trader barge and Clyde S. Vanenkevort tug. The officer also recommended that a letter of warning be issued to another crew member.
"However, upon further review of the facts of the case, relevant federal regulation and Coast Guard policy, the Coast Guard decided to not pursue further action," said Cmdr. Michael Hjerstedt, chief of prevention for Sector Sault Ste. Marie.
The severing of the American Transmission Co. cables beneath the Straits released about 800 gallons of dielectric fluid from the cables after the anchor gouged Enbridge’s Line 5 in the midst of a heated, years-long debate over the pipeline’s safety. The state has since decided to encase Line 5 in a tunnel beneath the Straits, but the continued operation of the pipeline remains a subject of litigation between the Canadian oil giant and the state of Michigan.
The dielectric fluid spill was considered "minor" by the Coast Guard. Neither PCBs nor benzene compounds were found in the fluid, and no sheen was ever observed on the water's surface.
The report also noted U.S. Coast Guard rules do not require ships to install alarms to alert them when an anchor inadvertently drops from a ship, though one was installed on the Erie Trader after the incident.
The absence of such a rule in the Great Lakes district that applies to lake freighters and articulated tug barges like the Erie Trader presents “a potential latent unsafe condition allowing for the accidental deployment of an anchor without the crew being aware,” the report said.
Federal regulations that took effect months after the incident should “prevent such occurrences,” said Coast Guard Capt. D.C. Barata in an October 2019 review of the findings. Barata is the director of inspections and compliance at Coast Guard headquarters in Washington, D.C.
Six months after the incident, the Coast Guard established a Regulated Navigation Area in the Straits of Mackinac prohibiting ships from anchoring within a mile of any charted cables or pipelines.
Problem not 'readily apparent'
The recommendation of regulatory action combined with the collection and analysis of “a significant amount of information” prompted the more than two-year review at “multiple levels within the organization” including the Coast Guard headquarters, Hjerstedt said.
It’s possible, Hjerstedt said, that during the Coast Guard inspection the brake pad misalignment discovered after the incident “may not have been readily apparent at the time of inspection."
The American Bureau of Shipping did not return a call and email seeking comment.
Safety systems for ATC’s six transmission cables and Enbridge’s Line 5 were tripped by the collision, but the Clyde S. Vanenkort and Erie Trader didn’t become aware of its dragging anchor until they neared Indiana Harbor and pulled in 360 feet of 2-inch chain and the 12,000-pound anchor that had lost its flukes somewhere in transit across Lake Michigan.
The report from the Coast Guard follows a June 2019 report from the National Transportation Safety Board, which concluded a combination of human error and mechanical failure likely led to the anchor drop incident.
The Coast Guard report came to similar conclusions, but went into more detail regarding the faulty anchor brake system and oversights by crew members.
In March 2018, shortly before its Coast Guard inspection, the 740-foot Erie Trader barge had repairs performed to its propeller system and a brake band on the starboard anchor that had cracked in 2017, according to the report. But the installation was performed with no specific instructions for replacement of the band.
Anchor incident detailed
When the Coast Guard inspected the ship on March 12, it visually inspected the anchor after being told a new brake band had been installed and found it satisfactory.
Six days later, when the American Bureau for Shipping performed its own inspection, the inspector was not told of the new brake pad but performed a functional test of the anchor and found the system was satisfactory.
Sometime after the inspections, two crew members tasked with bow watch on the Erie Trader saw that the starboard anchor was protruding 1 to 2 feet from the barge. They assumed the brake system repairs still had not been completed, according to the report.
“Both men came to an agreement that they would no longer touch the starboard system and would only clear and secure the port anchor,” the report said. “They reasoned that since they were the only two crew members operating the anchors that this would not be a problem.”
On March 30, the tug and barge departed Duluth, Minnesota, for Indiana Harbor, a journey that would take the ship across Lake Superior, through the Soo Locks, west across the Straits of Mackinac and then south to Indiana Harbor.
Sometime between March 30 and April 1, both the paw and the claw — two of three mechanisms employed to prevent against an inadvertent anchor release — were disengaged, leaving only the brake to hold back the 500-plus foot chain and 12,000-pound anchor.
The Coast Guard was unable to determine who disengaged the paw and claw, but noted “it would have been impossible for these devices to become disengaged on their own.”
The ship moored along the Soo Locks March 31 because of ice conditions so formidable that a crew member described the sound of the ice hitting the ship as “thousands of freight trains hitting the hull.”
When the ship departed the locks the morning of April 1, a Coast Guard camera at Sector Sault Ste. Marie showed the starboard anchor protruding 1 to 2 feet from the barge with ice formations on it.
As the vessel entered the Straits, one of the crew members told the second mate he had secured the anchors “but did not actually verify the starboard anchor to be secured.”
The Coast Guard believes headwinds up to 45 miles per hour and waves of 6-8 feet closer to the Straits likely jostled the iced anchor. The “weight of the chain and anchor on the improperly installed brake would have grown exponentially” and pulled the anchor down farther.
At that point, the second mate noticed he should be traveling at 15 mph, but was actually traveling at 12.4 mph.
Near 5:30 p.m., the ship passed under the Mackinac Bridge, around the same time Enbridge received a signal from its pipeline threat scan system and ATC received a signal that its protective relays had tripped offline. By the time the ship passed into Lake Michigan, officials theorize the water was deep enough that the anchor was no longer touching the ground.
By April 2, ATC alerted the Coast Guard and National Response Center that 800 gallons of dielectric fluid had leaked.
On April 3, as the Erie Trader neared Indiana Harbor at the south end of Lake Michigan, the crew member heard a noise like ice hitting the hull and peered over the edge to find 360 feet of anchor chain deployed. When the chain was pulled up, the anchor was found to be missing flukes.
The Coast Guard boarded the Erie Trader near the Soo Locks on April 6 and immediately saw the missing flukes on the starboard anchor. No drug or alcohol testing was performed on crew members because it was five days after the incident.
During a follow-up inspection May 7 in Oregon, Ohio, the Coast Guard found a “noticeable gap” between the brake drum and liner and friction spots and areas where paint “was burned away.”
The Coast Guard recommended disciplinary action for both crew members, noting that “if all options had been investigated instead of assumed the crew may have discovered that the starboard anchor had been deployed before the incident occurred.”