Lax Crewmen on Michigan Vessel Caused Anchor Strike

(July 15, 2019) — A much-enumerated, singular anchor strike has mushroomed into a casus belli. Michigan’s governor, the state’s top law enforcement official, and their political and environmental supporters demand the expedited shutdown of Calgary-based Enbridge Inc.’s Line 5 pipeline beneath the Straits of Mackinac. The probable cause of the April 2018 incident has been laid to failure of the vessel’s anchor detail to secure the anchor, and by the improper adjustment of the anchor brake band by the engineering crew that replaced the brake liner, reports the National Transportation Safety Board (NTSB).

As reviewed by NTSB in its maritime accident brief, at 5:32 p.m. local time on April 1, 2018 the articulated tub and barge (ATB) Clyde S VanEnkevort/Erie Trader was westbound with a crew of 14 in the Straits of Mackinac, Michigan. The barge’s starboard anchor, undetected by anyone onboard, released, paid out, and dragged on the bottom about 230 feet below. It struck and damaged three underwater electrical transmission cables and Line 5. About 800 gallons of dielectric mineral oil leaked into the water from the electrical cables; the dual Line 5 pipelines sustained only superficial damage, causing only one minor dent on one line and two insignificant dents on the other. Both pipelines were subsequently determined to be structurally sound. The cost to repair and replace the cables, however, was estimated at more than $100 million.

The Clyde S VanEnkevort is a 10,800-horsepower tugboat owned and operated by VanEnkevort Tug & Barge of Escanaba, Mich. The tugboat was connected to the barge Erie Trader, which is 740-feet-long with a 78-foot beam. The combined length of the ATB was 845 feet.

During the 2017-2018 winter season, the crew replaced the Erie Trader’s cracked top brake band liner on the starboard anchor windless brake, which had been out of service since October 2017. The barge was fitted with two stockless B-type anchors, each weighing 12,000 pounds. Both were connected to a two and five-eights-inch stud link chain. Each anchor chain was six shots long (one shot equals 90 feet) and each shot weighed about 5820 pounds. Typical for large vessels, the anchor system was designed with redundant mechanisms to protect against unintended release: the pawl (chain stopper) and the devil’s claw.

The incident voyage began on March 30 when the ATB got under way from Duluth, Minn. bound for Indiana Harbor, Indiana with a cargo of iron ore. The voyage would take the ATB eastbound through Lake Superior to the Sault Sainte Marie locks, or Soo Locks, on the border between the U.S. and Canada. After passing through the locks, the ATB would enter Lake Huron before turning west through the Straits of Mackinac and then south through Lake Michigan to its destination port of Indiana Harbor.

According to the crew member on watch March 31, when ordered to clear anchors at Gros Cap Reef he checked only the port anchor. He told investigators he did not clear the starboard anchor because he believed it was still out of service awaiting repair. On April 1, entering the open waters of Lake Huron, the second mate radioed the crewman on bow watch to secure the anchors. The same crewman again secured only the port anchor, because it was the only one he cleared the previous evening at Gros Cap Reef. The ATB continued on its passage, passing Mackinac Bridge. The second mate told investigators nothing was abnormal with the handling characteristics of the vessel during his six-hour watch.

Nor did the captain notice anything amiss the following day, April 2, when he returned to the wheelhouse, noting only that the ATB was making way more slowly than expected considering its load. The charted depth was now 324 to 356 feet. On approach to Indiana Harbor, it was again time to clear the anchors. Only then did a crewman observe the starboard anchor chain in the water, trailing aft of the hull. Four shots, 360 feet, of chain were in the water. When the anchor was recovered its flukes were missing but the shank was still there. None of the ATB crew members knew when the anchor paid out, nor did they hear any unusual noises or detect any abnormal handling characteristics during the passage from Soo Locks to Indiana Harbor. Further, the captain told NTSB investigators he was unable to determine the amount of time the anchor dragged.

What he and his crew did know is that along their transit of the Straits of Mackinac, about a mile west of the Mackinac Bridge and extending west of the structure, is a long-ago charted and published area with underwater pipelines and transmission cables running in a general north-south direction. Restrictions are in place prohibit- ing anchoring, trawling, or dragging. Such restrictions are intended to heighten mariners’ caution, diligence, and adherence to onboard procedures. Yet the marine casualty report the vessel captain submitted on April 6 stated that “the starboard-side anchor was not secured properly and released without anyone’s knowledge at an unknown place and time.”

During the voyage, the anchors were ordered cleared when the vessel passed Gros Cap Reef. Neither of the two able seamen onboard, who were responsible for clearing and securing the anchors, stated that they checked the starboard hook. Although the second mate said he ordered the anchors secured when departing De Tour Reef, the last order to secure them before the dragging incident, the able seaman on watch said he did not actually secure the starboard anchor despite communicating to the wheel- house that all anchors were secured.

The irony and artifice are unmistakable. Culpability for the one-off anchor strike lies squarely with the negligence of the Clyde S VanEnkevort/Erie Trader crew, namely the captain. But political and environmental opprobrium has instead been heaped on Enbridge Inc. If even muted criticism has been levied at Michigan’s VanEnkevort Tug & Barge, or for that matter the Great Lakes maritime community at large, it has been drowned by misdirection. Enbridge is the innocent party bitten, though the energy company and its downstream customers have been targeted for castigation, calumny, and dispossession.

(SOURCE: The Weekly Propane Newsletter, July 15, 2019)