Casualty briefs

Briefs Broanna
Courtesy TSB
Bro Anna is shown moored above Upper Beauharnois Lock on the St. Lawrence Seaway on Aug. 30, 2017, the day after the tanker grounded. An electrical overload caused a blackout and shut down the ship’s main engine, the bow thruster and the steering gear.

TSB: Overloaded thruster caused tanker grounding
A loaded gasoline tanker that ran aground last year in the St. Lawrence Seaway near Beauharnois Locks in Quebec had lost all electrical power, according to Canada’s Transportation Safety Board (TSB).

The Singapore-flagged Bro Anna had taken on cargo at the Port of Montreal and was upbound for Oakville, Ontario, when the incident occurred at about 1815 on Aug. 29, 2017. The ship lost power just minutes after clearing the Upper Beauharnois Lock and hit the breakwater on the south side of the Beauharnois Canal.

TSB investigators conducted an inquiry into the accident, which did not cause any pollution or injuries. The agency traced the electrical failure to Bro Anna’s bow thruster circuit-breaker trip and time delay settings, which were set to accept a higher load than the bow thruster’s main circuit breaker.

Crewmembers first recognized a potential problem with the electrical system at 1654 when the bow thruster shut down. After the second engineer was unable to reset the breaker and alarm, the chief engineer responded and the bow thruster came back online.

At 1809, the master shut down the bow thruster, three minutes after leaving the lock’s confined spaces. This caused a “brief fluctuation” in the thruster’s load indicator, the report said, which spurred the master to restart the thruster. At that time, crew in the forecastle heard a loud sound, and engine room crew reported vibrations nearby.

“In this occurrence, the bow thruster went into overload and the bow thruster’s local circuit breaker was able to accept a higher load due to the incorrect trip and time delay settings,” the TSB report said. “The bow thruster’s main circuit breaker received the overload, and the power management system’s only option to safely control that overload was to open the main circuit breakers for the three auxiliary generators.

“This caused the blackout and shut down the main engine, the bow thruster and the steering gear,” the report continued. “The three auxiliary generators kept running while the emergency generator started and connected to the emergency switchboard. The investigation was unable to determine the source of the overload.”

The TSB noted that a few weeks earlier, Bro Anna sustained a bow thruster and generator failure while approaching Eisenhower Lock. Authorities attributed that incident to “the bow thruster’s thermal overload protection system.”

The TSB determined circuit breakers for Bro Anna’s three auxiliary generators were set to manufacturer’s settings, but at a level lower than the bow thruster’s circuit-breaker settings. As such, they could not accept the thruster’s higher load.

Bro Anna’s breakers have since been reset to the manufacturer’s standards. The TSB said managers of the ship, which is operated by Maersk Tankers, also notified crews on other vessels in the fleet to check for similar settings issues on bow thrusters.

Information on possible damage sustained in the accident was not available.

Two rescued after barge hits Minnesota motorboat
Two people were thrown into the Upper Mississippi River near Red Wing, Minn., after a barge tow ran into their disabled motorboat inside the navigation channel.

The 4,200-hp towboat Bill Stegbauer was upbound with six dry-cargo barges when the tow collided with the 15-foot pleasure craft, which was out of gas and drifting, U.S. Coast Guard spokesman Dana Schmitt said. The incident happened on July 28 at about 1315 at mile marker 791.

Red Wing County sheriff’s deputies pulled the boaters from the water uninjured. The towboat, its barges and the motorboat were not damaged, and no pollution was reported.

Additional information about the accident was not available. “I can’t speculate on where it collided,” Schmitt said, referring to where the barge tow struck the drifting vessel. “But due to the fact there was no damage, pollution or injuries, it was deemed not a reportable casualty. Luckily, nobody was hurt.”

Southern Towing of Memphis, Tenn., operates Bill Stegbauer. The 140-foot towboat has a retractable pilothouse and was built in 1975, according to Southern’s website. The company did not respond to requests for comment about the accident.

NY tug guided to safety after losing steering
A tugboat pushing nine barges loaded with stone lost steering while underway in the Hudson River in New York City, but a more serious incident was avoided due to the quick response of a nearby vessel.

The 3,000-hp Buchanan 12 was traveling southbound on Aug. 8 at about 1300 when its steering failed near the Lincoln Tunnel, the U.S. Coast Guard said. Sector New York issued a safety bulletin and Hayward, a U.S. Army Corps of Engineers drift collection vessel, responded to the scene.

Hayward was able to keep the tug and barges out of shoal water until assist tugs arrived,” the Coast Guard said in a news release. “A boat crew from Coast Guard Station New York also arrived on scene to monitor the situation and keep other vessels clear of the tug and barges.”

Two unnamed assist tugs arrived about an hour later at 1415. They helped the disabled tug steer the barges to Greenville Yard in Jersey City, N.J., then assisted Buchanan 12 to Caddell Dry Dock in Staten Island for repairs.

The cause of the steering malfunction has not been disclosed.

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