Maritime Casualty News, May 2020

Fatal collision leads to safety alert on accurate AIS data

The U.S. Coast Guard has issued a safety alert highlighting the importance of broadcasting accurate automatic identification system (AIS) information, particularly for vessels operating on inland waterways with bends, bridges and other obstructions.

The service issued the alert May 13 as a result of an ongoing investigation into a fatal collision on the Mississippi River. The alert said neither vessel broadcast the total length of their tows over AIS. 

“The first vessel’s AIS broadcast showed its length at 72 feet, but the overall length of the vessel and its two-barge tow was 672 feet,” the Coast Guard said. “The second vessel’s AIS broadcast showed the length at 200 feet, but the overall length of the vessel and its 40-barge tow was 1,600 feet.

“Without the information regarding the total length of the other vessel and its tow, the operators did not have a full understanding of the pending passing situation. As the vessels rounded the bend and completed their turns, they collided, causing the downbound towing vessel to capsize and sink with several fatalities,” the alert continued. The Coast Guard did not identify the vessels involved or where the accident occurred on the river.

The service recommended that operators take steps to ensure they are accurately reporting the overall dimensions of their towboat and their tows. The service also recommended that inspectors and investigators be aware of potential AIS issues when investigating casualties. 

The full alert can be viewed here.

Faulty dead reckoning cited in Puget Sound yacht sinking

Federal investigators determined a yacht sinking in Puget Sound that caused an estimated $500,000 in damage stemmed from faulty dead reckoning.

The operator of the 71-foot cabin cruiser Silver Lining grounded on a charted shoal known as the Sisters near Hood Canal Bridge with eight people aboard. The vessel took on water and sank, according to the National Transportation Safety Board (NTSB), which released the report during Safe Boating Week earlier this month. 

“As a navigational reference, the owner waited until the dinghy he was towing 100 feet astern passed the navigational marker on the southern part of the Sisters rock formation before slowing the boat’s speed and turning to port 10 to 20 degrees,” the NTSB said. “Shortly after the starboard engine stopped, the engine shutdown alarm activated and the vessel began to vibrate as three loud banging noises came from the hull. 

“The boat then came to a stop and the port engine shut down on its own. After the automatic bilge alarm sounded, the owner checked the engine room and confirmed the vessel was taking on water,” the agency continued. All eight people on board put on life jackets and escaped into a 12-foot dinghy. 

The NTSB determined that Silver Lining’s operator failed to properly determine the vessel's position while approaching the west span of the Hood Canal Bridge from the south, “resulting in damage and uncontrolled flooding after striking the charted Sisters underwater shoal.”

The NTSB’s casualty brief describing the incident can be found here

Casualty flashback: May 1956

Two freighters traveling in opposite directions collided near Point Sur, Calif., during the overnight hours, and four men aboard one of the vessels died. 

SS Marine Leopard was sailing from San Francisco to San Pedro, Calif., when its bow struck SS Howard Olson sailing north from San Pedro to Coos Bay, Ore., with a load of lumber. The collision happened May 14 after 0200 in clear, calm conditions.

According to a Coast Guard report from late 1956, the two ships were lined up initially for a port-to-port passage. Both vessels made course changes leading up to the collision, and SS Marine Leopard’s bow slammed into SS Howard Olson’s starboard side at almost a 90-degree angle. SS Howard Olson’s bow broke off, and the vessel sank soon afterward. Its crew abandoned ship into the dark sea covered in fuel oil. 

Three of SS Howard Olson’s crew died as a result of aspirating water and oil, the Coast Guard said. A fourth victim was never found and was presumed dead. 

The Coast Guard determined the mate aboard SS Howard Olson violated the “rules of the road” by not moving to starboard for the port-to-port passage. A similar finding was made against the captain of SS Marine Leopard for failing to sound the ship’s whistle when moving to starboard. The service recommended action against both men for negligence, although it is unclear if either ever faced criminal or civil sanctions. 

The full investigative report can be found here.

By Professional Mariner Staff