The USS Fitzgerald (DDG-62), an Arleigh Burke-class destroyer, collided with a merchant container ship about 56 nautical miles from Yokosuka, Japan on Friday, causing “severe damage” to the destroyer and the death of seven crewmembers.

The event occurred the early morning after midnight hours Japan time and the afternoon EDT in a busy shipping lane when the Fitzgerald collided with the Philippine-flagged merchant vessel ACX Crystal. The Crystal is over three times as massive as the Fitzgerald.

The Arleigh Burke-class guided-missile destroyer USS Fitzgerald (DDG 62) returns to Fleet Activities (FLEACT) Yokosuka following a collision with a merchant vessel while operating southwest of Yokosuka, Japan. U.S. Navy photo by Mass Communication Specialist 1st Class Peter Burghart/Released.
The Arleigh Burke-class guided-missile destroyer USS Fitzgerald (DDG 62) returns to Fleet Activities (FLEACT) Yokosuka following a collision with a merchant vessel while operating southwest of Yokosuka, Japan. U.S. Navy photo by Mass Communication Specialist 1st Class Peter Burghart/Released.

Various U.S. Navy and Japanese Coast Guard officials have given somewhat conflicting timelines of the collision ranging from 1:30 to 2:30 a.m. The Navy reported the collision time of approximately 2:20 a.m. but the Japanese Coast Guard changed this assessment to 1:30 after interviewing the crew of the Crystal.

The Crystal was chartered by the Japanese company NYK Line, which said on its website that the company and the shipowner “are fully cooperating with an investigation being conducted by the Japan Coast Guard.” The merchant vessel was built in 2008 and has a crew of 20.

The collision affected the Fitzgerald’s forward starboard side both above and below the water line, causing damage and rapidly flooding a machinery room and two berthing spaces for 116 crew.

Vice Adm. Joseph Aucoin, commander of the U.S. Seventh Fleet, noted in a Sunday press conference the damage included a “significant impact” under the ship’s pilothouse on the starboard side with a large puncture below the waterline, which opened the hull to the sea.

The cabin of the commanding officer, Cmdr. Bryce Benson, was also directly hit, trapping him inside it. Benson only took command of the Fitzgerald last month and was one of three patients that required medical evacuation from the ship. A Japan Maritime Self-Defense Force (JMSDF) helicopter transferred him to U.S. Naval Hospital Yokosuka.

A Navy spokesperson said via email that the service adheres to the international set of “maritime rules of the road” to prevent collisions. This provides maneuvering requirements for standardizing ships maneuvering at sea to avoid collisions for both commercial maritime and military ships.

Officers and enlisted persons that navigate Navy ships are required to complete extensive training before arriving on their ships “and must demonstrate the requisite knowledge and performance to qualify for specific watch stations onboard ship,” the spokesperson said.

Bryan McGrath, a former commander of the USS Bulkeley (DDG-84), wrote at War On The Rocks about those rules of the road, called the Convention on the International Regulations for Preventing Collisions at Sea (COLREGS 1972). In international law ships are supposed to maneuver in specific ways to avoid a collision. When two ships are on a path to cross, meet, or overtake specific regulations direct one with the privilege to stay on course (stand on) while the other should give-way to alter course and avoid a collision.

McGrath said while there are clearly defined terms in the rules for all sorts of situations on who gives way, “the problem is that humans on each ship are making this determination and, as we all know, to err is human.”

Navigators on a ship can mistake overtaking and crossing situations and then have conflicting views of which ship should hold course.

He added that these kinds of issues are compounded at night. While daytime interactions are based on the “visual presentation the other ship offers” and assess your location relative to it and act accordingly, at night lights of varying colors and visibility arcs are used to make a virtual picture of what one would see in the daylight.

However, fog, obscured lighting, and other issues can prevent one ship’s lights from being properly assessed by a second ship to best understand relative orientation and movement

McGrath also noted while radar is very helpful and often accurate in laying out ship paths and positions, “sometimes, the weather and waves conspire to create cluttered radar pictures. Such clutter is especially prevalent close to the ship.”

The clutter may also make it hard to keep a steady track on a contact, creating confusing evaluation of its course and speed.

The Arleigh Burke-class DDG has a Lockheed Martin [LMT] SPY-1 phased array radar, SPY-67 surface search radar, SPS-64 navigation radar, and commercial surface search radar to keep watch on nearby shipping traffic.

McGrath also highlighted while the Fitzgerald is relatively maneuverable, on the sea ships cannot stop quickly. A container ship like the one in this incident may take up to 2.5 nautical miles to stop and has a turning radius of over half a mile, according to formulas used under the International Maritime Organization (IMO).

Rear Adm. Charles Williams, commander of Task Force 70, noted the work of the sailors in keeping the ship stabilized and preventing it from possibly sinking.

“I want to highlight the extraordinary courage of the Fitzgerald Sailors who contained the flooding, stabilized the ship and sailed her back to Yokosuka despite the exceptionally trying circumstances.”

Aucoin also explained what the crew was able to do.

“The crew’s response was swift and effective, and I want to point out – as we stand by the ship – how proud I am of them. Heroic efforts prevented the flooding from catastrophically spreading which could have caused the ship to founder or sink. It could have been much worse,” he said.

Vice Adm. Joseph Aucoin, commander U.S. 7th Fleet, speaks to the press on June 18 about the USS Fitzgerald (DDG-62) after a collision with a merchant vessel. U.S. Navy photo by Mass Communication Specialist 1st Class Peter Burghart/Released.
Vice Adm. Joseph Aucoin, commander U.S. 7th Fleet, speaks to the press on June 18 about the USS Fitzgerald (DDG-62) after a collision with a merchant vessel. U.S. Navy photo by Mass Communication Specialist 1st Class Peter Burghart/Released.

Aucoin also noted the Fitzgerald’s crew navigated with a magnetic compass and backup navigation equipment to get it back to port. One of two shafts were locked as well.

“Because of the tireless damage control efforts of a resolute and courageous team, the ship was able to make its way back to port safely on its own power last evening,” he said Sunday.

Aucoin highlighted the Navy would investigate the incident.

“We owe it to our families and the Navy to understand what happened.” Under his authority, Aucoin is initiating a Judge Advocate General Manual investigation into the collision and will appoint a flag officer to lead that investigation. He also said there would be a safety investigation.

The U.S. Coast Guard is set to take the lead on the marine casualty investigation.

“We recognize that there are other organizations who have equities in this incident, and we expect they will conduct their own separate investigations. More information on any further investigations will be forthcoming,” Aucoin added.

He said he would not speculate on how long the investigations will last.

Acting Secretary of the Navy Sean Stackley emphasized that “in due time the United States Navy will fully investigate the cause of this tragedy and I ask all of you to keep the Fitzgerald families in your thoughts and prayers as we begin the task of answering the many questions before us.”

The Seventh Fleet commander aslo expressed gratitude to Japan’s quick assistance and support.

“Japanese Coast Guard ships and helicopters were the first on scene and our first medevac, the ship’s commanding officer, Cmdr. Bryce Benson, was accomplished thanks to a JMSDF (Japan Maritime Self-Defense Force) helicopter.”