What caused Navy destroyer’s deadly collision?

In this June 18, 2017 file photo, damaged section of the USS Fitzgerald is seen at the U.S. Naval base in Yokosuka, southwest of Tokyo. The U.S. Navy has identified the seven sailors who died when their destroyer collided with a container ship off Japan on Saturday.(AP Photo/Eugene Hoshiko, File)

Early Saturday morning, a U.S. Navy destroyer collided with a Philippine container ship off the coast of Japan, resulting in the deaths of seven Navy sailors. The USS Fitzgerald, a missile destroyer based at Yokosuka Naval Base in Japan, collided with the ACX Crystal, a merchant vessel three-times the size of the Fitzgerald, which caused severe damage to the destroyer’s starboard side.

To understand what might have caused the collision and how sailors prepare for this type of disaster, we spoke with Peter Boynton, chief executive officer and co-director of Northeastern’s George J. Kostas Research Institute for Homeland Security. Boynton previously served as an officer in the U.S. Coast Guard, where as captain of the port for Connecticut and Long Island he led the rescue of an oil tanker aground on Long Island. He also served as commanding officer of three Coast Guard cutters over the course of 10 years of sea duty and holds an unlimited Master’s license for ocean-going vessels of any tonnage.

What was your initial reaction to the news of the collision?

I felt from my time in the Coast Guard that people who serve in the Armed Forces truly have dangerous jobs. It’s a tragic reminder that danger exists, even when not in combat. What we ask them to do is inherently dangerous. It’s worth stressing that, because we ought to appreciate what these men and women are doing around the globe even when they’re not at war. It’s also a burden for the families, and I send my condolences to them and crewmembers.

My next thought, having been involved in a number of casualty investigations, is that we don’t have all the facts yet. It’s easy to form conclusions ahead of time, but we need to take a deep breath and take the time to investigate. I’m happy to see that there will be a U.S. Navy, U.S. Coast Guard, and Japanese investigation into this incident.

What initial conclusions did you draw from seeing the damage that the USS Fitzgerald suffered in the collision?

The pattern of damage does suggest, given the information available, a “crossing situation.” There is a set of navigation rules called “COLREGS” that detail the kinds of approach situations that may take place between vessels at sea. It could be one vessel overtaking another, or two vessels meeting each other head-on. The third is a crossing situation. This is similar to a road intersection for cars. Of course, there are no streetlights in the ocean, but there are rules that govern which vessel has the right of way. These international rules of the road have been around for a long time. An old version was signed by President Lincoln, and the current version was signed by President Carter in 1977 and applies to all vessels at sea.

What is a “crossing situation”?

In a crossing situation, the vessel on your starboard has the right of way. In this case, that would’ve been the ACX Crystal, based on the limited information we have so far. Beyond those three situations, there are also special circumstances, and that’s what we don’t yet know about this specific incident. We don’t know what type of maneuvering was taking place prior to the collision. For example, the COLREGS include a “special circumstance” when there are more than two vessels meeting. There could have been additional vessels nearby at the time of the collision that played a role in the maneuvering, but we don’t know that yet. There’s also a rule that says if vessels are in “extremis,” meaning that collision is imminent, and action by one vessel alone is no longer sufficient, then both vessels become burdened and both are required to maneuver to avoid collision, regardless of which vessel may have originally had the right of way.

Reports from The New York Times and comments by the admiral indicated that the captain’s cabin was severely damage and that as a result the captain was lucky to be alive. If that means the captain wasn’t on the bridge, then that would be highly unusual. All naval vessels have “standing orders,” which are a set of instructions from the captain to officers standing watch on the bridge of the ship. They specify certain circumstances when the captain must be called or notified during certain situations. Typically, a vessel approaching within a certain range is one of those circumstances where the captain would be called. It’s typical that the captain would be on the bridge when another vessel is nearby, or “close-aboard” in nautical terminology. A merchant ship colliding with another ship when the captain is not on the bridge raises questions, which the investigations will look into.

Additionally, the admiral said that the crew of the USS Fitzgerald was awakened by the violence of the collision. I’m surprised to hear that because all naval vessels are equipped with a set of alarms, with each alarm having a distinctive tone to indicate specific emergencies. There’s a specific alarm for collisions. Basic protocol stipulates that if a vessel is about to collide, the last line of defense is to sound the alarm and make an emergency announcement, which is called a “pipe.” The alarm and the announcement give the crew a chance to brace for the physical violence of a collision, which can cause injuries or casualties. It’s also the last line of defense for the ship itself. When the collision alarm is sounded , crewmembers are also trained to close any watertight doors or hatches that remain open. Closing watertight hatches is important for the safety of the crew and ship because it limits the extent of flooding from the collision.

In terms of the flooding, we can see from the photos that there was extensive damage to the top-side of the Fitzgerald, but we can’t see the damage below the water line. Most ships, such as the Crystal as well as naval vessels, are built with a bulbous bow that extends underwater beyond the bow of the ship that is visible above water. The bulbous bow provides significant advantages for the efficiency of the ship moving through the water by changing the shape of the bow wave. By the time the bow of the Crystal hit the Fitzgerald’s top-side, the bulbous bow underwater would’ve already hit and penetrated the Fitzgerald’s hull below the waterline, creating substantial damage and flooding that we can’t see in the photos.

What methods do ships use to detect other vessels in the ocean?

The area where this collision occurred is reported to be a busy shipping area, with around 400 ships passing through daily. Under the COLREGS, all vessels are required to have lookouts. It’s pretty low tech to have a person with binoculars on the lookout, but it remains an important way to maintain situational awareness, such as the location of other vessels around the ship. Reports indicate it was a clear night at the time of the collision, so a low-tech visual lookout should have provided a visual indication of an approaching ship. In a busy area, it can be difficult to distinguish between many ships, but the configuration of navigation lights that are required by the COLREGS provide a means to determine the “aspect” or direction that other ships are heading. In a crossing situation, the side lights, which are red and green, act somewhat like traffic lights. Whether all of the navigation lights were operating correctly on each vessel is another question the investigations will examine. In this situation, the Fitzgerald should have seen the red side light on the “port” or left side of the Crystal. And the Crystal should’ve been able to see the green running light on the “starboard” or right side of the Fitzgerald. If this were in fact what happened, then this type of crossing situation would indicate the Crystal having the right of way, with the Fitzgerald being the “burdened” vessel, required to maneuver to keep clear of the Crystal unless other special circumstances applied.

There’s also sophisticated sensing systems, like radar, on both merchant ships and warships that are used to track the relative motion of the ships and determine whether or not they will intersect, assessing the risk of collision. The radar displays show vessel tracks and indicate whether vessels are approaching each other, and at what range, referred to as “closest point of approach” or “CPA.”

Another method to avoid collisions between ships is bridge-to-bridge radio telephone, also required by the COLREGS. There are predetermined channels and frequencies for ships to communicate with each other so that they can understand each other’s intentions. It’s another layer for ships to safely navigate, particularly in busy shipping areas.

So what happens next?

It’s important to give these investigations time. There should be plenty of recorded data, similar to what is recorded by flight recorders, or black boxes, following plane crashes. And there should be records of radio communications as well. With this information, investigators should be able to reconstruct what happened in the moments leading up to the collision.