The USS Fitzgerald collided with a Philippine-registered container ship off Shizuoka Prefecture’s Izu Peninsula early on Saturday.
The Japan Coast Guard is investigating why the Aegis-equipped destroyer carrying a high-performance radar was involved in such a collision. In clarifying the cause, the focus will be mainly on the two ships’ positions, routes and whether they were keeping an appropriate lookout.
Who is responsible?
The course the container ship took just before and after the collision is known. It left Nagoya Port on Friday evening and proceeded east toward Tokyo Bay. According to automatic identification system (AIS) signals, which show the positions of vessels, the ship suddenly changed its course to south at around 1:30 am on Saturday. Soon after that, it changed its course again to east. Around 2 am on the day, it started to make a U-turn and proceeded westward for about 30 minutes as if it was traveling back.
Meanwhile, detailed positions of the destroyer are not known. It is thought it left the Yokosuka base on Friday and traveled southward. A central part of the destroyer’s right side and the left part of the container ship’s bow were damaged. Therefore, it is believed that the container ship was positioned on the right side of the destroyer just before the collision. However detailed relative positions at the time of collision are unclear, including whether either vessel was trying to cross in front of the other or if they were trying to pass one another.
Under the Law on Preventing Collision at Sea, when two ships are about to collide, the ship responsible for avoiding a collision is determined by the positions of the vessels. The JCG strongly believes that the two ships collided around the time the container ship made an abrupt change of course at around 1:30 am. The JCG intends to continue its investigation.
An Aegis-equipped vessel has a SPY1 radar, which can simultaneously detect a few hundred objects and deal with more than 10 objects.
A senior official of the Maritime Self-Defence Force said: “The objectives of a SPY1 radar are basically attacks from the sky, including ballistic missiles. The performance of its ship-to-surface-vessel radar that detects other vessels during sailing is not greatly different from that of a civilian vessel.”
Therefore, sailors usually monitor ship-to-surface-vessel radar on a bridge that is set high up in the center of the vessel, and lookout personnel keep watch to confirm there are no other vessels around.
In the case of the MSDF, it is said that about 10 people on duty are positioned on the bridge during the night, and there are lookout personnel on the left, right and rear.
It is believed the two vessels could have been aware of each other’s position by radar or visually checking, relying on signal lights, as there was no fog and visibility was said not to be bad at the time of the collision.
“We usually complete actions to avoid collisions a few kilometers off in order to leave enough margin for error,” another MSDF senior official said. “The ways [the two vessels] were damaged show there was a very strong collision, not just light contact. It is highly possible that actions to avoid collision were delayed for some reason.”
The US Navy and the JCG will strengthen their investigations in a full-fledged manner. It remains to be seen whether the coast guard will be able to conduct a sufficient investigation into the US side, as the Japan-US Status of Forces Agreement may be a “hurdle.”
Questioning US military personnel requires the consent of the U.S. military. A senior official of the coast guard said, “The U.S. military’s cooperation is indispensable to determine the cause of the accident.”
The coast guard plans to ask the US military for cooperation in its investigation.
However, an official of the US Navy in Japan in charge of the matter told The Yomiuri Shimbun that the priority was on the rescue of the missing and that the cause of the accident is being investigated.
“Investigation and research are difficult without the cooperation of the US military, so whether they can get US cooperation will be an important point in determining the cause of the accident,” said a past head of the former High Marine Accidents Inquiry Agency.
“However, it will be not easy to get information as [topics related to] Aegis vessels are highly confidential.”
Collision likely to impact missile defence
The recent incident in which the US Navy destroyer USS Fitzgerald collided with a container ship could deal a heavy blow to the security of Japan and the United States, including missile defence cooperation.
According to the USNavy in Japan and other sources, the Fitzgerald is equipped with a ballistic missile defence (BMD) system, which consists of Aegis and Standard Missile-3 (SM-3) systems. The Aegis system is capable of detecting and tracking ballistic missiles.
The US Navy’s 7th Fleet stationed at the Yokosuka Naval Base in Kanagawa Prefecture has seven Aegis-equipped vessels with the BMD system, including the Fitzgerald.
The seven US Navy destroyers and four BMD-capable Maritime Self-Defence Force destroyers are engaged in vigilance and surveillance activities in the Sea of Japan and other areas in preparation for possible missile launches by North Korea.
However, destroyers have to leave these areas every few months for regular inspections, post-inspection training, to allow crew members to rest and other reasons.
In addition, as BMD-capable Aegis-equipped destroyers of the 7th Fleet also belong to the USS Ronald Reagan aircraft carrier’s strike group, the vessels are supposed to undertake tasks for the strike group as well.
Under such circumstances, Japan and the United States are forced to manage the tight conditions, thereby limiting the number of destroyers available to dispatch for duties to the Sea of Japan.
As the collision heavily damaged a section around the SPY-1 radar of the vessel — a key component of the Aegis system — there seems to be no prospect of getting the destroyer back on duty early.
According to sources, the US Navy has intensively deployed BMD-capable Aegis-equipped vessels for the 7th Fleet to take precautions against North Korea. Therefore, it is not easy to bring in the same type of vessel from other fleets.
“With North Korea about to complete its capability to fire multiple missiles simultaneously, it is hard to say that our preparedness [for Pyongyang’s possible missile launches] is adequate, even in the current situation,” a high-ranking Defence Ministry official said. “The latest incident could make the situation even worse.”