Collision in the Inland Sea

On the morning of Jan. 15 around 8 a.m., a small sports fishing boat and the Maritime Self-Defense Force’s 8,900-ton tank-landing ship Osumi collided in the Inland Sea, killing two of the four men aboard the boat.

In the area where the collision occurred — off Atada Island of Otake, Hiroshima Prefecture — there are many islands and sea traffic is heavy. But on the morning when the collision happened, the weather was fair and the sea was calm.

At this point, details surrounding the collision, including the movements of both vessels just before the collision, have not been determined. The Japan Coast Guard and the Japan Transport Safety Board need to carry out a thorough investigation and the MSDF must extend its full cooperation.

One of the survivors from the sports fishing boat said the 7.6-meter-long boat was cruising in a forward direction when the 178-meter-long Osumi, located behind it, increased its speed and struck the boat’s starboard side. Marks, several tens of meters long, believed to be from the collision, were found on the port side of the Osumi — stretching from the middle of the hull toward the stern. The collision occurred while the Osumi was heading from the MSDF base in Kure, Hiroshima Prefecture, to a shipyard in Tamano, Okayama Prefecture, for maintenance.

The other survivor gave the following account: When the fishing boat and the Osumi were moving forward in parallel, a freighter came from the right to cross in front of them. The MSDF ship, which was behind the boat, first turned to the right to avoid the freighter. After the freighter passed, the MSDF turned to the left and struck the boat.

But according to PASCO Corp., which collects and analyzes geospatial information, there are no records of the wake of the freighter that the survivor mentioned. There is a possibility that no such freighter existed.

One factor that must be discerned through the investigation is whether the Osumi’s observation capabilities were sufficient. Because the ship’s bridge is located to the right from the center line of the deck, there is a blind spot in the port side area for crew members in the bridge.

There have been other accidents involving MSDF ships over the past three decades. Among them were a July 1988 collision between the submarine Nadashio and an anglers’ ship off Yokosuka, Kanagawa Prefecture, in which 30 aboard the latter were killed; a February 2008 collision between the Aegis destroyer Atago and a fishing boat off Boso Peninsula in Chiba Prefecture, with the two aboard the fishing boat first listed as missing and then regarded as dead; and an October 2009 collision between the destroyer Kurama and a South Korean container ship in the Kanmon straits.

In the Nadashio incident, the final maritime accident tribunal decision equally blamed both the submarine and the anglers’ ship. In the Atago incident, an insufficient watch on the part of the Aegis destroyer was blamed.

The MSDF should disclose all information related to the latest collision accident. It also should examine whether MSDF members have drawn proper lessons from past accidents and are strictly following prescribed measures to avoid maritime accidents. If inadequacies are found, new steps to avoid such accidents should be implemented.