The Russian tanker Nakhodka, which broke apart and sank off the Sea of Japan coast in January, was too old and worn out to weather the rough seas, a Transport Ministry panel concluded July 31.
The panel’s report brushed aside Russia’s argument that the 13,157-ton tanker, which spilled at least 5,000 kiloliters of heavy oil and caused massive environmental damage on a wide coastal stretch, sank after hitting a submerged object. The ministry panel, led by Hideomi Otsubo, professor of engineering at Tokyo University, briefed Transport Minister Makoto Koga on the final result of its six-month investigation on the accident, which occurred off Shimane Prefecture on Jan. 2.
“Normally, ships are designed to last for about 20 years, whereas the Nakhodka was 26 years old,” Otsubo told a news conference. “The accident was caused by the shipowner’s policy (of continuing to use the aged tanker).” The 177-meter tanker broke apart 51 meters behind the bow, and it appears the ship was destroyed by a high wave almost instantly, according to the report.
The durability of the Russian tanker, which was built in 1970 in Poland, had substantially decreased by the time of the accident due to the deterioration of its steel-sheet hull, and the force of the waves was too strong for the tanker to endure, the panel said. An examination of the bow section, which drifted to the shore of Fukui Prefecture and was later taken by barge to a Hiroshima shipyard for inspection, revealed that corrosion and other deteriorating factors rendered the steel deck and hull plates 20 percent to 35 percent thinner than they were when the ship was launched.
At the time of the accident, weather in the Sea of Japan was very rough, but the wind and waves were not severe enough to destroy a large ship the size of the Nakhodka if it had been in sound condition, the panel said. When the ship broke apart, waves were estimated at up to 15.3 meters high and wave troughs were about 126 meters, according to the report.