Japanese release findings of tanker blast investigation

Report finds MV Star was damaged by explosives in Strait of Hormuz last July

Last July, the M Star arrives in Fujairah after a mysterious explosion in the Strait of Hormuz dented the Japanese oil tanker’s hull.

DUBAI // A Japanese oil tanker damaged in the Strait of Hormuz last July almost certainly sustained an external blast, according to the findings of what is probably to be the final investigation into the incident.

The report on the M Star was completed by Japanese authorities in December and made available to The National yesterday.

It did not determine the source of the blast. The UAE had deemed the incident a terrorist attack and the US called this explanation “valid”.

“Unfortunately, we cannot decide if the cause was a terrorist attack, but we cannot deny the possibility,” said Hiroaki Sakashita, the safety and environment director at the Japanese Maritime Bureau, who led the investigation.

No further probe is expected by Japanese or other related authorities. The UAE Coast Guard said the case was closed, and the US Navy Fifth Fleet, which patrols the waters, said it only helped with the Japanese investigation. The regional manager handling maritime administration for the Marshall Islands, where the M Star is registered, declined to comment.

The tanker, which is owned by Mitsui OSK Lines, was struck on July 28 while carrying 270,000 tonnes of crude oil from the UAE to Japan. The blast severely dented the hull, broke windows and doors and injured a crewman.

The report ruled out other theories that had been suggested such as a freak wave, collision, internal explosion or landmine.

“A sea mine cannot be justified as the cause of the incident because the damages in the water were small,” it said. “The explosion occurred at the height between the water surface and the upper deck, and impact air pressure was diffused spherically.”

Investigators analysed 25 samples from the M Star but did not find any trace of explosives. Nor did they find any connection between the explosion and a small vessel that was seen on radar zipping around the tanker shortly before the incident.

Soon after the attack, a group called the Abdullah Azzam Brigades claimed responsibility. No terrorist attacks had previously been reported in the Strait of Hormuz, through which 40 per cent of oil shipped by tankers passes.

The US Department of Transportation warned last November that the Abdullah Azzam Brigades still posed a threat in the waterway.

“The group remains active and can conduct further attack on vessels in areas in the Strait of Hormuz, southern Arabian Gulf and western Gulf of Oman,” it said in an advisory.

Japan shared its findings with the US, UAE and other Gulf countries, said Ichio Motono, the director of the security management office at the Japanese Maritime Bureau.

About 10 people worked on the investigation, drawing on reports from crew, the Voyage Data Recorder and evidence from the vessel.