Q+A-What could have damaged Mitsui OSK's tanker?

News was prepared under the information support of Online Daily Newspaper on Hellenic and international Shipping "Hellenic Shipping News".

31 Jul 2010

A Japanese tanker may have collided with a submarine or a mine in the sensitive Strait of Hormuz oil shipping route, UAE port officials inspecting the ship said on Thursday.
Japanese shipper Mitsui O.S.K. Lines Ltd has hired a specialist on military attacks to help investigate its 333 metre tanker M. Star, which was damaged early on Wednesday while travelling from the Gulf with a cargo of crude oil for Japan.
The incident had for a time stirred fears of an attack in the Strait, the route for 40 percent of the world's seaborne oil and gateway to the oil-producing Gulf, where al Qaeda has threatened to attack shipping.
Here are some questions and answers on what may have caused the damage.
Was it a freak wave?
Authorities in the UAE launched an inquiry into the incident after officials had initially said the damage was caused by a quake-related wave.
But a freak wave was ruled out by a general manager of Fujairah port.
Maritime experts added that it was not feasible that the damage caused to the vessel was from a freak wave. A picture of the tanker showed a large square dent had been made to its starboard quarter on the one side of the hull.
"When you see really bad wave damage it tends not to be just in one place. This is a really specific area on the tanker that was damaged, so it does not make sense," said Graeme Gibbon-Brooks, chief executive of maritime intelligence company Dryad Maritime.
Modern commercial vessels were built to be able to cope with North Atlantic weather conditions.
"So you are talking of up to force 12 mountainous seas and more than 100 knots of wind -- that is what a ship is designed for," a shipping source said.
The 2008 built M. Star also has a double hull.
Could it have been pirates?
Piracy was ruled out, as the type of damage the tanker sustained did not bear the hallmarks of how seaborne gangs operated. The incident also occurred too far north from where pirates had been active in the past.
Pirates have used rocket propelled grenades in attacks in the Gulf of Aden and maritime sources said RPGs could not have caused that type of damage to the tanker.
A Lloyd's List report speculated that damage may have been caused by a grenade attack.
What about an attack by a group?
Maritime sources have not ruled out the possibility of an attack but said there was still too little information to reach any definite conclusion.
"It is impossible to know immediately what happened. One scenario is that it could have been attacked, and other that it could have been a collision or an accident," said Jonathan Wood, global issues analyst with consultancy Control Risks.
"If you are someone with operations in the region, you're probably taking more care with security and again watching very closely."
Was it an internal explosion inside the ship?
Some shipping sources speculated that the damage may have been caused inside the tanker itself but others said the picture taken of the vessel indicated it was caused from outside.
"It was an internal explosion the hull damage would have been convex not concave shaped," said John Dalby, chief executive of maritime security company MRM.
A maritime source said separately, another scenario is that one or more storage tanks imploded due to the inadvertent creation of a vacuum inside them as a result of the mismanagement of pumps.
Vessels have many tanks, for ballast, for fuel, for water, and they have to be cleaned, maintained and managed by pumps. If liquids are removed and air is not let in, the resulting vacuum can collapse the tank, producing a sound like an explosion.
Could the tanker have struck a sea mine?
Maritime experts ruled out a sea mine as it would have caused damage underneath the tanker and there would have been hull penetration.
"This is not damage that I would associate with a mine or torpedo," said Gibbon-Brooks, a former mine clearance diver and above water warfare officer with the Royal Navy.
"From the evidence, it looks like it's an external event that has been delivered from the sea surface," he said.
Could it have collided with a submarine?
A Fujairah port official said on Thursday a submarine collision could have caused the damage.
"The damage is too uniform. It's almost a perfect square which indicates a man-made object -- it could have been a submarine," said Dalby of MRM which provides risk assessments to companies.
"It could also have been the bull nose end of a jetty at one of the loading ports where the tanker may have come into contact with

Source: Reuters