The last time I saw damage like that shown in the Photo, (Starboard side aft probably a slop tank), was when a P/V valve jammed shut and the cargo/ballast pump put a vaccuum on the tank. I don't know the age of the ship, but if it is a double hull, it would be fairly easy to pull a vaccuum in the double hull with a stripping pump, if the vents were shut off of course.

As the scantlings failed between the main brackets, the noise would sound like an explosion.

 

Well, that would be two of us.

(Seen it done on a bulk carrier, where deck vent on a saddle tank was crudded up, and, no names no pack drill, a passenger ship...)

 

ooh that looks very suspiciously like vacuum damage - assuming fairly standard construction that is around the aftermost wing ballast tank.

Could be something else of course but nothing i have seen.

 

I have, in a spirit of devilment, circulated that photo to my Superintendents, one of whom is a tanker man, offering a reward in beer to anyone who comes to the same conclusion...;-)

 

Judging by the condition of her paintwork she looks as though she has just come out of drydocking/overhaul, I wonder if that has anything to do with what appears to be a vacuum caused damaged.

 

A very good chance that the P/V valves were chocked, and or, the ballast(?) vents were closed after a stagger test following docking, which could account for the need to pump out the space. Or someone forgot that there was ballast in the tank for docking trim.

 

It certainly looks like vacuum damage, but it looks too far aft to be a slop tank - abaft the bridge wing support.

More likely a fuel tank or a wing ballast tank.

The corrugations are visible above the larger collapse, and the tank has collapsed between frames and below a horizontal girder.

Release of the innocent and search for the guilty begins ........

B/R

 

On that basis Roddy, I'd have to go for a wing ballast tank, as a bunker tank wouldn't corrode and weaken the scantlings, also there's usually not enough, "suck", on a fuel transfer punp, as there is on a main ballast pump.

Steel damage looks like about 40-50 tonnes. Althouigh there could be a lot more cracking, above the main damage.

 

The location of the damage is too far aft for a wing ballast tank and too far forward for the aft peak. This is somewhere in the vicinity of the engine room and is more than likely to be a fresh water, fuel settling/service or lube oil tank.
My technical colleagues reckon that this has been caused by vacuum and would be possible on any tank providing you pull a suction long enough.
Steelwork in tanks is designed for the stress and pressure to be exerted outwards on the tank skin, so the vacuum required to cause distortion is much less than the pressure to cause the tank skin to distort outwards.
The noise made by an implosion is very similar to that of an explosion.

 

It is actually right in the normal position for the aftermost wing ballast tank in most modern tankers - fresh water tanks are usually aft and big bulk lub and fuel tanks are inboard of these tanks - in effect making them double skinned. Its not so much the type of pressure its any pressure - there is a lot of square inches there so a little pressure either way is an enormous amount of force.

 

According to Equasis information, she was built 2 years ago...

IMO number : 9515436
Name of ship : M. STAR (since 01-12-2008)
Call Sign : V7QT7
MMSI : 538003436
Gross tonnage : 160292 (since 01-12-2008)
DWT : 314016
Type of ship : Crude Oil Tanker (since 01-12-2008)
Year of build : 2008
Flag : Marshall Islands (since 01-12-2008)
Status of ship : In Casualty Or Repairing (since 28-07-2010)
Last update : 30-07-2010

 

According to my son, 2nd engineer on the EXXON tanker Alrehab, which is tied up along side MV Star, the explosion caused the bridge windows to blow inwards, injuring the second mate.

 

Bob, that's very useful - your son is certainly the best source of information we are going to get.

Lloyd's List today mentions damage to the starboard lifeboat as well.

Any further comments from your son very welcome!

 

I have asked him to try and get some photographs

 

Well, a two year old ship, is not going to have weaked/corroded scantlings. so that tosses out a corrosion problem. Could be an airburst bomb or mine, which could account for the bridge windows. Or even a large explosive charge thrown off the vessel which exploded when hitting the water, a bit far fetched perhaps but cannot see any other explanation.

 

Might just be me but it looks like the damage stops at the water line - so i would guess it was not a water borne explosion - which would ba much more devastating


I suppose the mate realising he had vaccuumed the tank could have gone up to the bridge smashed a couple of windows and kicked the 2/O in the nuts

 

Now we have the further information it does seem a bit strange that an air burst has only confined the damage to a particular area of the Hull. Although I suppose they could have been dumping some Pyrotechnics off her.

 

It would be a large lump of pyrotechnics geordie.

 

I am with you on this one Billieboy, It all seems a bit odd for it to be as the result of an explosion which has been previously indicated although I am sure the source is reliable and only passing on what he was told by the Ships Crew. It is very localised and you would expect more upperwork damage possibly to her Funnel bearing in mind it was supposed to have blown some of the Bridge windows in, unless it's from a hand held rocket launcher that has not exploded on contact. So lets say possibly a vacuum problem which will have "jarred " the ship causing other damage, although I like S.M.'s "theory" on how the other damage was caused(Thumb). However in writing the above a block of Carbide smaller than the size of an OXO cube in a Cocoa tin (with a hole drilled in) makes a one hell of a bang to the point of the old Chief dashing out of his cabin thinking one of the Boiler's had gone.(Jester)

 

Just a thought:

The ship will no doubt have been built with automatic double penetration welding of the side shell and stiffeners on a panel line/block line, with hand welding of the ring frames iwo the intercostals and subdecks.

Now, if I were to speculate that the hand welding of two of the ring frames to the intercostals just above the waterline may have failed, but the machine welding has stood up...

...I would think we might get the shape of damage that we see from a vaccuum problem.

Please correct me if I am astray here.

 

It would be on a, "non-cargo block", too which could slip inspection. It still doesn't explain the Bridge windows though, unless a sudden movement of the accomodation block compressed the glass.

 

MOL inspects damaged VLCC
(July 30 2010) Mitsui OSK Lines (MOL) started to inspect the damaged VLCC ‘M Star’ last Thursday, while the vessel was at anchor off Fujairah.


The vessel suffered an explosion while outbound near the Strait of Hormuz, early last Wednesday.


Masahiko Hibino, the company’s tanker safety head, told Bloomberg in Tokyo that the vessel was anchored off Fujairah.


He declined to comment on the cause of the blast on board the VLCC, which was initially thought to be as a result on an ‘attack’.


However, the vessel may have been involved in a collision, Moosa Murad, general manager at the Port of Fujairah, said.


Hibino said that 10 people were working on the investigation, which was being aided by the US Navy and the UK authorities.

It was unclear how long it will take, he said on Thursday.


The explosion, which “may have been caused by an external attack,” occurred at 5:30 am Tokyo time Wednesday, injuring one of the crew, MOL said in a statement.


The tanker, anchored about 10 miles off Fujairah, will likely remain there for three to four days, Murad said.


‘M Star’ was heading to Chiba from the UAE, where it had loaded the crude.


Earlier, Junto Endoh, general manager in MOL’s Doha liaison office, speculated that the damage was caused by “maybe an attack, not a spontaneous accident; it may be a terrorist attack.”


The vessel — crewed by 16 Filipinos and 15 Indians — was carrying 270,000 tonnes of crude but did not suffer any spillage.


Initial assessments from MOL found that one lifeboat was blown off the ship and there was some damage to the starboard tanks.


At the time of the incident, the tanker was delivering a cargo to Cosmo Oil, a Japanese refiner partly owned by Abu Dhabi interests, according to Katsuhisa Maeda, a spokesman for Cosmo.


She was scheduled to arrive at Cosmo’s Chiba refinery, near Tokyo, on 17th August, he said.

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There is a larger & clearer photo of the dent on the BBC News website...

http://www.bbc.co.uk/news/world-middle-east-10803239

 

I still say vacuum damage, and have been on older tankers where there was a ballast tank abreast of the engine room.

They were separate from the SBT system and ER GS pumps were used to fill and empty them.
In fact I never saw one used in anger, they were always empty.

The usual progression from forward in a single skin ship was cargo wing, slop tank, pumproom or cofferdam, bunker tank, ballast tank, then ER and Steering Gear.

Loss of the lifeboat could be due to the deck being pulled down below the davit, though you can't see that in the photo.

An implosion like that would certainly be quite violent.

Let's see what they come up with, or choose to keep quiet.

B/R

 

My main reason for sticking to vaccuum, is that even if there was an airburst explosion, the paintwork would be damaged!
As Roddy says the deck being pulled down could explain the loss of the life boat and, as I said earlier, the damage to the bridge windows.

 

I see that MOL are not discounting an on board cause; also that Intertanko has weighed in, a bit prematurely I think.

 

Andrew,
I've been reading all the reports whilst travelling this week and fully agree with your comments. I find it difficult to believe the current reports and am still scepticle of the latest MOL story. Chris

 

Has there been any further information been released on the M. STAR incident? I enjoyed reading all the 'posts' on what could have happened. Very informative, thanks.

 

Thank you woodend, I'm glad that someone appreciates the deductive process, it's not the sort of minor casualty that would occur on a banana or fruit boat. I have to admit that I've only run into three vacuumed tanks, although one of them was an over pressured membrane gas tank!,(that was expensive!).

 

We need a photo of the deck. In the two implosions I was involved in,
the deck failed before the shell but both were in the cargo area,
It's conceivable the deck was pulled down, and when the side shell failed
and released the vacuum the deck sprung back and produced
the pressure pulse that blew in the window. If so (and its a long short),
the deck should be deformed upward.

KTF

 

Safety at Sea International - Dedicated to Safety at Sea | 05 Aug 2010


M. Star: suicide bomber said to be responsible Terrorists claim VLCC attack
A TERRORIST group linked with Al Qaeda has reportedly released a statement saying it attacked the Mitsui OSK Lines VLCC M. Star last week.

"Last Wednesday, after midnight, the martyrdom-seeking hero Ayyub al-Taishan … blew himself up in the Japanese tanker M. Star in the Strait of Hormuz between the United Arab Emirates and Oman," the Brigades of Abdullah Azzam group said in a posting on a militant website, Reuters reported. The group has been based in southern Lebanon.

The statement could not be immediately verified, the news agency said, but it was consistent with the conclusions of explosives experts interviewed by Fairplay that the dent had probably been caused by a small craft with a bomb aboard.

Several investigations have been taking place since the tanker’s crew reported an explosion on 27 July. The vessel has a large square-shaped dent in its hull just above the waterline. The possible explosion of a rogue sea mine is also still being investigated.

An MOL spokeswoman told Fairplay that the company has only just received reports of the militants’ statement and is seeking to “find out if it’s true or not”.

Suggestions that the damage had been caused by a rogue wave or a rocket-propelled grenade have been ruled out by investigators.