Container Ship Breaks In Two, Sinks 361
Cliff Stoll writes "Along with 7000 containers, ship MOL Comfort broke in half in high seas in the Indian Ocean. The aft section floated for a week, then sank on June 27th. The forward section was towed most of the way to port, but burned and sank on July 10th. This post-panamax ship was 316 meters long and only 5 years old. With a typical value of $40,000 per container (PDF), this amounts to a quarter billion dollar loss. The cause is unknown, but may be structural or perhaps due to overfilled containers that are declared as underweight. Of course, the software used to calculate ship stability relies upon these incorrect physical parameters."
Great photos (Score:4, Informative)
Re:Declared underweight? (Score:4, Informative)
It was my understanding that the cranes weigh each container as they are loaded on the ship. This is done because they can't afford mistakes in calculating the center of gravity of the ship. There is no honor system.
Re:So do those containers sink or float? (Score:5, Informative)
Nagasaki, Japan (Score:4, Informative)
According to Wikipedia:
Mitsubishi Heavy Industries, Nagasaki, Japan
http://en.wikipedia.org/wiki/MOL_Comfort [wikipedia.org]
So when did Japan become a 3rd world country that lacked advanced and sophisticated systems?
END COMMUNICATION
Re:Declared underweight? (Score:5, Informative)
Perhaps they could paint a line on the side of a large vessel floating in water and see if the containers displace enough water to submerge the line. Oh wait, that's what they do with all container ships. It's impossible for the whole ship to be over weight. It is possible to have a poorly distributed load, but that's not likely to cause the type of accident that happened here (it would more likely lead to capsizing).
Overweight containers are more of a financial issue than a safety issue. Leaving 500 containers on the dock or leaving under-loaded are both bad for business.
Re:Declared underweight? (Score:2, Informative)
That doesn't pass the sniff test: every cargo ship has a built-in way of determining precisely how heavily it's loaded. It consists of a few ounces of paint, and it's called a Plimsoll line...
Re:Declared underweight? (Score:5, Informative)
Moments, how do they work?
If you load the shit out of the topmost containers, it gets tippy as fuck. As an example of "huh", there's a thing that's going on the mast of a ship that I've worked on. The thing doesn't weigh that much -- although it's being loaded by crane, I could lift it by myself.
To compensate, way more ballast than I can lift is going in the hull.
Re:Declared underweight? (Score:5, Informative)
Many cranes DO have a scale built in. 250,000 Kg capacity accurate to 50Kg. That should do the job.
Re:Declared underweight? (Score:4, Informative)
That line doesn't mean shit when the bow and stern are crested across two wave peaks.
Re:Declared underweight? (Score:2, Informative)
So... how does that relate to overloading?
I didn't say anything about how this accident was caused, I only responded to someone who implied that shipping companies overload their ships and let the insurance companies cover their asses with a simple fact that it's not possible to get away with putting too much weight on a ship. I have no idea how you came to the conclusion that I don't know the possible problems associated with a poorly distributed load, since that's not what was being discussed.
Re:Declared underweight? (Score:5, Informative)
The usual tariff is based on a concept called "weight-measure", which works like this:
- For cargo less dense than water, a given tariff is per cubic meter.
- For cargo denser than water, the tariff is per metric ton (one cubic meter of water weighs one metric ton).
If you think about it, this makes perfect sense, because anything heavier than denser than water has to be accompanied by enough air (i.e. empty space inside or outside the container) to make the average density of the shipment equal one, and anything lighter than water takes up just as much space in the ship as heavier cargo would. The result is that if you have e.g. a 2000 TEU ship, and each TEU is 35 cubic meters, a full ship will always generate 70,000 tariff units, whether it be laden with cotton candy or iron pellets.
Of course, shipping companies play both ends against the middle and can, with optimization, get better than 100% billing (e.g. by using fluffy stuff like household goods to provide the airspace needed to compensate for containers full of car engines).
In a previous incarnation I was a Systems Designer at a major container shipping company.
Re:Declared underweight? (Score:4, Informative)
I was referring to the regulations about the number of crew required on a train, specifically the short lines. For short lines the number is now one engineer, no conductor, no brakeman. Having two people in the cab allows them to double check their work, not perfect as a recent plane crash shows but it is more likely that the correct number of hand brakes will be set if two people are double checking their work.
Another recent example was the train bridge collapse outside of Calgary due to the CPR inspectors OKing an old bridge when the water was to high to even consider sending divers in to check the footings. In that case disaster was averted through luck as anything.
The large railways have been pretty good about the self regulation but since the CPR has gotten new management who's priority is higher profits things are going down hill. The experienced workers are being heavily encouraged to retire or being let go and the newer, cheaper workers just don't have the experience and have management breathing down their necks demanding more production. A potential for another large accident due to de-regulation and management that is more interested in bringing up the profits this quarter.
The Mississauga accident seems to have little to do with regulations, just a hot bearing that got too hot.