Unsteady As She Goes, Mate

November 2, 2013 7:59 AM

Containership’s Structure Visually Flexing in Heavy Seas — Underdeck time lapse video (16x normal speed) of the 294 meter MOL Excellence as she rolls, pitches, and yaws during a voyage from Tokyo to Los Angeles. Large ships are designed to flex while underway, but when seas get rough they can break like the MOL Comfort on June 17, 2013.
posted by cenoxo (37 comments total)

Thinking of that as a big steel thing and flexing like a train is a big nope.
posted by drewbage1847 at 8:13 AM on November 2, 2013 [1 favorite]

Boeing 777 wing flex test.
posted by infinitewindow at 8:17 AM on November 2, 2013 [11 favorites]

If you got a visceral thrill out of those pictures of the MOL Comfort wreck, there's plenty more waiting for you at cargolaw.com.
posted by JoeZydeco at 8:21 AM on November 2, 2013 [5 favorites]

Makes sense to me. Most stuff that lasts can bend some.
posted by thelonius at 8:25 AM on November 2, 2013

The cargolaw.com is good, thanks.

Captain Shettino

Ihihi Capitan Shittino indeed. The man is still hated all over Italy for behaving the exact opposite of how a captain is expect to behave. To add further insult, it appears he's blaming a malaysian who was at the rudder at that time. Conveniently the malaysian appears to be back to his country, where of course he's trilled by the prospect of making himself available to prosecutors.
posted by elpapacito at 8:26 AM on November 2, 2013

Friggin' sweet. I've heard about this phenomenon first when I became interested in the Titanic many, many years ago, but I've never seen a video that so perfectly illustrates it. Thanks!
posted by entropicamericana at 8:27 AM on November 2, 2013

I was on a cruise ship a few years ago in semi-rough waters.

Hoping to see something like this, I went to one of the middle decks, which had a hallway that ran the entire (900+ foot) length of the ship. Even standing at one end of the hallway, looking all the way down to the other end, and specifically looking for it, I couldn't detect any flexing.

Related: I have heard that this is why larger airplanes have a curtain at the middle - so that passengers won't see the plane flexing.
posted by Hatashran at 8:27 AM on November 2, 2013

Good grief, I haven't seen a site worse than cargolaw.com since somtime in the 90s.

I work in the logistics industry and my ears prick up every time I see something about containerships. This video was very interesting, thanks. We had a relatively small number of containers on the MOL Comfort. As a company we have a surprisingly small liability when containers are lost. Which is, I guess, why we also sell insurance.
posted by lhauser at 8:35 AM on November 2, 2013 [1 favorite]

Cool thing, disappointing video. The MOL Excellence video is super-speeded up, and still doesn't look like much is happening. (The video graphic says 16x.) The video I want is from inside the Comfort.
posted by anotherpanacea at 8:49 AM on November 2, 2013

Yay! More video for my grad vibrations class! Thanks!
posted by mondo dentro at 8:50 AM on November 2, 2013

Isn't this how marine archeology works?
How protected are the contents of these containers?
posted by oceanjesse at 8:53 AM on November 2, 2013

@anotherpanacea — The "flex while underway" link has passageway views on a different ship.
posted by cenoxo at 8:55 AM on November 2, 2013 [1 favorite]

Aircraft can do this as well. Someone will doubtless (gently please) correct me but the oldtimers told me that because of different design philosophies Boeing aircraft flexed in the wings but McDonnell Douglas flexed in the fuselage, and this was sometimes visually apparent (i.e. omgweregoingdown! apparent).
posted by fingerbang at 9:13 AM on November 2, 2013

During World War II, a significant number of cheap, mass-produced Liberty Ships (with a design lifetime of only 5 years) suffered from hull fractures and failures until modifications were made.
posted by cenoxo at 9:29 AM on November 2, 2013

Working for a company that relies on cargo containers arriving safe and on time, I feel for the companies that lost merchandise or parts and supplies on that vessel. What a nightmare for all involved.
posted by HMSSM at 9:42 AM on November 2, 2013

because of different design philosophies Boeing aircraft flexed in the wings but McDonnell Douglas flexed in the fuselage

I used to regularly ride in one of these between Travis AFB and Okinawa. Aside from that sinking feeling you got sitting in the rear few rows when the aircraft rotated for takeoff (you would go down about 10 feet when the nose lifted!), you could look up the aisle from the rear and see the floor flex. Never saw that in a Boeing, for sure.
posted by pjern at 9:44 AM on November 2, 2013 [2 favorites]

Working for a company that relies on cargo containers arriving safe and on time, I feel for the companies that lost merchandise or parts and supplies on that vessel. What a nightmare for all involved.

I lost almost everything I owned in 1980 coming back from Germany when the container holding my belongings was lost overboard in a November North Atlantic storm. 20,000 photographs and slides, all my darkroom equipment, souvenirs from Africa and Asia. It was devastating.
posted by pjern at 9:47 AM on November 2, 2013 [5 favorites]

I looked at all those containers going into the sea, thinking of the crap we are dumping into the ocean.
posted by Annika Cicada at 9:51 AM on November 2, 2013 [2 favorites]

Don't worry, Annika Cicada. A good number of those lost containers wash up on shore somewhere.
posted by JoeZydeco at 10:16 AM on November 2, 2013

infinitewindow: "Boeing 777 wing flex test. "

I will never hear the number 154 and not think of this test.
posted by JohnnyGunn at 10:16 AM on November 2, 2013 [8 favorites]

Those containers full of sneakers often don't sink. They are a hazard to navigation.
posted by Mei's lost sandal at 10:37 AM on November 2, 2013 [1 favorite]

I can't help but wonder if video like this dampens the enthusiasm of those Mefites who were so enthusiastic about traveling by merchant marine vessel the other day. I know that for myself, just watching it is making me want the bucket (I get seasick easily).
posted by Fnarf at 10:46 AM on November 2, 2013

...all those containers going into the sea...

It could will be worse with 20 of the new 400 meter, 18,000 TEU capacity Maersk Triple E class container ships under way.

Just more things to go bump in the night: All is Lost (2013) trailer, starring Robert Redford.
posted by cenoxo at 11:10 AM on November 2, 2013 [1 favorite]

I looked at all those containers going into the sea, thinking of the crap we are dumping into the ocean.

Who needs containers? just park it on the top deck it'll be fine...
posted by Lanark at 11:20 AM on November 2, 2013 [5 favorites]

A good number of those lost containers wash yt up on shore somewhere.

I knew before clicking that one of those links would be to the glorious dorito enbeachening.
posted by elizardbits at 11:59 AM on November 2, 2013

Like airplane wings, ships are designed to flex so they won't break in half. I know, I know, but it would be even more common without the flexing. In WWII they experimented with welding instead of riveting for shipbuilding and found that ships that couldn't flex enough were much more prone to break in half and sink at random.
posted by localroger at 12:00 PM on November 2, 2013

@fingerbang, I worked at Douglas Aircraft in the 1980s. This is spot on and the aeroelasticity gurus talked about it freely. DC-10 wings would displace about half what 747 wings would do under similar loading, while the fuselage would distort as @pjern suggests with the DC-8. Further, Lockheed aircraft were a bit more flexible radially in the fuselage than even Douglas ones, and I remember well observing this in an L-1011. The distortions in the fuselage translated to obvious oil-canning when things got a bit rough.
posted by jet_silver at 1:55 PM on November 2, 2013 [2 favorites]

jet_silver: I am interested in why the difference in design philosophies between Boeing & Douglas- do you have any insight?
posted by pjern at 2:04 PM on November 2, 2013

(Feel free to throw in Lockheed, Convair, Airbus, or whomever else too, why not?)
posted by tss at 3:32 PM on November 2, 2013

I looked at all those containers going into the sea, thinking of the crap we are dumping into the ocean.

I read an article once discussing how much oil was dumped in there by WW2 naval warfare. It's a lot, but histories of the war never seem interested in things like that.
posted by thelonius at 3:43 PM on November 2, 2013

Who needs containers? just park it on the top deck it'll be fine...

Ha! I lived in Toyama in the 90's, and later on in Tsuruga, and encountered many Russian sailors. It was just after the end of Communism, and they were freer to travel, and they were always hauling back old television, bicycles, used cars and fridges. I lived out in the country about an hour by foot from the port and you would see these Russian guys dressed shabbily wearing fur hats and old leather jackets, searching out a place that sold used stuff.
posted by KokuRyu at 4:12 PM on November 2, 2013

Wooden ship crews sometimes exploited the flex of their ships in heavy seas, to shove in additional oakum to badly leaking joints. The point wasn't to pack them so full as to stop all seawater leakage, as this might actually open them more. The trick of seamanship was to keep just enough oakum in the joints to keep the water to a trickle the bilge pumps and pump crew could handle without undue effort. Experienced crews could tell when a ship was "creaking" just right, for the conditions she was facing, and was neither over or under packed with oakum.

"... It's a lot, but histories of the war never seem interested in things like that."
posted by thelonius at 6:43 PM on November 2

Eh, considering that Allied and Axis sunk shipping and lost warships amounted to something around 9 million deadweight tons total (my rough estimate, based on 1544 U.S. ships sunk, plus known losses of Axis vessels), of which only about 4 to 7 per cent would have been fuel oil, even counting tanker loads and ship tenders, it probably wasn't a whole lot more than annual average natural ocean floor seepage of oil, asphalt, and gas from natural formations over crude oil holding salt domes under the oceans. But a lot of leakage of oil from sunken ships probably did occur in places like the Leyte Gulf, which are not naturally oil holding locations. Still, the old wrecks have done remarkable service in spreading out the leakage over time, which allows the marine environment, including bacteria and algae to break down the hydrocarbons, with less damage to the environment than it might suffer if raw oil hit shoreline and estuary environments in sudden great mass. The wreck of the USS Arizona is still slowly leaking oil (sometimes referred to as "the tears of the Arizona" or "black tears"), drops to pints released at time, more than 70 years since she was sunk at Pearl Harbor. And yet a 1999 federally funded report on water quality in Pearl Harbor by University of Hawaii researchers stated, in part:

"... Pearl Harbor is one of the largest sheltered harbors in the USA and the only harbor wholly owned and controlled by the U.S. Navy. The facility contains numerous maintenance service facilities and has been the site of continuous Navy operations for more than 50 years. Previous investigations by Navy contractors have analyzed sediment samples from the harbor and found tributyltin, a single PCB (Aroclor 1254), significant levels of total PAHs, and several phthalates (plasticizers). Other samples contained low levels of DDT degradation products. Chlorinated pesticides were not detected. Significant amounts of total sulfides were also detected in most sediment samples indicating anaerobic biological activity. Ammonia was also found in most sediment samples. Detectable concentrations of several metals (arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc) were also found. TCLP analyses for the same metals found all below reporting limits. Despite the presence of all these chemicals, the water column has not been found to be highly toxic (less than allowable) and fish tissues were not such that specific advisories were required or adverse biological effects were expected. This indicates that not all of the chemicals are bioavailable. Additionally, in 1996 there was a oil spill of 16,000 gallons (bunker fuel oil No. 6) in a stream near its mouth into the harbor from a Chevron oil pipeline that passes through to a nearby electric-power generating plant. The heavy oil initially sank and most was recovered. No other oil spills have been reported in the area. All of these findings can be expected from such a large harbor facility which has been in service for as many years and has serviced as many vessels in as many different maintenance facilities. The Pearl Harbor sediment and associated water column are ideal sources of "real" samples for conducting research into rapid and easy immunochemical techniques (suitable for field use) for extraction, identification, and quantification of toxic organic chemicals for both pollutant monitoring and assessment of bioavailability. ..."

[emphasis added]
posted by paulsc at 4:35 PM on November 2, 2013 [4 favorites]

@oceanjessee: How protected are the contents of these containers?

Steel shipping containers have door seals and are weatherproof, but not necessarily waterproof. If lost overboard, they can float and present a navigation hazard, but eventually they will take on water and sink. From Vero Marine Insurance — Containers overboard:

Most dry cargo containers are steel boxes weighing between two tonnes and four tonnes, and are constructed to be weather-proof, rather than watertight. If empty they sink as a result of water ingress. If full, they may float for a while: air trapped in the cargo may hold a box on the surface until the cargo becomes waterlogged.
...
Containers are rarely watertight. Most have small openings and distortions. However, if 11 kg of seawater per hour entered a 20’ container, it would take some 57 days it to sink; and some 183 days for a 40’ container! These times may be considerably shortened by the in-water deterioration of seals, but this does indicate that floating containers can remain a hazard to shipping for some time.

Our information is that most containers do in fact sink. This may be due to the effects of poor maintenance, the fact that a container is a fragile object not intended to fend off a boarding sea, the initial distortions as the container breaks free, the subsequent impact with the ocean and the battering of loose cargo.
...
In rough weather, boxes may be smashed up by the waves. With up to 20 tonnes of cargo moving inside, the containers soon tend to lose their structural integrity. Refrigerated boxes and tank containers create the greatest threat, because of their inherent buoyancy, but because of their high value, from $25,000 to $70,000 each it makes it worthwhile for companies to build in tracking devices. Such containers may in any case be easier to spot with the naked eye or by radar.
...
Unfortunately, when a container or containers are lost overboard, there is rarely a news release and the fact is seldom publicised by the shipping company. The loss is only revealed to those in a need to know situation i.e. the shipowner, the exporter and importer, and the insurer.

Compared to the total number of containers shipped across Earth's oceans every year, only a very small percentage are lost. However, as more enormous container ships are built, that number will probably rise.
posted by cenoxo at 4:39 PM on November 2, 2013 [2 favorites]

More about the fate of lost containers in the WebEcoist article Deep Cargo: An Ocean Of Lost Shipping Containers.
posted by cenoxo at 5:08 PM on November 2, 2013 [2 favorites]

@pjern, I never got a straightforward answer to this question and only after quite some time have I a few theories about it.

The first is the airplane business is tough, and deciding to create a new one is not taken lightly. It's said that each new airframe is a bet and if you lose that bet the company folds up. Therefore, every advantage an organization thinks it has goes into the new airframe and systems. Things that worked well before tend to be done again and even if two different organizations were to evolve from the very same design, after a few models some small decisions would be cumulative and result in very different approaches to the same set of problems. Therefore, just perceiving an advantage becomes a part of the body of organizational prejudices that leads to design preferences and once those perceptions are set in motion they get into design checklists and review criteria and quality assurance standards, and calcify into rules.

The second is that spite in an organization tends to cast a very long shadow. I worked in propulsion and one of the propulsion design tasks is fuel gauging. It was said that the fuel gauging guru had been either personally offended or professionally shafted by the rep from the usual fuel gauging subcontractor and he refused thereafter to do business with them. He biased everything so an alternative contractor got all the business. Lather, rinse and repeat across multiple specialties over a few generations of airplanes - designers live a long time and I worked with people who designed the DC-6 - and pretty soon you have divergent equipment in avionics, controls, engines and landing gear. It's the same in manufacturing, too: if (e.g.) an air pack (air cycle machine, which takes engine bleed air for control of the inside pressure and temperature) comes back with a problem and the subcontractor screws up the resolution or otherwise causes trouble on the production line they get a black mark and those are cumulative across decades. Subcontractor selection can and does get biased by such things.

Therefore, I think the different answers to what ought to be flexible came about more by chance than by intent. Either manufacturer could have switched to the other's point of view, but in doing so they would discard critical advantages and be less competitive - in other words there is more than one way to skin a cat, which is about what you'd expect for complex systems.
posted by jet_silver at 5:15 PM on November 2, 2013 [7 favorites]

Everything flexes some. Calculating this is actually a big part of learning how to be (certain kinds) an engineer. Nothing is truly rigid. If you want to feel something disconcerting, find either a suspension bridge or a steel truss bridge near you, walk out mid-span and wait for a semi to go by. It will move several inches to foot depending on the span and design. It is supposed to do that. But it really freaks people out. Skyscrapers flex in the wind. Cars (especially convertibles) flex over bumps (in modern cars it really isn't perceptible, but you can feel it in old ladder frame trucks). Houses even flex in the wind and when earthquakes hit.
posted by bartonlong at 5:31 PM on November 2, 2013 [1 favorite]

paulsc: "And yet a 1999 federally funded report on water quality in Pearl Harbor by University of Hawaii researchers stated, in part: ...Despite the presence of all these chemicals, the water column has not been found to be highly toxic (less than allowable) and fish tissues were not such that specific advisories were required or adverse biological effects were expected. This indicates that not all of the chemicals are bioavailable"

Not picking a fight here, but your framing is a little dishonest - Pearl Harbor is a Superfund site, with harbor sediments being included as areas of interest (in addition to a bunch of other surface issues) impacted by decades of industrial activity. Googling around shows there are lots of reports that indicate the harbor itself is frequently dredged, and special disposal considerations have to be taken into account at times as the concentrations of some metals and organic compounds are too elevated for open ocean disposal. There is a reference I found to a massive dredging operation after the bombing to remove material but I can't find any sources for the original.

In addition there are some problems with the abstract you cited - namely that they seem to be focused on PCBs, PAHs, and pesticides because they were assessing the usefulness of SFE and enzyme linked immunosorbent assays as tools. Looking at some of the other reports for Pearl Harbor these are clearly not the only contaminants of concern, but maybe the only ones that SFE and ELISA analyze for? I've never heard of either before today. Their summary of the 1996 bunker fuel release is inaccurate also - it was over 40,000 gallons, and the bunker fuel didn't all just sink. Bunker fuel density varies such that some of it floats and some of it sinks (pdf).

And enough could be said about that Popular Mechanics post to debunk it as the PR puff piece it is, but I think we did that with several thousand comments while the Deepwater disaster was unfolding. But if you want just one here you go: Corexit.
posted by Big_B at 2:29 PM on November 4, 2013