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The Risk of Cargo Liquefaction (maritime-executive.com)
125 points by cwwc 11 days ago | hide | past | favorite | 55 comments

A while back I was (very tangentially) involved in an investigation relating to a near-disaster relating to this. https://www.taic.org.nz/inquiry/mo-2007-207

Iron ore is heavy and hard to transport. But at some points in the production process, the ore often ends up as a sort of "sand", and if you mix it with water you can get a slurry. Sometimes iron ore is transported by pipeline, and one thing you can do (and is done not infrequently) is pump the ore slurry into a ship, drain the water, and then sail to another port, pump water back in, pump the slurry back to shore, and repeat.

If for some reason you can't drain the water (due to equipment failure or running out of time due to an approaching storm), and leave port with a cargo full of ore slurry, then as the ship rocks back and forth, waves can deposit more and more iron sand on one side of the ship, causing a gradually increasing list. And of course, once you've got a list, gravity brings more and more iron sand to the lower side, increasing the list. The report downplays it a bit, but in the linked case the ship was quite close to just flipping upside down and sinking by the time they made it to shelter.

An interesting reversal of the issue in the original link, since rather than dry cargo becoming inadvertently liquefied, here the cargo started liquefied, but was incorrectly not de-liquefied.

Amusingly, while trying to find the report to refresh my memory, I found the same ship had ANOTHER incident with the same cargo two years later: https://www.taic.org.nz/inquiry/mo-2009-210

Liquefied cargo is oddly dangerous.

As seen in "The Martian" by Andy Weir. (Spoilers!)

> “At the microscopic level, the protein cubes were solid food particles suspended in thick vegetable oil. The food particles compressed to less than half their original size, but the oil was barely affected at all. This changed the volume ratio of solid to liquid dramatically, which in turn made the aggregate act as a liquid. Known as “liquefaction,” this process transformed the protein cubes from a steady solid into a flowing sludge.”

Also as seen in construction - coping with or preventing ground liquefaction under the vibration of an earthquake is a major consideration in foundation design. San Francisco's SoMa district is particularly prone to the phenomenon given its high water table and sandy soil, and so all construction there needs to include analysis of liquefaction risks in its regulatory filings.

Liquefaction under the normal pressure of a building's weight can also be a problem, and may have contributed to the notorious sinking of the (also in SoMa) Millennium Tower.

Many low-lying sections of Tokyo, Osaka, and other Japanese cities were built on landfill and are at risk of liquefaction in earthquakes. Government agencies issue detailed maps [1, 2] showing the degree of danger in each location.

Awareness of the dangers of liquefaction in Japan was kickstarted by buildings that tipped over in an earthquake in Niigata in 1964 [3]. A video showing many vivid examples of liquefaction after the big 2011 earthquake is at [4].

My family and I lived for more than a decade in a high-rise apartment building on a landfill island near the Tokyo waterfront, and the risk of soil liquefaction in a major earthquake was never far from my mind. We now live in Yokohama on a hill that is marked on the maps as relatively safe [5], but most of the nearby stores and train stations are in high-risk areas.

[1] https://doboku.metro.tokyo.lg.jp/start/03-jyouhou/ekijyouka/...

[2] https://www.pref.osaka.lg.jp/attach/31241/00267400/PL-Osaka....

[3] https://www.geoengineer.org/education/web-class-projects/ce-...

[4] https://www.youtube.com/watch?v=GviJkVEMfwQ

[5] https://www.city.yokohama.lg.jp/kurashi/bousai-kyukyu-bohan/...

Yup, that's the same reason SoMa is at such risk

Liquifaction was a huge problem for the Christchurch earthquake a decade ago. Many of the suburbs had 100% of houses destroyed and the areas were not rebuilt (Google: red zone Christchurch).



Came here to make this same comment. My father in-law has been in construction for 60 years, this is one of his favourite words. Neat to see it here on HN.

I've been involved in several projects using Explosive Densification to combat soil liquefaction, its pretty dang fun.

That is, using a sequence of explosive charges to improve soil compaction by breaking bonds and driving out latent water content. It triggers a cycle of liquefaction and then compaction afterwards.


We had a lot of liquefaction in Christchurch during the 2011 quake.


We often take maritime shipping for granted as it is a very old industry, but these very large, heavy and powerful boats are insanely hazardous workplaces, and there are both the incentives and the deregulation to transform them into death traps for employees. As is implied in the case study mentioned, when the ship's master declined to test cargo for humidity level... More stats here https://www.theguardian.com/world/2015/jan/10/shipping-disas...

Probably the biggest safety improvement for the dry bulk sector in recent years has been Indonesia's protectionist ban on nickel ore exports.

> death traps for employees

This is really sad. Millions of dollars worth of cargo, and yet they put the lives of the sailors at such risk.

The profit margins for a single transit is quite small. There might be $100 million in cargo, but the shipping company might only get $40K for transporting it.

The other issue with port regulations is that they aren't really enforced except to provide an (bribery) income for the port master.

I've heard a number of stories of some ports that effectively require bribery to get your ship cleared. If the ship captain elects for the actual inspection instead, the port master will intentionally delay the ship for weeks.

Iirc Argentina is the required bribery country to the point of companies planning for it.

Care to guess what the minimum wage per month is for seafarers?


Well, it's mostly regulation that sets the incentives to transform them into deathtraps, not deregulation.

The regulations I am talking about are immigration restrictions. If people from poorer countries could migrate freely to more productive countries, they could be more picky about which jobs to accept.

And unlike any particular (safety) regulation that can be gamed easily, it's much harder to game your employees' demands when they have good outside options.

This is of course the classic libertarian default counter argument. Zoom out enough and reduce government until the situation is shaken up so that the original discussed problem can be arguably speculated to be less relevant in the brave new world. Abracadara, the original problem was too much government.

Yes. There's a lot of this on HN it seems. Of course the argument doesn't hold up to evidence... Places like Somalia, Haiti, Yemen, etc. are great concrete case studies to understand what really happens in places with minimal or non-existent governments. The evidence doesn't exactly point towards major advancement in workers' causes.

It used to be called Startup News.

Given those pro-capitalist beginnings, the site has drifted relentlessly leftwards over time.

Oh no, you’re straw man of libertarian ideals has proven easy to defeat!

Libertarians don’t want non-existent governments as the highest priority. The key priority is using markets to determine prices and a critical part of that is being able to enforce property rights. A big government focused on enforcing those rights is completely supported by libertarians.

Well sure but that's not an argument in favor of libertarianism as an answer to the dangerous working conditions for ship crew either. A government that is focused on property rights, just like the flags of convenience under which most maritime shipping takes place, doesn't care much about labor regulations or immigration in the first place. In a way, international waters are already the "libertarian state".

In some sense, yes. See https://www.econlib.org/archives/2005/07/the_economics_a.htm... and https://www.econlib.org/archives/2017/05/cruise_ships_an.htm...

I was suggesting that if you want to help workers, you need to give them access to better outside options.

Interesting passage:

> The following email exchanges occurred on the 24th December between the Company ship manager and the Master stating “Since the cargo is very wet, would suggest to do Can testing as per IMSBC code. Although not listed in appendix A, it is better to be cautious.” In reply, the master wrote, “what do you mean by testing procedure please clarify."

Ship's master, who is responsible for the proper loading and safety of the ship, does not know how about how to test for moisture content. How is this possible? Is this the best they could find to watch over that big, expensive ship?

Loved that reply from the company: "it is typically performed by an alert Master before loading any particular parcel of cargo."

You do not want to know the quality of pilots/masters found on huge ships that are operating at lowest cost.

Well now I do. Any stories?

Hmm, I've been known to test a moisture content or two.

Around the clock for 40 years now.

Liquefication is so common it's no surprise any more.

Well, the vessels I work have cargoes like alcohol, acetone, paint thinner, etc ;)

These ships have 3 to 5 or more compartments separating the cargo from port to stbd and about a dozen from bow to stern. In addition to ballast tanks etc. So the constant liquid movement does not produce the instability that can occur in a solid-cargo ship having only a single compartment between the port & stbd.

Solid cargoes I normally do not do, except sometimes when an asphalt gets logged in.

I must say I usually find no fault, nope, no fault at all.

But, and it's a big but, when things don't go exactly as planned the scale can be somewhat overwhelming.

At the begining I did on-board measurement for a year before earning a premier port laboratory.

I almost never go to the docks any more unless it's really serious, the cargo surveyors just bring the official samples in. So I still know how it is.

Anyway, one time way back then I was loading a number of chemicals onto a multi-grade ship and the acrylonitrile had some stowage in a couple deck tanks in addition to some normal compartments. Deck tanks as the name implies look like (sometimes are) rail cars without wheels, welded to the deck in spots.

Now this monomer is an organic cyanide derivative which is a lot nastier than your everyday benzene or methanol. Just as flammable, more sickening. And we got to sample it when the movement is 95 percent complete. Normally you would be looking down into a hatch at your reflection in tonnes of product, but a deck tank you must climb.

I get up there and the tank is just starting to overflow, acrylo is everywhere, they had failed to slow down enough for the smaller tanks so it was pouring down the sides and running down the deck.

Instinct kicked in and I quickly filled my bottles by hand, got out of there and let them have their incident to themselves for a few hours before they called us back to calculate the losses.

Another time we had loaded 3,000 tonnes of (flammable) para-xylene so there was a lot of samples and I left mine on the deck when I went into the deckhouse. After doing all the paperwork we went out the other door and those were not my samples so we had to go back the other way. Just inside the doorway in the last office there was a small trashcan fire just getting started where someone had thrown a butt on their way out.

My partner stomped on it and his foot almost caught on fire, then we ran with the wastebasket into a laundry room and filled it with water.

Nobody noticed, we had to go and find the Chief Mate and inform him how we saved his ship. He gave us each a bottle of liquor.

And these both happened in Texas City, location of the deadly Texas City Disaster:


This stuff is pretty standard in heavy industry.

Technical office workers (programmers are some of the worst about this) tend to have this idea that everything is done consistently and perfectly all the time. In reality everything's done by humans and it isn't done perfectly pretty often. But because the cleanup is also done by humans the failures are mostly handled near where they happen rather than being sent through the system so you don't get failure modes like one piece of software that chokes on a config doesn't bring down a noticeable fraction of the internet.

It's not unheard of in the Philippines and Indonesia for surveyors that frequently reject unsafe cargoes to receive death threats from shippers/miners

Costa Concordia D:

"Ass covering when I like it and lack of understanding when I don't"

(not to say that the article doesn't make the same implication)

It's impossible to tell from such a brief exchange whether the guy was fishing for them to tell him exactly what to do or was genuinely unaware. "If you want something non-standard you need to spell out exactly what you want so my ass is covered when you're not satisfied" is not exactly an uncommon response to a request for something that isn't SOP.

This seems to be a surprisingly common problem, responsible for 1-3 sinkings per year.[1]

[1] https://www.nautinsthk.com/pluginAppObj/pluginAppObj_152_02/...

Looks Like it's someone's job to do penetration testing on soil.

I always wondered if CS Foresters story about the cargo of rice was founded in truth. (not liquefaction, but the problem next door: bulk cargo which changes volume)

A grain cargo not properly stowed acts like a liquid in the holds due to the heeling motion of cargo shifting. Much like when you walk to your desk with a full mug of coffee. The cargo rapidly and unexpectedly shifts in the hold. Thats what brings the vessel down so quick. The issue of liquefaction is well known but what is sad is dry bulk trade is still the Wild West and something such as costs of hiring an outside Surveyer to sample the cargo prior to loading to see if cargo exceeds its total moisture limit - at which point cargo is more at risk-. will be a key point of negotiating (abt usd 5k ) it’s sad really. But think most owners would pay cost on their own acct, even if if the charterers don’t pay. unfortunately it’s all driven by market forces. The master has an insane amount of stress and due to that normally only work for 6 mo contracts before spending time on shore. They make decent wages, but true the typical ABle bodied seaman not making much, but what they make and the benefits they get from decent ship owners is a lot vs. what is back home. The worst thing is with COVID, crew could not get off the ships, with some being well past their contracts - like 15 mo. Because counties would not let them disembarke and customers would not allow in their contracts. Lots of green washing and nice “talk” but the Global supply chain has little room for worrying about the individual.

It probably was a hell to debug after the first ship with such cargo capsized unexpectedly.

Nah, the problem is as old as sailing.

Sometimes the cargo liquefies for a short period when shocked, then stops flowing. This would cause the ship to list as the cargo takes a new shape.

Hard to debug is when the problem causes ships to be lost with all hands. Think in terms of early planes flying into cloud cover and reliably spiraling to crash.

something like this was a plot point in one of the Neal Stephenson wrist-breakers [0]. <elided plot spoilers>

[0] https://en.wikipedia.org/wiki/The_Baroque_Cycle

Container ships mitigate this problem since the cargo is restricted from moving all over the ship, and is instead confined to its own container.

How often are containers used to ship bulk commodities like those described here? I suspect "not often" because of the benefits of treating the bulk commodities, well, in bulk, rather than loading.

Surely containers would be safer from the issues described such as liquifaction, but the costs probably prevent the shippers from adopting them. Besides, it's no skin off their back and they'rr insured anyway, right? /s

Certainly none of the major bulks (iron ore, coal etc.), and most of the minor bulks (bauxite, alumina etc.) rarely do. But plenty of commoditised cargoes that trade most frequently in units of up to ~1,000kg (PVC granules, sugar) do/can use containers fitted with a liner.

This is the test to see if your cargo is too wet to safely load. It requires a cone and a hinged plate. Perhaps $200 worth of test equipment, the lack of which causes the loss of a $30 million+ ship


I was worried about some niche Rust related news!

Moreover, with Liquid Haskell existence...

here's video of a ship going down because of cargo liquifaction...


Why was the title changed to replace the ordinary word liquefaction? I clicked the link because I had not seen "liquification" before. Not sure it's even a real word.*

* (to the extent there even is such a thing as "real" and "not real" word)

It’s a real word, but inappropriate in this context. Liquefaction is what the article describes, liquification would be actual melting of the cargo.

If your nickel-ore dry bulk cargo is undergoing that kind of liquification, your ship will likely also be experiencing adverse handling.

My guess is the submitter just typed the headline from memory and made an intuitive noun form of "liquify," which in typical English fashion does not actually follow the rule implied by similar words such as "stratify" to "stratification" or "certify" to "certification."

You guessed right. Fixed now. Thanks all!

All my words are declared integer.

So I suppose words are really inexact.

Once can use fractional words for increased precision.

Then there's the matter of rational and irrational words.

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