Why Does Solid Cargo Turn Into A Liquid? - Liquefaction & Dynamic Separation Explained!
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- เผยแพร่เมื่อ 2 ต.ค. 2024
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In this video, we explain how Liquefaction and Dynamic Separation effect bulk cargo and why they are so dangerous.
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All content on this channel is provided for entertainment purposes only. Although every effort has been made to ensure the content is accurate and up to date, it remains the responsibility of the viewer to determine its accuracy and validity. The content should never be used to substitute professional advice or education.
Sounds like there is a strong incentive for the loaders to always say the bulk cargo is safe that makes the regulatory limits meaningless without the ship (or ideally a third party) also checking them.
Reminds me of the States in the 2000s. Only a couple "independent financial rating firms". To increase sales they provided higher ratings than the competition. After losing bids, you'd get looser. And so on. After a decade of ever looser ratings ----------> CRASH.
That is true but in this case it also changes the value of the cargo, as the water is worthless, only the bauxite is wanted
Or the shipping company too. Waiting at port for the cargo to dry - or maybe waiting for better weather before loading? - eats away at profitability. Financial projections aren't met and exec.'s don't get their bonuses. I could definitely see home office telling the captain, implicitly via company culture, to just put down 10% in the form, don't worry about it, and get going so that we can make the delivery on time.
@@jimmiller5600pppp
@@196cupcakeyes seeing “10%” is suspicious. A measurement might normally be 9.8% or something less even. Maybe when they see 11% they round down so its a mild lie. It seems procedurally if loading in the rain it should be expected to go up throughout the process and some extra step done. Perhaps heaters in the cargo could dry it with a hygrometer to know when its good enough. Maybe a condenser coil to recover the water to drink. Electricity is probably much cheaper than the value of the cargo lost
I can report that I have personally been down to the wreck and I can 100% confirm that the Bauxite in what remains of Bulk Jupiter's hold is VERY wet.
Is it over the 10% TML?
i’d reckon is pretty close to 100%
I laughed at that way more than is reasonable
Wetter than a haddock's bathing costume.
Also, the Titanic's pools are still filled with water.
Interesting. I've heard about liquefaction in a completely different context. Namely with earthquakes that have the same effect on some types of grounds, causing buildings to lean and topple over.
The Christchurch earthquakes in New Zealand suffered liquefaction causing the majority of the damage and destruction. Whole suburbs were condemned and there is a ban on rebuilding them for at least 20yrs? This is aside from the city centre though where the actual earthquake did the destrution and death.
Also with earthen dams! If not properly engineered they can liquefy (typically due to a large moisture content, and ‘bad’ soil) during an earthquake. Potentially releasing all of the water it impounds at once!
The ground doesn't shake, it seems to move in waves.
3:35 NOW bauxite has a TML of 10%. At the time of the accident it did not. This is shown on page 18 of the accident report which has an excerpt of the IMSBC code at the time of the accident which shows bauxite was a Group C cargo with no TML whatsoever. The Bulk Jupiter accident is what caused bauxite to have a TML. The first official guidance regarding bauxite being a liquefying cargo came in the form of a Circular from the Cargo Convention in 2017.
The 10% moisture limit on the cargo declaration form was mostly for informative purposes. Just like the cargo is brown and made up of various sized particles. It should raise questions if the cargo falls outside this criteria, but there was nothing at the time preventing a ship from setting sail with bauxite cargo having a moisture limit above 10%.
TML is a material property more than an administrative number. So all materials have a TML. Very interesting that there was no requirement to be below TML.
@@FekDindad-xy9vz No. TML is absolutely an administrative property. It is defined in the IMSBC code as, "the maximum moisture
content of the cargo which is considered safe for carriage in ships not complying with the special provisions of subsection 7.3.2. It is determined by the test procedures, approved by a competent
authority, such as those specified in paragraph 1 of appendix 2."
A.k.a. you only need to worry about TML if your ship has not been specifically designed in a way to avoid the moisture content hazards. It is an administrative thing. Material property is the most important part of it, but there are other factors to be considered such as hold subdivision and nature of voyage.
Source: Engineer on ships who regularly inspected cargo declarations (which contain the moisture content of the chartered cargoes) in a port which received bauxite.
@@phantomsplit3491
Great comment, thanks!
@@phantomsplit3491 TML is important for more than just ships. Trucks trains conveyors all have a TML. It's a physical property of a material.
Of course people write administrative limits around physical properties. But rule books don't change how a material liquefies. Notice how your quote says the administrative number is determined by a physical test.
And as the case in the video shows TML exists even if there is no rule book. It was the physical property of the bauxite that determined when it liquified not adherence to regulation.
Source. Engineer who dewaters bulk material for transport in more than just ships.
@@FekDindad-xy9vz A material's ability to undergo liquefaction due to entrained water is a material property. Defining a limit for this is administrative based off that material property and the type and duration of voyage. Congress or the IMO isn't going to change the melting point of raw copper, but they can pass legislation saying if you may be exposed to hot surfaces then you need PPE and safety procedures. It is an administrative control of a material property. TML is the same thing. It is an administrative control. Congress or the IMO can change what limit of moisture you are allowed to ship a raw bauxite at.
If you ship bauxite ore 600 miles from Yucatan to New Orleans on a bulk carrier with non-divided cargo holds then there is a TML. If you take that same bauxite ore and put in some open hopper barges and transport it more than 1,000 miles upriver from New Orleans to Chicago then there is no TML. Same material, same material properties. But one has a transportable moisture limit, the other does not.
In good memories of:
Ronel Andrin
Gibbson Ranara
Jerome Dinoy
Alexis Bacalla
Joseph Damasen
Lot Correos
Reydante Mendoza
Ricky Gapasin
Jonniefer Aleta
Renato Toribio
Wynfred Balazo
Edgar Melecio
George Espliguera
Edwin Acebo
Rosifo Sansolis
Gilbert Flora
Mark Causarin
To save the googling i had to do. This is a list of the crew of the Bulk Jupiter. All hands were lost except one cook.
@@wolf06291980damn, why’s it always a cook? kitchen staff be something else
I first heard of liquefaction when a hydro dam's canal collapsed in N.Z (Ruahini power station canal collapse, Sep. 20 1981). The engineers had been warned by local farmers that the local substrate was not to be trusted but nobody took them seriously at the time. Big mistake. Later I read a book on the same subject "Snow Tiger". Not remotely marine related but liquefaction plays a role there too.
Ruahihi is the name of the power station. Opened by then Prime Minister Sir Rob Muldoon, it collapsed THE FOLLOWING DAY.
@@peterfinucane8122That's right. Had it collapsed a day earlier, who knows how many people would have died. We regularly travelled on that road it took out. Scary idea.
Moral of the story: Talk with the people who have known the ground for generations.
I work in bulk cargo dewatering. Bauxite, iron ore, coal, lithium, all kinds of mineral concentrates. Transport moisture limit is always an absolute hard limit, there is never any arguing about it. If the product has high moisture it doesnt get shipped.
The fact this stuff was shipped at potentially 20% moisture is completely insane. No chance in hell this was a developed country
And anyone who has ever worked with the product will immediately see the difference between 10% and 20% moisture. One is a damp sand, the other is mud.
That sinking was straight up criminal. People should be in gaol.
Seems like Kuantan Malaysia is the port where she loaded bauxite
Don't know about that. With corruption anything can go.
South Korea is considered a developed country and yet the Sewol ferry disaster occurred. In part due to absolute corruption in South Korea commercial shipping.
At the time of the Bulk Jupiter accident, Bauxite was not known to be prone to liquefaction. The cargo was categorized as a Group A cargo following this accident.
@@phantomsplit3491that's unbelievable. I've worked with bauxite and alumina residue dewatering and we had TMLs for both. Although that was with truck transport.
I am curious what would happen if you add a seperation wall along the center line. Would that make a difference?
Yes, but you lose cargo space and make loading and unloading more difficult.
Some ships do have them.
With open barges you sometimes seem small seperation "walls" at the bottom of the cargo. Apparently a little bit of wall can be enough to avoid a lot of movement. They usually have to remove them when gravity unloading them at port.
They do this - add baffling - with liquid storage tanks. It's called the Free Surface Effect. If I remember correctly, the effect is proportional to the square of the free surface area. So dividing the space is quite effective at reducing the effect.
so yes there's a safer way but it costs more @@oaw117
I was thinking the same thing, it's just a vertical wall right? How can that cost so much cargo space that ship-builders don't add them?
But then I realised how much force such a giant baffle would be under when one hold is empty and the other filled with thousands of tonnes of bulk cargo. A baffle like that would need to be so strong and heavy, it starts to make sense it's not worth it.
You could make it much thinner if you only ever filled both holds equally but that would make loading and unloading a nightmare I guess.
Loader of a cargo plane. "What? No there aren't li-ion batteries in this. Wait, maybe a few but don't worry we'll load them in their designated area". Meanwhile the entire was palette was li-ion, loaded into the wrong section and men die desperately trying to make sure a 747 doesn't go down in a residential area. Until shippers are held responsible and do serious time, this will continue to happen across all transportation fields.
Can you please explain why li-ion batterys are bad for planes?
Lithium fires bad, even worse on a plane
@@barklet6110They spontaneously combust.
@@barklet6110 If they catch on fire then you have an out of control fire at 30K feet. They are supposed to be located in a spot where if they ignite for whatever reason, the damage will be contained. The 747 that went down the pallet was placed directly under mission critical controls and the heat was so intense that it burned through the fire protection. Started melting flight controls and other systems and down we go. Li-ion in stacks is like charcoal briquettes. Light just one in a pile and in a few minutes you have a nice hot fire.
@@barklet6110
If lithium ion batteries start burning, it's a self-sustaining reaction.
And it doesn't use oxygen.
So any fire protection measures you might have, will not work (sprinklers, pumping in N2, gaining altitude so there's not enough O2, etc).
Also, there's a LOT of energy stored in those batteries, and if all of it gets converted into heat (and rather fast), there's no way to vent it quickly enough, nor to sufficiently insulate key systems.
Well, the cargo certainly has a high moisture content NOW.
Why aren't bulk cargo hulls divided longitudally?
This is allowed to be done instead of messing around with TML. But these subdivisions add so much time to the unloading and hold cleaning process that most ships find it better to eliminate the issue by transporting dry cargo, rather than mess around with the subdivisions.
Plus the water in cargo = useless weight which hurts fuel economy on the ship and (depending on cargo density) can reduce the amount of product the ship can carry on a voyage.
money
There are sensors for water ingress in every cargo hold ~1m above bottom. We use to test them with sponges soaked with fresh and sea water before cargo loading, because system could show if water is from cargo or from sea. We carried grain mostly and everybody was scared that some leak from drain system would not spoil cargo.
"Ships are not static" at 0:36. Well, yes, that is rather the point lol
I was expecting it to be about small grain-like pellets such as the tessonite pellets on the derbyshire
Whole vid on rice as a cargo. Similar problem.
Love to log in and learn interesting things about ships and shipping. Excellent video as always
I first learned about liquefaction from The Martian, and I've been confused ever since. Thanks for clearing it up m8.
Also good to look up for earthquakes and various building collapse events. Part of the port of San Francisco is loose fill across a century and in one quake some of that fill went liquid under some buildings.
definitely check the Palu 2018 earthquake in Indonesia
@@billytanadi8303 I pulled one example of many. It was certainly not the worst in terms of damage or human lives lost.
Great on you for the regular posts that are interesting.
Clicking on TH-cam when you should be sleeping and finding the most worthwhile video first is priceless!
The Brazil Nut Effect” what a great term. I’ll use that one in my daily conversation! Thanks 🤠
Shouldn't cargo holds be divided longitudinally with strong bulkheads for bulk cargo? It would limit traversal run of cargo.
that then limits what cargo you can load, and makes cargo operations difficult.
@@katelights Indeed, but prevents sinking by cargo displacement. What is more expensive, in the end?
@@wafikiri_ You know, it seems pretty dangerous for these ships to use combustible fuels like MGO. And boilers are practically bombs, looks at all the explosions in the 1800s. We should only allow ships to propel themselves via sail.
The above is sarcasm if you can't tell. There are exemptions for ships to carry cargo over the TML if they have adequate baffles and bulkheads installed to mitigate free surface from shift and/or liquefaction. Most ships don't use these exemptions because they slow down unloading operations so tremendously. And make more places for dust and dirt to build up, making it hard for a crew to clean to make sure their next cargo is not contaminated by the previous one. Imagine you finish discharging coal, and are about to load rice. The more bulkheads and frames there are, the more stuff to clean to a food grade standard.
sadly, for lots of companies, the loss of an occasional vessel is deemed an acceptable risk in order to save money on outfitting their fleet with safety measures. They have insurance, after all @@wafikiri_
Axial baffles in the hold would be the solution, or at least minimise the resultant list , but so impede off-loading as to be impracticable.
The loaders measure the moisture content but have an obvious conflict of interest in reporting , like the stated weight of goods in a container , the figures should be taken with a grain of salt.
Of course, the buck stops with the ships master , in this case he even said the cargo looked "a bit wet" . Then again , he serves at the owners pleasure and was obviously loathe to incur their displeasure, wherein the second conflict of interest arises . Sitting in an office elsewhere , securing a profit on their investment may (being generous) take primacy over the safety of the crew , the loss of the Ocean Ranger oil rig being a good example of this.
So all told , the ship was most likely lost due to fiscal reasons with a bit of physics thrown in.
Often wondered why a vibration probe is not used to compact and settle a cargo when loaded.
The regular suspects: time and money.
money
Excellent content and superb animations! Well done!
Just to ask the question, do they not dehumidify the holds?
Id have thought with water usually going to the surface, you could at least slowly dry it away on a long voyage?
My guess is that they do have it but it cannot counteract the moisture from seeping in by normal means. Hence the "safe limit" restriction. The only thing the dehumidifying probably could do is slow down the process but not eliminate it entirely
Edit: I also wanna add that it might also be possible that a dehumidifier is not feasible for a bulk cargo considering the size of the cargo. So it might also increase the cost significantly to add and operate a dehumidifier of that scale.
If its a 40,000t cargo at 10% moisture thats 4,000t of water. If youre criminally irresponsible and load 20% moisture then youre dehumidifying 8,000t of water.
Very good idea, unfortunately these companies only Care about time and money 🤑✌️
would baffles in the hold also be effective?
The cargo should (per international regulations) be dehumidified on shore prior to loading. Meaning a ship's dehumidifier would be unneeded weight. Slowing the ship down, costing extra fuel & maintenance.
In the case of this ship it was loaded in violation of these rules, likely due to corruption & kick backs.
Lest we forget; safety regulations are written in blood.
I bet it’s moisture content is well above ten percent now. 😂😂😂
Apparently there was one survivor of this sinking, and he was the cook, so presumably had no idea about what happened in the hold or on the bridge.
I hope he's doing ok.
Still one of my favorite channels!
This also happens with humans after we reach a certain density in a crowd we start to move and bands and streams like a river. This is the physical action that usually causes a stampede
Love your vids
Me too! 🙋🏻♂️
I learn so much from watching your video. Thanks.
The sand sensed the vibe of the situation
question about the Dynamic Separation, if all or most of the liquid makes its way to the top of the cargo could you not just pump out the excess water? Maybe they cannot because it would take particles of the bulk cargo and dump it into the ocean but interested to hear your or commenters thoughts or if this has been done/looked at before.
The issue is that it doesn't usually form as just a liquid, more of a slurry of fine particles suspended in the water that are more like a fine silt or slurry. Basically just really watery mud and pumping it out would damage pumps.
@@TIXLTIF makes sense, cheers
@@TIXLTIFpumping slurry is very common. Not hard to do at all. But it requires slurry pumps and people who know what to do with them, which costs money.
Never trust Bauxite, I have no reason for this distrust but I do
Wouldn't keeping the centre of gravity below the centre of buoyancy solve most of the problems of ships capsizing?
@@elknackebroto7447 Why?
😂
Buoys have the same concept. Ever seen one upside down? No matter the weather, they stay upside up.
@@elknackebroto7447 Moving the centre of gravity or buoyancy higher or lower does not make it heavier or more buoyant. It just changes the location of the forces, not the magnitude.
@@RonakDhakan It *may* be possible to design a ship with a hull where this is possible. But the word "may" in that sentence is doing a lot of heavy lifting.
The center of gravity on a cargo ship like a bulker is a massively, massively changing value depending on whether the vessel is on a cargo voyage or a ballast voyage. How do you keep KB above KG when the vessel does not have cargo onboard?
Also just think about what you are asking. Center of buoyancy is the center of the underwater portion of the hull. Center of gravity is the center of mass. If KB is to be greater than KG then this means your cargo all needs to be very low on the ship, and there needs to be a large part of the ship above this to provide buoyancy (depending on cargo density). This makes a ship have a greater depth, which means they cannot go into shallow ports. It means you cannot make effective use of a double bottom, since that brings down your KB with regards to KG.
Maybe she even ran into a very very lost WW2 mine, or something like that
(the point being you cannot know, not until you inspect the wreck at least)
So .....how do oil tankers prevent their liquid cargo from washing around during rough seas and destabilising the ship?
I sat down in the toilet looking for entertainment. I didn’t think I’d stand up having learnt about dynamic separation. Thanks! 😆
Strang that there are no sensing devices used in the ship's hold for cargo in an open hold loading operation or dewatering devices that could pump off the top slurry if it were to occur during transport. Dollers over safety rules.
Why they don't build ships with wall along cargo space, that should prevent this.
First heard of liquifying after the m.v.Lovatt disaster
So quicksand is something we should worry about.
It's crazy how much thinkings goes through a ship's crew, it's not as simple as I thought at all.
How do oil tankers deal with this?
There are baffles and walls in place, effectively seperating the tanks into many smaller tanks that don't suffer from this problem too much.
they have many separate tanks so the liquids cant slosh around as much. also you can fill the tanks all the way to the top so they have no room to slosh about.
@@zockertwins Tankers do not have baffles in the cargo tanks. Too much of a pain to clean, and therefore old cargoes are able to contaminate future cargoes. They just have more tanks that are completely separated by longitudinal bulkheads to minimize the free surface effect. And once you get past a certain point, the more full a tank is the less effect that free surface has. So they load their tanks up all the way or not at all so that there is no free space for a fluid to slosh around in.
yeah, they're also loaded via pipe rather than via bucket @@katelights
We we may not know what Bulk Juptier's cargo moisture content was, but I can say with confidence that the moisture content of her cargo now is 100%
More information on this, from a chief engineer: th-cam.com/video/iG_EknYj5go/w-d-xo.html
So what you’re telling us that if you’re talking a ferry don’t transport chips because they’ll be crunched to flour?
Like the soil liquefaction after an earthquake...
Do you know where bull Jupiter loaded the bauxite?
Well the moisture content is 100% right now
This is also a problem on the toilet
bruh 11 hours ago and i have notifications on
Is it possible to have some dehumidifiers in the ship to help this?
No. The energy requirement is enormous, and drying bulk goods needs specialist equipment.
This is also a problem in civil engineering:
en.wikipedia.org/wiki/Quick_clay
where seemingly solid ground can suddenly liquify due to mechanical disturbance (vibrations from construction machijnery, blasting) and collapse structures.
Certain types of clay are especially prone to it: They are fine grained and the mineral content of the soil consists of microscopically small flat platelets, which are stacked together like a house of cards. If water gets into this structure, it acts as a lubricant and any mechanical disturbance can cause these house of cards structures to collapse and turn the formerly solid soil into liquid mud.
Why not build a wall at the middle of the ship lengtwise? That would separate it to two containers that have a hard time sloshing too one side.
This is allowed to be done instead of messing around with TML. But these subdivisions add so much time to the unloading and hold cleaning process that most ships find it better to eliminate the issue by transporting dry cargo, rather than mess around with the subdivisions.
Plus the water in cargo = useless weight which hurts fuel economy on the ship and (depending on cargo density) can reduce the amount of product the ship can carry on a voyage.
money
Thanks man and God bless!
Seems to me that a relatively simple way to mitigate the effects of liquid or potentially liquefying cargo is to have them carried in a ship with separate cargo holds for port and starboard. Cargo holds are already split lengthwise, why not crosswise?
Comments for the algorithm
Even if cargo is at
Which is why cargo hatches are often tested for watertight integrity. They have gaskets which are normally watertight seals by the nature of the weight of the cargo hatch weight pushing down on them. Then on top of this they have cleats which further secure the cargo hatches. And any moisture that does get by can then collect in gutters just inside the hatch seals, and drain from pockets at the front and back of the hold.
If a cargo hatch fails catastrophically then you are looking at a flooding issue, not a TML issue.
Hi CasNav!
What if ships were masculine?
could loading the cargo in layers separated by fabric (such as used in engineered soil) help prevent this
Wouldn't a potential solution be to add a movable roof to set on top of the cargo keeping it level? Would that work or is it too expensive to implement?
Could this risk be mitigated with the use of baffles in the holds?
They might have split up or they might have capsized
They may have broke deep and took water
Yeah, we keep track of it. they don't.
Wouldn't a dampener stop this problem? Sorry i dont have alot of maritime knowledge
👍👍👍
well, now it has 100% moisture
Are the arrows in minute 1 opposite. Shouldn't buoyancy be above the center of gravity?
Buoyancy above gravity means you have capsized
@@phantomsplit3491 maybe I am confused but I think it's the other way around
@@rtarouca
You _are_ confused :)
Center of buoyancy results from the displaced water, so it can never be above the water line!
Center of gravity is the entire ship, including all the bits that make it not-a-submarine (yet).
So every ship will capsize when it keels over beyond a certain point.
@@MrNicoJac OK :). But let me explain my confusion. Buoyancy pulls up and gravity down. Looking from the bow, let's say boat leans to the right. The buoyancy moves to the right, the center of gravity stays in the same point. Is buoyancy is pulling the boat up and to the centre line, then it can be bellow the center of gravity. If you think of this as levers then we need to understand how these levers would work to level the ship and keep it stable. If you don't agree, let me know
it would be interesting to find the ship and test the moisture content of the cargo once and for all.
😂
I bet it would be above 10%
Considering it's on the bottom of the ocean, I'd say the moisture content is pretty high.
@@WormBurger who would've thunk?
Gypsum can have a moisture content 30-40%
Different materials will have different moisture limits - such as "fat" clays
*WHY THE SHIP did not have its cargo* space divided into two sections along its length, not just perpendicularly?
This would have allowed to completely disregard the issue of liquefaction. The capsizing would have been then hard to achieve even if the cargo was water.
Because the subdivision greatly slows down loading and unloading. Since it is unloaded via a clamshell bucket. Putting a bulkhead down the middle of the hold slows down loading and unloading tremendously, and is unnecessary if you actually don't transport cargo above the TML.
@@phantomsplit3491 there are many types of buckets, some allow effecting unloading from 90 degrees upright spaces. And port equipment allows to change the buckets pretty quickly. The issue is that full costs/expenses analysis for both scenarios can produce different results for different situations, so my guess is that since the solution is not significantly better overall, there is no urge to implement it.
money!
Nice Video, greetings from germany!
Is this a re-upload???why do i remember seeing this?
There was one about grains doing the same thing that is a pretty similar video, maybe it is that one?
Chief Makoi did a video on the same subject, some time ago...
First thing I did was scroll through the video to see if you showed yourself. Didn't find it. THANKS. Now I can immerse myself into this world of wonderful animations while enjoying your narration without any sudden distractions bringing me back to the world of human faces. Thanks for taking our feedback seriously. 🙏.
Come on man , he looked fine lol😅
@@ashj_2088 Nobody said he wasn't. Gotta stick with either 2D or 3D, stop switching Ds on us.
what's the matter, are you so norwegian and antisocial that you can't handle seeing a face?
He said he did that as an experiment, but it didn't work out so he stopped doing it.
@@oslonorway547 switching dzss , sorry I didn't realise the seriousness of this overall sensitive situation , will c2 it the relevant action is taken 🥷💂🧟
🇭🇲😀
A stick moisture meter for plants is 5$ no tools for the job🤑🪦