Containers overboard

[Kukri]

A report from within the shipping industry:

Shipping organisations set out to tackle rising number of containers lost overboard - Splash247

 

[capnsensible]

Watching large vessels rolling even in fairly benign seas is a bit fascinating. Full marks to those on the bridges of modern vessels, especially when anchored, empty and waiting for orders.

 

[newtothis]

< 0.001% of all containers shipped are lost overboard.

 

[Stemar]

Which is still over 3000. That's a LOT of containers travelling around the planet.

 

[Kukri]

Which is still over 3000. That's a LOT of containers travelling around the planet.

A container floating in the sea is a steel box which is not watertight.

If it is:

(a) full of goods in expanded polystyrene packaging
or
(b) an empty refrigerated container with lots of insulation
or
(c) an empty tank container

it will float for a long time.

Otherwise, it will sink.

 

[Blueboatman]

“ so, we was sailing along, yeah ? And then there was this almighty bang . We abandoned ship and jumped onto this container that was handily bumping down the topside of the sinking yacht .. amazingly it was full of fridges and woks and bbqs , so we were saved. But they didn’t have much in them to eat . Hey Ho… then we found the fishing rods and waterproof satellite radios “ ?

 

[Charlie Boy]

“ so, we was sailing along, yeah ? And then there was this almighty bang . We abandoned ship and jumped onto this container that was handily bumping down the topside of the sinking yacht .. amazingly it was full of fridges and woks and bbqs , so we were saved. But they didn’t have much in them to eat . Hey Ho… then we found the fishing rods and waterproof satellite radios “ ? ALL WITH CHINESE INSTRUCTIONS THOUGH

 

[Blueboatman]

Oh yes
Luckily there’s a customer helpline international number ( Shanghai business hours) ?

 

[newtothis]

Which is still over 3000. That's a LOT of containers travelling around the planet.

Back of a fag packet calculation shows that, if all of them were floaters, you'd have a very high risk of running into one 30 sq metre container for every 120,000 sq km of sea you sail through.
Be careful out there.

 

[LittleSister]

Which is still over 3000. That's a LOT of containers travelling around the planet.

Out of general interest, what period is the 3,000 for? (Annually?)

A container floating in the sea is a steel box which is not watertight.

If it is:

(a) full of goods in expanded polystyrene packaging
or
(b) an empty refrigerated container with lots of insulation
or
(c) an empty tank container

it will float for a long time.

Otherwise, it will sink.

Again out of general interest, what proportion (presumably small?) would you estimate your floating types would form of the total containers at sea? Also, being lighter, would they be more likely to be loaded in the upper tiers of containers on the ship (and therefore much more prone to being lost)?

Back of a fag packet calculation shows that, if all of them were floaters, you'd have a very high risk of running into one 30 sq metre container for every 120,000 sq km of sea you sail through.
Be careful out there.

Our coastal waters are rather more heavily trafficked by container ships than the total oceans/seas' average, with extensive areas where even sunken containers could be a hazard to us.

As it happens I'm not unduly bothered about the lost container problem, but it does give one a shudder to think of it when bowling along on a dark night!

 

[Kukri]

I think perhaps one container in a dozen on board a container ship and stowed on deck will float if it goes overboard.

This guesstimate is built on two boxes in five being empty, one box in twenty being a reefer, one in a hundred being a tanktainer, and maybe one in ten containing stuff in expanded polystyrene .

 

[capnsensible]

Back of a fag packet calculation shows that, if all of them were floaters, you'd have a very high risk of running into one 30 sq metre container for every 120,000 sq km of sea you sail through.
Be careful out there.

I would imagine you would only have to dong one to have a bad hair day though.

 

[Kukri]

I would imagine you would only have to dong one to have a bad hair day though.

I think I am much more worried about a pod of teenage orcas off the coasts of Spain and Portugal.

 

[mjcoon]

Back of a fag packet calculation shows that, if all of them were floaters, you'd have a very high risk of running into one 30 sq metre container for every 120,000 sq km of sea you sail through.
Be careful out there.

In particle physics (IIRC from 50+ years ago) there is a concept of a nucleus cross-section within which a travelling sub-atomic particle may intercept the nucleus. With extreme exaggeration the unit is called the "barn". wikipedia/Barn_(unit)

There must be a similar cross-section in the sea that a yacht may collide with a floating object. This will be of the order of 10m wide or less. So to sail through 120,000 sq km of sea you would have to have a track of 12,000,000 miles I think - but please check!

 

[newtothis]

Out of general interest, what period is the 3,000 for? (Annually?)
Again out of general interest, what proportion (presumably small?) would you estimate your floating types would form of the total containers at sea? Also, being lighter, would they be more likely to be loaded in the upper tiers of containers on the ship (and therefore much more prone to being lost)?
Our coastal waters are rather more heavily trafficked by container ships than the total oceans/seas' average, with extensive areas where even sunken containers could be a hazard to us.
As it happens I'm not unduly bothered about the lost container problem, but it does give one a shudder to think of it when bowling along on a dark night!

The 3k was an annualised average figure for 2020-2021. But that was affected by two major incidents in the winter of 20/21, including One Apus, which lost c.1900 and Maersk Essen, which lost 750.
The average over 14 years - the length of time people have been counting - is 1,600, and even that is boosted by the total loss of MOL Comfort, which had 4,200 on board.
I wouldn't worry too much about UK waters as these events tend to take place in the Pacific or Indian oceans, although Maersk did lose a bunch in Biscay a few years back.

 

[newtothis]

The 3k was an annualised average figure for 2020-2021. But that was affected by two major incidents in the winter of 20/21, including One Apus, which lost c.1900 and Maersk Essen, which lost 750.
The average over 14 years - the length of time people have been counting - is 1,600, and even that is boosted by the total loss of MOL Comfort, which had 4,200 on board.
I wouldn't worry too much about UK waters as these events tend to take place in the Pacific or Indian oceans, although Maersk did lose a bunch in Biscay a few years back.

this is what it looks like when 1,800-plus boxes fall off your ship...

 

[Biggles Wader]

this is what it looks like when 1,800-plus boxes fall off your ship...
View attachment 137319

Should have used a rolling hitch. Clue in the name!

 

[newtothis]

Should have used a rolling hitch. Clue in the name!

Now formally know as parametric rolling hitches.

 

[Kukri]

I’m not a Naval Architect but I’ve known a few…

What I think parametric rolling is:

If you look at the snap of the “ONE Apus” in Newtothis’s post #16, above, you see that she has a very wide flat counter stern and a wide flat flare above the water at the bow.

This is in aid of carrying more boxes whilst burning less fuel. Most modern big boxboats look like this.

Now, let us assume that the ship is under way and there is a long swell. Let’s further assume that the swell is coming from the port quarter. The swell picks up the port side of the counter, passes under the ship’s flat barge shaped mid body, and picks up the flare of the starboard bow. This makes the ship roll. The speed of the swell will be faster than the speed of the ship. If the speed of the wave and the speed of the ship are such that the roll imparted by the wave passing under the ship has the same period as the ship’s own roll period the wave will amplify the roll and may do so quite dramatically.

I hope this makes sense!

 

[mjcoon]

I’m not a Naval Architect but I’ve known a few…

What I think parametric rolling is:

If you look at the snap of the “ONE Apus” in Newtothis’s post #16, above, you see that she has a very wide flat counter stern and a wide flat flare above the water at the bow.

This is in aid of carrying more boxes whilst burning less fuel. Most modern big boxboats look like this.

Now, let us assume that the ship is under way and there is a long swell. Let’s further assume that the swell is coming from the port quarter. The swell picks up the port side of the counter, passes under the ship’s flat barge shaped mid body, and picks up the flare of the starboard bow. This makes the ship roll. The speed of the swell will be faster than the speed of the ship. If the speed of the wave and the speed of the ship are such that the roll imparted by the wave passing under the ship has the same period as the ship’s own roll period the wave will amplify the roll and may do so quite dramatically.

I hope this makes sense!

Sounds like simple resonance to me...