Containers in the sea. I was wrong. many apologies

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Mirelle

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A couple of years ago there was a thread on this subject, and I, working as I do "in the business", rather pooh-poohed the idea that boxes routinely fall off merchant ships in large numbers.

I was wrong. The two shipping companies that I have spent my career with do not lose boxes over the side in large numbers.

However, on Saturday I was chatting to the Master of one of our ocean greyhounds in his day cabin at Felixstowe when he said "When the "XXXX Bridge" (Japanese ship in the next berth, right ahead of us) pulls out, have a look at the "XXX XXXX" ahead of her (naming our Most Hated Competitors). We were within a few miles of her through that depression in the Western Approaches on Thursday, same route, same cargo. She lost fifty boxes!"

I did, and she had. Collapsed container stacks are not easy for terminals to sort out, so the evidence was still there.

The ship which I am not going to name was the same size as ours (very big) and even newer.



<hr width=100% size=1>Que scais-je?
 
Howdy - would this be the one that was there when I was sailing past on Sunday with a pile of very collapsed looking containers and a fair bit of head scratching going on? Even had the harbour masters boat along side preventing anyone getting too close, lest one of the most precarious ones fall off. she looked like she had hit something as well with a big scrape along the starboard quater just below where the collapsed containers were.

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Yup. Missed the scrape - could not see that from where we were. We were right at the upriver end, on the newest bit of Trinity Terminal. Possibly damage due to the boxes going over?<P ID="edit"><FONT SIZE=-1>Edited by Mirelle on 01/11/2004 11:11 (server time).</FONT></P>
 
Someone once told me that there are 100,000 "floating" or missing at any one time! Sounds unlikely I know but he was confident in the estimate. Plus, they've been washed up still afloat, 4years after loss at sea. Polystrene packaging!

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Any idea what proportion....

Any idea, Andrew, what proportion of containers are likely to "float" rather than sink to the bottom?

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When the cruise liner Norwegian Dream came into Dover following her collision with the cargo ship Ever Ready 5 years ago, several containers from the latter were balanced precariously on her smashed-in bow. It was a remarkable sight, but no-one thought to ask how many more had gone overboard in that incident.

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So why is not possible to fit some sort of valve in them, so that if they fall overboard, then they sink. This would surely be simple and would also if necessarry alow them to be watertight until actually overboard.
Personally I think this should be legislation.
Though I openly admit I have no idea what I am talking about

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The thought of meeting one of these containers floating just awash worries me. The chances of spotting it in time to take avoiding action must be slim to nil, and a collision will probobly result in a very rapid sinking.

I wonder if it would be possible to fit containers with some sort of hydrostatic release device, similar to that used on liferafts, to open a hole in the container to sink it?


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Can these containers really float just below the surface?

I mean the chances of the density of the container / goods being exactly right to not either sink slowly or sit slightly out of the surface is negligable.

I really would need to see this "just below the surface container" to believe it.

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Good idea, but...

Good idea, but the problem is the stuff inside the container. If it's full of heavy machine parts, it'll probably sink in any case. But if it's full of lighter stuff, sealed in poly bags, with polystyrene foam packaging, there could be enough bouyancy to keep the container afloat even if it had a huge hole in it.

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Re: Any idea what proportion....

Not the kind of thing you ever see washed up on the tide are they? I used to live near Margate and there were quite a few people who worked beaches at low water looking for interesting flotsam, it's always appealed to me too.

Just imagine finding one of those on the morning dog walk, err, I think we'll need a bigger wheelbarrow.

<hr width=100% size=1>John
http://www.on-line-marine.com
 
Does anybody know how many craft have collided with containers? I can think of two definites in ten years.....

If we are talking these small numbers then perhaps this is a theoretical rather than real problem.

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It\'s about like this

The tare weight of a twenty footer is 2550 kg, about 4500kg for a 40ft box

The internal volume of a twenty is 33 cbm, 67 cbm for a forty, 76 for a 40ft hugh cube box.

Now, container ships are built around their "14 ton homogenous" capacity that is to say their ability to load 20ft containers weighing 14 tons including the tare weight of the box.

You will see at once that such a container will float. Water will get in very soon, since the door seals are not designed to be watertight, but the issue then becomes, "What is the permeability of the stow ?"

A container of household effects will be off to the bottom in no time; a container of PC components and TVs, packed in expanded polystyrene, in polythene bags, will float very happily for ages.

Generally speaking, our ships, and no doubt everyone elses, come in from East Asia fully laden with containers around 14T homogenous; they go out with a few containers carrying heavy things (tiles and bathroom fittings are a big UK export, along with waste paper - Germany exports machinery and car components, and so on) and a good many empties on the top.

You can see that the containers leaving Europe will almost all sink, those coming in will very often float...

<hr width=100% size=1>Que scais-je?
 
Re: Awash and on a wave near me.

Crossing to Eire one night we had about an 8ft swell. We got quite excited thinking we could hear whales sounding. We fired up the spotlamp only to find a container about 30m away to port. It was submerged to the point of being awash and, with the wave action, it was making the sounding noise and spurting water into the air.

Nobody to tell as we were outside VHF range. We did broacast but no response. Logged it and told the HM at Kinsale but that was a day or so later.

Guess we, 12 in the crew, were lucky.

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