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Author Topic: Who calculated the stability?  (Read 3952 times)

BarryM

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Who calculated the stability?
« on: July 21, 2007, 11:24:40 am »

At the moment of lift the mass of the object is transferred to the derrick head.......
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Shipmate60

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Re: Who calculated the stability?
« Reply #1 on: July 21, 2007, 11:29:33 am »

OOPs!!

Bob
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rats

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Re: Who calculated the stability?
« Reply #2 on: July 21, 2007, 11:36:51 am »

That looks like incredibly cold water - hope there were no injuries
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Stavros

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Re: Who calculated the stability?
« Reply #3 on: July 21, 2007, 12:13:26 pm »

OOPS BETTY I think I got it wrong again!!!!!!!!!!!!!!!!!!!!!!
Stavros
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Bunkerbarge

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Re: Who calculated the stability?
« Reply #4 on: July 21, 2007, 12:26:58 pm »

In answer to the original question:  No-one!!
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BarryM

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Re: Who calculated the stability?
« Reply #5 on: July 21, 2007, 12:38:53 pm »

At least the guy standing on the foremast at the end should get an award for agility!

BarryM
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John W E

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Re: Who calculated the stability?
« Reply #6 on: July 21, 2007, 01:58:50 pm »

I wouldnt like to be the gent standing on the quayside looking at the awful mess, look at the tension on the ropes (mooring springs) between the bollard on the quay and the ship.  If one of the ropes were to snap - it would cut someone in half no problem no problem.


john e

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Colin Bishop

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Re: Who calculated the stability?
« Reply #7 on: July 21, 2007, 03:11:36 pm »

Maybe that's how the other guy ended up on the mast!
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DickyD

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Re: Who calculated the stability?
« Reply #8 on: July 21, 2007, 04:26:17 pm »

Did the Captain lose his no claims bonus ? ???
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MikeK

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Re: Who calculated the stability?
« Reply #9 on: July 21, 2007, 05:27:14 pm »

As she doesn't seem to be listing at all in the3rd picture, after she had taken the weight - I wonder if she had some sort of heeling tank  that worked initially, as pictured in (3) but failed to transfer the ballast as the load moved over the center line, ergo bloody big weight PLUS all the ballast on the same side = dockie running up the side of the mast  :o :o (Just needs some busybody switching the heeling pump from auto to manual - been there, seen it, got the tee shirt  :-[ )

MikeK
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Shipmate60

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Re: Who calculated the stability?
« Reply #10 on: July 21, 2007, 05:31:14 pm »

Yes Mike I was wondering about that.
The Turning Moment should be the same either way. so should have gone over when taking the weight, and any free stab tank should have gone over with it.
Unless the skipper took his wallet over to that side  :)

Bob
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MikeK

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Re: Who calculated the stability?
« Reply #11 on: July 21, 2007, 05:42:07 pm »

Doubt if it would be the poor old skipper Bob - maybe the cook/stwd they are known to be enterprising men  ::) ::)
As the ship obviously is built to take more than the occasional heavy lift I would definitely suspect a faulty automatic heeling tank or as I say someone switched it over and forgot. Many is the time on the ro-ro's and little box boats I've been on I've wondered where the hell the list is coming from to find that same little switch causing all sorts of mischief !

Mike
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MikeK

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Re: Who calculated the stability?
« Reply #12 on: July 21, 2007, 07:34:09 pm »

Interesting terminology on the low loader in that third picture - 'dogged by bad luck' maybe  ::) ::)

Mike
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Colin Bishop

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Re: Who calculated the stability?
« Reply #13 on: July 21, 2007, 07:54:18 pm »

Could explain the lapse of attention to the heeling tank maybe?
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Bunkerbarge

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Re: Who calculated the stability?
« Reply #14 on: July 22, 2007, 09:24:19 pm »

As she doesn't seem to be listing at all in the3rd picture, after she had taken the weight - I wonder if she had some sort of heeling tank  that worked initially, as pictured in (3) but failed to transfer the ballast as the load moved over the center line, ergo bloody big weight PLUS all the ballast on the same side = dockie running up the side of the mast  :o :o (Just needs some busybody switching the heeling pump from auto to manual - been there, seen it, got the tee shirt  :-[ )

MikeK

I think that is the point.  As long as she remains perfectly upright the upset GM doesn't have a lever to act on so she would theoretically remain upright.  It is only when she goes that initial fraction of a degree off perfectly vertical that she will suddenly go over.

I don't know if heeling tanks on heavy lifts such as this are designed to counteract cargco weights but I would be surprised if they are.  They would have to work extreemly fast, take up a lot of internal space to be able to counteract such instabilities, and could be an inherent source of disaster.  I honestly believe they got thier sums wrong with this one.
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Colin Bishop

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Re: Who calculated the stability?
« Reply #15 on: July 22, 2007, 09:26:30 pm »

Bunkerbarge - I thought you were somewhere over the Atlantic! Or has the flight been delayed?
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DavieTait

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Re: Who calculated the stability?
« Reply #16 on: July 22, 2007, 09:35:44 pm »

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JayDee

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Re: Who calculated the stability?
« Reply #17 on: July 22, 2007, 10:18:54 pm »

Hello,
 A very moving story, what a terrible price to pay for employment.
John.  :'(
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MikeK

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Re: Who calculated the stability?
« Reply #18 on: July 23, 2007, 09:21:53 am »

When you read of the tragedy, it makes it pointless being armchair experts. I guess there must have been fatalities in the other accident you posted Barry ??

MikeK
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BarryM

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Re: Who calculated the stability?
« Reply #19 on: July 23, 2007, 09:37:44 am »

Unknown Mike as I cannot make out the name. Perhaps somebody else can throw some light on it?

Barry M
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farrow

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Re: Who calculated the stability?
« Reply #20 on: October 14, 2007, 11:26:11 pm »

I believe I read a MAIB report on the matter, she is not the first to capsize while loading. She was at virtually 0 distance GM stability and she was held up by her mooring warps holding her tight to the jetty.
When the derreck took the weight of the tank and swung it out board, the GM went negative and she lost the support of the jetty. Which caused her to overcome her warps and capsize. Because she was loading cargo her holds where open and allowed engress of water.
So yes nobody was doing their cargo stability sums correctly.
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MikeK

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Re: Who calculated the stability?
« Reply #21 on: October 15, 2007, 09:22:20 am »

I'm sure there are others here that have experienced the heart stopping feeling when, having been forced to load the ship so she was a little tender (!), on letting go and the tug taking the weight to pull her off the quay - the first reaction was the ship slowly lurching over  :o :o in direct proportion to the vertical movement of your stomach  :-X Usually followed by a trip to the next port taking corners very gently on 'two wheels' ! Or was it only me ? :D

MikeK
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Dave Buckingham

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Re: Who calculated the stability?
« Reply #22 on: October 15, 2007, 01:28:05 pm »

Hi Mike K and all
I have done it many times and have the trousers to prove it.

What I cant understand is if the GM was low the ship would list onto the quay as you started picking the load up no matter how the moorings were.

All tanks should be as far as practical full or MT to stop free surface.

Could the ship be on the bottom to start with?

Dave
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MikeK

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Re: Who calculated the stability?
« Reply #23 on: October 15, 2007, 02:55:40 pm »

I agree with your thoughts, Dave - something just doesn't add up there and I don't mean the stability calcs

As for the change of trousers, how many times have I heard the remark "Little bit tender isn't she Mate?"  as we flip-flopped out the breakwater and me itching to check the figures for the umpteenth time, just for reassurance - Ah memories  ::)

Mike
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farrow

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Re: Who calculated the stability?
« Reply #24 on: November 08, 2007, 06:10:55 pm »

Have read the MAIB report, no one was doing thier stability sums correctly,. The vessel was held upright by her mooring warps to the wall, when the derrick swung out with the load. The vessel lost the wall support and the moorings gave way and over she went.
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