What happened with: Bulk Weight Measurements using Ship Draft?

[known100]

Lucky that I made a print-out of this thread to verify myself that I won't see ghosts!
From lexonrey (Materials) and in this Forum "Marine/Ocean engineering other topics" was on May 12, 2003 the thread.
Ref. thread321-55901
With several replies, containing their individual input.
When I was ready to add, no such thread is anymore traceable!
GregLocock and ccfowler entered their valuable input.
Sucked off as well into oblivion? Pity.
Who can help them / that all back or explain the reason.
Thank you.

PS. How to Attach? as in @hotmail etc.
Or do we type out while in the Forum at a time?

 

[marineram]

Alive and well if I follow your question. Naval architects determine the weight of a vessel for stability purposes by modeling the hull form in a computer and then measuring the freeboards (the distance of the hull above the waterline) and the specific gravity of the water it is in. They then can determine the amount of water displaced by the submerged portion of the hull. The weight of the water displaced is equal to the weight of the vessel (Archimedes principle). It is really the only accurate way of the determining the weight of a large vessel. Other methods but far less accurate are weighing the vessel in a drydock or syncro-lift.

Ship operators will record their drafts fore and aft and use them to look up their displacement on a "table of hydrostatics" or their "curves of form" documents developed for them by naval architects so that the ship's operators can determine their voyage stability. Now the same is done partially by computer on board with draft reading input from draft guages (sensors installed in the hull).

Hope this helps,
Marineram

 

[Focht3]

Threads are occasionally deleted - the reasons vary. (I'm not the one doing the deleting; I just know some of the reasons why.) Sometimes it's because the post was by a "lazy student"; sometimes it's because someone behaved inappropriately (racial slurs, profanity, personal attacks, etc.)

And occasionally the original poster asks that a thread be deleted.

If the thread is up for more than a week before it is deleted, it's possible that Google "harvested" the page. And even if it was up for only a few days, you ought to look there - you never know!

 

[lexonrey]

I was trying to find an answer to how the Shipping World handles the difference between the bulk cargo measurement using ship draft ( as per the ship captain ) and land based weighers. Can't find any possible leads throught the internet. That was the reason I was not paying attention to the thread I started, was assuming it would be there later on for me to fall back and refer to later on. I was planning to use the replies to form a pseudo-report which will compare the two method of measurement for my bosses. I am an Instrument Engineer working for Aluminium Bahrain B.sc., Arabian Gulf, and I am asked to explain the reason why Belt Weighers are reading more than what the ship captains reports as loaded cargo of calcined coke.

Known100, you mentioned that you had made a printout of the thread. Is it possible to fax it to me, whatever you got, so I can have something to write about.
Attn. Leandro Rey Go-Soco
Fax: 973-830459

Is there a way to retrieve those threads...

 

[IRstuff]

You might try to send and email to the tech support for this site. There have been some problems with the server in the past.

TTFN

 

[known100]

Dear ENG-TIPS Colleagues:
In humble reply to: marineram; Focht3; IRstuff and of course lexonrey.
Happy that the "link" is re-born.
I will pursue the feed-back to lexonrey
(Had one time a full cargo of iron pellets from Bahrain to East Malaysia!).
For marineram:
The point was that I gave my added explanation.
And was looking forward to enter it into ENG-TIPS.
I still prefer to do this, so that others as well can read.
And not only (by fax) to lexonrey.
And for lexonrey:
Prefer to do this per E-mail, since it has more than one full A4 size of text.
For IRstuff:
Not the 6th. July Hackers Contest!
Finally for Focht3:
You're right, you ought to look again - you never know!
Thanks all.

Known100
(Marine Dredging).

 

[lexonrey]

to known100: Thanks in advance. email to u0549@alba.com.bh
to IRstuff: will do that.

As far as i remember from the thread, long tonnes is used as unit for the ship draft measurement. Our Belt weighers ( we have 14 belt weighers all over the plant ) is totalised in Metric Tonnes. What is the conversion. Am curios, it could just be conversion problems, seem unlikely, but will find out.

I understand that Ship draft is used for measuring bulk cargo due to the fact that Insurance (Lloyds) rates uses the same. Am curios also if Ship Draft is an international Standard (ISO), because all Instruments is calibrated against these Standards. And it is common practice in my trade to make sure that International Standards is used by both, when comparing two measuring systems, otherwise I will be lost, like what i am.

To known100: Have you had experience of disputes between shipper and ship with regard to cargo. Say, the shipper had used a separate weigher in measuring the cargo into the ship, but the ship captain had reported it differently. Does shipping contracts between the two parties cover such disputes.

 

[lexonrey]

Below is the letter sent to me by Known100 on this subject. An attachment is included which i will publish tomorrow.

---------
Dear Leandro;

Thanks for informing me your E-mail address and this makes it a bit easier to forward you my comments (purely out of practice / experience).

I do attach herewith the 2 A4 pages as "Draught surveying: A practical view".

Then a short reaction on your ENG-TIPS message of 8th, July:
The use of Long Tonnes and Short Tonnes and Metric Tons or Tonnes:
You see that through history there just can not be a fully standardized method in anything!
In America they are really the Champions on this: Even bushels are used for a bulk cargo and in particular grain (wheat and sorghum and soya etc.).
The main thing is the used cargo Form at the table in front of the surveyor and the cargo officer. They have printed either LTs. or MTs. and they work on that throughout.
Don't mix somewhere halfway your calculations!
Such a cargo loaded or cargo discharged statement has all kinds of appearances, lay-out models and entry fields as you can imagine. Also no standard, although similarity.
One LONG Ton equals 1016 kilograms and thus 1.016 Metric Tons.
One LONG Ton equals 2240 pounds and equals 1.120 Metric tons. Confusing!
One SHORT Ton equals 32000 ounces, but you wouldn't go that far down for cargo!
One SHORT Ton equals 2000 pounds. See the difference with a LONG Ton?
And one SHORT Ton is then equal to 0.89287 Long Ton. Which way you want?
I think and hope that out of my letter you will extract a lot of explanation for your case.
Most likely you shouldn't make that connection about Lloyds and the ship's draught.
It has to do with it, yes, but not because of!
Ship's Draft (or DRAUGHT) is NOT so to say an ISO Standard!
It is the same as when you see in a cook book: Take one teaspoon of salt or sugar.
Or take a table spoon of flour. Teaspoons and tablespoons are never exactly the same.
It became just a way to do measuring by applying draught MARKS on sides of the vessel.
Or on sides of a square barge, how else would you do measuring?
About the calibration case: Yes, all instruments should be calibrated (regularly).
But not this, because of that! Even the length of one meter is measured in comparison to the STANDARD METER in Paris in the museum. That is a platinum stick kept under very special conditions such as temperature and humidity!
And to COMPARE two measuring systems, you do not use the ISO. Funny?
You have to use the correct conversion factor! See above. And I did'nt even use ISO.
If you want to have a good data-base of conversion factors, then I would suggest you to log on to the search engine GOOGLE.COM (or Google.com) and just type in at the blinking cursor: Conversion tables - weight - electricity - area - (or whatever). And print out!
About the dsiputes:
Yes of course, at many places, and that you can read as well in my letter.
It depends mainly on how important or how valuable the cargo is.
Important and valuable is here NOT the same!
If you have a cargo of 64,000 Long Tons of coal for the power plant and their plant can not receive the amount yet, then they make fuss about it and say that you brought in far too much!
They should be happy, you would say. No, they must have extra means to store the excess.
Or whatever excuses they make up.
Further matter is mentioned in my letter. Captain and shore surveyor must at the end of loading and discharging come to an agreement which shall not be too far off from acceptable (Charter Party) figures. The 5% MOLOO (= More Or Less Owners' Option).
Sometimes a particular cargo could have been sprayed before loading and this might be evaporated during the trip from A to B.
Cargo of cold rolls (= steel plates rolled) can be very expensive and is weighed in the mill.
Still at the end you have to take the accurate draught reading before sailing to see the total cargo on board (maybe not only those cold rolls) and sometimes you get surprises.
Anyhow, hope to have a bit more background information for you.
I will see where I saved the previous ENG-TIPS threads.
For you the main point is to come to an agreement with the ship's staff, your weights obtained and the INDEPENDENT Surveyor. This comes in the record (Bill of Loading).

Kind greetings,

Known100
(Marine Dredging).