Rigging analysis for horizontal drum 1

[jtseng123]

Dear all,

We have several large diameter horizontal vessels: 21' diameter x 72' long. No lifting lugs were welded to vessels. CG and weight are known. Only sling(polyester fiber rope) will be used around the shell for lifting. Vessel vendor did not specify lifting points, but it is very easy to pick two location for lifting.
Questions : (1) who shall run the vessel stress analysis at the sling location, vessel vendor or rigging contractor ? (note: stress at the center of the drum is a very simple calculation and small, not a concern, but sling may crush the vessel wall, that is the major concern) (2) Will wooden slates be able to reduce shell stress at the sling locations ? Is it ok without wooden slates ?

 

[desertfox]

So to summarise you want someone here to say

1/ it will be okay with or without wooden slates on a vessel whose weight and material and C of G is unknown, not to mention the wall thickness and not even a drawing or picture of the drums.
2/ I would of thought the vessel designers would have put lifting lugs on but I have no idea what was in the contract with the vessel manufacturer.

So if I asked you the same question as you have asked here what would your response be?




“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[r6155]

See:
1)Bechtel Rigging Handbook

2) Practical Guide to LOLER UKCS-TI-010
LOLER Lifting Operations and Lifting Equipment Regulations

Regards

 

[jtseng123]

r6155, thanks.

 

[chicopee]

I personally think that GL Noble Denton " Guideline for Marine Lifting and Lowering Operation" may be more suitable. There is extensive general information on structural analysis requiring conscientious reading.

 

[MJCronin]

Can you supply more information about these massive but fragile horizontal vessels ??

What is the design pressure and the intended contents ?..... Certainly not Crude Oil, I hope ...

What is the wall thickness, your materials and type of end/head configuration ?

You don't have some kind of gusseted flat head, do you ????

Are there photographs or data sheets or drawings available ?..... Were they assembled without any documentation ?

At 21' diameter and 72' long, were they either shop or field fabricated ? ... Are they sitting in the shop right now ?????

As they seem to be horizontal vessels, are they to be supported on two or more saddles or buried underground or what ?

No documentation that you can share ???...... NO cameras in your part of the world ?...

More information = Better answers

MJCronin
Sr. Process Engineer

 

[MJCronin]

jtseng123....

Thanks for all of your professional participation in this thread...

Your willingness to provide additional information and communication means that you are not someone who "gets what he wants and splits !"

Keep up your good work and Engineering Professionalism !!!

MJCronin
Sr. Process Engineer