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Saddles for transportation missing. Why? 1

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TrustButVerify

Mechanical
Sep 27, 2023
48
Hello folks,

Recently, I just posted here some words about the lack of understanding between vendors designing pressure vessels, and companies doing the transportation for installation on site.

Here is a picture quite curious I would like to share.

Why the vendor cannot design the vessel for carrying out transportation without the need of placing wood between the trailers and the vessel?

As you can see in the picture, the transport company placed wood to mitigate the stability of the convoy. My question is: did they ask the vendor if you can place the wood there? Why not to design the vessel with more saddles? Why not to reduce the distance between saddles?
 
 https://files.engineering.com/getfile.aspx?folder=7f8b94e4-8eea-478b-b6ea-04e6455d8c82&file=Eng-tips.png
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It's clearly a vertical vessel being transported horizontally.

I doubt anyone during design knew exactly which trailer was going to be used to move such a long tower so just leave it all to the transportation company is actually the most efficient way of doing it.

Maybe it is actually designed to only be supported at the two ends? but the transport company wanted more rigidity.

Designing any vessel with three or more supports is actually (I think) very difficult - doesn't it become indeterminate or something? as you can't be sure how much load is actually being taken by each one as a small movement or misalignment changes all the stresses.

Here's the picture

Eng-tips_fuintz.png


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
The vessel looks to be supported on the two cradles.
I don't understand what the purpose of the two stacks of wood is. They will cause a very localised stress in the shell, and therefore will cause a dent if they were to support the vessel.
Looks dodgy.
 
I'm sure the engineering was done for transportation and the construction team works together with the transportation team (I worked in a similar situation).
It has 4 support points to evenly distribute the load on each bogie. The wooden support is complemented (with wood) according to the level of the road, at each moment of transport.

See the photo: the (steel) saddle on the left is tilted.

Regards
 
I see 2 large saddles designed by the vessel manufacturer. I don't agree that the best location is so close to the top head, but there must have had reasons for locating it there.

I don't understand why the 2 saddles aren't in the middle of their respective trailers in order to spread the load evenly to all the wheels.

I see an additional tie-down with wood close to the rear saddle. This tie-down means the trailer assembly must stay as a single rigid trailer, rather than cleverly flexing around corners. This also makes the saddle loads statically indeterminate. I wonder how badly damaged it was by the time it reached site? The transport company should not be adding tie-downs where they aren't specified by the vessel designer.

It's not obvious to me if there's another tie-down where the workers are standing. If there is it just makes things worse.

There are so many things wrong in this photo I almost wonder if it's real. However a long career has taught me real life problems are like this and no one would fake so many bad things st once.
 
There are bigger pressure vessels being designed with 6, 7, 8, even up to 10 saddles for land and marine transportation purposes.

So, if that case is indeterminate, how they calculated the loads to design the vessel accordingly?
 
There are many things that seem bad but there are good things, it is due to lack of experience in the field (not on the desk).
In this type of large transport, all situations have been studied.
But sometimes "disaster."

Regards
 
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