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Effect of Container Crane on Mobile Floating Harbor Stabilization
Hai everyone,
Currently i am doing my thesis about the effect of container crane on the mobile floating harbor (MH). Basically MH is similar to the floating crane with the purpose of loading and unloading container from ship to the barge. My objectives are to find out the motion of the floating structure due to the effects of the crane size, height and the container location during loading and unloading. Mine scope will be focusing on the rolling motion.

So far, i am facing a lot of unknowns and questions prompted.

Can i simply use the basic rolling motion equation to identify its stability?

How can i identify the damping coefficient moment?Can i neglect it to simplify the equation?

what is the effect of the moment generated during loading and unloading ??(added mass, damping coefficient moment, restoring moment, or excitation moment)
The main points is how i can i identify the effects of the crane toward the structure motion.

Does anyone has any idea on it or any suggestion or references that i can refer to?

Lastly thanks for any reply..i am appreciate any helps that you could give me.^^
Kiu Ung Tiau
Responses
 
Effect of Container Crane on Mobile Floating Harbor Stabilization
Kiu, You write of "the rolling motion" during loading and unloading, but such motion would not be acceptable, because "a rolling motion" is a turning motion and if even slightly more than usual could mean that the floating crane would turn turtle and sink.

Th traditional method of transferring a heavy weight by crane on a ship from a ship to land is by flooding the lower part of the ship to offset the movement of the load.

For example, in the 1970s (when I a Merchant Navy marine engineer) I was on a freight ship specially fitted with a 200 ton "Stulken" heavy lift derrick for the forward holds.

But the ship used to wallow about in a corkscrew motion like a `bath tub` at sea and (more times than I can count) in rough weather the aft end of the ship would lift so rise so far that the propeller would come out of the water before slamming back about half a minute later sending a shudder throughout the entire ship and with everyone on board waiting for the propeller shaft to shear and rip off the propellor. :(((
Frank John Snelling
Effect of Container Crane on Mobile Floating Harbor Stabilization

Dear Frank,
Yes i being told that rolling motion should be avoided during any operations. The experience shared was so amazing that the ship faced different motion.

However in order to complete my thesis, i have to identify the effect of these operation toward the motion of the structure mainly concentrated on rolling motion.


For example:
If we neglect the crane stabilizer, what is the maximum distance of the crane operation so that the structure is safe.

Secondly, if the crane is elevated to a higher position to load the container, is it the motion wont affected?


Of course, will the motion affected if a big crane was installed on the structure.

Thanks
Kiu Ung Tiau
Effect of Container Crane on Mobile Floating Harbor Stabilization
Kiu Ung Tiau, I suggest you talk to some civil or marine engineers, because what you are asking for are mathematical equations.
Frank John Snelling
Effect of Container Crane on Mobile Floating Harbor Stabilization
Thanks Frank John Snelling
I really appreciate your words.
Kiu Ung Tiau
Effect of Container Crane on Mobile Floating Harbor Stabilization
You are welcome. :)
Frank John Snelling
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