Load capacity for overhead traveling crane

[21121956]

Hello everybody:

For a power plant under development, the heaviest load to be lifted is 38 tons. The overhead traveling crane for this plant has been specified with a capacity of 45 tons.

I would like to have access to a book, a technical paper or something like that, in order to ascertain what are the criteria in selecting the proper load capacity for overhead traveling cranes; obviously, taking into account the safety factors.

Thanks for your comments.

El que no puede andar, se sienta.

 

[boo1]

What segment of the power industry are you working on?

for non nuclear consider Whiting Handbook

http://www.cranebuzz.com/IndustryStandards/Whiting Crane Handbook.pdf

or pdhonline

http://www.pdhonline.org/courses/m245/m245content.pdf

an example of Ansys analysis was:

http://www.ansys.com/staticassets/A...library/confpaper/2002-Int-ANSYS-Conf-108.PDF

ASME B30.2-2011 Overhead and Gantry Cranes (Top Running Bridge, Single or Multiple Girder, Top Running Trolley Hoist),
ASME B30.17-2006 Overhead and Gantry Cranes (Top Running Bridge, Single Girder, Underhung Hoist)

 

[21121956]

Hello everybody:

Thanks boo1 for your response. This application is for a small hydropower plant.

El que no puede andar, se sienta.

 

[Medeski]

Demag has double-grider overhead travelling cranes up to 50t.
Link

And also a free(?) design software. I can't speak to its accuracy or ease of use but it may be worth checking out.
Link

I don't know if any of this helps for you, but if you hunt around the Demag website they may have some white papers on crane design or some design manuals if you inquire.

 

[21121956]

Hello everybody:

Once again, thanks to boo1 and Medeski.

I have a couple of questions on this subject:

1. In the document of the link

http://www.pdhonline.org/courses/m245content....

on the page 9 it can be read:

“The design load for the crane system is based on the rated capacity plus 15% for the weight of the hoist and trolley (capacity x 1.15) and an additional 25% for impact (capacity x 1.25) for a total design capacity x 1.4. (Note 25% impact factor is good for hoists speeds up to 50 fpm)”.

In this particular case, what should be the proper interpretation of the word "impact"? Is it, for instance, when the load being lifted impacts against something?

2. On the same page, it is noted that the crane test loads are typically specified at 125% of the rated capacity by both OSHA and ASME.

Could someone tell me the name of the documents where I can find those specifications?

Thanks in advance.

El que no puede andar, se sienta.

 

[IFRs]

Impact should include running the crane to the end stops on the rails ( oops ) and loads settling or falling ( also oops ).

 

[tbuelna]

21121956-

If your overhead crane is rated for 45T, this would normally mean that it can safely lift a stable load of 45T when positioned anywhere within its normal range of travel. Most structures designed for supporting loads over/near workers are analyzed using a FoS of at least 5.0 on UTS. This includes beams, cables, sheaves, hooks, etc.

If your overhead crane system is rated at 45T, then you should have no reservations about using it to lift a 45T load. Of course, it may be possible to safely lift a bit more than 45T depending on where your load is positioned relative to the supporting structures of the crane system. The system operation manuals should provide guidance for limits on lifting.

Good luck to you.
Terry

 

[boo1]

for ASTM B30.2 try:

https://law.resource.org/pub/us/cfr/ibr/002/asme.b30.2.2005.pdf

 

[21121956]

Hello everybody:

boo1, the last saturday I found a more recent edition of this standard: ASME B30.2-2011 (Revision of ASME B30.2-2005). Anyway, thank you very much.

By the way, IFRs and tbuelna, thanks for your comments.

El que no puede andar, se sienta.