Allowable Crane Deflection (Picked up by Cantilevered Beam)

[Structural Eng 7]

Hi All,

I have a Crane Runway beam that is picked up at the end of the runway by a transverse beam. The transverse beam is actually cantilevered and I am wondering what the thought is on the allowable deflection of the cantilever. Does say L/600 still apply? or is there another process to go through?

Any help is much appreciated.

Regards,

 

[Structural Eng 7]

To Clarify... the 'L' I am referring to would be the crane runway span.

 

[Shu Jiang PEng SE]

Calculate the deflection at the end of the crane run way, get the ratio of the crane run way length (distance from the runway end to the adjacent vertical support) to the vertical displacement at end of the runway. Then check if the defection meet CMAA requirements bases on the crane classification.

The essential of the check is to make sure the slope of the crane runway is not too steep and not causes trolley travelling troubles.

 

[BAretired]

A limit of L/600 would be acceptable but perhaps a trifle severe.

If a typical runway beam deflects L/600, the end slope is 1/200 for a simple span with concentrated load at midspan. If the end support of a runway beam deflects L/600 when the load is at the end, the maximum slope of the runway beam is 1/600.

If the object is to provide a maximum slope of 1/200 for the crane to climb, you could permit a deflection of L/200 on the end support; however it might be more prudent to permit a deflection of L/300 or L/400.

BA

 

[Structural Eng 7]

My thoughts were L/300 would suffice but wanted to check someone else's thoughts on the situation as this is my first crane structure design and it's been a 'doozy'. So essentially, if I have a 25' runway span, my deflection at the end of the runway could be 1" and the slope would still be in the acceptable range for crane travel?