CMAA Crane Deflection Criteria

[SteveGregory]

The criteria is more stringent for higher duty CMAA classifications (A-F). Does this standard apply to the bridge beams as well as the runway beams?

I am checking a bridge crane with a fixed hoist on the bridge (no trolley).

Is the defection criteria meant to reduce fatigue or maintenance of the rail and the mechanical parts or both?

 

[humanengr]

As I recall Crane Bridge Criteria differ from the runway beam criteria. You may have to dig a little deeper into the CMAA Standard for Crane Bridge design.

In addition to the reasons you mentioned, the deflection criteria is to limit the differential deflection between
the runway beam on one side and the runway beam on the other. In other words, reduce the vertical slope of the Bridge
as the runway deflects on one side.

If the fixed hoist is in the center of the bridge, all else being equal, the beams on each side of the runway
should deflect equally. I would still use the CMAA deflection criteria for the reasons you mentioned and others.