Specifying a Bridge Crane Capacity

[sundale]

If one is specifying a bridge crane with say a 20 ton pick weight, do you call out a 20 ton or 1.25 x 20 ton = 25 ton crane? I know that per OSHA a crane is proof loaded to 125% its rated capacity and am a little unclear about who applies the safety factor on the load rating. The actual crane member design safety factors are per the service class allowable fatique stresses.

What the common practice to tell the crane manufacturer what you want as far as the load rating goes?

Thanks in advance for your help.

 

[JAE]

You would specify the 20 ton crane for the crane manufacturer. The required safety factors would then be applied to that in all calculations for the crane, hoists, trolleys, bridge, crane beams, crane beam supports, etc.

On the crane itself, it would be posted for all to see: 20 tons

 

[sundale]

Thanks, JAE. I thought it was that simple.