how does a crane operator's knowledge of where the centroid is generally located for most uniform objects help them perform their job more safely?
If an object is uniform, it's a fair bet the centre of mass will be at the centre of the shape. If lifting with slings, he will have them placed equidistant from centre, at an angle to each other not exceeding 60 degrees. He will then lift a little, and can tell by the angles from vertical of each sling whether or not the CM is under the centre of the crane cable. If not, he will lower the load, and have someone adjust the sling positions. Having slings equally loaded ensures a level load when lifting, and when a load is level it is a much safer lift than when it tilts one way or the other. A tilt would mean greater force in the sling on the low end. The load could slip out, or the excess force could break the sling.
Usually it is the rigger who attaches the lifting gear not the crane operator who needs to know about centriods and even then the real trick is getting the slings or other lifting devices in the exact place. That tends to be a bit of trial and error unless the lifting points are clearly marked.
