Which of the following is a source of boom side loading?

• A. Dragging a load along the ground (from any direction)
• B. Lifting the load directly under the boom tip
• C. Operating the crane with the load on the ground in a balanced, vertical line
• D. Extending the boom beyond its normal length

Answer: (A)

Side loading on the boom occurs when a horizontal force is transmitted to the crane through the load, not aligned with the crane’s vertical plane. Dragging a load along the ground creates a horizontal component because the load resists movement with friction against the surface. That sideways pull travels back through the hoist line into the crane, pushing the boom to the side and increasing side loading. Lifting the load directly under the boom tip or keeping the load vertically on the ground keeps forces aligned with the crane’s centerline, so there’s mainly a vertical load and little to no side loading. Extending the boom beyond its normal length changes reach and overall load, but it doesn’t introduce a sideways force by itself, so it isn’t a source of side loading.