Net capacity represents the usable lifting capacity after accounting for the weight of attachments and other deductions that reduce what the crane can actually lift. Gross capacity is the maximum load the crane could lift in that configuration before those deductions. Deductions include the weight of the hook block, slings, rigging, and any other attached equipment, plus any required safety allowances. So you subtract these deductions from the gross rating to get the net capacity. That’s why the statement describing net capacity as gross capacity minus deductions is the correct one. Net capacity cannot exceed gross, it depends on deductions, and it is not the sum of gross capacity and deductions.

Stability comes from a wide, level foundation. Extending all outriggers fully and leveling the crane before lifting creates a solid base that distributes the crane’s weight evenly and keeps the center of gravity over the base. This minimizes tipping risk, especially on uneven ground, because every outrigger bears load and the crane sits level, allowing the rated lift to be maintained. When ground is uneven, use solid footing, mats, or cribbing under the outriggers as needed and adjust until level before starting the lift. Skipping outriggers, using only one side, or deploying them partially undermines stability and is not safe for lifting.

Net capacity is the actual lifting capacity available after accounting for reductions. You start with gross capacity—the maximum load the crane can lift under standard conditions—and then subtract deductions that reflect safety factors, rigging, line dynamics, wind, temperature, and other influences. This gives the usable capacity for a given setup. For example, if the gross capacity is 10 tons and deductions total 1.5 tons, the net capacity is 8.5 tons. The other formulas don’t reflect this practical relationship: net capacity isn’t derived from subtracting deductions from the load to be lifted, nor is it the opposite of deductions minus gross capacity, nor simply the load weight itself.

Understanding the load’s center of gravity and its orientation is crucial because they determine how the weight behaves when you lift. The center of gravity is the single point where the load’s weight effectively acts. If the rigging or the load geometry places that point away from the crane’s lifting line, the weight creates a tipping moment and can cause the load to tilt, rotate, or swing. That shifts the actual load on the crane and changes the forces the crane must resist. The crane’s rated capacity is based on a specific CG position, a given radius, and a particular boom angle. When the CG is offset, the horizontal component of the load increases, which reduces the safe capacity you can use at that setup. In short, misalignment can dramatically reduce how much weight you can lift safely and raises the risk of tipping, load rotation, or uncontrolled movement. Good rigging aims to keep the CG as close to the crane’s line of lift as possible and to maintain the load in a near-vertical orientation, using appropriate spreaders, slings, or taglines to control balance and sway. This isn’t something you can neglect. It applies to every lift, not just tall or unusual loads, and it’s not about superficial details like color or automatic handling. Proper attention to CG and orientation makes the lift stable, maximizes usable capacity within the load chart, and prevents dangerous situations.