Abstract: A method for calculating a crane capacity for a crane having a variable position counterweight at a locked position includes determining a boom combination and determining a maximum capacity at a hook position for the boom combination. A maximum target value for an operating condition dependent on a balance of the crane is determined. An indication of the locked counterweight position is received. At least one new target value for the operating condition dependent on the balance of the crane between the variable position counterweight at the locked counterweight position is established. A new capacity of the crane is calculated by decrementing the maximum capacity of the crane proportionally to a difference in the maximum target value and the at least one new target value. Cranes and crane control systems may employ this method.

Abstract: A method for calculating a crane capacity for a crane having a variable position counterweight at a locked position includes determining a boom combination and determining a maximum capacity at a hook position for the boom combination. A maximum target value for an operating condition dependent on a balance of the crane is determined. An indication of the locked counterweight position is received. At least one new target value for the operating condition dependent on the balance of the crane between the variable position counterweight at the locked counterweight position is established. A new capacity of the crane is calculated by decrementing the maximum capacity of the crane proportionally to a difference in the maximum target value and the at least one new target value. Cranes and crane control systems employing the method are also disclosed.

Abstract: A system and method for calculating a crane capacity for a crane having a variable position counterweight at an intermediate position is disclosed. In the method a boom combination is determined and a maximum capacity at a hook position is determined for the boom combination. A target value for an operating condition is established dependent on a balance of the crane between the variable position counterweight and a load on the hook. An indication is received of an intermediate counterweight position, and a load is calculated for the hook at the hook position for the boom combination and the intermediate counterweight position that results in the operating condition having the target value to determine an intermediate capacity. The intermediate capacity is compared with the maximum capacity and the lower of the maximum capacity and the intermediate capacity is output.

Abstract: A system and method for calculating a crane capacity for a crane having a variable position counterweight at an intermediate position is disclosed. In the method a boom combination is determined and a maximum capacity at a hook position is determined for the boom combination. A target value for an operating condition is established dependent on a balance of the crane between the variable position counterweight and a load on the hook. An indication is received of an intermediate counterweight position, and a load is calculated for the hook at the hook position for the boom combination and the intermediate counterweight position that results in the operating condition having the target value to determine an intermediate capacity. The intermediate capacity is compared with the maximum capacity and the lower of the maximum capacity and the intermediate capacity is output.

Abstract: A system and method for positioning a movable crane counterweight is disclosed. In the method, a boom orientation is determined, a first counterweight position is determined, a first crane capacity at the first counterweight position is determined, a second counterweight position is determined corresponding to a second rearward stability associated with the boom orientation. A second crane capacity at the second counterweight position. A load on the crane is determined and the counterweight is positioned at a third position between the first counterweight position and the second counterweight position dependent on the boom load, and the first crane capacity.

Abstract: A system and method for positioning a movable crane counterweight is disclosed. In the method, a boom orientation is determined, a first counterweight position is determined, a first crane capacity at the first counterweight position is determined, a second counterweight position is determined corresponding to a second rearward stability associated with the boom orientation. A second crane capacity at the second counterweight position. A load on the crane is determined and the counterweight is positioned at a third position between the first counterweight position and the second counterweight position dependent on the boom load, and the first crane capacity.