MacGregor’s smart ARC claims 30% faster cargo handling8 May 2012
Cargotec has developed a new smart device for cargo handling, the MacGregor Active Rotation Control (ARC), which it claims can reduce handling times by 20–30% during ship loading operations.
Designed as an alternative to the power swivels typically used for ship loading operations, the ARC tool consists of an electrically driven power swivel fitted with a cutting-edge frequency control system that is coupled to a motion reference sensor.
After an operator has programmed the ARC with the alignment needed to place cargo into its final position onboard a ship, the reference motion sensor continuously monitors the load’s alignment, relative to its final resting position, throughout handling.
Feedback of this information from the reference motion sensor allows the variable frequency-controlled power swivel to account for the crane’s movement and external effects, such as wind and choppy waters, to maintain the correct alignment.
Explaining the benefits of the ARC, Cargotec’s sales & technical support manager for marine cranes, Magnus Södersten, said, “Cargo positioning or spotting may easily account for as much as 40 percent of the total crane cycle time, especially when slotting unit loads such as containers and pulp spreaders. Anything which helps to reduce the spotting time can therefore yield a big gain in productivity and energy savings.”
Commenting on the high skill levels required from operators of cargo handling cranes using typical power swivels, Södersten said, “The skills of the crane driver are an important factor, which are reflected not least in the speed with which the cargo is spotted when slotting it in the ship or landing it on the quay.
“Torque introduced into the crane wire during slewing compensation requires hard-to-judge counter correction, added to which are unpredictable movements of the load caused by wind, heel and/or knocks against other cargo or ship structures.”
Cargotec says that operators using the system will be able to significantly reduce handling cycle times and damage to cargo through faster and more efficient precision handling.
The ARC system can be retrofitted to the new, modern MacGregor cranes.