LTW matches the number of cranes required to the throughput of a facility. “We have many installations where there are four aisles and one crane or five aisles and three cranes, depending on the throughput,” says Hull. He cites an installation with 60,000 pallet locations that had been operating with 24 crane aisles that now operate efficiently with just six LTW aisle-changing cranes.
“Customers can install a system based on the number of pallet positions they need for today and for projected future needs. But they only need to put in the number of stacker cranes they need today, adding additional cranes when necessary,” adds Hull.
Another operational benefit with sustainability results is the power-saving technology designed into these cranes. “The lift truck industry refers to this as regenerative braking, while we refer to the process as capturing and reusing the leftover electricity,” Hull says.
As the carriage lowers, LTW software allows the power to be captured from the lifting motor, which now becomes the generator. “We capture that AC power and when the stacker crane slows down, the electric motor shuts off and the crane now works under deceleration, at which point we capture that power. We can put that captured power into our small grid inside the building to help power other equipment like conveyor systems, lights in the office, or other stacker cranes. Any additional power can return back to the city’s power grid.”
LTW aisle-changing cranes operate with AC power. So by not using batteries, companies can avoid the high costs associated with battery maintenance and safety concerns.
“There are no hydraulics on our equipment, greatly reducing maintenance costs. As a manufacturer of ASRS solutions, we are dedicated to controlling the aftermarket costs of our equipment and in Europe we have continually guaranteed 99-percent uptime on our equipment over a 15-year period,” Hull reports.
About two years ago, Schaefer US introduced the Schaefer Orbiter System (SOS) that had been operating successfully in Europe over the last three years. “It is a pallet shuttle system operating on a capacitive charge, so there are no batteries involved,” Berres explains. The system consists of the Orbiter satellite with a docking station, designed for high-density storage solutions using any type of material handling equipment.
One use of the Orbiter shuttle is riding on the ASRS crane as the load-handling unit, Berres reports. “Every time the Orbiter is docked to the crane, it receives its capacitive charge from the docking station so it can begin its journey down the aisle with a pallet on top as it stores or retrieves the pallet. The advantage to this solution is it is not degraded by cold environments like a battery-operated shuttle is and it doesn’t require the change-outs that a battery does for charging cycles. You also don’t have to deal with the caustic chemicals involved with battery usage, so there is a definite maintenance advantage with our system.” The docking station provides the capacitive charge within seconds, providing enough energy for the shuttle to complete its travel down the rack aisle and back.
Berres notes the system was designed as a way to improve the efficiency of operating a pallet shuttle in the cold storage environment. “Although the Orbiter can work in any environment, it is well-suited for the cold storage environment because it does not rely on batteries.”
Schaefer offers ASRS solutions for everything from pallets to cases and totes, and it can retrofit cranes into 32-foot-high to 36-foot-high buildings. “A more sustainable product for retrofits is our Orbiter, which is capable of stacking pallets 20 deep, eliminating the need for extra aisles,” Berres says. “We can integrate our Orbiter system into an ASRS that has a single crane operating and servicing both sides of the aisle, each storing pallets up to 20 deep.” The system can also be integrated into other forms of automation to improve the energy footprint. “We can integrate into your automated picking processes such as automated case picking, layer picking, and standard pallet-in/pallet-out applications that can be done without the use of forklifts.”