Across the myriad of America’s manufacturing industries, from food and drink to automotive and aviation, safety and throughput are the key drivers for innovation in overhead cranes. "There’s a general trend towards higher efficiency and higher productivity, so customers want to do more with less. That means equipment that’s greener so it has lower energy consumption, and faster, higherduty cycles so that means greater automation and more sensors," says Gustavo Oberto, Conductix’s managing director for region Americas.
One such industry is the automotive, where production processes are constantly under review.
For the ever-evolving ergonomic needs of the automotive sector, Demag has developed the DCMS-Pro chain hoist, the only infinitely variable speed chain hoist on the market. The DCMS-Pro allows one-handed chain hoist operation and load handling; lifting motions at almost double the rated speed in the partial load range; quick-change coupling; and simple replacement of the load handling attachment.
The chain hoist also has fine control at slow speed and a creep lifting speed from 0.15m/ minute.
"That’s now becoming popular across all sectors, but especially the automotive industry," said Martin Marincic, Demag’s product manager, overhead cranes, North America.
The use of remote controls, which improve safety by allowing the operator to stand further away from the crane, is another technology that’s becoming more mainstream, according to Joe St Clair, information systems manager at Hoosier Crane.
"Radio controls are much cheaper and more reliable than they were five years ago," he said. "Whereas they used to be a luxury, we now sell a three-motion, two-speed radio system for $625.
"More injuries probably occur on smaller cranes because they’re used more frequently but, at that price, you can afford to put it on smaller cranes."
St Clair also identified a trend of using smarter below the hook manipulators on smaller cranes, enabling one person to move a part or product that may have taken two or three people to handle manually.
"We built one manipulator that hooked below a workstation crane that allowed the customer to pick up an 8ft-long, 200lb cam shaft and rotate it so it came out of one machine horizontally and was loaded into another machine vertically."
Another technology in demand in the automotive sector, and other industries using heavy overhead cranes, is anti-sway technology.
This electronic control system alters the acceleration profile of the bridge and trolley, reducing the load swing back and forth when first, the load is accelerated and, just as importantly, when it is decelerated.
"Swaying loads is a very unsafe condition," said Marincic. "Anti-sway technology has become very popular in automotive and coil handling facilities, but it really applies to any heavy load.
"If you have a coil of steel that’s out of control on a hook, once it starts swinging you really can’t stop it until you’ve let the pendulum effect die down. The strategy is not to let it swing in the first place."
The anti-sway technology modifies the acceleration rate that is commanded to the variable speed inverters on the crane so that even if the operator commands a very fast speed change, the crane is smart enough to accelerate slowly so it stays under control. Although anti-sway technology slows the crane, the additional control actually raises throughput.
And there are many developments that lead from anti-sway. The logical next step is semi-automatic pick and place controls, which are smart enough to cope with an obstacle in the crane’s path.
"You have no-fly zones and appropriate sensors and feedback devices which will prevent the crane from making the automatic move," said Marincic.
GW Becker has also identified a trend of customers wanting greater automation, telemetry feedback for crane status, faults and changing parameters, positioning and collision avoidance.
"These requirements benefit manufacturing companies by reducing product damage, improving product quality, reducing labour costs, and through more consistent moves and improved maintenance activities by providing predictive and preventative maintenance opportunities," said marketing and business development manager Brent Rozar.
Careful, and specialist, handling is also called for in the aviation industry where the loads are large and heavy.
"Because of the structure of an airplane hanger you have to take a different approach to the whole crane process," said Marincic. "The crane runways are part of the building structure so there’s a lot of interface design to get the load handling capacity of the building and the crane up to the point where you can safely handle a fuselage or wings that can weigh 20-25 tons."
And the handling itself requires a high degree of finesse.
"To lift a fuselage you can have up to eight different picking points so control is crucial. It’s a challenge to synchronise eight different hoists so you keep each hook within +/-10mm of each other," said Marincic. A Siemens PLC controls the lifting as well as the movement once the load is lifted.
It’s this sort of handling that Demag is applying to the new Airbus assembly facility in Mobile, Alabama. Here 10 process cranes will be used for final assembly of the Airbus A320 in three production hangars. Measuring up to 66.5m in length, the cranes have a maximum load capacity of 25 tons.
Technology is also helping industries improve efficiency through better inventory control. "Automation can be linked to customers’ SAP systems or their main frames to provide inventory control on the plant floor. This means you can upload and download orders from the front office to the crane, and tell it which coil or load you want. It makes the business side of it much more efficient," said Marincic.
This automation raises the safety level for operators and improves efficiency, not just by boosting throughput, but by also providing information on how the crane is performing. "Products in the industrial market are often dumb products — they do their job but there’s no feedback, no data to show how they’re performing," said Oberto.
To address this, Conductix is incorporating much more intelligence into its products. "If you have a lot of equipment in a single plant, maintenance crews have to walk around inspecting every piece but now you can add intelligence which alerts the crews that something is needed ahead of time and tells them exactly which unit needs to be replaced. That’s of tremedous value to everyone," said Oberto.
It is technology that’s aimed particularly at larger manufacturers.
"Smaller manufacturers with one or two cranes can do maintenance more easily but a much larger manufacturer with 100-200 cranes operating 24/7 those are the kind of industries that demand technology that’s beyond what we used to see in the industry," he said.
Whiting Corporation says it is developing technologies that don’t monitor just the condition of the equipment, but the operator as well.
"Coupling operators with condition monitoring creates a vastly more useful view into the overall operation of your equipment as operators have a huge impact on the life of the equipment," said Edward Yakos, senior vicepresident of corporate development.
"Pairing products like AccessPoint which puts engineering control between your high-risk and high-value equipment such as overhead cranes and your workers, and LiftLog, which monitors and reports every lift made on an overhead crane, gives supervisors a complete picture of the overall crane utilisation, by operator."
Whiting’s crane product group supervisor, Alan Horgan, said the company’s design methodology helped customers to get the most out of their cranes.
