"Mill-duty", as displayed on the coil grab, refers to the high level of work cycles that the equipment is designed for, explained Josh Berryman, lifting specialist at Mazzella Alabama Sling.
A 37.5-ton capacity mill-duty coil grab has been installed beneath the hook of a 40-ton capacity overhead crane at a Monarch Steel Company Inc. facility in Decatur, Ala.
The coil grab was manufactured by The Caldwell Group, a Rockford, Illinois-based company that specializes in both standard and custom lifting equipment. Mazzella Alabama Sling Center, a Caldwell Group distributor, provided the coil grab to the Monarch steel service center, located in Decatur in northern Alabama.
The grab replaced a previous coil grab that had become damaged over time; the facility opened in 2004. It is rigged below a 92-ft. span top-running double-girder crane, with a single hoist, manufactured by Zenar. The grab carries coils from the processing machine to a floor storage area, over a distance between 100 and 200 ft.
Josh Berryman, lifting specialist at Mazzella Alabama Sling, said, "The crane has a standard hook block, but there is a scale system between the block and hook. The hook-scale assembly is used to monitor the weight of the coils being lifted. The crane and grab are operated by a single operator in a standing position, using radio remote control."
He explained that the coils are typically the same size but do vary in dimensions and weigh up to a maximum of 75,000 lb. (37.5 ton). The maximum outer diameter is 80 in., while the largest inner diameter is 20 in. Coil widths range from 25.5 to 76 in.
The crane is Service Class 3 and Crane Manufacturers Association of America (CMAA) Class D, meaning it is rated for heavy service application. The grab is ASME BTH-1 Design Category B, designated when the conditions of the lift are not always defined or predictable, or when load conditions could be severe.
Monarch's customer base includes appliance manufacturers and the auto industry. The tier 1 and tier 2 suppliers to the auto assembly plants rely on these steel service centers, which act as a bridge between metal producers and end consumers.
Monarch is headquartered in Cleveland and is one of the country's largest providers of hot rolled, cold rolled and galvanized steel product. In addition to the site in Decatur, a third service center is located in Cadiz, Ky.
For more information, visit www.caldwellinc.com.
This story also appears on Crane Equipment Guide.
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