Nedstaal received a solution that was efficient, low-wear, safe and energy-saving

Nedstaal received a solution that was efficient, low-wear, safe and energy-saving

‘Ideal’ crane built for steel producer

In Stahl CraneSystems and Crane Builders’ solution for Nedstaal, a grab uses two rope hoists and a rope-bracing system to move vertically, without rotating

December 2015

Stahl CraneSystems and its Dutch partner CraneBuilders have developed a crane for steel producer Nedstaal that best suits the rough environment in which it operates, ensuring efficiency, safety, energy savings and less wear and tear.

“Nedstaal needed a particularly robust and reliable crane in this environment,” says René Rohde, CraneBuilders’ project manager, and explains: “Our crane system works with Stahl CraneSystems wire rope hoists and a grab with an off-standard rope bracing system. By working together and making use of the versatile German crane technology we were able to develop the ideal crane system for our customer.”

Nedstaal produces high-quality steel for steel treatment companies. Its core business is made-to-order small batches of 30 to 50 tonnes. Nedstaal is able to produce hundreds of different types of steel depending on the composition of the raw materials and the processing. Both the individually produced steel grades and the short delivery times are of crucial importance for the company’s success and depend on a high material throughput in the production chain and that requires reliable technology.

The new crane in the front section of the building is equipped with a grab for picking up steel cylinders safely and quickly. The grab is lifted and lowered by two wire rope hoists mounted on a double rail crab.

In this type of grab solution, extremely high forces act on the rope drum and cause the rope and rope guide to wear quickly. Short maintenance intervals and unplanned downtimes would be the result of this.

“We worked together with Stahl CraneSystems and developed a low-wear solution with two wire rope hoists specially adapted to this application,” says CraneBuilders’ Marco Lindhout. “Our design means that the grab can be moved absolutely vertical and without rotating, even if there is a slight asynchronism or one of the hoists comes to a stop,” Lindhout continues. A sophisticated rope bracing system at a set distance below the wire rope hoists makes this possible.

“The customised rope reeving over several sheaves holds the load free of oscillations during travel and the angled ropes have a stabilising effect,” explains Peter Kittsteiner, who as Stahl CraneSystems’ area sales manager was involved in developing the solution. This also avoids stress on the rope drum caused for example by diagonal pull. “Sometimes you don’t need that much technology – a lot of problems can be solved intelligently and extremely efficiently with plenty of experience and the right idea,” said Lindhout.

Project manager Rohde explains: “Our crane control feeds the energy produced by frequency inverters and brakes back into the grid, so we can reduce the crane’s total energy consumption.”

To enable the crane to function trouble-free in spite of the high build-up of dust, CraneBuilders decided to use two AS 7 wire rope hoists from Stahl CraneSystems. The robust hoists are regarded as particularly reliable, they are low-maintenance and have no trouble coping with high ambient temperatures and adverse conditions.

The successful collaboration between CraneBuilders and Stahl CraneSystems has a long tradition.

CraneBuilders emerged from Stahl CraneSystems’ Dutch subsidiary as an independent crane builder and together with its sister company CraneSolutions has grown into one of the Netherlands’ leading crane builders.

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