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Crane Hot Line

New Fiber Rope Can Replace Steel Without Crane Modification

Oct. 21, 2022 - In cooperation with rope specialist Trowis GmbH, Wolffkran has developed a high-performance fiber rope that will be showcased on a Wolff crane at Bauma 2022.

The new rope, named chaRope, offers all the general advantages of synthetic ropes, plus the unique advantage of being able to be substituted for steel rope 1:1, without modification of the crane.

To date, chaRope’s manufacturer, Trowis, uses a rope cover made of a special fiber composite that which was developed in close collaboration with Wolffkran.

"Thanks to the unique design, the chaRope fiber rope has the same diameter as a steel rope and is thus significantly thinner than comparable products from competitors," said Thomas Heidrich, CTO and member of Group Management Board at Wolffkran GmbH.

"The rope design consists of a multi-layered, twisted rope core made of high-tensile high-tech fibers and an abrasion-resistant, thin-walled fiber composite cover," explained Dr. Thorsten Heinze, managing director of Trowis. "Thanks to this structure, we can offer 12- and 16-mm diameter crane ropes at market entry."

"All Wolff cranes with 12- or 16-mm steel wire rope can be equipped with the new chaRope fiber rope. The ropes are fully compatible with the crane series, and no adjustments to the rope sheaves, hoisting gear, or load capacities have to be made," said Thomas Heidrich. "In our current portfolio, this applies to all models in the Wolff Clear series, the new Wolff 21 FX cranes, and the Wolff 8033.16 Cross."

Cover Makes the Difference

Aside from its small diameter, the unique fiber composite design of the rope cover has further advantages over conventional, braided covers: It is monolithic, also called seamlessly impermeable.

As a result, moisture can't penetrate to the inside of the rope, nor can lubricants or fiber abrasions leak through to the outside. "The rope does not run dry, even after many years, and the environment is not polluted with microscopic plastic," said Peter Streubel, managing director of Trowis GmbH. Furthermore, the rope cover offers 100% UV protection for the interior core and serves as an indicator of when the rope needs to be discarded. The rope must be replaced if it shows damage, such as material degradation, cracks, or twists.

The fibers of the rope core are made of extremely dimensionally stable material. As a result, the core hardly plasticizes, preserving the rope's round cross section. Because of this, chaRope can be used in the most challenging environments, keeping its shape regardless of the temperature.

Light, Economical, Sustainable

The chaRope fiber rope weighs roughly 80% less than steel rope. This enormous savings in weight not only enables greater lifting capacities, but is also significantly easier and safer handling during transport, assembly, and rope changing.

Thanks to the fiber compo-site design developed by rope specialist Trowis, chaRope has a life span that is at least four times greater than a conventional rope made of steel wire. Furthermore, the ropes need not be relubricated or cleaned, and the rope sheaves hardly experience wear. For the customer, this means reduced maintenance work and greater crane availability while also conserving resources.

Trade Fair Premiere at Bauma 2022

The chaRope fiber rope has been undergoing extensive testing on a spooling test bench. It will shortly undergo comprehensive field testing in Wolffkran’s UK rental fleet and also make a first appearance on the new Wolff 6021 FX at Bauma.

“We look forward to celebrating an additional trade fair debut with the chaRope fiber rope,” said Heidrich. “The test phase will be completed in June 2023, and the rope will be available on the market in August 2023. As of that time, we will supply all Wolff models with 12- or 16-mm rope, optionally with the steel or fiber version. We will also successively fit cranes in our rental fleet with the new fiber rope. In the medium term, we plan to develop further fiber ropes with other typical diameters together with Trowis, to offer the entire Wolff crane range with the innovative fiber rope.”


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