New Wolff luffer

The Wolff 235B offers a maximum load capacity of 8t in single-fall and 16t in two-fall operation and jib lengths from 30 to 60m. Wolffkran says with a 50m jib, the tip load is 4.1t, outperforming its competition.

Its 60kW hoisting winch allows for working speeds of up to 130m/min and a rope storage capacity of 620m. It comes with a connection to the two-metre tower UV/TV 20 and can reach a maximum freestanding height of 82m using standard components from the modular Wolff tower system. Thanks to its active absorber, the Wolff 235B achieves a smaller minimum jib working radius of 10% of the jib length.

In terms of performance, Wolffkran said this model replaces the popular Wolff 224B and ranks between the hydraulic Wolff 166B and the next larger Wolff 275B in the lower load moment range, thus fulfilling the demands of construction sites with a high volume of concreting work on high-rise buildings.

The Wolff 235B was developed in close collaboration with Wolffkran customers from the UK, who have decades of experience in handling luffing cranes on inner-city construction sites. “The result is a Wolff with a proven duty chart that is unrivalled when it comes to assembly and versatility,” said Wouter van Loon, product manager at Wolffkran.

The hoisting gear of the new model is positioned on the jib rather than the counter jib as is typical. “This makes it possible to reeve the hoisting rope on the ground and thus completely pre-assemble the entire jib,” said van Loon, adding that it is a novelty for luffers of this size.

The luffing gear can be mounted either on the counter jib or on the tower top during the assembly process, which offers more flexibility with regard to the size of the mobile crane needed. The second option has the advantage that the entire tower top including the hoisting gear with pre-reeved pulley block can be transported and lifted onto the crane as a single unit. In addition, the cabin platform with the Wolff Cab and switch cabinet can be placed on the empty counter jib during transportation. Further, overall low component weights ensure that a Wolff 235B can assemble another of its kind at a jib radius of 40m.

Another key aspect in the development of this model was the economical maintenance of the crane, which led to the decision to use an identical winch for both the hoisting and the luffing gear. Wolffkran opted for the tried and tested 60kW winch Hw1160FU that is used in numerous other of its models, which is also the case for the slewing gear and the frequency converters that are used in the 235B. This facilitates economical warehousing as fewer different spare parts have to be stocked and also simplifies training of service technicians. The same principle applies to the 8t counterweight blocks that are used in all of the next larger Wolff luffing jib cranes. Further features facilitating maintenance include the use of maintenance-free multi-disk brakes and the positioning of the luffing gear at the bottom of the tower top.

For the Wolff 235B, the proven Wolff crane control has been enhanced with a brake testing function allowing the main and secondary brakes to be tested independently of each other. Further included as standard is the Wolff Link remote diagnostic and maintenance tool with real-time display of the crane operator’s monitor, fine drive modes and automatic power optimization for the hoisting and luffing gear, an anti-collision interface, as well as the Wolff Boost function increasing load capacity by 10%.