Wolffkran Wolff 6020.6 clear

In 2017, after nearly a decade since the introduction of its successful 6015 Clear series, Wolffkran launched the new Wolff 6020.6 Clear flat-top tower crane. This model was developed as part of Wolffkran’s renewed 140 mt-class series, replacing its predecessor with significant advancements in technology, assembly efficiency, and operational performance. The Wolff 6020.6 Clear — a 6-ton capacity crane — became available to customers starting September 2017, alongside its 8-ton counterpart, the Wolff 6020.8 Clear.

A key focus of the new design was adaptability and ease of integration into diverse job sites. Both the 6020.6 and 6020.8 Clear models can be connected to three different tower systems: the narrower UV 15 and the wider TFS 20 and UV 20 tower configurations. This compatibility enhances deployment options on sites with varied spatial or structural needs.

Engineers at Wolffkran redesigned the trolley system to improve movement precision and minimize wear. The updated design eliminates wheel flanges on the rollers, instead incorporating a new guide roller on the jib that optimizes the trolley’s path. Additionally, the lower belt connection of the jib was re-engineered to distribute structural forces more efficiently. This redesign allowed the use of smaller, more manageable bolts, simplifying assembly and improving overall practicality on site.

The Wolff 6020.6 Clear comes with a 25-meter basic jib equipped with the trolley gear and can be extended up to 60 meters in 2.5-meter increments. The slewing frame features a single slewing gear, a slew bearing with central lubrication and slip ring system, and an operator cabin station with the control cabinet. The counterjib includes the hoisting platform and the appropriate counterweight blocks to balance different configurations.

In terms of drive technology, the Wolff 6020.6 Clear employs frequency-controlled squirrel cage motors that are fully thermally protected. The hoisting winch (Hw 628.1 FU) delivers stepless hoisting speeds up to 108 m/min (depending on load) and supports a hook path of 190 meters in 2-fall operation, ideal for medium-to-tall buildings. Slewing is driven by one slewing gear fitted with an electrically operated weathervaning device and automatic wind force compensation, enhancing stability and operational safety.

The crane’s electrical system supports supply voltages ranging from 380 V to 460 V at 50 or 60 Hz and features bus technology for streamlined communication between systems. Incremental absolute encoders track all operational movements, while an electronic load measuring device at the basic jib section feeds real-time load data to a multilingual graphic display in the operator’s cab, ensuring precise control and diagnostics.

Safety on the Wolff 6020.6 Clear is enhanced through electronic overload protection with WOLFFBoost technology. This system automatically reduces hoist speeds as loads approach their maximum capacity, increasing overall load moment limitation. Additional safeguards include a working space limiter, anti-collision interface, WOLFFLink data transfer system, a trolley rope breakage safety device, and menu-guided setup for all overload and limiter settings from within the operator’s cabin.

For erection and climbing, the crane uses the Wolff slug bolt connection system and supports both external hydraulic climbing devices (KWH 15.2 for 1.5-meter towers and KWH 20.3.1 for 2.0-meter towers) and internal climbing systems (KSH 15 and KSH 20 M). It can be installed on cross frames KR (with corner distances between 3.2 and 10 meters) for stationary setups, or on Wolff undercarriage units (UW) or traveling cross frames (KRF) with gauges from 6.0 to 10.0 meters, depending on project requirements.

Overall, the Wolff 6020.6 Clear stands as a modern, robust, and highly adaptable tower crane designed to meet the challenges of today’s high-density construction sites. It delivers excellent lifting capacity, smooth operation with frequency-controlled drives, and superior safety and diagnostic systems, building on Wolffkran’s legacy of engineering excellence in tower crane technology.