ODE to Amsterdam – seven WOLFF cranes on Oost-erdokseiland

24.06.2020 | Press Release

The location of the construction site, surrounded by water, existing buildings, and the tracks of the central railway station, required a sophisticated assembly concept since there was only one place where the 500 tonne mobile could be positioned. It was used to erect the first WOLFF 700 B luffing jib crane at a distance of 28 meters, which then installed the second WOLFF 700 B. This, in turn, assembled the three WOLFF 355 B luffing jib cranes on site. A WOLFF 7032.12 clear and a 5014 city were erected as support cranes at the beginning of this year. The particular foundation structure of the building also required customized foundation anchors for the WOLFF cranes. "The construction site's location requires a high degree of coordination in the daily workflow and the entire logistics. The crane concept plays a decisive role here," says Tobias Wallner, Senior Project Construction Manager at Züblin.

Efficient concept with space saving luffing jib cranes

Due to the prevalent strong winds on Oosterdokseiland, the WOLFF 700 B cranes were installed on 3.30 meter towers and the 355 B cranes on 2.90 meter towers, allowing them to work freestanding in stormy weather conditions. Thanks to their small minimum jib radius and working range limitation, the luffing jib cranes can operate safely on the cramped construction site without getting in each other's way, despite moderate tower heights between 47.2 meters and 54.2 meters. "Lower tower heights mean lower costs. Paired with the high lifting capacities of the WOLFF luffers, we were able to offer the customer a particularly cost-effective solution," explains Carsten Druske, Head of Rental Germany and Branch Manager WOLFFKRAN Dortmund.

The construction site's immediate vicinity to the railway tracks and the entrance to an underground car park are particularly demanding for crane drivers and service technicians as these areas may not be slewed over and must be generously omitted by the working range limitation. Consequently, any construction work close to these areas has to be performed after-hours, when the system can be safely switched off, requiring several night shifts from the WOLFFKRAN service team.

Teamwork for lifting heavy steel

"The structure of the building is technically highly complex," explains Tobias Wallner. "Heaviest steel components meet in-situ concrete and prefabricated construction combined with constantly changing geometries". When lifting steel columns weighing up to 28 tonnes and precast concrete parts weighing up to 15 tonnes, the WOLFF cranes can fully utilize their high load capacities of maximum 50.0 tonnes (700 B) and 28.0 tonnes (355 B). WOLFFKRAN's Technical Support Team also calculated several special lifts for the steel parts weighing up to 35 tonnes, which were performed as tandem lifts by the two 700 B luffers.

Already during the planning phase, Züblin benefited from the crane manufacturer's years of experience in planning and servicing cranes on major international projects. "The assignment in the Netherlands requires a separate risk assessment for each erection and dismantling as well as a schedule that has to be submitted before the start of construction. Besides, all cranes need to be equipped with additional safety features, such as warning signals and a mandatory hoist for the crane operator," explains Carsten Druske. Due to the special light conditions near the sea, all cranes were fitted with a camera system, enabling the crane operator to monitor the load and lifting process on a screen.

Successful partnership

"A refined assembly concept, complex tandem lifts or the flexible adjustment of the working range limits during the construction phase - the job required a partner with the necessary experience and technical know-how alongside offering an economically efficient overall concept. We found this partner in WOLFFKRAN," says Tobias Wallner. The building shell is of the ODE project is scheduled to be completed end of 2020 and stands for the successful continuation of the long-standing partnership between WOLFFKRAN and Züblin. Over the past year, the two companies have realized numerous construction projects together, including high-rise projects in Frankfurt and power plant projects in the Netherlands.