Wolffs on tallest tower

More than a dozen Wolff tower cranes are working on the construction of what is claimed will be the world’s tallest skyscraper.

Roots Group Arabia is using thirteen Wolff cranes in Saudi Arabia for the construction of the Jeddah Tower, which will be “more than 1,000 metres above sea level”. The contractor is working on behalf of Saudi Arabian construction and real estate company, Saudi Bin Ladin Group (SBG). The Jeddah Tower will be at the centre of a new district being built along the Red Sea in Obhur. It stands on 270 piles that between 45 and 110 m deep 1.5 to 1.8 m in diameter. The project is a 530,000 square metre mixed use development that includes a hotel.

The cranes are twelve saddle jib type 7532s, primarily for moving loads on the ground and for construction of the podium at the base of the tower. The other crane is a 355 B luffer with 40 m jib and 28 tonnes capacity. It is erected in the triangular core of the tower, central to the Y-shaped building’s floorplan. A second Wolff 355 B was still to be set up soon after the time of writing in early-January, both on 48 m towers. They will rise with the building using internal climbing, up to about 580 m.

In the next phase one of the luffers will be moved to a special platform at a height of 538 m, where it will work on the outside of the building to a hook height of 734 m. After that it will be dismantled and then reassembled at 630 m above sea level, to achieve its expected ultimate hook height of almost 800 m, Wolff said.

High wind speed is a challenge for the cranes at this elevation. Combining the internal climbing tower segment KSH 23 and the HT 23 tower elements protect the tower against distortion even though they are only 2.3 x 2.3 m, Wolff said. Long lift cycles means a demand for high hoisting speed. “Our Wolff 355 B cranes are impressive on these sites due to their very high working speeds of up to 185 m/min and a hook path of 920 m,” said Habib Mikati, Wolffkran ISS managing director, in Dubai.

In the last six years Roots has used more than 200 red Wolffs on construction sites in Saudi Arabia, for example, at the King Abdulaziz International Airport in Jeddah, the Princess Nora bint Abdulrahman University in Riyadh and in Mecca on the ongoing extension of the Holy Mosque.