The first units of Liebherr’s new 700 tonne capacity crawler crane, the LR 1700-1.0 (Liebherr’s successor to the LR 1600/2), have been delivered to two German crane companies: Hofmann Kran-Vermietung, based in Paderborn, and Wasel, from Bergheim.
Hofmann, a subsidiary of the crane hire firm Bracht Group, has already used the LR 1700-1.0 to help construct a large wind turbine at the Holzhausen wind farm near to where the company is based.
The company erected a Nordex Delta 4000 wind turbine on top of a prefabricated concrete tower with a hub height of 164 metres. The heaviest components were the nacelle and drivetrain with a total load of 75 tonnes.
Operating under higher wind loads
The LR 1700-1.0 was equipped with a 165-metre-long main boom, including nine lattice boom sections of Liebherr’s wider H-Version (the ‘H’ stands for ‘heavy’), each 12 metres long. “The H-Boom lets us operate under higher wind loads,” explained crane operator Christoph Bergmaier.
According to Liebherr the greater wind tolerance of this boom configuration can save the crane and assembly teams time on site as they do not need to stop as much due to excessive wind.
Liebherr said it allows wind speeds of 11.2 metres per second for the LR 1700-1.0 – as for all current LR crane types with special wind power equipment configurations. With only a minimally reduced maximum load, this value increases to 13.4 metres per second. The manufacturer says this is an advantage for customers and end users, because normally the wind stops work at speeds of nine metres per second.
Time saved ballasting
Time saving is also offered by the crane’s VarioTray divisible derrick ballast and V-Frame. “These allow us to work with 60 tonnes of derrick ballast during the entire assembly of the turbine – so we don’t have to carry out any time-consuming ballasting,” Bergmaier added. The large ballast pallet is only docked for erecting or taking down the lattice boom – a procedure that Liebherr says takes around ten minutes with just four bolts.
Liebherr said the continuously adjustable V-frame ballast radius enabled the blue-painted Hofmann crane to operate in relatively little space on the construction site near Paderborn – even during the slewing process.
The crane successfully completed assembly of the wind turbine components with a radius of 26 metres.