Telescopic is the word
By Alex Dahm09 January 2009
Liebherr's new 1,200 tonne capacity LTM 11200-9.1 carried out its first task in September for owner Mammoet.
According to the company it also marked the beginning of a new era in which telescopic boomed cranes will take on the work previously exclusive to lattice boom crawler cranes.
The 9-axle crane helped extend a radio tower in Amsterdam, Netherlands, to a height of 146 m. The crane's configuration consisted of a 55 m main boom, telescopic extension, 90 m luffing fly-jib and Y-suspension.
A shorter, 54 m fly-jib, was used for the first five radio tower section lifts. Loads reached 67 tonnes and were lifted to a height of 112 m.
Next, segments weighing 9.5 tonnes each were hooked on to the luffing fly-jib which was extended to 90 m.
Some 202 tonnes of counterweight was used, along with a 13 x 13 m supporting base of and the Y-suspension positioned a 45° angle.
The new crane has also impressed Mammoet with its economical transportation. For the job in Amsterdam, 16 truck loads, additional to the crane carrier, were necessary. "[This is] roughly five trucks less than necessary for a crawler crane with a comparable configuration," comments Kees Herrijgers, Mammoet leader of operation.
"But the crane will demonstrate its greatest efficiency when it moves to jobs with its 100 m main boom," adds the company.