March 6 - Two Liebherr LTR 11200 telescopic crawler cranes have been deployed on a wind farm construction project in Saterland, Germany.
The 510-tonne crawlers, with the main boom retracted, are able to move along 5 m wide gravel tracks without being dismantled or having ballast weight removed. According to Liebherr, the time savings are enormous; normally three to four days is required to dismantle and erect a lattice boom crane of this size.
Wind turbine manufacturer Enercon operates one LTR 11200 crane. It has been configured with a seven-section telescopic boom and short erection jib, which is capable of hoisting concrete components weighing up to 128 tonnes.
When the wind towers have been lifted to 30 m a second LTR 11200 - operated by crane contractor Karl Hartinger - is used to erect the turbine tower up to height of 105 m.
If a single crane were used in the installation process, the luffing jib and ballasting would require constant alteration.