Maxikraft wind conversion
By Euan Youdale17 October 2011
MaxiKraft used its 1,250 tonne capacity Terex CC 6800 crawler crane with a new wind kit to erect an Enercon 3 MW wind turbine in Germany. IC reports
Germany-based MaxiKraft Kran- und Schwerlastlogistik deployed its Terex CC 6800 lattice boom crawler crane with the specially-designed wind power kit, which it developed with the manufacturer, to erect the Enercon E-101wind turbine in Breidenbach, Central Hesse, Germany.
Positioning the rotor on the nacelle completes the wind turbine construction process. In Breidenbach, the lifting operation demanded complete focus from the MaxiKraft team, said a Terex spokesman, as they raised the 130 tonne turbine, with a rotor diameter of 101 metres to a height of 133 m.
To prepare the CC 6800 for the lifting operation, an S1 wind power kit was deployed for the first time with this crane model. It converts a standard crane into one specifically for wind turbine erection.
The S1 kit consists of three 12 m heavy load boom sections, which are attached to the boom foot section, reinforcing the base of the lattice boom. Using an SSL/LSL boom combination, the crane achieves a height of 156 m, plus the length of the offset tip with assembly hook.
"The definitive advantage offered by such a wind power kit is that our standard crane can be adapted for erecting increasingly tall wind turbines. This concept does not merely increase the crane's practical utility, it also augments long-term cost efficiency for us as operators," explains Steffen Lehmann, from the MaxiKraft large cranes division.
A practical advantage is the simple assembly of the wind power kit: conversion is no more complex than a conventional mast assembly, says Terex. Superlift ballast is required during erection, however. In Breidenbach, this was calculated to weigh 450 tonnes. A Terex installation specialist provided support to MaxiKraft during its first project with the wind turbine kit.
The Terex CC 6800 operated at a 32 m radius and carried 250 tonnes of superstructure counterweight, as well as 80 tonnes of central ballast. The superlift ballast weighed 120 tonnes.
Raik Hanisch, the crane operator, explains his experience of using the S1 kit. "The challenge inherent in such a lifting operation lies in turning the rotor while it is suspended in mid-air and bringing it to the vertical assembly position. Since the mast bearing of the wind power kit is positioned at a precise perpendicular, it is very close to the crane's point of rotation; this, of course, proves extremely advantageous when carrying out manoeuvres."
About the CC 6800
The Terex CC 6800 lattice boom crawler crane offers a nominal lifting capacity of 1,250 tonnes, a load moment of 13,840 tonne-metres and a maximum tip height of 216 m. The superlift radius can be adjusted from 15 to 24 m. The greatly simplified assembly procedure permits quick setup of the crane and allows lifting operations to begin quickly, offering excellent return on investment, says the manufacturer. The CC 6800 achieves a speed of 1.1 km/h, assisted by the Quadro drive and it has an hydraulically-assisted boom section pinning system, which are standard features.
MaxiKraft is part of the Kran- und Schwerlastlogistik Group, comprising the aforementioned company, along with Maximum GmbH, Kranlogistik Sachsen GmbH, and Kranlogistik Lausitz GmbH. It has about 400 employees.
The company has 17 locations across five states in Germany and provides cranes for lifts up to 1,000 tonnes and transportation services for payloads up to 300 tonnes, as well as machine transportation and plant relocation services, steel and concrete assembly services, and tower crane transportation and erection services.