Carbon fibre tie bars
28 February 2008
Liebherr is first to take the leap into carbon fibre composite structural components with the introduction of tie bars made of the tough but lightweight material. They are fitted on the new LR 1300 crawler and a modified version of the heavy duty HS 895 HD crawler.
“The new tie bars are made of CFK [a composite material using unidirectional extruded carbon fibres in polymer resin], a world first for this type of product. The special properties of carbon fibre and its relative lightness mean it offers great potential for technical progress, which will be of benefit to users,” says Liebherr's Wolfgang Pfister.
Compared to conventional steel bars, Pfister adds, CFK bars are up to three times lighter and have a higher static load capacity and greater long-term rupture strength with the same level of rigidity.
“The great benefit for the user is that the lower weight of the components enables greater jib lengths. In turn, this means that the user can operate on construction sites with greater working heights and greater working radii. In addition, the crane has up to 50% more load capacity than was previously possible, particularly at large working radii”.
Long-term stability is another advantage of the CFK bars over fine-grained steel.
“When putting up a heavy crane or duty-cycle crawler crane, it is not necessary to have an additional crane to handle the bars and securing cables. In practice, such commercial advantages can be crucial when using crawler cranes weighing up to 300 tonnes,” Pfister added.