Liebherr cranes make expensive floating crane use superfluous.

Liebherr cranes make expensive floating crane use superfluous.

November 29 2018

The Mammoet outlet in Leuna made quite an impression with a smart solution and the use of two large Liebherr mobile cranes on a site in Berlin. The positioning of lattice supports weighing around 80 tonnes for a future municipal railway bridge from just one side of the river made both financial and logistic sense compared to the use of a floating crane, which was also considered.

The installation of three lattice supports for the substructure of a bridge over a side channel of the River Spree proved to be a complicated logistical challenge as a result of the space available. One bank near the site could not be used for a crane as it was already home to a construction crane. Therefore, the contractor initially planned to erect the supports using a floating crane. However, as a floating crane was not available for some considerable time, the managers had to seek an alternative solution. The decision was made to adopt a suggestion by the crane specialists at Mammoet based in Leuna which plan to install the 40 metre lattice constructions from just one bank of the river. Furthermore, the crane job would not only be completed more quickly, the cost would also be significantly lower than the original floating crane version.

Because the company’s own mobile crane with a 1200 tonne lifting capacity was not available in the short term for the hoist, Mammoet planning staff obtained a machine from Megalift based in Bremen to complete the demanding job in the German capital. This powerful Liebherr LTM 11200-9.1 mobile crane was fitted with a 48-metre luffing jib. This made it responsible for the hoists to the opposite bank and therefore for the large radii. The modern crane had to handle a gross load of 40 tonnes with a distance of around 50 metres. An LTM 1750-9.1 was assembled very close to it to take hold of the other end of the supports. Due to its significantly smaller radius, this mobile crane managed to operate with a smaller support base of ten by ten metres. In fact, there was no more space available at the extremely restricted assembly site. 

The ends of the supports had to be placed under the existing structure

The steel lattice constructions were then swung over the water by the two Liebherr cranes with great care. The main difficulty involved the end phase of the hoists, as the ends of the supports had to be placed several metres under the existing bridge connection on the opposite side of the canal. However, Heiko Bischoff, at the controls of the more powerful crane, and the crane operators in the Mammoet machineprecisely followed the commands issued by the marshalling fitters and move the components accurately into their final positions.