Cutting it fine

With the help of a Terex CC 2500-1 lattice boom crawler crane, Riga Baumann lowered a tunnel boring machine, complete with cutter head, into position in Düsseldorf, Germany.

Challenges in the preparatory work, carried out by Riga Baumann, to expand Düsseldorf's Wehrhahn metro, included some 60 lifts in a severely confined space and on a very tight schedule, said Terex: the crane had to be assembled and dismantled overnight, between 9 p.m. and 5 a.m.

lowering the 130 tonne, 9.5 m diameter cutter head demanded the greatest precision. "We had to position the load precisely, so that the technicians in the construction pit could mount the cutter head at the front of the 65 m long tunnel boring machine. To allow us to work within the available 12 m radius, we rigged the Terex CC 2500-1 with a 54 m SH main boom, superlift configuration and 100 tonnes of superlift ballast," explained Tim Langer, the CC 2500-1 operator.

A second support crane was required during part of the lifts, as components had to be turned without touching the ground.

"The compact design of the CC 2500-1 helped as it is designed for rapid crane assembly and dismantling. One of the main reasons for choosing the Terex CC 2500-1 for this project was that space limitations ruled out using a mobile crane," said Uwe Langer, project manager.

To get the tunnel boring machine ready on time, the Riga Baumann team had to work round the clock for two weeks, and the lifting work was carried out five hours ahead of schedule, added the company.