A contracting consortium of Spie and GTM has begun work on a tunnel to extend the Metro underground railway in Toulouse, France. To lower the 7.8m diameter tunnel boring machine, weighing 330t, down a shaft they turned to lifting contractor Montalev Levage. Montalev used a 500t gantry fitted with a pair of 200t strand jacks, placed on a skidding system. Montalev managing director Yan Billard explained that the gantry crane was used because it was already on site, having been used to offload the TBM sections and handle them during assembly and welding. During the six week project, completed in August, only the one lifting system was used all around the site. ‘It was not necessary to book a big crane for a long time (very expensive) or to book each week different cranes according to the loads to be lifted,’ he said. ‘The disadvantage of a gantry crane is the fact that concrete beams are necessary underneath our skidding system. But, generally, for a big lattice boom crane with superlift for instance, it is also necessary to install reinforcements underneath outriggers.’
