Three Liebherr tower cranes of the EC-B Flat-Top type handled all lifting work on the raw construction of the AI project in the Part-Dieu district of Lyon for 14 months. Construction company GCC Auvergne Rhône-Alpes deployed a 340 EC-B 12, a 205 EC-B 10, and a 150 EC-B 8 to build a mixed-use building complex with office space, apartments, and a roof terrace on one of France's most cramped inner-city construction sites.

The construction site is wedged between the Part-Dieu shopping center and the Tour Oxygène, a tower approximately 115 meters high. The available space for crane positioning was tight, and the booms sometimes had to swing past the Tour Oxygène facade with only three meters of clearance. Hook heights of up to 73 meters were required to serve the building across its entire raw construction height – from the lower office floors to the peaks of the residential towers.

340 EC-B 12 as main crane with 73 meters hook height

The main crane, a 340 EC-B 12, was installed on an 8-meter-high foundation. This configuration increased the hook height to 73 meters with a boom length of 57.5 meters. With a maximum load capacity of 12 tons, the flat-top crane covered the vertical reach needed to serve the building throughout the entire raw construction phase. The elevated foundation provided the geometric freedom to precisely align the crane's working radii with the construction schedule.

The second crane, a 205 EC-B 10, operated at a hook height of 68 meters and a boom of 52.5 meters. It handled the most challenging space situation of the entire project: its boom swung past the adjacent Tour Oxygène facade with only three meters of clearance. This configuration required precise modeling of swing areas, load paths, and wind behavior during the planning phase, before the first crane component was assembled on site.

150 EC-B 8 for base area and material supply

The third crane in use, a 150 EC-B 8 with a hook height of 47 meters, covered the lower levels and material supply to the base area throughout the entire construction cycle. The combination of three flat-top cranes made it possible to carry out lifting operations continuously over the entire 14-month period – in one of France's most densely built city blocks.

The AI project, commissioned by developer Cogedim and designed by Japanese architect Sou Fujimoto, comprises 21,000 m² of office space, 85 apartments in two staggered residential towers, a roof terrace above the seventh office floor, and a green courtyard. Caisse d'Epargne Auvergne Rhône-Alpes is opening its new flagship branch on the ground floor.

Circular economy and urban design transformation

The demolition of the previous building took place between 2022 and 2024, while construction of the AI project ran until 2026. During the demolition phase, materials from the predecessor building were checked for possible reuse in the new construction or preserved as historical witnesses to the site's history, rather than simply being disposed of. These circular economy principles are part of the ongoing transformation of Lyon's Part-Dieu district, which houses one of the largest concentrations of tertiary sector office space in France.

The integration of 2,000 m² of green outdoor space, including a landscaped courtyard, counteracts the urban heat island effect that had historically been intensified by the dense development in this part of Lyon. The mix of social, moderate-rent, and market-rate housing within high-quality office space reflects an urban planning approach that seeks to interweave residential and business districts.

Flat-top design as a solution for cramped construction sites

Liebherr's flat-top crane design proved to be a decisive solution for the exceptional spatial conditions of the construction site. The three EC-B cranes mastered the challenges through a combination of precise planning and the inherent advantages of this design. The elimination of a tower cap allows flat-top cranes to operate even in situations with limited airspace and dense neighboring development – a decisive advantage in inner-city locations like Part-Dieu.

The AI project demonstrates how modern crane logistics can function on inner-city construction sites when technical precision and site-specific configuration work together. The combination of elevated foundations, precisely calculated swing radii, and the coordination of three cranes in tight quarters enabled efficient construction operations over 14 months – despite the extreme spatial constraints in one of France's most dynamic business districts.