A Liebherr MK 88-4.1 mobile construction crane from the Ponticelli group of companies repaired a historic Paris bridge and reinstalled damaged parts of a temporary artwork on the Pont-Neuf, the oldest bridge in the city.
The installation, 'La Caverne du Pont-Neuf' by French artist JR, was created as a tribute to the legendary wrapping of the Pont-Neuf by artists Christo and Jeanne-Claude, first installed in 1985. The inflatable structure is approximately 120 metres long. In early June, violent gusts of wind and hail damaged parts of its outer shell.
Rapid response on a confined site
Ponticelli, a French lifting and industrial services company, says it was on site just a few hours after the damage occurred to work out the best technical solution together with the client. “As well as repairing the tarpaulin, we had to carry out a lifting operation safely in almost constant wind and under considerable time pressure,” said Louis-Arthur de Quatrebarbes, head of the handling and lifting agency at Ponticelli.
The Pont-Neuf has limited space for work and welcomes a large number of daily visitors. Load-distribution plates reduced ground pressure, while safety and traffic management measures ensured the operation could be carried out safely.
Equipment choice driven by tight conditions
Originally, the team planned on using a larger Liebherr mobile crane, but the tight conditions led to the MK 88-4.1 being moved in for the repairs. Its 45-metre-long trolley jib reached all the damaged areas of the structure, while the four-axle design enabled easy relocation from one side of the bridge to the other, where there was also storm damage. The short set-up time and compact outrigger system further facilitated the operation.
The crane cab offered the additional benefit of being able to move at working height, providing the operator with a clear view of the approximately 18-metre-high structure and of the rope access technicians. Boom-mounted spotlights ensured optimal illumination of the work area during night-time operations.
Night shifts, wind monitoring and preparation
The repair work was carried out over four night shifts. Damaged fabric sections weighing between 200 and 400 kilograms were lifted and reattached in collaboration with rope access technicians. Because the construction site was located in a wind corridor along the River Seine, weather conditions were continuously monitored, and communication between the crane operator and the rope access technicians took place continuously via radio.
Before work began, the team performed site inspections, load calculations and collision analyses of the surrounding buildings. A 360-degree test subsequently confirmed the planned crane positioning.
Project outcome
For Ponticelli, the project was far more than a conventional lifting operation. “We are proud to have been part of this work of art. To quote JR: ‘The installation of the artwork is part of the artwork’ — and so is the crane,” de Quatrebarbes said, adding that the visually striking deployment of the MK crane created a magical moment.
The crane's use on the Pont-Neuf was presented as a demonstration of its strengths in demanding inner-city projects, where heritage conservation, confined spaces and a high level of precision come together, combining reach, compactness and flexibility.