A Liebherr MK 88-4.1 mobile construction crane from the Ponticelli group of companies repaired a historic bridge and reinstalled a damaged piece of artwork in Paris. On the Pont-Neuf bridge, the crane was used to repair the damaged art installation "La Caverne du Pont-Neuf," created by French artist JR. According to the source, its compact design, rapid deployment and reach allowed the mobile construction crane to complete the task in the confined conditions of central Paris.
The temporary artwork 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.
Just a few hours later, French lifting and industrial services company Ponticelli developed a lifting solution. "We were on site just a few hours after the damage occurred to work out the best technical solution together with the client," said Louis-Arthur de Quatrebarbes, head of the handling and lifting agency at Ponticelli. "As well as repairing the tarpaulin, we had to carry out a lifting operation safely in almost constant wind and under considerable time pressure."
Working on Paris's oldest bridge
The Pont-Neuf is the oldest bridge in Paris, with limited space for work and a large number of daily visitors. Load-distribution plates were used to reduce ground pressure, while safety and traffic management measures supported a safe operation.
The team originally planned to use a larger Liebherr mobile crane. Because of the tight conditions, the Liebherr MK 88-4.1 was moved in instead. Its 45-metre-long trolley jib reached all the damaged areas of the structure, and 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, giving the operator a clear view of the approximately 18-metre-high structure and the rope access technicians. Boom-mounted spotlights ensured illumination of the work area during night-time operations.
Four night shifts
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.
For Ponticelli, the project was far more than a conventional lifting operation. "We are proud to have been part of this work of art," de Quatrebarbes said. "To quote JR: 'The installation of the artwork is part of the artwork' — and so is the crane. The visually striking deployment of the MK crane created a magical moment."
With its deployment on the Pont-Neuf, the Liebherr MK 88-4.1 mobile construction crane demonstrated its strengths in demanding inner-city projects, where heritage conservation, confined spaces and a high level of precision come together and call for a combination of reach, compactness and flexibility.