A Liebherr MK 88-4.1 mobile construction crane operated by the Ponticelli group of companies repaired a historic bridge and reinstalled a damaged artwork in central Paris. Working on the Pont-Neuf, the crane restored parts of an art installation titled 'La Caverne du Pont-Neuf', created by French artist JR. According to the manufacturer, the crane's compact design, rapid deployment and reach allowed it to complete the task within the confined conditions of the city centre.
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.
Within a few hours, the French lifting and industrial services company Ponticelli had 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."
As the oldest bridge in Paris, the Pont-Neuf offers limited space for work and receives a large number of daily visitors. Load-distribution plates were used to reduce ground pressure, while safety and traffic management measures allowed the operation to proceed safely.
Compact crane chosen for tight conditions
The team originally planned to use a larger Liebherr mobile crane, but the tight conditions led it to bring in the MK 88-4.1 instead. Its 45-metre-long trolley jib reached all the damaged areas of the structure, and the four-axle design made it easy to relocate 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 work.
The crane cab could additionally 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 optimal illumination of the work area during night-time operations.
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 the crane operator and rope access technicians communicated continuously by 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, quoting the artist: "The installation of the artwork is part of the artwork — and so is the crane." He added that the visually striking deployment of the MK crane created a magical moment.
Following its deployment on the Pont-Neuf, the Liebherr MK 88-4.1 demonstrated its strengths in demanding inner-city projects. Where heritage conservation, confined spaces and a high level of precision come together, the mobile construction crane offers a combination of reach, compactness and flexibility, according to the manufacturer.