A Liebherr MK 88-4.1 mobile construction crane, supplied by the Ponticelli group of companies, repaired a historic Paris bridge and reinstalled a damaged piece of artwork on it. The work took place on the Pont-Neuf, where the crane restored a damaged art installation titled 'La Caverne du Pont-Neuf,' created by the French artist JR. According to the company, the crane's compact design, rapid deployment and reach allowed it to complete the task within the confined conditions of central Paris.
The temporary artwork was conceived as a tribute to the wrapping of the Pont-Neuf by artists Christo and Jeanne-Claude, first installed in 1985. The inflatable structure measures approximately 120 metres in length. In early June, violent gusts of wind and hail damaged parts of its outer shell. Ponticelli, a French lifting and industrial services company, developed a lifting solution within hours of the damage.
"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. He added that in addition to repairing the tarpaulin, the team had to carry out a lifting operation safely in almost constant wind and under considerable time pressure.
Working within a confined heritage site
The Pont-Neuf is the oldest bridge in Paris, offering limited space for work while welcoming a large number of daily visitors. Load-distribution plates were used to reduce ground pressure, and safety and traffic management measures were put in place to keep the operation safe.
The team had originally planned to use a larger Liebherr mobile crane. Because of the tight conditions, the MK 88-4.1 was brought in instead. Its 45-metre-long trolley jib reached all the damaged areas of the structure, while the four-axle design made it easy to relocate from one side of the bridge to the other, where storm damage had also occurred. A short set-up time and a compact outrigger system further supported the operation.
The crane cab could be moved at working height, giving the operator a clear view of the roughly 18-metre-high structure and of the rope access technicians. Boom-mounted spotlights provided illumination for the night-time work.
Four nights of lifting
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 site lies in a wind corridor along the River Seine, weather conditions were monitored continuously, and the crane operator and the rope access technicians stayed in radio contact throughout.
Before work began, the team carried out 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 went beyond 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.
According to the company, the deployment on the Pont-Neuf demonstrated the MK 88-4.1's strengths in demanding inner-city projects, where heritage conservation, confined spaces and a high level of precision meet. In such settings, it said, the mobile construction crane offers a combination of reach, compactness and flexibility.