A Liebherr MK 88-4.1 mobile construction crane operated by the Ponticelli group of companies repaired a historic Paris bridge and helped reinstall a damaged inflatable artwork on the Pont-Neuf, according to Liebherr.
The temporary installation, 'La Caverne du Pont-Neuf,' was created by French artist JR as a tribute to the wrapping of the Pont-Neuf by artists Christo and Jeanne-Claude, which was 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 hours of the damage, Ponticelli, a French lifting and industrial services company, 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. It has limited space for work and receives a large number of daily visitors. Load-distribution plates reduced ground pressure, while safety and traffic management measures were put in place to allow the operation to proceed safely.
The team had originally planned to use a larger Liebherr mobile crane. Because of the tight conditions, the Liebherr MK 88-4.1 was brought in instead. Its 45-metre-long trolley jib reached all the damaged areas of the structure, and its 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 operation.
The crane cab could 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 the work area was optimally illuminated during night-time operations.
Four night shifts
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 was located in a wind corridor along the River Seine, weather conditions were monitored continuously. The crane operator and the rope access technicians communicated continuously by radio.
Before work began, the team carried out site inspections, load calculations and collision analyses of the surrounding buildings. A 360-degree test then 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. "The visually striking deployment of the MK crane created a magical moment."
According to Liebherr, 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 precision come together. The company describes the crane as offering a combination of reach, compactness and flexibility for such work.