Against the Paris skyline, 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. Working on the Pont-Neuf, the crane restored damaged sections of an art installation titled 'La Caverne du Pont-Neuf,' created by French artist JR. Its compact design, rapid deployment and reach allowed the crane to complete the task under 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 in 1985. The inflatable structure is approximately 120 metres long. In early June, violent gusts of wind and hail damaged parts of the outer shell, and within hours Ponticelli, a French lifting and industrial services company, had developed a lifting solution.
A tight, windswept job site
"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 reduced ground pressure, while safety and traffic management measures kept the operation secure.
Selecting and positioning the crane
The team had 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, while the four-axle design made it easy to relocate the machine from one side of the bridge to the other, where there was also storm damage. A short set-up time and a compact outrigger system further supported the work.
The crane cab's ability to move at working height gave the operator a clear view of the approximately 18-metre-high structure and of the rope access technicians, while boom-mounted spotlights lit 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 site sits in a wind corridor along the River Seine, weather conditions were monitored continuously, and the crane operator and rope access technicians stayed in constant radio contact.
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.
More than a lifting operation
For Ponticelli, the project went well beyond a conventional lift. "We are proud to have been part of this work of art," de Quatrebarbes said, citing the artist JR: "'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."
With 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.