Ponticelli MK 88-4.1 repairs JR’s Pont-Neuf artwork in Paris

Liebherr MK 88-4.1 mobile construction crane repairing the La Caverne du Pont-Neuf art installation in Paris

Liebherr MK 88-4.1 handles night-time repair of JR’s ‘La Caverne du Pont-Neuf’ installation in central Paris

French lifting and industrial services group Ponticelli has used a Liebherr MK 88-4.1 mobile construction crane to repair storm damage to artist JR’s walk-in installation ‘La Caverne du Pont-Neuf’, working over four night shifts on the oldest bridge in Paris.

The 45-metre trolley jib of the Liebherr MK 88-4.1 reaching the damaged sections of the installation
Load-distribution plates under the Liebherr MK 88-4.1 protecting the historic Pont-Neuf bridge deck
The height-adjustable cab of the Liebherr MK 88-4.1 during night-time work over Paris

The temporary artwork, a walk-in rock grotto created as a tribute to Christo and Jeanne-Claude’s legendary 1985 wrapping of the Pont-Neuf, is built around an inflatable structure roughly 120 metres long. In early June, violent gusts and hail tore into parts of the outer shell, and Ponticelli was called in almost immediately to work out a lifting solution with the project managers.

“We were on site just a few hours after the damage occurred to work out the best technical solution together with the client. As well as repairing the tarpaulin, we had to carry out a lifting operation safely in almost constant wind and under considerable time pressure.”

— Louis-Arthur de Quatrebarbes, Head of the Handling/Lifting Agency, Ponticelli

Why the taxi crane beat a bigger machine

A larger mobile crane had originally been pencilled in for the job, but the constraints of a listed bridge in the middle of Paris – limited space, heavy footfall and strict protection of the historic structure – swung the decision to the four-axle MK 88-4.1. Its 45-metre trolley jib reached every damaged area of the roughly 18-metre-high structure, while the compact outrigger footprint and short set-up time allowed the crane to be shifted quickly from one side of the bridge to the other, where the storm had also left its mark. Load-distribution plates spread the ground pressure across the old bridge deck, and extensive traffic and safety management kept the site under control.

Four night shifts in a wind corridor

The repair itself ran over four night shifts. Damaged fabric sections weighing between 200 and 400 kilograms were lifted back into position and reattached by rope access technicians, with the crane operator in constant radio contact. Because the bridge sits in a wind corridor along the Seine, weather conditions were monitored throughout. Site inspections, load calculations and collision analyses against the surrounding buildings preceded the lifts, and a 360-degree test confirmed the crane’s positioning before work began.

The MK’s height-adjustable cab proved a particular asset, giving the operator a clear view of the structure and the rope access team, while the boom-mounted floodlights lit the work area through the night.

Part of the artwork

For Ponticelli, the job went beyond a routine lifting contract.

“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. The visually striking deployment of the MK crane created a magical moment.”

— Louis-Arthur de Quatrebarbes, Head of the Handling/Lifting Agency, Ponticelli

The deployment underlines the niche the mobile construction crane has carved out in inner-city work, where heritage protection, tight footprints and precision have to be reconciled on a single site.

Facts

  • Crane: Liebherr MK 88-4.1 mobile construction crane
  • Operator: Ponticelli
  • Jib: 45 m trolley jib
  • Structure: approx. 120 m long, approx. 18 m high
  • Loads: fabric sections of 200–400 kg
  • Duration: four night shifts
  • Location: Pont-Neuf, Paris, France

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