Motor driven cable reels from Conductix-Wampfler for the world’s largest offshore overhead gantry crane

May 2017. Conductix-Wampfler, one of the world’s leading manufacturers of energy and data transmission systems to mobile consumers, has delivered the power supply units for the world’s largest offshore overhead gantry crane. The special crane is being used in the construction of a new road around the island Réunion. When completed in 2018, the six-lane highway will connect the capital city, Saint Denis, with Possession for a distance of about twelve kilometers. The most spectacular construction section is a viaduct leading 5.4 kilometers off the coast into the Indian Ocean. It must withstand cyclones with speeds of up to 144 km/h as well as waves up to ten meters high.

Construction project under unusual framework conditions

The construction project is being realized by the French consortium Bouygues Travaux Publics, VINCI Construction Grands Projets, Dodin Campenon Bernard, and Demathieu Bard Construction. For the construction, a great number of heavy equipment will be used, including 16 different crane types. The key component for the construction of the viaduct is the offshore overhead gantry crane from Enerpac, a market leader in high-pressure hydraulic tools as well as products with controlled exertion of force and solutions for the precise positioning of heavy loads. Enerpac has already successfully completed the tests with the special crane at its production sites in the Netherlands.

Load-bearing capacity of up to 4,800 tons

The overhead gantry crane comprises two pairs of lifting traverses with a total width of 30 meters and a load-bearing capacity of 4,800 tons for lifting, moving, and lowering the concrete blocks that are needed to build the coastal highway. Its design is meant to withstand tropical marine environmental conditions. The blocks are lifted and lowered using a reeving hoist system based on eight grooved drum winches. The longitudinal movement of the portal is conducted using a roller trolley system with two roller trolleys per lifting traverse. Engines drive each roller trolley with hydraulic drive and planetary gears. The wheels run on two parallel rails that are mounted onto the runway beam on the barge. Long-stroke cylinders affect the continuous lateral movement of the portal winches.

Six motor driven cable reels for high loads

Conductix-Wampfler provides the six motor driven cable reels for high loads that supply the giant with energy. Two mono-spiral motor reels with a magnetic coupler (MAG Drive) provide the power for the longitudinal travel of the crane bridges on the barge while four random wind reels ensure the supply of the load handling attachments.