Offshore highway uses pier positioning and handling system

Enerpac has developed a handling and adjustment device for a large offshore gantry crane in Reunion Island. The device will be used to lift and lower the piers bases onto a level gravel surface on the seabed, and for making adjustments to the base vertically and horizontally.

The pier positioning and handling system, which uses technology available throughout Australia and New Zealand, is lifted and controlled by Enerpac’s Over Head Travel Crane (OHTC). The OHTC comprises two pairs of lifting beams, with an overall width of 30 m and a lifting capacity of 4800 tonnes for lifting, moving and lowering the concrete blocks for the offshore highway.

The French consortium Bouygues Travaux Publics, VINCI Construction Grands Projets, Dodin Campenon Bernard and Demathieu Bard Construction are constructing a 5400 m bridge for a new offshore highway in Reunion Island, located East of Madagascar in the Indian Ocean. The highway (Route du Littoral) will connect Saint Denis — the administrative capital of La Réunion — with La Possession. It replaces the existing coastal road, which is exposed to falling rocks and flooding from swells and tropical storms.

The crane is classified as A5 for the structure classification and M5 for the mechanism classification and designed to operate in tropical marine conditions (IP66). Design and testing conforms to Bureau Veritas code for Offshore Units.

The Enerpac OHTC will be used on the Zourite jack-up barge. Lifting and lowering is accomplished with a reeved winch system, based on eight grooved drum winches. Longitudinal travelling of the gantry uses a trolley arrangement comprising two trolleys per lifting beam. Each trolley is propelled with hydraulic drive motors and planetary gearboxes.