May 4 - Enerpac's 4,800-tonne capacity gantry crane mounted on a Zourite jack-up barge has set sail for Reunion Island, where it will be used to install precast viaduct columns for a new coastal highway being built around the island.

Enerpac was awarded a contract to build the offshore overhead gantry crane for French consortium, Bouygues Travaux Publics, VINCI Construction and Demathieu Bard Construction in May 2015.

The crane will be used to build the 5,400 m offshore viaduct, which will form part of the new 12.3 km highway, dubbed Route du Littoral, with three lanes in each direction.

The EUR1.7 billion (USD19.5 billion) coastal road around the French island is believed to be France's most expensive road, with works scheduled for completion in 2018.

The viaduct will connect Saint Denis - the administrative capital of La Reunion - with La Possession and replaces the existing coastal road, which is exposed to falling rocks and flooding from swells and tropical storms.

In line with the technical approach suggested by the consortium, the viaduct will be mainly (95 percent) built using prefabricated elements, most of them brought in by sea.

Enerpac will use the huge crane to pick up recast viaduct columns for the new coastal road being built around Reunion Island in at least 200 foundation block lifts.

The Enerpac over head travel crane (OHTC) comprises two pairs of lifting beams, with an overall width of 30 m, and a lifting capacity of 4,800 tonnes for lifting, moving and lowering the concrete blocks for the ring road.

Testing of the crane has been conducted at Enerpac's Hengelo facility on one of the pairs of beams and included lifting 1,100-tonne blocks, synchronised lifting of the block with a hook from each beam, and checking the crane's positioning, as well as lifting and lowering accuracy to 1 mm.

The Zourite jack-up barge - which was constructed in Poland - is being transported to Reunion Island aboard the Offshore Heavy Transport's semi-submersible vessel, Hawk, and is expected to arrive in June.

Crane manufacturer Manitowoc has also supplied 16 cranes to the island for assistance in the construction of the highway, including a Manitowoc 12000E-1 crawler crane, seven Grove all-terrain cranes and two Grove rough-terrain cranes.

The Manitowoc 12000E-1 is a 110 t capacity crawler crane and is fitted with a 70 m boom. The Grove all-terrain cranes range in lifting capacity from 35 to 220 tonnes. The cranes will remain on the project for two years.