At the beginning of 2017, Louis Dreyfus Travocean repaired on behalf of RTE and National Grid 4 of the 8 submarine cables being part of the IFA2000 electrical link between France and England.
The cables of this link are buried in pairs, and form 4 routes about 1 km apart from one another. The defaults concerned 2 of these cable routes and were located off Folkestone, about 6 km away from the English coast, in 20 to 25 meters of water (LAT).
As soon as the defaults were notified on 25th of November 2016, Louis Dreyfus Travocean mobilized a small boat, the Florelle, which enabled RTE to carry out its tests at sea, as well as a survey vessel, the Bibby Athena, which performed the Multibeam, sonar and TSS survey of the sites of the defaults at the beginning of December 2016.
In addition to a guard ship and a Crew Transfer Vessel based in Dover, Louis Dreyfus Travocean chartered three support vessels with dynamic positioning:
- – The first one, the Olympic Triton, was mobilized at the end of December 2016 in Dunkerque. Its role was to debury the cables, to prepare them to facilitate the work of the repair vessels, and then to protect the repaired cables. The ROVJET 806, the MED1 machine and a diving spread were installed on board, and the vessel was on site as of the 2nd of January 2017.
- – The second vessel, the Siem N-Sea, was mobilized in Dunkirk in early January. It was charged with repairing a pair of cables. A cable tank, a cable way, a cable chute, tensioners, a dive spread, a ROV and repair equipment were mobilized onboard this vessel, which also embarked a length of about 1800m of spare cable.
- – The third vessel, the Normand Flower, mobilized as of the 20th of January 2017, was charging with repairing of the other 2 cables. It was also equipped with a cable tank in which 1600 m of spare cable were loaded, as well as a cable chute, a cable way, tensioners, a ROV and repair equipment.
Offshore repair operations were carried out in parallel on both sites. The first pair of cables was repaired and put back into service on the 17th of February 2017, and the second pair on the 2nd of March 2017.