France's Barillec Marine is to supply key systems for an LNG hybrid water injection dredge on order at the Socarenam shipyard in Boulogne. To be called Ostréa the dredge is being built to serve the Port of Bordeaux under a EUR 20 million contract placed in December 2017 by EIG Dragages-Ports and will be the first dual fuel newbuild vessel built in France (other than LNG tankers).
The Barillec contract, which represents close to 7,000 hours of work, involves the design and supply of the main panel for hybrid energy production, the main and auxiliary dual-fuel/electric propulsion and an innovative energy conversion system.
The two main propulsion assemblies will each include an electric motor with nominal power of 1,200 kW at 1,600 rpm. The bow thruster auxiliary propulsion system will comprise an electric motor with nominal power of 400 kW at 1,500 rpm. The two dredge pumps will each have a power of 500 kW. The energy conversion system will convert the upstream 690V/60Hz energy to the downstream 400V/50Hz network and will be equipped with two 150kVA decoupling transformers.
This hybrid dual-fuel system is particularly energy efficient. The frequency converters help optimize the operating parameters of the main machines, azimuth thrusters and bow thruster. Efficiency is bolstered by variable speed and a dynamic ship positioning system. In addition, a Power Management System (PMS) helps regulate the operation of machines and further improves the ship's energy performance.
The innovative system will enable the new dredger to be propelled mainly by LNG The use of this fuel and of water injection dredging will make the Ostréa–the future name of the dredger–an eco-efficient ship with a lower environmental footprint.