In February Gaz de France ordered a 74,000 cu. m. LNG carrier from Chantiers de l'Atlantique, with an option for a second vessel. The French have maintained a strong hold on this high-tech, high-value ship type despite the general migration of gas ship orders to the Far East. In particular, Bureau Veritas helped develop the concepts for the vessels, and developed unique new rules to allow the yard and owners to break new technological frontiers.
"BV has consistently been the world leader in LNG carriage, since development of membrane LNG carriers was first begun," says Bruno Dabouis, commercial manager of BV's marine division. "Now we will class these new vessels, which are a quantum leap forward in cost-effective LNG transportation. The innovative features in these ships will set the benchmark for the rest of the world to live up to."
The ships have two key innovations. The traditional steam turbine plant will be replaced by a low-pressure dual fuel diesel electric system, and the cargo gas will be carried in the new GTT CS1 membrane system.
BV developed the safety concept of the low-pressure dual fuel diesel/gas engine, and has issued new rules for such engines. These are unique, and set new standards for this type of machinery plant.
BV's consultancy division, Tecnitas, worked with GTT on the complex calculations and modeling needed to develop the cost-effective CS1 containment system. CS1 was granted BV concept approval earlier this month.
The dual fuel diesel electric propulsion system is designed to offer advantages. For one, it is designed as a more compact installation, allowing cargo space to be maximized in the hull. In addition, it is designed to reduce gas consumption compared to the conventional turbine installations.
The CS1 containment system reportedly combines the best features of the proven Mark III
and NO96 membrane systems. It offers increased strength, faster fabrication, and a cost reduction of 15 percent compared to existing systems.