Bureau Veritas has been chosen to class the 153,500 cu m liquefied natural gas (LNG) carrier ordered by Gaz de France from Chantiers de l’Atlantique. This largest ever-built LNG carrier is due for delivery in 2005. 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 CS1 membrane system developed by Gaztransport & Technigaz (GTT). BV helped to develop the concepts for the vessel, including unique new rules.
BV co-operated with Wärtsilä for the development of 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. The dual-fuel diesel-electric propulsion system offers several advantages. As a more compact installation, it allows the shipyard to maximise cargo space in the hull. It will reduce gas consumption compared to the conventional turbine installations. Operators will have more flexibility with respect to crewing, as engineers familiar with turbine installations are now in short supply. Maintenance is simplified as generator sets can be taken of line and maintained on passage. Machinery redundancy is enhanced, cutting the risk of a power failure.
BV also cooperated with GTT on the complex calculations and modelling needed to develop the cost-effective CS1 containment system. CS1 was granted BV concept approval in 2002. The CS1 containment system 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 per cent compared to existing systems. Partial loading conditions are also possible, improving operational flexibility.