LR Awards AiP to DSME for VLEC Design
Classification society Lloyd's Register said it has awarded Approval in Principle (AiP) to South Korean shipbuilder Daewoo Shipbuilding & Marine Engineering (DSME) for its 98,000-cubic meter very large ethane carrier (VLEC) design with new cryogenic material High Manganese Austenitic steel (High MnA) and sloshing-free tank, the first VLEC design to use this type of material.
DSME’s 98,000 m3 VLEC design is made of DSME-patented ‘Type B’ tank so it can operate with partial loading due to a sloshing-free tank design making vessel operations flexible and efficient, and facilitating multi-port loading/unloading requirements. The newly developed VLEC design also has the potential to carry a variety of different gases such as liquefied natural gas (LNG), commercial ethane/ethylene, pure propane, commercial butane, commercial propane, mixture of propane and butane in any proportion and propylene.
LR carried out the design appraisal of the midship section, construction profile and the shell expansion drawing of this new VLEC ship design, to ensure compliance against LR’s prescriptive Rules. A structural design assessment, sloshing and scantling assessments were also conducted by LR in accordance with its ShipRight Procedure.
In December 2018, the IMO’s Maritime Safety Committee (MSC) at its 100th session approved the Draft Interim Guidelines regarding the application of High MnA, making this steel more visible and feasible as a competitive cryogenic material. Currently, the application of High MnA steel is only defined for the use of LNG cargo and/or fuel tank, however the material could be expanded as a tank for other cargoes with higher design temperatures than LNG, such as ethane (-90 degree C) and ethylene (-104 degree C) and other specified cargoes as above with same manner as for 9% nickel steel case.
Odin Kwon, DSME Executive Vice President and CTO, said, “This is a significant milestone for DSME towards an unexplored market and demonstrates our commitment to taking a step forward to help meet the challenge of the diversity and flexibility as featured in the new market. We are excited to be collaborating with Lloyd’s Register on this initiative who have an excellent technical and commercial insight. We believe this will trigger a new market curiosity with a commercially viable solution.”
Mark Darley, LR North Asia President awarding the AiP, said, “Lloyd’s Register was the pioneer of High Manganese Austenitic steel adoption (through its first-ever LNG-fueled 50,000 m3 bulk carrier) so we’re proud to be partnered with DSME now for this innovative design, particularly as ethane/ethylene is becoming more visible in our industry. The cost of this steel is competitive against conventional high-nickel equivalents and is expected to help reduce capital costs in LNG-fueled and LNG carrier systems, helping our clients stay competitive and economically efficient.”