New trends in the LNG market with regard to vessel size and operation modes require state of the art knowledge and experience to meet the coming challenges in the industry

Purpose

The sea borne LNG transportation is increasing dramatically. Not only is the industry increasing in size, it develops new trade routes, new ship designs and new operations.

From the approval of the first dedicated liquefied gas carrier in 1949, DNV has been involved in and providing standards for all major development projects within the gas carrier industry, including the development of the membrane tank system in the early 60’s, through the development of the Moss spherical tank system in the early 70’s and up to the latest developments in different concepts for transportation of compressed natural gas (CNG).

The industry is in continuous change, resulting in new trade routes, new ship designs and new operation modes which will subject the traditional containment systems to loading situations that has been rather infrequent in the past. In addition also new cargo containment systems are being developed.

DNV has carried out extensive R&D and developed tools and methods to ensure that the industry can meet the new challenges while maintaining the same high level of safety as before.

Benefits

DNV Maritime Consultancy provides integrated services covering all aspects of early design development, through design verification and documentation for class and authority approval to upgrading/conversion and life extension of existing carriers. Within all types of gas carriers, DNV has developed rules, guidelines and Classification Notes for hull and containment system strength assessment, including an extensive Classification Note on sloshing assessment of Membrane type LNG carriers.

Features

The services available to the gas carrier industry and include: 

• LPG carriers
  Independent tanks type A (refrigerated tank with atmospheric pressure)
  Independent tanks type C (pressurised tank)
  
  Load and response assessment of cargo containment system and supporting structure 

• LNG carriers
  Membrane tanks – load and response assessment of cargo containment system, pump tower and supporting hull structure
  Independent tanks type A concepts
  Independent tanks type B (spherical, IHI SPB, Flex)
  
  DNV has leading edge competence and tools for providing advice and guidance for assessment of loads, response and strength of membrane tanks. Based on extensive numerical studies and model testing, DNV has developed procedures for assessment of liquid motion and sloshing loads as basis for strength assessment of the load bearing insulation system, hull structure and pump tower. 

• CNG carriers
  Steel tanks
  Wrapped composite steel tanks
  Composite tanks