Classification society ClassNK has approved a new spray-form insulation system for an IMO type B fuel tank developed by Nihon Shipyard and Hankuk Carbon.

The system is intended for use on ships fuelled by LNG or ammonia as the industry looks to expand alternative-fuel options, ClassNK said in an emailed statement on Wednesday. 

While type C tanks remain the most common choice for LNG-fuelled vessels, type B tanks are attracting more interest in designs that require larger fuel capacities, including ammonia-fuelled ships and large container vessels.

The new system applies insulation in a sprayed form rather than using conventional panel-based methods.

“For the design concept and result of demonstration mock-up test for the Spray form insulation system of IMO Type B tank, ClassNK conducted its safety review based on part N of its ‘Rules and Guidance for the Survey and Construction of Steel Ships’, which incorporates the IGC Code, and also part GF, which incorporates the IGF Code,” ClassNK said.