ClassNK has issued an Approval in Principle (AiP) to Kawasaki Heavy Industries, Ltd for the design of a cargo containment system (CCS) of the world’s largest capacity (40,000 m3 class per tank) developed for use on a large liquefied hydrogen carrier.

Since hydrogen does not produce CO2, it is intended to be used as a renewable energy source to achieve a decarbonized society. In 2017, ClassNK released the “Guidelines for Liquefied Hydrogen Carriers,” which describes the safety criteria for liquified hydrogen carriers based on the IMO’s Interim Recommendations for Carriage of Liquefied Hydrogen in Bulk. In addition, ClassNK conducted a classification survey during the construction of SUISO FRONTIER*1, a groundbreaking liquified hydrogen carrier with a 1,250m3 carrying capacity designed by Kawasaki in accordance with its rules and guidelines.

Following a request from Kawasaki, ClassNK conducted a design analysis of the newly built CCS*2 for a hydrogen liquified carrier using its Part N of Rules for the Survey and Construction of Steel Ships, which incorporates the IGC Code, as well as its guidelines, which include the IMO’s interim recommendations. In addition, based on the HAZID risk assessment findings, a thorough safety assessment of the CCS was performed, leading to the issuance of the AiP.

The following are the key features of the CCS as announced by Kawasaki:

Allows vast volumes of cryogenic liquefied hydrogen to be transported thanks to tank capacity comparable to that of large liquefied natural gas (LNG) carriers.
Has an independent, self-supporting design with a flexible structure that can respond to thermal contraction when loading cryogenic liquefied hydrogen.
Includes a newly developed, high-performance heat insulation system that reduces the amount of boil-off gas (BOG) generated as a result of heat ingress.
Designed to efficiently use BOG as a ship’s fuel, resulting in lower CO2 emissions from liquefied hydrogen transport operations.