ClassNK awards AIP to Imabari’s LPG dual-fuelled bulker

Japan’s classification society ClassNK has granted an Approval in Principle (AiP) to Imabari Shipbuilding Co. for the concept design of a 180,000 DWT LPG dual-fuelled bulk carrier developed in cooperation with Mitsubishi Shipbuilding Co.

This was the first LPG dual-fuelled bulk carrier in the world to be granted an AiP, ClassNK said.


According to Imabari Shipbuilding, the design eliminates the need for special consideration of boil-off gas handling LPG at room temperature and high pressure, which makes the ship’s operation easier.

In addition, the ship has been designed with extensive consideration towards cost competitiveness by eliminating the use of low-temperature materials such as stainless steel and cryogenic insulation.

LPG tank is planned/designed to be installed in the aft area of the bridge and with round-trip distance capacity between Japan and Australia.

“And, as for supplying LPG to the ship, nowadays, LPG supply bases and infrastructure facilities are globally more developed and improved, which makes the ship’s operation more flexible. This is another motivation to create this design,” Imabari specified.

This ship design adopts ClassNK’s guidelines on safety requirements for other viable alternative fuels besides LNG.

Namely, alternative fuels like methanol, ethanol and LPG, have lower flashpoints compared to traditional fuels, therefore particular attention needs to be given to ensuring adequate safety precautions when using low-flashpoint fuels in order to decrease the potential risk of fire and explosions that may arise as a result of fuel leakage onboard the ship.

International safety requirements for low-flashpoint fuels have been discussed at IMO and as a result, the International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF Code) has been adopted and enforced. The current code, however, does not address specific regulations for alternative fuels other than LNG.

Accordingly, in 2019 ClassNK released its own guidelines in order to promote the design of alternative fueled ships.