What is believed to be the first accreditation for ‘Machinery Room Safety for Ammonia’ (MRS) will be granted by ClassNK for the ammonia-fuelled medium gas carrier (AFMGC) currently being developed by a consortium that includes Nippon Yusen Kabushiki Kaisha (NYK) and Nihon Shipyard (NSY).
MRS is a Class notation demonstrating a ship is equipped with ammonia safety measures for the machinery room. MRS also confirms the vessel meets the highest safety measures under the guidelines for ammonia-fuelled ships.
The consortium to which NYK and NSY belong is aiming for delivery of a 40,000m3 AFMGC by the end of November 2026, from Japan Marine United Corporation’s Ariake Shipyard. The development comes under the Green Innovation Fund Project by Japan’s New Energy and Industrial Technology Development Organization (NEDO). One of the greatest challenges in the ship’s development is to overcome toxicity in the machinery room. It is essential to have measures to keep the crew safe, such as a design to avoid ammonia leakage from piping and tanks. To overcome toxicity, the consortium has conducted a risk assessment reviewed by ClassNK, risk assessments and safety measures from a user’s point of view led by NYK’s engineers, and a study of the ship’s specifications to realise the highest level of safety.
The minimum design requirements for using ammonia safely on board are regulated in the ammonia-fuelled ship guidelines issued by ClassNK. To receive an MRS notation, it is necessary to satisfy the optional functional requirement to minimise personal exposure to leaking ammonia in the machinery room. This notation will be granted only to ships that meet the functional requirement and secure the highest level of safety.
The consortium is continuing with vessel development, and creation of operation manuals for actual operations, aiming for delivery by November 2026. ClassNK aim to further improve safety for ammonia-fuelled ships through technical knowledge and achievements, including MRS accreditation, with the collaboration of the consortium members.
Image: 40,000 m³ ammonia fuelled ammonia gas carrier (source: ClassNK/JLA)
