Building on findings from its previous studies, Maersk Mc-Kinney Moller Center for Zero Carbon Shipping (MMMCZCS) has issued a new publication with a guide to the emerging solutions for ammonia-fueled vessels from a ship design perspective.
The report ‘Emerging ship design principles for ammonia-fueled vessels’ addresses oceangoing containerships, bulk carriers, and tankers but does not include coastal vessels and passenger ships.
It aims to help shipyards, ship designers, and operators/owners navigate through main decisions when developing new ammonia-fueled ship designs, covering the ammonia liquid gas storage, handling, and safety aspects.
As explained, the guiding principle of the publication is the safety of crew and shoreside personnel with safeguards and design considerations introduced along with tools to manage and mitigate risks.
The report lists identifying risks and creating mitigation plans as imperative in the early ship design process and implementing safeguards like double-wall emergency shutdown systems, remote monitoring, and proper PPE to ensure crew safety.
This publication also points out some regulatory gaps and variations regarding ammonia-fueled ships.
Addressing ammonia’s relatively low energy density, the analysis showed that designs for ammonia dual-fuel vessels are unlikely to achieve the same endurance as those using fuel oil without increasing ship dimensions or sacrificing cargo capacity. The targeted endurance will dictate the dimensions and location of storage tanks. For tankers and bulk carriers, these will likely be cylindrical tanks on deck, while for container ships, the design will vary depending on vessel size, the MMMCZCS said.
The report states that safe ammonia-fueled vessel design can be achieved by incorporating ammonia-specific fuel technology into traditional gas-fueled vessel technology. The storage condition, type, and location of storage tanks will dictate the rest of the equipment layout. With the help of risk assessment tools and gas dispersion studies, the optimal locations for vent outlets, vent masts, air intakes, and other system components (e.g., bunker stations) can be defined.