A joint study into ammonia safety onboard ships undertaken by the Lloyd’s Register (LR) Maritime Decarbonization Hub and the Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping (MMMCZCS) has found that a range of mitigation methods, from ship design to crew training and operations, are required to keep toxicity risks to crew within published tolerable limits.

“Recommendations for Design and Operation of Ammonia-Fuelled Vessels based on Multi-disciplinary Risk Analysis” presents the most comprehensive study to date of the effectiveness of risk mitigation measures in three ammonia-fuelled vessels: a container ship, a tanker and a bulk carrier.

Seen as one of the most promising alternative fuels for the maritime energy transition, ammonia can be combusted with almost no carbon dioxide emissions. However, using ammonia as a shipping fuel can create potential safety hazards, including toxicity. It is crucial for shipping’s stakeholders to understand the risks of ammonia as a shipping fuel and the safeguards that can be implemented to reduce them to tolerable levels.

Using Quantitative Risk Assessment (QRA) analysis, a powerful data-driven method that allows users to assess risk in a quantitative and granular manner, the joint study has been able to identify vessel design and operational measures that would reduce ammonia risks to a tolerable level.

The QRA provides recommendations for design and operation of ammonia-fueled vessels to embed higher levels of safety for crew. Recommendations included:

• lower storage temperatures to reduce safety risk;

• provision for two or more separate spaces containing different groups of equipment that could leak ammonia;

• monitoring and minimizing of access to and length of time spent in spaces containing ammonia equipment;

• ventilation outlets from spaces containing ammonia equipment placed in a safe location, adequately separated from areas accessed by crew; and

• installation of multiple sensors of different types to detect ammonia leaks.

To complement the QRA, the second section of this report summarizes insights from an analysis of human factors considerations that will be impacted by a transition to ammonia fuel use. These include competence and training needed to improve safety on ammonia-fuelled vessels; safe work practices and standard procedures that need to be implemented through systematic change management programmes; and effective occupational health safeguards, such as personal protective equipment (PPE).

To enable sustainable and scalable new energy pathways such as ammonia as a marine fuel, we must advance technological developments. However, in the eagerness to transform, we must do so without compromising safety and reliability, by employing a strong risk-based change management approach. Care of our seafarers and strong safety management are imperative. This study has given us deep insights into risk and will provide critical understanding and intelligence to help guide the industry towards safe application of ammonia as a marine fuel.

—Claus Winter Graugaard, Chief Technology Officer, Onboard Vessel Solutions, Mærsk Mc-Kinney Møller Center for Zero Carbon Shipping

The two decarbonization centres have been involved in a number of ammonia projects. LR is undertaking key feasibility studies into using clean ammonia to refuel ships at the world-scale ports in the Pilbara region of Western Australia. The MMMZCS and its partners are jointly conducting a feasibility study to establish a supply chain for the provision of green ammonia ship-to-ship bunkering at the Port of Singapore.