Home NR671 ammonia-fuelled ships - tentative rules The purpose of this Rule Note is to provide a set of design and installation requirements for the classification of ships using ammonia as a fuel. Reference Title Edition NR671 R01 Ammonia-fuelled ships - Tentative Rules Jul 2022 Check related documents: NR467 Rules for the classification of steel ships NR529 Gas fuelled ships NR670 Methyl/ethyl alcohol fuelled ships NI647 LPG-fuelled ships NR547 Ships using fuel cells Check other Bureau Veritas rules and guidelines.