Part A. General Requirements for Ships Using Ammonia as Fuel

LR 1-01 The requirements in the Rules and Regulations for the Classification of Ships using Gases or other Low-flashpoint Fuels, Preamble, and Rule and Regulations for the Classification of Ships using Gases or other Low-flashpoint Fuels, Part A and Part D are applicable to the use of ammonia, together with the additional requirements herein.

LR 1-02 To support the demonstration of equivalent safety for the use of gases and low-flashpoint fuels other than natural gas as required by the Rule and Regulations for the Classification of Ships using Gases or other Low-flashpoint Fuels, Part A, specific requirements for the use of ammonia as fuel are included in this Appendix.

LR 2-01 The requirements and definitions in the Rules and Regulations for the Classification of Ships using Gases or other Low-flashpoint Fuels, Part A, 2 General and its sub-Sections are applicable to the use of ammonia, together with the additional requirements and definitions herein.

2.1 Application

Unless expressly provided otherwise, these requirements apply to ships to which part G of SOLAS Chapter II-1 applies.

2.2 Definitions and terminology

LR 2.2-01 The definitions stated from Appendix LR2, Part A, 2.2 Definitions and terminology LR 2.2-02 to Appendix LR2, Part A, 2.2 Definitions and terminology LR 2.2-07 are in addition to, or qualify, the definitions stated in Part A, 2.2 Definitions

LR 2.2-02 'Fuel Valve Unit’ (FVU) refers to the series of fuel regulation and control valves before the consumer, including the ‘double block and bleed’ arrangement. The Fuel Valve Unit is commonly referenced with varying terminology, including ‘gas valve unit’, ‘GVU’, ‘gas regulating unit’, ‘GRU’, ‘gas train’, or ‘fuel valve train’.

LR 2.2-03 'Fuel’ in the context of these requirements means Anhydrous Ammonia (NH₃), either in its liquefied or gaseous phase.

LR 2.2-04 'Hazard’ means something with the potential to cause harm.

LR 2.2-05 'Inherently Safer Design’ means consideration has been given to eliminate hazards or where this is not possible, and hazards can be realised, reduce the severity and scale of consequences, and reduce the likelihood of accidents.

LR 2.2-06 'Master fuel valve’ is a remotely activated and system activated valve in the fuel supply line to the ammonia fuelled machinery which is located outside the machinery space in which the ammonia fuelled machinery is located and is as close as possible to the ammonia fuel preparation equipment.

LR 2.2-07 ‘Toxic area’ means and area in which a toxic gas atmosphere is or may be expected to be present, in concentrations such as to require special precautions to minimize harm to the persons on board.

2.3 Alternative design

LR 2.3-01 These requirements contain functional requirements for all appliances and arrangements related to the use of ammonia as fuel.

LR 2.3-02 Appliances and arrangements of ammonia fuel systems may deviate from those set out in these requirements, provided such appliances and arrangements meet the intent of the goal and functional requirements concerned and provide an equivalent level of safety.

LR 2.3-03 The equivalence of the alternative design should be demonstrated as specified in SOLAS Chapter II-1, Regulation 55 and approved by the Administration. However, the Administration should not allow operational methods or procedures to be applied as an alternative to a particular fitting, material, appliance, apparatus, item of equipment or type thereof which is prescribed by these requirements.

LR 3-01 The requirements in the Rules and Regulations for the Classification of Ships using Gases or other Low-flashpoint Fuels, Part A, 3 Goal and functional requirements and its sub-Sections are applicable to the use of ammonia as fuel, together with the additional requirements herein.

3.1 Goal

The goal of these requirements is to provide for safe and environmentally friendly design of ships and in particular their installations of systems for propulsion machinery, auxiliary power generation machinery and/or other purpose machinery using ammonia as fuel.

3.2 Functional requirements

LR 3.2-01 The safety, reliability and dependability of the systems shall be equivalent to those achieved with new and comparable conventional oil-fuelled main and auxiliary machinery.

LR 3.2-02 The probability and consequences of fuel-related hazards shall be limited to a minimum through arrangement and system design, such as ventilation, detection and safety actions. In the event of leakage or failure of the risk reducing measures, necessary safety actions shall be initiated.

LR 3.2-03 The design philosophy shall ensure that risk reducing measures and safety actions for the fuel installation do not lead to an unacceptable loss of power.

LR 3.2-04 Toxic areas and hazardous areas shall be restricted, as far as practicable, to minimize the potential risks that might affect the safety of the ship, persons on board and equipment.

LR 3.2-05 Equipment installed in hazardous areas and toxic area zones shall be minimized to that required for operational purposes and shall be suitably and appropriately certified.

LR 3.2-06 Unintended accumulation of explosive, flammable or toxic gas concentrations shall be prevented.

LR 3.2-07 System components shall be protected against external damages.

LR 3.2-08 Sources of ignition in hazardous areas shall be minimized to reduce the probability of explosions.

LR 3.2-09 It shall be arranged for safe and suitable fuel supply, storage and bunkering arrangements capable of receiving and containing the fuel in the required state without leakage. Other than when necessary for safety reasons, the system shall be designed to prevent venting under all normal and abnormal operating conditions, including idle periods.

LR 3.2-10 Piping systems, and containment and overpressure relief arrangements that are of suitable design, construction and installation for their intended application shall be provided.

LR 3.2-11 Machinery, systems and components shall be designed, constructed, installed, operated, maintained and protected to ensure safe and reliable operation.

LR 3.2-12 Fuel containment system and machinery spaces containing a source that might release fuel into the space shall be arranged and located such that a fire or explosion in either will not lead to an unacceptable loss of power or render equipment in other compartments inoperable.

LR 3.2-13 Suitable control, alarm, monitoring and shutdown systems shall be provided to ensure safe and reliable operation.

LR 3.2-14 Fixed gas detection suitable for all spaces and areas concerned shall be arranged.

LR 3.2-15 Fire detection, protection and extinction measures appropriate to the hazards concerned shall be provided.

LR 3.2-16 Commissioning, trials and maintenance of fuel systems and machinery shall satisfy the goal in terms of safety, availability and reliability.

LR 3.2-17 The technical documentation shall permit an assessment of the compliance of the system and its components with the applicable Rules, guidelines and design standards used and the principles related to safety, availability, maintainability and reliability.

LR 3.2-18 A single failure in a technical system or component shall not lead to an unsafe or unreliable situation including a failure which prevents the safety system from operating on demand.

LR 4-01 The requirements in the Rules and Regulations for the Classification of Ships using Gases or other Low-flashpoint Fuels, Part A, 4 General requirements and its sub-Sections are applicable to the use of ammonia, together with the additional requirements herein.

4.1 Goal

LR 4.1-01 The goal of this Appendix is to ensure that the necessary assessments of the risks involved are undertaken to eliminate or mitigate any adverse effect to the persons on board, the environment or the ship.

LR 4.1-02 An inherently safer design shall be sought early in the development cycle where the greatest opportunity exists to eliminate hazards or reduce the severity, scale and likelihood of any adverse consequences. This is to focus on prevention of failure and increased reliability and redundancy. Where this is insufficient, protection of those on board is to focus on:

• 1. firstly, passive means, such as physical barriers, containment, separation, natural ventilation and absence of ignition sources; and,
• 2. secondly, active means, such as detection, isolation, mechanical ventilation and extinguishment.

4.2 Risk assessment and Risk Based Certification (RBC)

LR 4.2-01 Risk assessments shall be undertaken in accordance with Lloyd’s Register’s (hereinafter referred to as LR’s) Risk Based Certification (RBC) process, where the risk assessments may identify required design changes to equipment, components, arrangements and safeguards to meet agreed risk criteria.

LR 4.2-02 Risk assessments are to be undertaken to ensure that risks arising from the use of ammonia as fuel to persons on board or to the safe operation of the ship are identified, minimized and satisfactorily managed. The risk assessments are to be documented in accordance with LR’s RBC process.

LR 4.2-03 Risk assessment is to consider normal operation, including maintenance, and reasonably foreseeable abnormal operation, e.g. that caused by foreseeable failures.

LR 4.2-04 The risks shall be assessed using acceptable and recognized risk analysis techniques, and loss of function, component damage, toxic impact, fire and explosion shall as a minimum be considered. The analysis shall help ensure that risks are eliminated wherever possible. Risks which cannot be eliminated shall be mitigated as necessary. Details of risks, and the means by which they are mitigated, shall be documented to the satisfaction of LR and in accordance with LR’s RBC process.

LR 4.2-05 The risk assessment required by Part A, 4, 4.2 Risk assessment shall address the following ammonia specific risk assessment items:

• 1. design and arrangement of the contaminated water holding tank, see Appendix LR2, Part A-1, 5.8 Bilge systems, LR 5.8-04 Bilge systems;
• 2. materials of construction of machinery, equipment and components, see Appendix LR2, Part A-1, 7, 7.4 Materials;
• 3. design and arrangement of the bunkering station, see Appendix LR2, Part A-1, 8, 8.3 Bunkering station;
• 4. dispersion of emergency toxic releases to atmosphere, see Appendix LR2, Part A-1, 9, 9.4 Safety functions of gas supply system;
• 5. protection of single walled piping outside of the machinery spaces, see Appendix LR2, Part A-1, 9, 9.5 Fuel distribution outside of machinery spaces;
• 6. engine Safety Concept, see Appendix LR2, Part A-1, 10, 10.3 Internal combustion engines of piston type;
• 7. fuel cell installation risk assessment, see Appendix LR2, Part A-1, 10, 10.4 Fuel cell installations;
• 8. coverage of waterspray systems, see Appendix LR2, Part A-1, 11, 11.5 Waterspray system;
• 9. toxic area zones, see Appendix LR2, Part A-1, 12, 12.6 Toxic area zones;
• 10. emergency ventilation rates, see Appendix LR2, Part A-1, 13, 13.6 Fuel preparation room and Part A-1, 13, 13.7 Bunkering station;
• 11. additional control, alarm and safety requirements beyond those stated, see Appendix LR2, Part A-1, 15, 15.3 General;
• 12. spaces, systems and equipment requiring gas detection, see Appendix LR2, Part A-1, 15, 15.8 Gas detection;
• 13. gas detector locations, see Appendix LR2, Part A-1, 15, 15.8 Gas detection 15.8.4; and,
• 14. control, alarm and safety instruments for other essential equipment, see Appendix LR2, Part A-1 15.11 Other essential equipment.

4.3 Limitation of explosion consequences

LR 4.3-01 An explosion in any space containing any potential sources of release and potential ignition sources should not:

• 1. cause damage to or disrupt the proper functioning of equipment/systems located in any space other than that in which the incident occurs;
• 2. damage the ship in such a way that flooding of water below the main deck or any progressive flooding occurs;
• 3. damage work areas or accommodation in such a way that persons who stay in such areas under normal operating conditions are injured;
• 4. disrupt the proper functioning of control stations and switchboard rooms necessary for power distribution;
• 5. damage life-saving equipment or associated launching arrangements;
• 6. disrupt the proper functioning of fire-fighting equipment located outside the explosion-damaged space;
• 7. affect other areas of the vessel in such a way that chain reactions involving, inter alia, cargo, gas and bunker oil may arise; or
• 8. prevent persons’ access to life-saving appliances (LSA) or impede escape routes.