AMMONIA-FUELLED SHIPS
TENTATIVE RULES
NR671 - JULY 2022
NR671 DT R01 JULY 2022
RULE NOTE
BUREAU VERITAS MARINE & OFFSHORE
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BUREAU VERITAS
RULES, RULE NOTES
AND GUIDANCE NOTES
These rules are provided within the scope of the Bureau Veritas Marine &
Offshore General Conditions, enclosed at the end of Part A of NR467, Rules
for the Classification of Steel Ships. The current version of these General
Conditions is available at the Bureau Veritas Marine & Offshore website.
The PDF electronic version of this document available at the Bureau Veritas
Marine & Offshore website https://marine-offshore.bureauveritas.com/
is the official version and shall prevail if there are any inconsistencies
between the PDF version and any other available version
.
Ammonia-Fuelled Ships - Tentative Rules - NR671
Table of Content
July 2022
2
Section 1 General
1 Application 4
1.1 Scope
1.2 Statutory requirements
Section 2 Ammonia-fuelled Ships
1 Application 5
1.1 Scope
1.2 Classification
1.3 Documentation to be submitted
1.4 Definitions
2 General design principles 7
2.1 Limitations of the toxicity consequences for persons on board
2.2 Limitations of the toxicity consequences for the environment
2.3 Risk assessment
3 Ship design and arrangements 8
3.1 Protection of ammonia fuel storage tanks against external damages
3.2 Location and protection of ammonia fuel piping
3.3 Leakage containments
3.4 Arrangement of spaces containing a potential source of ammonia release
3.5 Arrangement of machinery spaces
3.6 Ammonia fuel preparation equipment
3.7 Regulations for bilge systems and drainage arrangements
3.8 Drip trays
3.9 Control of ammonia vapours
4 Fuel containment system 12
4.1 General
4.2 Operating conditions of the storage tank
4.3 Design and arrangement of ammonia tanks
4.4 Tank pressure relief systems
5 Materials and general pipe design 13
5.1 General
5.2 Materials
5.3 Prevention of phase changes in ammonia supply lines
6 Bunkering 14
6.1 General
6.2 Arrangement of the bunkering station
7 Fuel supply to consumers 14
7.1 General
7.2 Secondary enclosure for ammonia fuel piping
7.3 Master ammonia fuel valve
8 Power generation including propulsion and other ammonia consumers 14
8.1 General
8.2 Diesel Engines
8.3 Fuel cells
9 Fire safety and explosion prevention 15
9.1 General
9.2 Inerting
9.3 Fire extinguishing
9.4 Static electricity
Ammonia-Fuelled Ships - Tentative Rules - NR671
Table of Content
July 2022
3
10 Arrangements for mitigating the consequences of ammonia emissions 15
10.1 General
10.2 Ammonia vapour processing systems
10.3 Water mist system
11 Ventilation 17
11.1 General
11.2 Arrangement of the ventilation systems serving spaces with risk of exposure to ammonia
12 Electrical installations 17
12.1 General
12.2 Electrical equipment for hazardous spaces
13 Control, monitoring and safety systems 17
13.1 General
13.2 Regulations for ammonia vapour detection
13.3 Personal protection
14 Inspection and maintenance 18
14.1 Onboard surveys
Section 3 Ammoniafuel Prepared Ships
1 General 19
1.1 Application
1.2 Documents and information to be submitted
1.3 Definitions
1.4 Ammonia main characteristics and consequences on the design of the ship installations
2 General requirements for the additional class notation
AMMONIAFUEL-PREPARED 22
2.1 Design principles
2.2 General arrangement
2.3 Ship structure and stability
2.4 Machinery
3 Additional requirements for notation S 23
3.1 General
4 Additional requirements for notation A 23
4.1 Access
4.2 Ventilation
5 Additional requirements for notation T 23
5.1 General
5.2 Design of the ammonia storage tank
5.3 Ship structure
6 Additional requirements for notation H 24
6.1 General
6.2 Design of the ammonia fuel handling system
7 Additional requirements for notation P 24
7.1 General
7.2 Design of the ammonia piping system
8 Additional requirements for notation B 24
8.1 General
8.2 Design of the ammonia combustion unit (thermal oxidizer)
8.3 Design of the refrigerating system
