Overview
ISO 10665:2024 - Ships and marine technology - Ship design - CNG and LNG propulsion system - defines requirements for the installation of compressed natural gas (CNG) and liquefied natural gas (LNG) propulsion systems and associated components on ships and crafts. The standard targets marine applications other than large sea‑going vessels covered by SOLAS Chapter II‑1 and excludes appliances with directly attached portable gas cylinders. It emphasizes technical suitability, safety, and environmental considerations associated with using natural gas as a marine fuel.
Key topics and technical requirements
ISO 10665 covers the full installation lifecycle and provides requirements and procedures for:
- Components: requirements for CNG cylinders, LNG fixed containers, vaporizers and fuel system components; fittings and container‑mounted devices.
- Installation requirements: general provisions for installers, structural modifications, container/cylinder mounting, lockers and securing arrangements.
- Gas distribution: design criteria for gas pipes, hoses, fittings, remote shut‑off valves and filling units.
- Safety systems: gas detection placement and alarm positions, forced ventilation and purging of engine spaces, and integration with electrical systems.
- Fire protection: provisions for fire‑extinguishing equipment appropriate to gas‑fueled propulsion.
- Operational documentation: mandatory owner’s manual (contents and format), commissioning records and certificates.
- Commissioning and testing: commissioning steps including tightness and leakage tests, initial filling procedures, fuel system tests and water trials.
- Environmental and human‑safety considerations: references to lifecycle and environmental aspects and training/qualification of technical personnel.
Applications and users
ISO 10665 is intended for practical use by:
- Naval architects and ship designers specifying CNG/LNG propulsion for small and medium vessels.
- Shipbuilders and outfitters installing fuel storage, piping, detection and ventilation systems.
- Marine engineers and system integrators commissioning and testing gas propulsion systems.
- Owners and operators implementing operational procedures, maintenance and owner’s manuals.
- Classification societies and regulators assessing compliance for non‑SOLAS II‑1 vessels.
Practical applications include newbuild and retrofit installations on ferries, workboats, tugs, recreational craft and other non‑SOLAS sea‑going vessels where CNG/LNG is chosen to reduce emissions and meet environmental regulations.
Related standards
ISO 10665 references and complements other standards such as:
- ISO 11439, ISO 12991 (onboard storage tanks and cylinders)
- ISO 12614, ISO 14469, ISO 15500 (fuel system components and connectors)
- ISO 13297 (electrical systems)
- IEC 60529 (IP code) and EN 3‑7 (portable fire extinguishers)
These related standards support component design, testing, personnel qualification and electrical protection for safe CNG/LNG marine propulsion installations.
Keywords: ISO 10665, CNG, LNG, ship design, marine technology, propulsion system, gas detection, ventilation, maritime safety, installation requirements.