Overview
ISO 8728:2024 - Ships and marine technology - Marine gyro-compasses specifies minimum construction, performance, and type testing requirements for marine gyro-compasses required under SOLAS (1974), Chapter V, Regulation 19. Aligned with IMO Resolution A.424(XI), this fourth edition updates technical and testing provisions to ensure reliable heading information, interoperability with bridge systems, and compliance with modern bridge alert management expectations.
Keywords: ISO 8728:2024, marine gyro-compasses, SOLAS Regulation 19, IMO A.424(XI), gyro-compass performance
Key topics and technical requirements
- Scope and definitions: Clarifies terms such as gyro-compass, true heading, and settled (three readings at 30 min intervals within 0.7°).
- Construction requirements: Minimum build and installation considerations for master compasses and repeaters.
- Performance requirements:
- Accuracy in latitudes up to 60°, including settling time and settle point error
- Residue and dynamic effects (alteration of speed and course)
- Synchronization between master and repeater compasses
- Interfaces for data exchange with ship systems
- Alert management: bridge alert behaviour, “Power fail” and “System fault” alerts
- Type tests (detailed test and verification procedures):
- Settling time, settle point error, Scorsby table tests, intercardinal motion, repeater accuracy and speed correction tests
- Environmental and electrical tests: voltage/frequency variation, vibration, temperature and damp heat
- Interface and alert management tests (including display equipment requirements)
- Marking and information: Required labeling and documentation for installation and survey
- Annexes: Normative guidance for ship surveyors, alert definitions, and IEC 61162 interfaces for VDR and external equipment
Practical applications - who uses this standard
- Gyro-compass manufacturers: design and certify equipment to meet SOLAS/IMO performance.
- Shipyards and system integrators: select and install compliant heading systems and repeaters.
- Ship operators and crews: ensure bridge systems provide accurate, stable heading and correct alert handling.
- Classification societies, flag administrations, and marine surveyors: verify compliance during certification and surveys.
- Maritime electronics and navigation suppliers: ensure interface compatibility (e.g., IEC 61162 family) with ECDIS, VDR and bridge displays.
Benefits: ensures SOLAS compliance, improves navigational safety, supports interoperability and consistent bridge alerting.
Related standards and references
Normative references include: IEC 60945, IEC 61162‑1/‑2/‑450, IEC 62288, IEC 62923‑1/‑2, and IMO resolutions MSC 302(87), MSC 191(79), MSC 466(101). These govern general maritime equipment testing, digital interfaces, display presentation, and bridge alert management.