Updated IMO guidelines for GMDSS radio installations on SOLAS ships

Eda Zenic -

The International Maritime Organization issued revised guidelines to harmonize the requirements for Global Maritime Distress and Safety System (GMDSS) radio installations on ships that must comply with the International Convention for the Safety of Life at Sea (SOLAS). These updated guidelines, approved at the 109th session of the Maritime Safety Committee (held from 2 to 6 December 2024), aim to clarify technical requirements and ensure consistency in the installation and operation of radio communication equipment.

Purpose of the Guidelines:

The primary goal of the updated guidelines is to provide Administrations, shipowners, ship operators, and manufacturers with clear and standardized instructions for installing GMDSS radio equipment. This ensures compliance with SOLAS Chapter IV and related IMO resolutions while maintaining international standards for safety and operational efficiency. These guidelines also address the responsibilities of marine electronics companies in ensuring proper operator training.

Scope of the Guidelines:

The guidelines apply to the installation of GMDSS radio equipment on SOLAS-compliant ships, including high-speed craft (HSC) and mobile offshore drilling units (MODUs). They also apply to certain voluntary or nationally mandated installations on smaller vessels, such as cargo ships under 300 gross tons (GT) and fishing vessels, wherever practical.

Key Features of the Guidelines:

  • General Provisions:
    • The guidelines emphasize that all radio installations must meet IMO and ITU (International Telecommunication Union) requirements and be type-approved by the relevant Administration.
    • They provide rules for installation on SOLAS ships, high-speed craft, and MODUs, with additional references to relevant sections of the HSC and MODU Codes.
    • For vessels not covered under SOLAS, the guidelines recommend following these standards as far as practical if GMDSS equipment is voluntarily or mandatorily installed.
  • Regulatory References: The document is based on several key international standards, including:
    • The International Convention for the Safety of Life at Sea (SOLAS).
    • ITU Radio Regulations.
    • IMO resolutions and circulars.
    • The International Convention on Standards of Training, Certification, and Watchkeeping for Seafarers (STCW).
    • ISO standards for bridge design and equipment arrangement.
  • Functional Requirements:
    • Detailed descriptions of the equipment necessary for different sea areas (e.g., Sea Area A3, which includes coverage by Inmarsat or other satellite systems).
    • Requirements for redundancy, functionality, and interoperability of GMDSS equipment.
  • Basic and Supplementary Equipment Requirements:
    • Guidelines cover a wide range of radio equipment, including VHF and MF/HF transceivers, EPIRBs (Emergency Position Indicating Radio Beacons), AIS-SARTs (Automatic Identification System Search and Rescue Transponders), and portable two-way VHF radios.
    • Specific recommendations for integrating equipment into bridge systems and ensuring operational readiness in emergencies are included.
  • Antenna Installation:
    • Instructions on the placement and configuration of VHF, MF/HF, and satellite communication antennas.
    • Emphasis on proper cabling and antenna tuners to ensure optimal performance and compliance with electromagnetic compatibility (EMC) standards.
  • Energy Sources:
    • Clear requirements for main, emergency, and reserve sources of energy, including specifications for radio batteries, uninterruptible power supplies (UPS), and automatic chargers.
    • Guidelines for ensuring continuous power supply to radio equipment during emergencies.
  • Electromagnetic Compatibility (EMC):
    • Detailed requirements for shielding cables, grounding equipment, and minimizing electromagnetic interference with other onboard systems.
  • End-of-Life Disposal:
    • Recommendations for the responsible disposal and recycling of obsolete radio equipment to minimize environmental impact.
  • Appendices:
    • Appendix 1 provides information on Inmarsat Recognized Mobile Satellite Services.
    • Appendix 2 details Iridium Recognized Mobile Satellite Services.

Implementation and Dissemination:

The IMO invites Member States to bring these revised guidelines to the attention of all relevant stakeholders, including shipowners, ship operators, equipment manufacturers, surveyors, and marine electronics companies. It also emphasizes the responsibility of marine electronics companies to ensure that ship operators are adequately trained in the use of installed GMDSS equipment before the systems are put into operation.