Amendments to FSS Code issued by IMO

The International Maritime Organization has issued resolution MSC.555(108) amending the International Code for Fire Safety Systems (FSS Code).

These amendments will come into force on January 1, 2026.

The amendments are part of the continuous effort to enhance maritime safety, especially in areas where technological advancements and operational practices evolve, such as with ro-ro passenger ships.

Amendments to the FSS Code

1. Fire Safety Systems on Ro-Ro Passenger Ships (Chapter 7)

A significant focus of the amendments is on enhancing fire-extinguishing systems for ro-ro (roll-on/roll-off) passenger ships, specifically those with weather decks designed to carry vehicles. These vessels pose unique fire risks due to the presence of vehicles and combustible cargo.

New Requirements for Water-Based Fire-Extinguishing Systems (Section 2.5):
- Scope of Protection: The fire-extinguishing system must cover the entire weather deck where vehicles are stored, as well as surrounding areas up to 8 meters from the deck’s boundaries or the next vertical boundary.
- Water Distribution: The combined capacity of the water monitors must deliver at least 2.0 liters per minute (L/min) per square meter, with a minimum output of 1,250 L/min per monitor. The water must be evenly distributed across the protected area.
- Monitor Placement: Monitors must be located outside the areas they protect and must ensure unobstructed coverage, even when vehicles are loaded at full capacity. Areas that can't be covered by the monitors must be protected by nozzles, delivering 5.0 L/min per square meter.
- Water Supply: The system must continuously supply water, capable of covering the full width and a 40-meter length of the weather deck (or the entire deck if it is shorter). The supply must be sufficient to meet the demands of the largest monitor.
- Fire Pumps: The system may use existing fire pumps or a dedicated pump. It should be capable of operating both the ship's fire main system and the weather deck’s fire monitors simultaneously. Special requirements are added if the ship carries dangerous goods.

2. Fire Detection and Alarm Systems (Chapter 9)

The amendments also introduce updated standards for fire detection and alarm systems. These changes are designed to improve early detection of fires and ensure that alarm systems are more efficient and easier to manage, particularly in ro-ro spaces.

Heat and Smoke Detector Standards:
- Operating Temperature: Heat detectors must operate within a temperature range of 54°C to 78°C. In high-temperature environments, such as drying rooms and saunas, detectors can operate at up to 130°C and 140°C, respectively.
- Linear Heat Detectors: Linear heat detectors must be tested according to updated standards (EN 54-22:2015 and IEC 60092-504), ensuring consistency and reliability across various types of ships.
Detector Placement and Spacing:
- The maximum allowable floor area per detector and the distances between detectors have been standardized. For example, smoke detectors can cover a maximum area of 74 square meters, with a maximum distance of 11 meters between detectors.
- For linear heat detection systems, the distance between sensor cables should not exceed 9 meters, with a maximum distance of 4.5 meters from bulkheads.
Alarm Systems on Ro-Ro Passenger Ships:
- Ships constructed on or after January 1, 2026, must have alarm systems that follow a consistent scheme in terms of vocabulary, colors, and positioning to ensure immediate recognition by the crew.
- The system interface must allow the crew to review alarm history and identify active alarms, providing clarity and ease of operation during emergencies.
- Detector Disconnection: On ro-ro passenger ships, smoke detectors in special category spaces and ro-ro spaces may be temporarily disconnected during the loading and unloading of vehicles to avoid false alarms. The disconnection must be time-limited and automatically reset once loading or unloading is complete. Heat detection functions cannot be disabled, and manual call points must always remain active.