FIRESAFE II: Open-Deck Detection Lessons

FIRESAFE II is not a vendor bake-off. It is the traceable evidence base under the vehicle-deck rules now in force: EMSA commissioned it in 2017, Bureau Veritas, RISE Research Institutes of Sweden and Stena Rederi carried it out, the final reports landed in December 2018, and the IMO's FSA Experts Group endorsed the work in November 2019 before it became interim guidelines and then SOLAS and FSS Code amendments.

What FIRESAFE II actually was

A Formal Safety Assessment on ro-ro passenger ships, structured as four work packages. FIRESAFE I, initiated by EMSA in 2016, had looked at electrical fire as an ignition source and at fire-extinguishing failure. FIRESAFE II, initiated in 2017, took the next stage of the incident: what happens after ignition. Its objective was set in cost-efficiency terms — improving ro-ro passenger ship fire safety through measures that reduce ro-ro space fire risk at a justifiable cost — which is why its outputs are framed as risk control options rather than as engineering recommendations.

• WP1 — detection, and the decision on when to activate the fixed extinguishing system.
• WP2 — containment and evacuation following a ro-ro space fire.
• WP3 — alternative fixed fire-extinguishing systems, their performance and their cost.
• WP4 — fire detection technologies for open ro-ro spaces and weather decks.

Two full-scale fire test campaigns supported that work: one on alternative extinguishing systems, and one on detection systems. The detection tests are the part most often cited and most often misdescribed.

What WP4 tested — and what it did not

WP4 was a suitability test of two technologies against two environments, not a ranking of the detection market. The systems selected for full-scale fire testing aboard a commercial ro-pax were fibre-optic linear heat detection for open ro-ro spaces and a thermal imaging camera for the weather deck. Both were found functional and suitable for the relevant ro-ro space environments.

That matters because the study is routinely summarised as a head-to-head across point smoke detection, aspirating smoke detection, linear heat detection, flame detectors and thermal cameras, with a winner declared. The published record does not support reading a competitive ranking out of the fire tests. Two technologies were selected for two environments and both passed. Any comparison of the wider technology field is a separate argument that has to be made on its own evidence, not attributed to FIRESAFE II.

Ventilation was named as the core problem

The single most useful finding is a constraint, not a product. WP4 identified the main challenge for open ro-ro spaces and weather decks as the potentially significant ventilation those spaces experience, which can delay and delocalise detection. The second verb is the one worth stopping on.

Delay is the familiar failure: airflow dilutes smoke and off-gas below a threshold, so the alarm arrives late. Delocalisation is a different and less discussed failure: airflow carries the products of combustion away from the source, so the alarm — when it does arrive — points at the wrong place. On an open deck with real wind across it, those two effects compound. A system can be both slow and wrong about position, and the second error is the one that sends a response to the wrong part of the ship. It is the same mechanism that decided the outcome on Norman Atlantic, where the fixed system was released into a deck that was not burning.

The risk control options that became rules

FIRESAFE's outputs are visible in the regulation now applying to the fleet. The studies proposed, among other measures: prohibiting open ro-ro decks on newbuildings; introducing minimum distances between openings on ro-ro decks for existing ships; requiring a fixed fire detection system and water monitors on weather ro-ro decks; extending CCTV coverage to all ro-ro spaces; and tightening cabling requirements.

The route from there to enforceable text ran through the IMO. In November 2019 the FSA Experts Group endorsed the studies as compliant with the Revised FSA Guidelines — the procedural step that lets an FSA be used as the evidence base for rulemaking. The IMO subsequently adopted interim guidelines under MSC.1/Circ.1615 and began the amendments to SOLAS and the FSS Code that have since taken effect. The CCTV recommendation in particular is the direct ancestor of the video-monitoring requirement operators are now meeting on vehicle decks.

How to read it in 2026

As a strong but bounded evidence base. Three limits are worth holding in mind when the study is cited in a specification or a class submission. It is an assessment of ro-ro passenger ships, not pure car carriers, so the accumulation and stowage assumptions differ from a PCTC's. Its fieldwork dates from 2017–2018 and predates the sharp rise in electric-vehicle cargo, so the fire scenarios behind it are not battery scenarios. And it is a Formal Safety Assessment, which means several of its most-quoted recommendations rest on cost-benefit modelling rather than on the full-scale fire tests.

Knowing which is which is the practical value. The ventilation constraint on open decks and the suitability of the two tested technologies come from full-scale testing. The prohibition of open ro-ro decks on newbuildings, the opening-distance rule and the CCTV extension come from the FSA's risk and cost analysis. Both kinds of finding are legitimate; they simply carry different weight when someone disputes them, and a technical argument is stronger for saying which kind it is leaning on.

Sources

• 1. EMSA — FIRESAFE II study page (emsa.europa.eu/firesafeii.html): initiated by EMSA in 2017; carried out by Bureau Veritas, RISE Research Institutes of Sweden and Stena Rederi; published and last updated 21 December 2018; work packages WP1 detection and decision on extinguishing activation, WP2 containment and evacuation, WP3 alternative fixed fire-extinguishing systems performance and costs, WP4 fire detection technologies for open ro-ro and weather decks; two full-scale fire test campaigns, with WP4 testing fibre-optic linear heat detection (open ro-ro spaces) and a thermal imaging camera (weather deck) aboard a test vessel.
• 2. EMSA — FIRESAFE studies overview (emsa.europa.eu/firesafe.html): FIRESAFE initiated 2016 on electrical fire as ignition source and fire-extinguishing failure; both studies conducted under Formal Safety Assessment methodology; risk control options including banning open ro-ro decks on new vessels, fixed fire detection and water monitors, minimum distances between deck openings, CCTV coverage in all ro-ro spaces and stricter cabling requirements; IMO FSA Experts Group endorsement of compliance with the Revised FSA Guidelines in November 2019; subsequent IMO Interim Guidelines MSC.1/Circ.1615 and amendments to SOLAS and the FSS Code based on EMSA submissions.
• 3. FIRESAFE II — "Detection systems in open ro-ro and weather decks" final report, and "Detection and Decision" Final Report Version 1.1, December 2018: both tested systems found functional and suitable for the relevant ro-ro space environments; the main challenge for open ro-ro spaces and weather decks identified as potentially significant ventilation, which can delay and delocalise detection.