Marine-Spec Thermal Cameras on Deck

Microbolometer arrays are commodity; the certificate is not. A thermal camera's route to marine type approval runs through EN 54-10 — the flame detector standard — while FSS Code paragraph 4.1.6 now requires heat detectors in vehicle spaces. Those are different regulatory slots, and which one a camera occupies decides what it can be fitted to satisfy. Resolution and NETD decide nothing until that is settled.

The standard that applies is not IEC 60945

IEC 60945 is the wrong reference, and it appears in vendor material constantly. It governs maritime navigation and radiocommunication equipment — its environmental categories, its salt-mist regime drawn from IEC 60068-2-52 Test Kb, its vibration profile from IEC 60068-2-6. Useful as a general benchmark for surviving a ship, but it is not the standard a fire detector is approved against.

Fire detection devices are tested to IEC 60092-504, the marine standard for electrical installations in ships covering control and instrumentation, with the detection performance itself proven against the relevant EN 54 part. Heat detectors, for instance, must be certified to operate before the temperature exceeds 78°C but not until it exceeds 54°C, tested to EN 54 and IEC 60092-504. Linear heat detectors take EN 54-22:2015 with IEC 60092-504. Control units add UL 864 in the US route. If a datasheet cites IEC 60945 and stops there, it has told you the housing might survive and nothing about whether the device can be approved as a detector.

A thermal camera is a flame detector, not a heat detector

This is the distinction that decides a specification, and it is rarely made explicit. The EN 54 series has parts for point heat, point smoke, line-type heat, aspirating smoke, flame, and point multi-sensor combinations — EN 54-29, -30 and -31 cover smoke with heat, carbon monoxide, and combinations of those. There is no EN 54 part that treats thermal imaging as a detector class in its own right. The route that exists for a thermal camera is EN 54-10, the flame detector standard, and certified products on that route are on the market.

Set that against what the amended FSS Code asks for. Paragraph 4.1.6, in force since 1 January 2026, requires heat detectors additional to existing smoke detectors in special category spaces and in open and closed ro-ro and vehicle spaces, or replacement of those smoke detectors with combined smoke and heat units. A device approved as a flame detector has not been approved as a heat detector. It may be an excellent instrument and still not discharge that particular duty.

Where an arrangement does not map onto a prescriptive category, the formal path is SOLAS II-2 Regulation 17, alternative design and arrangements — an engineering analysis submitted for Administration approval rather than a certificate held up against a clause. Whether a given Administration would accept a thermal-imaging arrangement against 4.1.6, and on what evidence, is a determination for that Administration and the class society, not something a vendor can assert.

What FIRESAFE II demonstrated, and where

One environment, one positive result, and a caveat that travels. EMSA's FIRESAFE II study — Bureau Veritas, RISE Research Institutes of Sweden and Stena Rederi, final reports December 2018 — selected two detection technologies for full-scale fire testing aboard a commercial ro-pax under work package 4. A thermal imaging camera was tested on the weather deck, and fibre-optic linear heat detection in open ro-ro spaces. Both were found functional and suitable for their respective environments.

Note the environment the camera was tested in. It was the weather deck — open, with clear lines of sight — not a densely stowed enclosed deck where sight lines end at the first vehicle roof. WP4 also identified ventilation as the main challenge in those open spaces, capable of both delaying detection and delocalising it, so that the alarm arrives late and points away from the source. A camera's optical geometry gives it no protection against the second effect.

What actually fails in service

Not the headline thermal resolution. The failure modes on a vehicle deck are environmental and mechanical, and they accumulate over a deployment rather than showing up at commissioning.

• Optics contamination — diesel exhaust residue and brake dust build a film on the germanium window and erode effective sensitivity long before anything reports a fault.
• Seal failure at the connector boundary, admitting moisture and producing internal condensation on the sensor package.
• Mounting drift after heavy weather, which moves the field of view away from the area the coverage statement claims.
• Calibration drift where there is no periodic shutter-referenced correction, which matters most on routes crossing large ambient swings.
• Line-of-sight loss as stowage changes — the same camera covers a different fraction of the deck depending on what was loaded.

What to specify

Ask for the certificate and the environmental report separately, because they prove different things. The certificate should name the EN 54 part and the marine environmental standard it was tested to — EN 54-10 and IEC 60092-504 for a thermal camera — and the specification should then state plainly which FSS Code duty the device is being fitted to discharge, and which it is not. A camera fitted as verification under the video monitoring requirement is a different procurement from one fitted as a detector under 4.1.6, and conflating the two is how a system passes survey on paper and surprises somebody at the next one.

On the hardware itself, ask for ingress protection with a salt-mist test history behind it rather than a bare IP number, a field-replaceable window that does not require re-calibration, periodic rather than power-up-only calibration referencing, and a stated maintenance interval for optics cleaning. And ask where the supplier's own environmental data comes from: industrial-plant service and vehicle-deck service are not the same duty cycle, and a mean-time-between-failures figure from the former tells you very little about the latter.

Sources

• 1. Lloyd's Register — Class News 07/2026, SOLAS amendments on fire safety requirements for ro-ro passenger ships: Resolutions MSC.550(108) and MSC.555(108) adopted at MSC 108, in force 1 January 2026; FSS Code paragraph 4.1.6 requiring heat detectors additional to existing smoke detectors in special category spaces and open and closed ro-ro and vehicle spaces, or replacement with combined smoke and heat detectors; application immediate for keels laid on or after 1 January 2026 and not later than the first survey on or after 1 January 2028 for existing ships.
• 2. Marine fire detection type-approval requirements (46 CFR Part 161 subpart 161.002 and associated FSS Code Chapter 9 provisions): fire detection devices tested to IEC 60092-504; heat detectors certified to operate before the temperature exceeds 78°C but not until it exceeds 54°C, tested to EN 54 and IEC 60092-504; linear heat detectors to EN 54-22:2015 with IEC 60092-504; control units to UL 864 with IEC 60092-504.
• 3. EN 54 series scope: parts covering point heat, point smoke, line-type heat (EN 54-22), aspirating smoke, flame (EN 54-10), and point multi-sensor combinations (EN 54-29 smoke and heat, EN 54-30 carbon monoxide, EN 54-31 smoke, carbon monoxide and optionally heat). Thermal imaging cameras are certified via EN 54-10; certified products exist on the market.
• 4. IEC 60945 — maritime navigation and radiocommunication equipment, general requirements and test methods; environmental categories including protected and exposed; salt mist per IEC 60068-2-52 Test Kb (cyclic sodium chloride), vibration per IEC 60068-2-6 Test Fc. Cited here to distinguish it from the fire-detection approval route, not as a requirement for detectors.
• 5. EMSA — FIRESAFE II (Bureau Veritas, RISE Research Institutes of Sweden, Stena Rederi; final reports December 2018), work package 4: thermal imaging camera tested on the weather deck and fibre-optic linear heat detection in open ro-ro spaces, aboard a commercial ro-pax; both found functional and suitable for the relevant environments; ventilation identified as the main challenge, capable of delaying and delocalising detection.