Ro-Ro and Car Carrier Management: Fire Risk, EVs and Deck Integrity

Why the vehicle deck is the problem

Roll-on/roll-off vessels and pure car and truck carriers are managed around a single dominant hazard. Everything else — cargo securing, ventilation, deck maintenance, crew training — is downstream of the fact that a vehicle deck fire is extraordinarily difficult to fight and has, on several well-documented occasions, resulted in total loss.

Add electric vehicles and the picture changes again. Lithium-ion battery fires can involve thermal runaway, which produces its own oxygen, burns at very high temperature, resists conventional suppression and can reignite hours later. There is no consensus "solution" — the practical response is prevention, early detection and containment.

Operational controls that reduce fire risk

1. Cargo acceptance discipline. State of charge limits for EVs where the operator's policy sets them; refusal of damaged or previously-recalled vehicles; verification of declared cargo.
2. Pre-loading inspection. Fuel leaks, damaged vehicles, aftermarket modifications, unsecured loose items.
3. Stowage planning. Segregation of EVs and higher-risk units, access lanes maintained for firefighting.
4. Detection. Frequent patrols where permitted, plus fixed detection appropriate to the deck.
5. Drencher readiness. Tested, sectionalised, with crew trained on isolation and sequencing.
6. Ventilation shutdown procedure. Rehearsed, because in an emergency it must be immediate.
7. Boundary cooling plan per deck, drilled.
8. Early decision to activate. The most consequential control of all — hesitation is what converts an incident into a loss.

The chart is a model, not a measurement, but its shape is uncontroversial in the segment: effectiveness collapses the later you intervene. Management attention should be weighted accordingly — toward cargo acceptance and detection, not toward heroic firefighting.

Cargo securing

Vehicles move. Lashing standards on car carriers and ro-ro vessels are governed by the Cargo Securing Manual, and the practical management issues are:

• Lashing gear condition — straps and chains degrade, and worn gear is a recurring inspection finding
• Competency of shore stevedores, who often do the lashing and are not under the master's control
• Verification by ship's staff before departure, documented
• High-and-heavy units requiring engineered securing arrangements
• Weather routing to avoid the parametric rolling and heavy weather that break securing arrangements

Deck integrity and structure

Ro-ro decks take continuous abuse from vehicle traffic, and ramps and bow/stern doors are safety-critical closures.

Watertight and weathertight door integrity carries obvious historical weight in this segment. Indicator systems must work, tests must be genuine, and records must be complete.

Stability and the free-surface issue

Activating a drencher system puts a large volume of water onto open decks. Drainage capacity and free-surface effect are stability considerations that must be understood before the emergency, and they must be in the ship's stability documentation and in the crew's training.

Commercial and regulatory context

Car carriers are highly EU-exposed on European trades, which brings EU ETS at 100% of applicable emissions from 2026 and FuelEU Maritime intensity obligations. Insurance is the other commercial dimension: after several high-profile vehicle-carrier losses, underwriters look closely at EV cargo policy, detection capability and crew training. A manager with a documented, evidenced fire-risk regime has a materially better renewal conversation.