Shipping electric vehicles (EVs) in enclosed roll-on/roll-off (Ro-Ro) garages introduces unique fire safety challenges, primarily stemming from the behavior of lithium-ion (Li-ion) batteries and the confined, densely packed nature of vehicle decks.
Due to the rapid and self-sustaining nature of thermal runaway, lithium-ion battery fires are highly resistant to traditional suppression methods and often require targeted cooling to prevent the propagation of the fire to other vehicles. Early detection is crucial to enable the crew to respond effectively.
That’s why in collaboration with a major shipping company and reviewed by the US Coast Guard, Fike Corporation has designed and supplied early warning fire detection systems for these Ro-Ro vehicle garages that store EVs.
Key Fire Hazards
- Thermal Runaway - Faulty or damaged Li-ion batteries may overheat and self-ignite, initiating a chain reaction that is difficult to suppress.
- Toxic & Flammable Gases - Combustion releases hazardous gases (e.g., HF, CO) that are both toxic and potentially explosive.
- Delayed Ignition - Batteries may smolder for hours or days before igniting, especially if damaged during handling.
- Re-Ignition Risk - Batteries can reignite due to residual internal heat or cell instability.
- Detection Challenges - Fires may originate in concealed battery compartments, which can delay detection.
- High Fire Load - Closely packed vehicles increase available fuel for fire spread.
Detection Technology Assessment: LASH FIRE WP9
The LASH FIRE (Legislative Assessment for Safety Hazards of Fire and Innovations in Ro-Ro Ship Environment) project, funded by the European Union's Horizon 2020 program, aimed to enhance fire safety on roll-on/roll-off (Ro-Ro) ships. Work Package 9 (WP9) specifically focused on identifying innovative detection solutions for improving fire detection, localization, and confirmation in all types of Ro-Ro spaces by evaluating new and advancing technologies, including:
- Physical separation using fire-resistant barriers
- Real-time heat and gas detection (e.g., Fiber optic LHD, gas/smoke sensors)
- MSIR flame detectors with onboard thermal imaging and video analytics
- Dedicated EV zones with enhanced suppression
- State-of-charge (SoC) restrictions during shipment
- Crew training specific to EV fire behavior and suppression
Fike’s solutions that meet these recommendations include:
Fiber Optic Linear Heat Detection (LHD) system uses fiber optic sensor cables to monitor temperature changes along their entire length, enabling continuous monitoring with high spatial resolution. The cables are durable and resistant to environmental stressors such as salt, humidity, and extreme temperatures, making them suitable for maritime environments. The system can pinpoint the exact location of a fire, track its spread, and determine the direction of its development. Integrated with visualization software, it allows for real-time monitoring and quick responses from the ship's bridge.
Fike Flame Detectors monitor for specific wavelengths of energy emitted from flames and provide fast detection when the flame is within the detector's field of view, or from energy reflected by surfaces such as vehicles, bulkheads, and deck material. The Fike flame detectors were tested in large-scale fire tests and showed promising results for use on weather decks and vehicle decks.
Fike Video Analytics has the ability to detect smoke in open and closed Ro-Ro spaces. Traditional smoke detectors can be delayed due to wind conditions or obstructions, as well as the time it takes for smoke to reach the ceiling, and design challenges such as deep beams in the ceiling deck head. Video detection systems can overcome these challenges by analyzing visual data to detect smoke patterns across the entire camera field of view, providing quicker and more reliable detection, regardless of the ceiling configuration. These systems can also assist the crew in confirming and localizing fires through live and recorded video via the analytics servers, reducing the time required for manual verification. Fike video analytics software is currently installed on hundreds of ships, monitoring for atmospheric oil mist in machinery spaces.
Expected Fire Sequence of Events
In the event of a faulty, overcharged, or damaged battery, an exothermic reaction occurs, generating heat internally and gases. As the temperature increases, gases build pressure to a point that either the battery cap or a seam opens to relieve pressure. This is referred to as off-gassing.
Visible, dark, flammable, and toxic gases such as hydrogen, CO, methane, ethylene, HF are released. These gases are hot and buoyant, causing them to rise around the sides of the vehicle. Depending on the quantity of gases, they can be visually detected by video analytics or identified by a temperature increase with LHD.
As the battery’s heat increases, creating a self-heating feedback loop, the heat accelerates the reaction, generating even more heat and leading to thermal runaway. Ignition of the gases then occurs, resulting in the battery catching fire, emitting flames, sparks, and more dark smoke and gases. As one small battery heats up or enters thermal runaway, its heat will cause a domino effect in adjacent batteries until the entire module, and then the vehicle, becomes fully involved.
The Fike multi-spectrum infrared flame detectors, installed around the perimeter of the garage, monitor for the presence of flames. Each flame detector is monitored for alarm and fault by the ship's fire alarm system. It also features an HD camera connected to a local area network via Ethernet. A Fike video analytics server, also on the network, records and monitors the camera video for dark, rising gases, and smoke. Video monitors, installed in the Engine Control Room (ECR) and the ship’s bridge, display live video from the cameras.
The Fiber optic linear heat detection cable, installed throughout the deck head (ceiling) of the spaces, is connected to a detection system featuring a low-power laser and signal processor, as well as a display of the garages’ fiber layout with temperature represented in colors. The system can provide live temperature readings with a resolution of 0.5 meters of the hotspot and an accuracy of 1/10 °C. The fiber system is configured with virtual zones and provides fixed temperature, rate of rise, and rate of change alarms. This solution provides a precise location of the fire, reducing the time required for firefighters to locate the fire in smoky conditions.
A summary of expected sequence includes:
- Video analytics detect hot gases or smoke within seconds to minutes, depending on quantity and visibility.
- Linear heat detection signals a temperature increase caused by rising gases and heat, and identifies the location of the fire.
- Flame detector identifies infrared energy from flames within seconds, requiring a line of sight or reflection.
These proven technologies, with low false alarm rates when properly configured, will experience minimal or no false alarms due to the confined space and low activity levels.
Project Contributors
The Fike system design involved collaboration between Fike and Marine Design Solutions of Long Beach, and installation managed by US Electric from Seattle, WA.
Rick Jeffress is Director of Business Development at Fike Corporation, specializing in marine and industrial fire protection. With over 30 years of experience and participation in UL, FM, and European Commission safety initiatives, he has led multiple advancements in fire detection for high-risk environments. Rick was a contributing member of the LASH FIRE Work Package 9 team.