Navigating the Risks: Ensuring Safety in Maritime Transport of New Energy Electric Vehicles
The global surge in new energy electric vehicle (NEV) exports has brought unprecedented growth to the maritime transport sector. Driven by the “dual carbon” strategy, China’s competitive edge in NEV production has propelled its automotive exports to new heights. In 2023, the country’s total vehicle exports reached 4.91 million units, a year-on-year increase of 57.9%, securing the top spot globally for the first time. Among these, NEV exports hit 1.203 million units, soaring by 77.6%. Maritime transport, particularly via ocean ro-ro ships, has emerged as the primary mode for these exports, fueling a boom in the related international shipping market. However, this rapid expansion is overshadowed by a series of alarming fire incidents involving NEVs during maritime transport, raising critical concerns about the safety of such operations.
A closer look at these incidents reveals a pattern of risks that the industry can no longer afford to ignore. In November 2010, a ro-ro ship owned by DFDS, identified as the H, fell victim to a fire.The crew had used a plug from a refrigerated container to charge electric vehicles on board. After 13 hours of charging, the battery pack exploded, resulting in two trailers catching fire. This early incident served as a warning sign of the potential hazards associated with lithium-ion battery-powered vehicles at sea.
Fast forward to June 2020, the Norwegian-flagged car carrier Y encountered a devastating fire in waters off Jacksonville, USA.The blaze originated from a lithium-ion battery in an electric forklift on board, which quickly spread to surrounding vehicles. The fire raged for eight days, completely destroying the ship and the 2,420 vehicles it carried, with losses amounting to a staggering $40 million. This incident highlighted the destructive potential of lithium battery fires in a maritime setting and the challenges in containing them.
February 2022 saw another major disaster when the car carrier R, operated by Mitsui O.S.K. Lines, caught fire during its voyage. Investigations strongly suggested that the fire was ignited by a lithium-ion battery in one of the electric vehicles on board, or that the battery accelerated and intensified the spread of the fire. The consequence was the sinking of the ship, along with the total loss of the 3,965 vehicles it was transporting, leading to losses exceeding $400 million.
In July 2023, the Panama-flagged car carrier F suffered a fire while en route to Port Said, Egypt. The fire started from an electric vehicle on the vehicle deck and rapidly spread throughout the entire ship. At the time of the incident, the ship was carrying 3,783 vehicles, including 498 electric vehicles, resulting in one death and multiple injuries. Then, in October 2023, Maersk’s L had to interrupt its voyage due to a fire in one of its containers, which was later found to be transporting a used electric vehicle upon review of the cargo list.
These incidents share a common thread: they all occurred in tightly packed ro-ro decks. Complicating matters, vehicle decks are typically located high in the ship’s structure. Using large amounts of water to extinguish fires in such areas can destabilize the vessel, potentially leading to capsizing. This presents a unique and daunting challenge for the maritime industry, making the prevention of electric vehicle fires and lithium battery explosions a pressing research topic.
To address these risks, it is crucial to first understand the nature of the hazards. Electric vehicles, which include plug-in hybrid electric vehicles, battery electric vehicles, and fuel cell electric vehicles, rely primarily on power batteries, with lithium nickel cobalt manganese oxide (NCM) and lithium iron phosphate (LFP) batteries being the most common types. The primary risk stems from the lithium-ion batteries themselves.
Thermal runaway is a key concern. This phenomenon occurs when a battery’s temperature rises due to external heating or internal heat generation. As the temperature continues to climb, the electrolyte in the battery boils, increasing internal pressure. Once the pressure reaches a critical point, the battery ruptures, releasing flammable gases. These gases mix with oxygen in the surrounding air, forming an explosive mixture that can ignite upon contact with a spark, potentially triggering a chain reaction as adjacent batteries are heated. Mechanical damage, electrical damage, and high-temperature environments are the main causes of thermal runaway in lithium-ion batteries.
Another significant risk factor is the inability to verify the quality of lithium-ion batteries in some used electric vehicles. The 2020 June and 2023 October ship fire cases were both caused by transported used electric vehicles. Due to these safety concerns, an increasing number of car carrier operators are refusing to transport used electric vehicles that pose potential risks.
Fighting lithium battery fires is particularly challenging. These fires spread extremely rapidly, progressing from initial combustion to intense burning in just a few seconds, with the rate of thermal runaway propagation increasing exponentially. The flames can reach temperatures exceeding 2,700°C and burn in a jet-like manner, making it easy for the fire to spread to nearby areas.
Traditional fire extinguishing agents such as carbon dioxide, dry powder, and foam are ineffective because they cannot penetrate the interior of lithium-ion batteries to halt the violent chain decomposition reactions occurring inside. The batteries therefore remain in a state of thermal runaway. Additionally, the positive electrode material in lithium-ion batteries acts as a strong oxidizing agent, while the negative electrode active material and electrolyte are reducing agents, making re-ignition highly likely.
Using water to fight such fires can quickly dissipate heat and lower the battery’s internal temperature, but the large amounts of firefighting water sprayed onto the ship’s hull can create a free surface effect, compromising the vessel’s stability.
Compounding these issues is the lack of adequate emergency response capabilities. Currently, there is a shortage of high-precision fire monitoring systems, and fire safety training specifically for electric vehicle fires is lacking, leaving crew members without the necessary professional firefighting skills.
Furthermore, there is a lack of unified measures to control the safety risks of maritime transport of electric vehicles. The International Maritime Dangerous Goods Code (IMDG Code) and relevant domestic standards only provide general principles for the container transport of new energy electric vehicles, leaving critical aspects such as packing, securing, and fire protection in need of standardization. Internationally, there are no established fire test procedures or approval standards for lithium battery fires in the context of fire safety. While China has conducted preliminary fire tests using a full-scale vehicle power battery pack as the fire source, based on the fuel vehicle model in the “Guidelines for the Design and Approval of Fixed Water-Based Fire Protection Systems for Ro-Ro Spaces and Special Category Spaces,” these are insufficient to support the formulation or revision of relevant standards.
To mitigate these risks, a comprehensive approach is needed, starting with the development of relevant technical standards and guidelines.
Firstly, there is an urgent need to formulate safety technical specifications for the maritime transport of electric vehicles. This includes conducting research on risk identification and prevention, defining clear requirements and standards for the maritime transport of electric vehicles, and guiding manufacturers and shipping companies in establishing their own safety standards. Special attention should be paid to used electric vehicles, with risk assessments and targeted preventive measures developed. Additionally, safety operation standards for container transport of new energy electric vehicles should be expedited, further regulating the approval process for electric vehicle transport, unpacking inspections, and strict requirements for packing materials, operating sites, technical solution certifications, and operational procedures.
Secondly, the development of safety supervision guidelines for shipborne electric vehicles is essential. This includes creating guidelines for the supervision of ro-ro transport of electric vehicles, specifying requirements for fire separation and fire protection arrangements in vehicle holds. For container transport, given that the stowage and lashing methods differ from those for ordinary dangerous goods, and that factors such as the rated load of transport brackets, the strength of lashing straps, and vehicle securing methods directly affect shipping safety, relevant supervision guidelines must be developed to outline safety supervision measures throughout the entire process from packing operations to administrative approval.
Thirdly, clear fire test standards for electric vehicles should be established. This involves developing product approval test procedures for extinguishing lithium-ion battery electric vehicle fires, determining vehicle test models and protocols, verifying the fire-extinguishing effectiveness of various fixed fire-extinguishing systems (including water-based and gas-based systems), and unifying inspection and certification standards for electric vehicle fire-extinguishing equipment to ensure product quality.
Strengthening on-board safety supervision is another critical measure. For ro-ro transport of electric vehicles, ships should develop on-board inspection checklists, focusing on high-risk components such as the power system, electrical system, and fuel tank to prevent battery or fuel leaks, and accidental activation or startup. Charging electric vehicles on board should be strictly prohibited to ensure battery performance remains controlled during transport. Electric vehicles should be stowed and isolated in designated areas with adequate safety distances maintained. Vehicles must be loaded and secured in accordance with technical documents such as the Cargo Securing Manual, with dedicated vehicle securing points scientifically positioned. Regular inspections of vehicle securing status should be conducted during transport, with necessary tightening of securing devices.
For container transport of electric vehicles, freight forwarders must enhance the review of cargo information provided by shippers, carefully examining details such as cargo names and properties to ensure the accuracy and completeness of documents such as the Material Safety Data Sheet (MSDS) for electric vehicle lithium batteries, UN38.3 test reports, and safety technical specifications, as well as ensuring the cargo is suitable for transport. Collaboration and information sharing between maritime authorities, customs, and other port units should be strengthened. A dangerous goods credit management system should be established, leveraging big data analytics to enhance credit management. Standardized inspection and disposal sites for shipborne dangerous goods should be developed, equipped with advanced equipment such as X-ray inspection machines, and standardized inspection procedures implemented to improve inspection efficiency.
Improving the equipment of shipboard fire prevention and extinguishing systems is also vital. Enhanced fire detection and monitoring systems should be implemented, including clear vehicle zoning, separation of people and vehicles, fire separation, and fire protection arrangements in vehicle holds, with thorough assessments of potential risks. Ro-ro spaces and special category spaces on ro-ro passenger ships should be equipped with additional high-precision detection instruments such as closed-circuit television (CCTV) systems, gas detectors, thermal scanners, and thermal imaging cameras to enable early detection of electric vehicle fire signs and minimize the spread of fires.
Explosion-proof electrical equipment should be installed in enclosed vehicle spaces, special category spaces, and ro-ro spaces, including lighting fixtures, fire detectors, and manual alarm buttons, to prevent sparks from equipment operation.
The installation of new fire prevention and extinguishing equipment is also recommended. For example, a South Korean company has developed a fire response system for car carriers, which includes additional sprinklers and special fire blankets made of high-silica glass fiber. Consideration should also be given to installing shipborne water sprinkler systems designed by a German company, with multifunctional environmentally friendly fire extinguishing agents such as F-500 foam concentrate or Firesorb added to the firefighting water to reduce water usage and extinguishing time.
Finally, enhancing crew management, training, and emergency drills is paramount. Crew members should receive thorough firefighting skills training, becoming proficient in the ship’s cargo hold structure, fire protection and ventilation arrangements, and fire isolation zoning. They should also have a detailed understanding of the potential causes of fires in ro-ro ship cargo holds and the key points of fire prevention and extinguishing operations during vehicle loading, unloading, and transport.
Crew members should also receive training in ship stability, carefully verifying vehicle dimensions, weights, and specific stowage positions, and taking into account temporary adjustments during loading to ensure accurate stability calculations.
Regular fire emergency drills should be conducted, simulating electric vehicle fires and other emergencies to familiarize crew members with the use of fire-fighting equipment and evacuation routes. Given the complexity of handling electric vehicle fires on board, ships and their affiliated companies should establish information communication mechanisms with port emergency response departments and terminals. In the event of a lithium battery-related fire, the relevant vehicles or containers should be reported immediately and handled on shore as soon as possible.
The market prospects for maritime export of new energy electric vehicles are promising. In the current context of insufficient ro-ro ship capacity, ro-ro transport and container transport with multiple vehicles per container will remain the main modes for electric vehicle maritime exports. By learning from past accidents, identifying safety risks, and implementing preventive measures in areas such as technical standards and guidelines, on-board safety supervision, fire prevention and extinguishing equipment, and personnel training and emergency drills, the industry can work towards ensuring the safety of new energy electric vehicle maritime transport.
This endeavor involves a long logistics chain, and any small flaw in production, transport, or management could lead to irreparable disasters during maritime transport. Therefore, ensuring the safety of new energy electric vehicle maritime exports requires the collective efforts of electric vehicle manufacturers, shippers, carriers (including non-vessel operating common carriers), declarants, and ship and shipping company management personnel, as well as the research and application of various new technologies.
Gong Fuzhong, Zeng Xuan, Gao Peng (Yantian MSA, Yantian, Guangdong 518000, China)
Journal of China Maritime
DOI:10.16831/j.cnki.issn1673-2278.2024.07.013