29 November 2023
Are the risks associated with Ro-ro Ships on the increase?
What is a Ro-Ro Ship?
Until the early 1950s, shipping cars was a hazardous, time-consuming and expensive business, which involved individual vehicles being loaded into the hold by the ship’s crane.
Ro-ro is an abbreviation for roll-on/roll-off. These ships are specifically designed to transport vehicles that can be driven onto and off of the ship. Ro-ro ships have ramps that enable the cars to be driven on and off the ship, and these ramps have chains or straps that secure the cars during the voyage.
Ro-ro ships are now a common sight in ports worldwide, and they are crucial to the global transportation of cars. However, these vessels pose unique dangers: some are well-known, other risks are emerging. Ro-ro's are closely aligned with the motor industry, which is undergoing a profound electronic transformation.
What are the dangers of shipping vehicles on a Ro-Ro ship?
One of the primary risks for ro-ro ships is their susceptibility to capsize due to uneven distribution on the vessel. Adverse weather conditions can cause cars to shift excessively, leading to instability and the potential capsize of the ship, which could have disastrous consequences. Equally, if cars are not properly secured onboard, they can roll over during bad weather and cause the ship to capsize.
The vessels are also more vulnerable to progressive damage from flooding as they do not have subdivision bulkheads, meaning water can flood the length of the ship.
Collisions are a risk for all vessels; ro-ros often operate in busy shipping lanes and can be difficult to see from other ships, especially in bad weather.
Fire has always posed a major risk for ro-ro ships. The cars they transport run on flammable materials, such as gasoline and oil. If a fire starts on a ro-ro ship, it can spread quickly and be difficult to extinguish.
Electric vehicles are set to become the global mainstream within the next two decades, meaning they will be the primary automotive cargo for ro-ros. Since 2020, there have been six ro-ro vessel fires, including high-profile total losses Höegh Xiamen and Felicity Ace.
The Hoegh Xiamen car carrier fire in June 2020 was caused by an electrical fault from an improperly disconnected battery in a used vehicle, resulting in the loss of 2,420 used vehicles and USD40 million worth of damages, according to the US National Transportation Safety Board.[1]
Felicity Ace, a ro-ro carrier owned and operated by Mitsui O.S.K. Lines, caught fire off the Portuguese coast on February 16, 2022, while it was carrying 3,965 new and used vehicles and sank on March 1, just under two weeks after the crew was safely evacuated. The cause of the fire is unknown, but salvage efforts were hampered by lithium-ion batteries igniting in some of the electric vehicles on board.
In September, the International Union of Marine Insurers (IUMI) published the findings of its investigation into electric vehicles (EVs) and found they don’t necessarily pose a greater fire risk than vehicles with internal combustion engine vehicles (ICEV), but there are considerable differences in storage, fire prevention and suppression.
Unlike ICEVs, EVs have the potential for thermal runway (when the battery undergoes an unstable chemical reaction) and this makes a fire harder to extinguish and increases the risk of re-ignition for an extended period of time.
What are the alternative methods of shipping vehicles?
IUMI’s investigation also flagged a distinction between ro-ros and pure car carriers: ro-ros can stow cars on open decks where airflow makes fire-fighting more challenging. However, car carriers often tightly pack vehicles, hindering emergency access and fuelling fire spread.
What can be done to prevent accidents?
In 2020 the UK Chamber of Shipping, Nautilus and the RMT Union published guidelines for ro-ro vessel vehicle deck safety, which recommended ship operators review their safety policies, paying particular attention to moving vehicles, “blindspots” noxious fumes and inadequate floor markings. It also encouraged updating training on vehicle decks for crew, as well as the need to monitor seafarer fatigue.
Nevertheless, fire has been the most recent focal point for ro-ro accident prevention. The Legislative Assessment for Safety Hazards of Fire and Innovations in Ro-ro ship Environment (Lash Fire) began in September 2019 and concluded in August 2023. With 26 partners from 13 countries, Lash Fire’s mandate was to develop and demonstrate operational and design solutions for all types of ro-ro.
The project recommended:
- Two-inch monitors, each with a modest flow of 1,250 lpm at 5 bar, can suppress a large fire, while minimising costs
- Any area of the weather deck should be covered by two fire monitors from opposing angles
- All fire monitors should have a remote control capacity
- The fire monitors should be placed up high to give a good suppression angle
- Autonomous robotic fire-suppression systems can rapidly detect and locate a fire and aim the water stream at and around the fire, and such systems could bring substantial benefits in terms of rapid intervention for a relatively low additional cost
In addition to these findings, IUMI’s report concluded:
- Early fire detection and rapid confirmation are crucial for a prompt fire-fighting response. Thermal imaging cameras and AI-powered systems are viable options.
- Drencher systems are effective for fire-fighting on board ro-ro and ro-pax vessels both for EV and ICEV fires and should be installed alongside video monitoring systems.
- CO2 extinguishing systems are successful in fighting pure car truck carrier fires and their capacity should be doubled. High-expansion foam fire extinguishing systems are also effective in preventing heat transfer from one vehicle to another.
- Early detection, confirmation, and rapid response time are critical for successful fire-fighting on PCTCs. Fixed systems should be employed before manual methods.
- A clear policy is needed for accepting or rejecting cargo. Vehicles, especially used ones, should be thoroughly screened for hidden damages.
- On board charging of ro-pax vessels should be allowed with appropriate safety measures and risk assessments. EV safety mechanisms are activated during charging.
Maritime safety is an evolving field and risk levels for all vessels can change over time. Risks associated with ro-ro vessels have always been influenced by weather conditions, maintenance and safety measures. Due to the stowing of cars on an open deck, ro-ros are more susceptible to the increased risk of extreme weather, which could cause flooding, collisions and the potential capsize of a vessel.
Yet it is the risk of fire that has recently preoccupied the industry, prompted by the string of recent incidents involving ro-ro vessels. While the latest findings suggest that EVs do not pose an increased risk of fire, they have also flagged important distinctions that shipowners must acknowledge.
The risks associated with shipping EVs will only increase as the world transitions to cleaner energy. A recent study by the National Transportation Safety Board found that newer batteries are less likely to ignite or explode than older or used batteries. Therefore the risk potential will become greater as a growing number of used electric vehicles and lithium-ion batteries are in circulation.
Battery malfunction often occurs during or following a charging cycle and can be intensified by faulty battery cells. The failure rate of lithium-ion batteries is low, but as the industry grows, so does the potential to manufacture uncertified batteries and devices.
As there is no unified regulation in this area, individual shipping companies are implementing their own requirements and best practices. Some shipping companies only approve electric vehicles with a desired state of charge of 50% or lower, while others have already installed CO2 fire suppression systems to ensure safety.
Lash Fire and IUMI have recommended that the weather decks of ro-ro passenger ships should have fire detection and remote control fire monitors. However, new SOLAS regulations approved in June 2023 will make it mandatory for all ships built before January 1, 2026, to have these safety measures. The ships need to be in compliance with these regulations by January 1, 2028. The details regarding these regulations are mentioned in the newly-approved FSS Code.
Starting from January 1, 2026, all ships built on or after this date must comply with new regulations. These regulations require the ships to have fire detection and remote control fire monitors on their weather decks from the outset.
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