In the latest TT Talk from international transport and logistics industry provider of insurance and related risk management services, TT Club, managed by Thomas Miller, the Club has reported on the frequent occurrence of explosions and fires in containers.
The Club reported sources suggesting that container fires might occur on a weekly basis, with statistics indicating that there was a major container cargo fire at sea roughly every 60 days.
There had been several well-publicized ship-board explosion and fire incidents involving laden containers over the past few years. As the size of container ships increased, so did the potential risk and consequence of a large explosion or fire incident.
The Club said that, despite certain regulatory and technical advances, there was little doubt that the capability to respond to a cargo-related fire at sea had not progressed in proportion to the increase in ship capacities and the variety of commodities being carried.
In the event of an incident at sea, TT Club said that the crew would do all that they could to control the incident. To help deal with a fire in a hold, a carbon dioxide (CO2) system would normally be installed if the ship was carrying dangerous goods. However, for CO2 to be effective, the hold would have to be sealed to retain the gas and prevent oxygen ingress. Following an explosion in a hold, the structure might have been damaged or hatch cover pontoons displaced, making the retention of CO2 impossible. In addition, hatch cover pontoons were not designed to be gas-tight, only weathertight, and thus it was likely that the CO2 would escape over time.
CO2 also has virtually no cooling effect on combustion, which meant that if oxygen re-entered the hold after the CO2 had been deployed, the fire might redevelop. Finally, a CO2 system would not be effective in controlling fire incidents involving hazardous substances that produce oxygen during decomposition.
In the case of an incident on a deck-stored container water would be the only option available to the crew as a first line of defence. Water could be beneficial as boundary cooling, and assisting in minimizing fire spread, it was unlikely to extinguish a fire inside a container in the short term – and the risk of cargo misdeclaration meant that water firefighting came with associated risks and generally might not be appropriate.
Seeking expert advice would be essential early in the incident. The expert would need to be provided with as much information as possible, including the location of the fire, the extent and description of the incident and, as a minimum, a copy of the cargo manifest – particularly the location of containers declared as carrying dangerous cargoes.
If the fire was in a hold, flooding of the hold with water might be considered, to above the level of the containers involved. But this would bring many additional problems. There was the risk that that more damage would result from the water than might have occurred from the fire. The packaging of various cargoes could be compromised by water, or explosion, or fire, it was likely that flooding the hold would produce a ‘chemical soup’ with contaminants from a multitude of cargoes. This could result in toxic substances or gases produced by mixing or decomposition of the various cargoes.
In addition to the potential for toxic substances and gases to be produced by the ‘chemical soup’, other cargoes were quite likely to be affected by heating or burning, also changing their properties and hazards.
Once an explosion or fire occurred, an investigation into the cause would normally be required. This could be a very complex and protracted operation in the larger incidents. Most investigations would follow a basic format. The starting point would often be witnesses or electronic evidence. – ‘where, when and what’. “As a lot of crew members now own mobile phones, photographs or videos of the early stages of an event are sometimes available”, TT Club observed.
Detection systems could also provide valuable information, such as where the smoke or fire was first detected. If the detection system was a gas extraction system samples or residues could be obtained from the inside of the extraction pipe work. Engine room alarm logs could provide indications of other system failures, such as the electricity supply to hold lighting.
Once the available witness evidence had been collected, an examination of the physical evidence would take place, including damage to the ship structure and containers. This might provide directional indicators of blast and or fire movement and intensity. Samples would be taken for laboratory analysis. This could be very complex, often involving a mix of substances, including both the original cargoes and the decomposition substances created in the incident.
Given the potential complexity and the extent of a large explosion on a container ship followed by a prolonged fire, a multi discipline team might be required, possibly including:
• Fire investigators
• Cargo scientists
• Marine engineers
• Naval architects
The Club observed that, due to the implications to the safety of the crew, the ship and the environment, prevention was much better than cure. It noted that much effort was underway internationally between the different stakeholders to prevent such incidents. This ranged from looking more closely at all elements of the cargo shipping process as well as seeking strengthening of ship-board processes.
Dave Myers, Fire Investigator, Brookes Bell (a member of the Thomas Miller Group), assisted the Club with the production of the article.