TT Talk - It pays to understand the characteristics of cargo you handle

Safety issues concerning lithium-ion batteries have come to the fore in relation to the new Boeing 787 Dreamliners, mentioned below; these raise questions for the handling and transport of large quantities of these batteries and other cargoes where there may be limited industry experience.

On 7 January 2013 a lithium-ion battery overheated and started a small fire in an aircraft that was on the ground at Logan International Airport in Boston. On 16 January 2013 an All Nippon Airways plane made an emergency landing at Takamatsu Airport, Japan, after it is reported that controls showed an error message regarding a battery malfunction and a smell was detected in the cockpit. All airlines, owning 50 Boeing 787 Dreamliners in total, grounded their planes. The Japanese and US aviation authorities are carrying out investigations into the incidents that have occurred.

Furthermore, ICAO has withdrawn permission to carry even small amounts (up to 35 kg) of lithium-ion batteries as cargo. At this point, it seems that the IMO is not undertaking a similar review of the carriage of batteries aboard ships, beyond what is already stated in the IMDG Code.

The lithium-ion batteries are used in the Dreamliner to power control systems. The use of these batteries is to make the planes lighter and more fuel efficient. Lithium-ion batteries have a high energy density which means they have more energy output per weight than other types of batteries. This is what makes them a good choice for use in portable electronics, such as mobile phones and laptops, and in this instance reduces the weight and fuel requirement for the Dreamliners. They are also used increasingly in the automotive industry, including to power electric vehicles.

The risks in this recent case and with portable appliances appear to be associated with charging the batteries, whereas incidents in the supply chain are likely to be connected to their charged condition as shipped and greater energy density, combined with rupture, ignition or explosion. Self-heating can occur when the batteries are exposed to a high temperature. Overheating or overcharging can potentially lead to 'thermal runaway'. When this occurs the heat generated by a ruptured battery cell can cause additional surrounding cells to become involved in a cascade effect. Metal impurities in the electrolyte of the batteries can also potentially cause short circuits.

Previous alerts have highlighted a number of incidents arising in the supply chain involving Nickel Metal Hydride (NiMh) batteries between 2000 and 2010. NiMh batteries use an entirely different chemistry to lithium-ion batteries. Most, if not all, of these cases were settled out of court as the battery manufacturers did not wish their products scrutinised in a public forum the adverse publicity which could result.

The common thread in the battery risk is, however, the effort manufacturers make to improve the energy density. For example, AA NiMh batteries went from 1800 mAhours to 2900 mAhours over the course of ten years. Lithium-ion technology is also packing more punch year by year.

This is, of course, important throughout the supply chain, but perhaps peculiarly for aircraft and ship operators, since lithium-ion batteries are manufactured in the Far East and transported around the globe. There have already been some fires on container ships involving lithium-ion batteries in modest quantities. There is currently no restriction on where these IMDG Class 9 UN 3090 cargoes can be carried. Recommended good practice at sea is that they be carried on deck, away from accommodation and overstowed to minimise solar gain. Until industry experience builds, it may be prudent to consider limiting the size of individual shipments of these batteries.

As lithium-ion batteries represent the chemistry of choice due to the weight and power advantages, it can be expected that the number and volume of shipments will increase. IFIC Forensics have investigated fires in different battery chemistries including lithium-ion batteries. Whilst most of these fires have been in appliances and associated with charging, a number involving shipments of NiMh and lithium-ion batteries have pin-pointed defects in the product or its packaging.

Other products which have a propensity to self heat, both in transit and in storage, leading to significant shipping losses, include activated carbon, calcium hypochlorite, coal and direct reduced iron (the latter two generally but not exclusively being carried in bulk). In general, the safest place to ship cargoes with a known propensity to self heat is on deck overstowed and away from the accommodation. Other, perhaps less obvious, cargoes have given rise to fires, particularly whilst in storage, including cotton, copper, fish meal and wood pellets. The last could be viewed as an emerging risk as part of the range of bio-fuels that are inevitably growing in importance as transported and stored products.

Fire risk, whether in the fixed or mobile environment, is a continuing concern and the results are frightening, injurious and costly. It is perhaps increasingly important not just to know what cargo is being handled but its specific characteristics - and impacts on the totality of the operation under your control or responsibility.

[We gratefully acknowledge the assistance in the preparation of this article of Dr Jim Lygate, Principal Investigator at IFIC


Staff Author

TT Club