Automotive sector fires: Challenges and potential fire detection solutions
21 July 2015
The potential cost of an automotive manufacturing plant fire ensures that safety, detection and preventive measures should never be compromised. Fires such as the one in 2012 at BMW's Tiexi (China) plant and the automotive parts plant in Revesby near Sydney (Australia) demonstrate the consequences of a major conflagration. Michael J Pickford of FireVu discusses challenges and potential solutions for the sector.
Automotive manufacturing fires do not always make the news. There is understandable sensitivity around these incidents, and often companies will not want them to be made public. But when they do reach the media, the illustration of the devastating costs of a fire can be illuminating.
BMW's Brilliance plant in Tiexi, China – a 1.5 billion Euro investment - suffered a large fire just two months after opening in 2012. The fire lasted nearly three hours before being extinguished by more than 100 fire crews.
BMW tried to play down the incident, claiming the fire was quickly brought under control and manufacturing would continue as normal. The alternative view, voiced by Chinese media, estimated that the damage could reach 100 million Euros.
While the big manufacturers make the biggest headlines, we should not overlook the effects of automotive supplier manufacturing fires. These can be even more devastating to the industry.
German chemical manufacturer Evonik Industries AG produces an obscure chemical called CDT. When a fire engulfed its Marl factory in 2012, a good proportion of automotive production worldwide was threatened. CDT is used to manufacture a resin called PA-12 that is essential to brake and fuel line production for cars -a third of the world's automotive industry supply came from that one source.
The fire led to as many as 200 automotive industry representatives meeting secretly in Detroit to try to hammer out an industry-wide emergency plan to deal with the shortages.
Even a minor fire could prove costly, and any disruption is going to hit the bottom line.
For instance, the 4,000 workers of BMW's Oxford plant annually make around 200,000 customised MINIs for consumers across the globe. Any disruption, such as a precautionary fire evacuation, can be measured in the hundreds of thousands of Pounds. The unnecessary release of fire suppressants can be just as costly. These are hidden issues, but there is no doubt that such incidents plague manufacturers.
The dangers inherent in manufacturing processes
The sources of danger are as diverse as the many different processes within plants, but certain core dangers can be identified. These include ball bearing and other components failures, production techniques that create intense energy often in close proximity to flammable debris that can accumulate over time, the use of lubricants and sprays and conveyor belts jamming.
Then the manufacturing safety professional must consider the space that car making plants occupy: the height of assembly areas and the large ground area they cover. We can also factor in storage spaces for flammable and volatile chemicals and substances, and holding areas for finished products before they are distributed. Also, many of these areas are unmanned for long periods.
Fire detection technology standards
Fire detection for UK manufacturing environments is governed by BS5839.
This requires a qualified professional to be responsible for conducting a risk assessment. If no-one is assigned to the task, the responsibility will be moved up the hierarchy as high as director or even owner level.
BS5839 requires that an assessment of the level of protection is made. The highest level – L1 – includes automatic fire detection in all rooms, on all escape routes and in all voids over 600mm in height. Sounders positioned throughout the building must achieve a minimum of 65dB(A).
This UK standard will have its equivalents elsewhere in the world, which may well differ in detailed requirements.
Fire detection options
The following three technologies are the key solutions used for early detection of potential fire danger within the car manufacturing sector.
1. Infrared Detection
Infrared detectors (IR) are simply transducers of radiant energy, converting energy in the IR spectrum into a measurable form.
Detecting IR energy emitted by objects takes away reliance on visible light and so obscured conditions should not affect its effectiveness, although thick smoke is an issue, as is oil and grease. A direct line of sight is required.
Most IR detectors are designed to ignore constant background IR radiation, and focus on the modulated part of the radiation. When exposed to modulated non-flame IR radiation such as sunlight, IR detectors become more prone to false alarms.
Operator verification ensures appropriate action can be taken, minimising false alarms.
2. Aspirating Smoke Detectors
Aspirating Smoke Detectors (ASDs) work by assessing the presence of smoke particles suspended in air that have been drawn through sample holes in a pipe network into a detection chamber.
VSD - Coloured segments show smoke building up
ASD is highly sensitive, often detecting smoke before it is visible to the human eye, which is particularly valuable in slow growth fires or where a fire develops in inaccessible or obscured locations.
However, the sensitivity to distinguish between smoke and dust in early stage fires can be compromised, as the size of dust and smoke particles can be similar.
There are technological approaches to reduce nuisance alarms, but compensatory technology may impact the sensitivity of a smoke detector and early warning reliability.
Future integration of ASD with intelligent detection systems, including remote monitoring and verification, will improve its effectiveness.
3. Video Smoke Detection
Video Smoke Detection (VSD) is a proven technology and detects danger by looking for smoke patterns, often at points that might be particularly vulnerable to fire risk.
Rather than waiting for a signal to trigger specific sensors, VSD can offer early warnings by cameras pointing at the subject space and looking for changes in variables. Problems arising from smoke stratifying and not reaching detection equipment are eliminated. It can also survey large open sites remotely.
If a complex has areas that could trigger alerts from signals that might resemble smoke, such as dirt from recycling plants, then such areas can be isolated. This allows safety staff to concentrate on the key danger areas.
Safety operators can work on site or remotely. With high quality video, they can determine if an alert is a real fire risk and take appropriate action. Alerts can be studied after the event to improve safety.
All manufacturing sectors are at risk from fire, but given the complicated supply chains and potentially massive consequences of disruption, car manufacturers and component suppliers have more to lose than many, as those dependent on Evonik Industries found to their cost.
This makes it particularly important that risks are fully reviewed, dangers assessed and systems put in place to detect and suppress fires at the earliest possible stage.