Ensuring fire safety in the marine environment
Published: 01 June, 2007
In such a hostile and challenging climate as the marine environment, it is imperative that the most appropriate fire detection system is chosen and that it is fit for purpose.
The salt-laden atmosphere is corrosive and makes it an extremely harsh place for sensitive electronic devices. The type of structures commonly found in marine locations, such as shipping, chemical processing plants and off-shore oil rigs, can also present vibration and noise levels that are higher than average. In addition, these locations often have limited installation space and there can be issues with limited power supply.
While corrosion, vibration, noise, cramped conditions and power issues are common factors, the term ‘marine’ can apply to a whole range of different situations with their own particular requirements. For example, in-vessel fire detection alone can range from a small transfer vessel with simple fire alarm requirements to supertankers that may require a more complex approach involving fire detection, voice evacuation for a multilingual crew and interfaces with other critical equipment such as air conditioning.
Indeed, large commercial and industrial vessels demand devices that are not only discreet enough for installation in public areas and cabins, but are also sufficiently robust to withstand the rigours of the engine rooms, laundries and kitchens. On modern ocean-going fishing vessels, the demands are equally varied. The ship is effectively an ocean-going processing facility with crew quarters, production areas and freezers - and the fire detection products have to meet all these requirements.
Industrial complexes are often located in marine environments in close proximity to docks or to incoming pipelines. Processing plants associated with onshore and offshore oil and chemical processing are prime examples. Again, the range of demands can vary from communal staff areas and plant rooms to production areas.
Potenially explosive atmospheres
In some marine environments, intrinsically safe fire detectors may be required for potentially explosive atmospheres created by the presence of flammable gases, vapours, mists or dusts. These devices will never create a spark even in the highly unlikely event of a fault.
The ATEX Directive 94/9/EC, adopted in 2003, harmonised the technical standards and legal requirements for products intended for use in potentially explosive atmospheres across the EU. Products complying with the ATEX Directive carry the CE Mark, which signifies that essential health and safety requirements have been met. Clearly, it is important that any devices selected for use in potentially explosive environments are compliant with the Directive.
It is also critically important in industrial applications of any type to avoid unnecessary interruption to production and that assets are adequately protected from fire risk. To achieve the right balance, it is necessary to ensure that the performance of the fire detection system is not adversely affected by its environment and that it is equipped to minimise the likelihood of false alarms. The addition of a marine environment into the equation demands a more rigorous assessment of likely sources of fire risk and installation issues to arrive at the correct product specification.
Fire safety in practice
Fire detector manufacturers use product design and development to address the technical and practical issues that arise in marine applications. For example, there are the physical space restrictions to take into account in confined living and working conditions. Some marine fire detectors, like Apollo’s Orbis marine range, now feature a low-profile design that is useful in areas with low ceilings or limited headroom.
While conventional fire detectors are sufficient for smaller marine applications, analogue addressable fire detectors are best suited to larger vessels and marine structures with more complex requirements which might include the need for phased evacuation, or interaction with other safety devices to isolate the seat of a fire. Apollo’s Discovery marine range is one example of the intelligent fire detection products currently available. Discovery detectors offer five selectable response modes, so are highly adaptable to the varying operating environments that can be encountered on marine applications. They also feature drift compensation and day/night switching for increased reliability.
Apollo Discovery marine fire detectors have recently been installed to protect the largest lifting vessel in Asia - a floating crane that can lift up to 4,000 tonnes in weight. The six loop fire detection system includes over 400 Discovery marine devices as well as some intrinsically safe fire detectors for hazardous areas.
As well as paying attention to the fire detectors themselves, there are ancillary products that can help in marine environments.
These include beacons and sounders that are loop-powered, which means they require less energy to operate and can be very helpful in areas with a limited power supply. Ingress of water into fire detectors is another risk in marine environments and devices like Apollo’s Deckhead Mounting Box are designed specifically to prevent contaminants entering through the rear of the base.
However sophisticated the fire detection system, specifying the best available technology is only half the story. Regular maintenance is equally important - particularly in harsh operating environments. The inherent problems of extremes of temperature, humidity levels, exposure to chemicals and other issues such as salt corrosion can affect the normal operating of systems.
The reasons for maintaining a fire detection system are twofold. First and foremost, there is a duty of care. This is life-critical equipment and if the fire detection system is not functioning correctly when a fire breaks out, people could suffer severe injury or even death. No-one wants that on their conscience. Secondly, there should be a healthy degree of self-interest involved in the decision to maintain a fire detection system, to protect valuable assets.
Over the past ten years, Apollo’s certified marine fire detectors have been used in a whole range of marine applications, from commercial tuna fishing vessels in New Zealand worth in excess of £6 million to a major oil and gas site off the Japanese coast.
Apollo predicts that the demand for marine fire detection products is set to continue, particularly in areas with rapidly growing economies. The US and China are particularly strong markets for marine products at present - Chinese shipyards have full order books for the next four to five years.
From a technological perspective, the trend with marine detection is following a similar pattern to that of ‘standard’ fire detection products. With both the main product ranges and solid partnerships in place to develop total fire detection solutions, fire detector manufacturers are beginning to develop more application-specific devices. These include sounders and flame detectors for marine environments.