IMO ruling on fire protection should favor water mist techniques

Marioff was founded in 1985 and from its base near Helsinki has established itself as a leading supplier of water-mist fire protection systems for use in buildings, ships, and the oil and gas industry. Its products have now been installed on over 100 offshore platforms and in more than 250 ships.

To illustrate the breadth of the company's activities, recent contracts have included systems for the National Portrait Gallery in London, the world's largest cruise liner, the 142,000 ton Voyager of the Seas, and the gas turbine spaces on Shell's Shearwater platform, soon to enter production in the North Sea.

A recent ruling from the International Maritime Organisation (IMO) could mean further business for the company. The IMO has stipulated that carbon dioxide-based fire protection systems in common use in ships' engine rooms must be backed up by local protection systems employing water to provide immediate defense against any fires that should occur. The ruling applies to spaces over 500 cu meters and covers passenger and cargo vessels as well as mobile offshore drilling units.

Paradoxically, the mechanism by which carbon dioxide systems are effective exposes people unlucky enough to be in the area of the fire to additional risk. Since the environment is quickly starved of oxygen, anyone trapped in the vicinity is in grave danger of suffocation. Consequently, before the carbon dioxide can be released, engines have to be shut down, personnel evacuated, and the space sealed. According to Petteri Saarinen, Vice-President of Marioff's land and offshore division, this process can take up to 20 minutes, during which the fire may develop freely.

The company's systems have been tested successfully against the IMO guidelines that pertain to local protection systems (IMO MSC Circ. 913) and have been granted Lloyds and DNV certificates of approval. Marioff appears to be the first company to reach this stage.

Saarinen said: "Although the ruling does not apply to fixed offshore platforms, we believe there are similar cases on some installations where carbon dioxide provides the main protection and where back-up water-based systems could be of value."

Marioff fire suppression systems are already used routinely to protect machinery spaces on offshore platforms. In the past year, the company has supplied 17 separate units to a leading Danish offshore operator and six have also been included on the recently completed Shell Shearwater platform. The platform forms part of a field development that has been characterized throughout by a very sharp focus on health, safety and environmental issues.

Self-contained water-mist systems, powered by their own dry nitrogen gas propulsion units (a concept developed a few years ago by Marioff) have been incorporated into the acoustic hoods on three compressor and three generator drive turbine packages supplied by Solar. The possibility of low ambient temperatures has meant the systems themselves have had to be enclosed within stainless steel, weatherproof cabinets with built-in heaters.

UK Sales Director, Ray Ackland, was responsible for Marioff's input to the project. He highlighted the fact that the systems were designed to comply fully with factory mutual approval criteria for this type of application, with customized interface and operational features designed to meet the client's own requirements for fixed fire protection systems.

"In critical situations like this, customers can now specify proven systems, which meet internationally recognized standards and provide significant safety and environmental advantages," he said.

Marioff's strong position in the market is heavily reliant on its proprietary Hi-Fog system, which it has extensively developed over the past several years. Incorporating specially designed spray heads and powered by either electric motors or compressed gas, the systems use only a small amount of water, which saves on weight and limits the amount of damage incurred by equipment and in surrounding areas. The company claims the fact that the systems use a minimum amount of low diameter pipework and widely spaced nozzles renders the systems cost-effective to install, especially when retrofitted.