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Fire fighting systems for machinery spaces based on latest IMO SOLAS standards By George Dicker, International Sales & Marketing Manager, Unitor Ships Equipment From July 2002, a revised set of IMO Safety of Life at Sea (SOLAS) standards for engine room protection becomes applicable for all vessels whose keel is laid after that date. Vessels requiring change The new SOLAS requirements are defined in the new IMO paragraph Amendment 2000 Chapter II-2 Regulation 10.5.6: -This paragraph shall apply to: Passenger ships of 500 gross tonnage and above and cargo ships of 2000 gross tonnage and above constructed on or after 1 July 2000; and Passenger ships of 2000 gross tonnage and above constructed before 1 July 2002, provided that such ships comply with the requirements of this paragraph not later than 1 October 2005 -Machinery space of category A above 500 m3 in gross volume shall in addition to the fixed fire-extinguishing system required in SOLAS chapter II-2 regulation 7 or SOLAS Amendment 2000 chapter II-2 regulations 10.5.1, be protected by a fixed water-based or equivalent local application fire-fighting system. Areas to be protected -The fire hazard parts of the internal combustion machinery used for the ships main propulsion and power generation; -Boiler fronts (burners) -The fire hazard portion of incinerators (burners) and -Purifiers for heated fuel oil Fire protection system objectives The primary objective of the fire protection system is to achieve a reduction in heat output from the fire and gain control of the fire in order to reduce the flame area and restrict it’s spread. The need to suppress the fire should not prevent the ship from being manoeuvrable, nor should its main power be lost. This does not imply that the ship, having suffered a fire, should be able to go on trading or that all the electrical generators should be operational. The equipment to be protected can be divided into critical and non-critical. Critical equipment is described as equipment that if shut down would cause a loss of power or could prevent the main engine from operating and thus loss of manoeuvrability.

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There are several needs above the objective that it must be met: • The system must operate without shutting down all power • Personnel can work in the protected space without protective equipment • Machinery space ventilation must remain operative, or a shut-down devise

must be installed that closes vents upon release of the system • The machinery space need not need be sealed (required when a gas

based fixed main flooding system is released) • When released, the system will not endanger life • This system must be able to run for at least 20 minutes • The system must be compatible with the fixed main fire fighting system

selected for the protected spaces Further, the system must be able to operate using fresh or salt water, with or without additives. The water supply can be from inside or outside of the machinery space. Any form of non-harmful additive can be used. The system can share common components from the fixed main fire fighting system. Components are to be fully tested, and the system independently tested to all stated IMO circulars. All system components are suitable for intended use, with attention paid to the prevention of pipe blockage. The system shall have its own detection and alarm system that gives warning of release. The system can be released either manually or automatically. Low-pressure systems are the preferred solution in the long run. Such systems are based on a simpler design, the components are less costly and the nozzle design is robust. The practical installation parameters are also addressed in the new SOLAS standard also addresses practical installation parameters with respect to nozzle location in relation to the protected equipment. “The system must not interfere with equipment maintenance, overhead hoists or moving equipment” The single system approach, with a uniform nozzle and limited pressure variable throughout the system provides the simplest installable and maintainable system over the life of the vessel (same nozzle design throughout the system). This provides a design that fits most vessel space arrangements while at the same time reducing the need for onboard spares and specialist skill to install and service. Vertical and horizontal nozzle placement is determined as part of the system testing requirements and in according to the following parameters:

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PROTECTEDOBJECT

1.5 m

16,0 m

PROTECTEDOBJECT

1.5 m

16,0 m

Minimum Height Deck head in generator or purifier areas Maximum Height Deck head or space above main engine crane, or hoist. Pressure rates Nozzle pressure range: 4 to 6 bar. Minimum nozzle height @ 4 bar is 1.5 m. Minimum nozzle height @ 6 bar is 2 m. Maximum nozzle height all pressures is 16 m. “Nozzles to be located vertically above the area to be protected and spaced in accordance with test results” The purpose of system testing is to determine the optimal location and number of the nozzles and limiting over-spray onto nearby equipment. The addition of foam can be seen to have a beneficial effect on the system performance whilst also enhancing the performance which may not have been envisaged when the system parameters where first set.

Test results from Unitor show that nozzles can be spaced up to two meters apart and at the corners of the protected equipment. Adding foam reduces the risk of pool fire and the time needed to surpress the fire.

Alarms Independent visual displays and audible warnings are included in the system requirement. The alarm must be located in a protected space at a main station and give a clear indication what zone(s) is/are released. This is an

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additional requirement to the alarm and detection system specified in SOLAS Regulation ll. Detection The regulation calls for a minimum of one unit per protected area. However the nature of the system, the equipment to be protected and interpretation of the rules indicates that two detectors will often be required, selected from the following (when two detectors are required, they should be different from each other): Smoke detectors respond to general condition in the area Flame detectors can be directed to deal with an isolated location Infrared units can detect through background smoke Areas to be protected The main consideration for electrical equipment protection is whether it is critical or not. If not critical, current approved enclosure standards should be employed. Boiler Fronts This equipment is not considered critical unless it is the only supply of trace heating to the fuel line for the main engine. In most cases, enclosure of IP22 is expected to satisfy this requirement. The location of the boilers suggests the main fire detection method can be limited to smoke detection. Incinerators Incinerators are not considered critical. Electric enclosures with smoke detection and the primary fire detector are recommended today are expected to be in compliance. Purifiers Main engine fuel oil purifiers are considered critical equipment. The current electrical enclosure standard appears to be IP54, and thus no additional requirements for protection are envisaged. The nature of the equipment suggests that a doubling of the detection equipment would prevent accidental release or release caused by a near by fire. Smoke and a flame detectors could be a viable solution. Main Engines The maneuverability of the vessel is crucial, so fire protection equipment is considered critical. Electrical equipment in the fire hazardous areas of the main engine are limited to detection and monitoring, and albeit important, not critical to the maneuverability of the vessel. It expected that a dual detection system would be employed to limit the possible accidental release of the system and flame or infrared detection with or without smoke detection is expected to be the preferred solution.

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Drives and generators Maintaining the power supply of the vessel is criteria, but this does not mean that the generator that is on fire must continue to run or that the fixed local application fire fighting system must continue to operate. Electrical equipment on a generator driver is limited to detection and monitoring, and albeit important but not critical to the supply of power to the vessel. The generators are not part of the equipment to be protected and at best may be subject to over spray from nozzle located over the drive. The electrical components of the generator are well insulated and thus IP22 protection should be adequate. Some generator arrangements have shrouding and may be considered as preventing overspray to nearby equipment. It is expected that a dual detection system would be employed to limit the possibility of accidental release of the system. Flame or infrared detection with or without smoke detection is expected to be a preferred solution. “Compatibility of the local and main fixed fire fighting systems needs to be considered” The machinery spaces of a modern vessel are protected with a manual arrangement consisting of a fire main with hose stations, a range of strategic position fire extinguishers of different types, which is supported by two fixed fire fighting systems. The first is a local system with a detection and release arrangement, supporting a main flooding system as the final resort. The main flooding system to day is mainly Gas (CO2) or high expansion foam using inside air (HotFoam), for smaller machinery spaces water mist is a possible solution. CO2 To day its normal the high pressure system, with system up to 300 and 400 cylinders, These systems need to be stored in its on insulated space, with both local and remote time delayed release mechanisiums. The gas is distributed to the protected spaces by high pressure, code weld piping, which terminates in the bottom of the protected spaces HotFoam HotFoam is a modern, high expansion foam solution that uses inside air and distributes foam from a number of strategically located generators positioned inside and at the top of the protected spaces. The system fills spaces at greater than 2 meters per minutes. This means that an engine room is filled within ten minutes. The system can be zoned to give a greater flexibility of operation. Compared to CO2, the system requires much less storage space and uses low pressure piping that does not need to be code welded. Piping required is also a lot less than with a CO2 system, since the piping is at the top of the protected space.

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HotFoam is an ideal alternative to CO2 when cargo hold protection is not required. HotFoam also has zero effect on GWP or the ozone and when released does not present any threat to humans. Supportive Documentation A technical data sheet on Unitor’s fixed fire fighting systems can be obtained at directly from Unitor’s corporate web site at http://www.unitor.com/. Select Products & Services > Literature. From here you can download a PDF copy of the information you need. Further information on fire extinguishers, hoses and safety equipment for engine rooms can be found in Unitor’s online catalogue and search facilities at Unitor Electronic Catalogue The Unitor web site also contains links to the main classification societies, where additional information can be found on the latest SOLAS needs for engine room fire protection system.