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16 Apr 2018

Fires on board your vessel

Posted in Maritime Industry News by Admin 0

Any fire on board a vessel is a very serious situation. Unless the fire can be quickly put out, there is a risk of it spreading and gaining momentum to very fast becoming a frightening threat to the vessel and the lives of those on board. When a fire situation occurs at sea, there is no fire brigade to call, it is the crew on board who will have the task of fighting the fire, for their own survival and to save the vessel, passengers and its cargo. It is therefore important that the crew are prepared for a fire situation, that they know the means provided for fire-fighting and are able to act with speed and decision. There are a number of built-in safety features on board a vessel, designed to limit the risk of fire and the spread of it, and the crew must have full knowledge of these and maintain their integrity.

Steel separations
One of the reasons for the engine room casing and various decks, bulkheads and staircases being made of steel is to limit a spread of fire. If there is a fire in the engine room, it is important that the fire may not readily spread to accommodation, bridge, lifeboat stations and cargo areas. Likewise, a fire in the cargo areas should not be able to gain access to the engine room, which is "the heart of the ship", where generators and fire pumps, the means to fight a fire, are located.

Therefore, get to know the built-in fire boundaries and maintain the integrity of such separations. Be careful when making alterations on board, and be especially aware that when new cables and pipelines are installed, their passage through steel decks and bulkheads must be made in a fire-proof way, by using the correct fire rated glands.

Air control
The good working condition of air ventilation fire flaps and the emergency stop of fans is essential, and so is the crew's full knowledge of other openings to the engine room that may need to be closed in a fire situation.

During surveys, Maritime Survey Australia has repeatedly seen air ventilator fire flaps which can not be closed and/or secured in closed position. Solidity of fire flaps should be checked and they should be moved regularly and maintained with grease not to freeze. There should also be means to secure the flap handles in a closed position and the open and closed position should be clearly marked. If fire flaps can not be secured, the draft of a fire is likely to throw them open.

If the vessel is fitted with a fire locker such as a CO2 locker, this should not be used for storage of flammable products and other gear. Access to the CO2 room should be limited to authorised personnel, to avoid accidental release.

One should also be aware of all other ways of air inlets to the engine room, such as various entrance doors, emergency exits and skylights. Doors leading to the engine room from the accommodation are fitted with devices for automatic closing. It is important that these are working, and that doors and door frames are not damaged, allowing passage of an air draft. Doorsills and coamings may be damaged by the moving of machinery parts to deck through doors in the engine room, causing obstructions for the full closing of the door. Doors should be tested by releasing them from the open position, to see if they close fully by the automatic device, and there should then be no openings between the door and the coaming.

The full closing of the doors should not be obstructed by the stretching of loose electric cables, hoses, etc., and also these doors should close tightly by their own means.

The engine room is a warm place to work, and the sweating crew may often arrange entrance doors to be kept open by the fitting of hooks, ropes, wedges, etc., to get an additional draft of air. This is often seen especially on doors leading through the steering gear flat. In the case of a fire, such doors may be inaccessible, and the hooks, etc., cannot be released to close the door. Air to the engine room can then not be closed off. Likewise, Maritime survy Australia  surveyors often see skylights or deck hatches at the top of the engine room and removable steel panels for the passing of spare parts being kept open by steel wire slings, etc. In a fire situation one may not remember that such items are kept open, and one may not have access to the location to remove the obstructing devices.

Combustible oil
On board a commercial vessel there is fuel oil, lubricating oil, hydraulic oil - all very combustible and the most likely nourishments of an engine room fire. MSA surveyors have met crew members who do not consider lubricating oil and hydraulic oil to be fire hazards, as such oils are seen to be difficult to light. That is, however, only a question of temperature. In an oil fire it is the gas above the liquid that burns, and if heated sufficiently by a fire, lubricating oil and hydraulic oil also become volatile and fire-hazardous.

All oil supply systems in the engine room are constructed in accordance with NSCV, classification and / or SOLAS rules, and there are built-in protections which the crew should be aware of, understand and respect.

Valves in fuel oil supply lines from day tanks are fitted with remote controls, operated from a location outside the engine room casing, so that fuel supply may be cut in an engine room fire. These devices are regularly inspected by Martime survey Australia's Surveyors and are normally in good working order. It is also important that such remote closing arrangements are clearly marked for the supply lines they serve, in order not to close the fuel to the wrong machinery. One may want to stop the main engine in a fire situation, but possibly not an auxiliary diesel engine supplying power to the fire pumps, for instance.

One breach of safety which MSA surveyors see on board most vessels they inspect is that the lower valve of the level glasses of oil tanks is forcibly kept open. Many crew seem to overlook this item, although it is clearly stated in classification, NSCV and statutory rules that such a valve is to close automatically.

A level glass is needed to check the contents of the oil tanks by daily readings. However, level glasses represent a weakness of the tank integrity, therefore a valve is fitted at the lower end, and provided with means for automatic closing. Normally such a valve is spring loaded and the crew member will have to bend down and keep a pressure by hand until the oil has risen in the level glass. These may take some time to fill up the level glass, and for the ease of work, crew members often secure such valves permanently in open position, by steel wire, blocks of wood, etc., or by ingeniously designed "thumbscrew" fittings.

During condition surveys, MSA surveyors find this serious breach of safety on board most of the vessels having tanks with level glasses. MSA Surveyors have also seen that in reports from engine room fires, there is often described a sudden and inexplicable increase in the power of the fire. One reason for this could be the breaching of level glasses on tanks and lower valves being secured in open position.

MSAs advice on this problem is to fit for instance foot-operated valves to the lower end of the level glass, thus avoiding the need for the crew member to bend down. Superintendents, masters and chief engineers should make sure that such safety devices are not tampered with and the crew member should think twice before securing such valves in open position.

All fuel and other oil pipelines should be maintained in good condition, arranged as required by class and IMO regulations. MSA surveyors occasionally see plastic and rubber hoses being fitted, instead of metal pipes. Such installations are dangerous and a serious breach of regulations. Any flexible coupling must be of an approved type and should be inspected regularly. Use only type 1 SAE J 1527 or ISO7840.

General cleanliness
For a fire to propagate in an engine room, it needs material for combustion. Oil should not be allowed to accumulate in drip trays, gutters and bilges, so a high level of cleanliness will normally be associated with a high level of fire safety. Drain pipes from gutters to oil collecting tanks should be kept open, oily rags should be disposed of in a correct manner and engines and floor plates cleaned regularly. Oily remains in bilges and in other areas below floor plates may at times need chemical cleaning to be removed.

In some vessels there is a large collection of used spare parts and items which are "nice to have". MSA surveyors have seen large collections of plastic sheets, cardboard, wooden planks, used paint tins, etc., being stored in fire-prone areas. "Good housekeeping" is a key word! Discard combustible materials, remove outdated equipment that may hinder access in a fire situation and enforce a high level of cleanliness. It is not particularly smart to store combustible materials behind an electrical switchboard, close to the exhaust pipe of a Diesel engine!

Sources of ignition
The sources of heat most likely to start a fire in the engine room are hot exhaust pipe and engine surfaces, bearings of rotating machinery heating up and defunct electrical equipment. Heat sources can of course also be introduced by human error, for instance the dangerous use of electric tools and welding equipment.

Insulation or lagging of exhaust pipes is often found to be defective, especially in the vicinity of the diesel engines, where removal of insulation is needed during engine maintenance. Also, flange connections and steel supports of exhaust pipes may often be inadequately insulated, as well as indicators and other instruments fitted. Look for signs of hot areas, such as paint discolouration and reddish rust surfaces.

Electrical installations will always represent a certain risk of sparks and fire, although the risk is reduced by the use of quality safety devices and close adherence to valid regulations. When a vessel is delivered from the yard as a new build, the electrical installation is normally in good condition, well tested by competent personnel.

The electrical installation on board a vessel is regulated by  NSCV, Class and SOLAS rules. A "megger test" by crew or shipyard and a superficial visual inspection by the surveyor is often all the attention the electrical installation receives. Thermographical examinations are considered a much better means for checking the fire risks of electrical installations, and such technology is now easy to obtain

MSA surveyors see a lot of dangerous, "home-made", electrical work on board older vessels. It must be emphasised that only qualified personnel should be allowed to work on electrical installations, only quality electrical fittings should be used and valid standards should always be followed. MSA recommends that you follow AS3004.

All rotating machinery may also represent a source of sufficient heat to light a fire, first of all by bearings of pumps, etc., heating up. Alertness and proper maintenance are key.

On larger vessels, a crankcase explosion is a particular danger when main bearings of a diesel engine crankshaft become damaged. The premature opening of crankcase doors following an oil mist or high bearing temperature alarm has been the cause of more than one engine room fire.

Fire-fighting capabilities
The standard equipment used for fighting a fire in the engine room of a ship is hand-held fire extinguishers, a large capacity extinguisher, fire pumps and fire hoses, and the fixed fire extinguishing system. This article will not discuss the advantages and disadvantages of various extinguishing media, but only highlight some observations made as to the practical use of the equipment.

  • Hand-held extinguishers should be in good condition, and stored correctly in locations as designed on the vessel's Fire Plan.
  • A fire extinguisher is not a place to hang coveralls etc. It should be easy to find and readily accessible.
  • The extinguishing medium should be compatible with the most likely fire risk, i.e., oil, electrical, etc., and the extinguisher should be regularly checked for full content.
  • The large capacity extinguisher has often been of a type very difficult to move around, so its location is of interest. Also, during fire exercises, one should test out how to best move the extinguisher around. Today there are also foam applicators installed which are easier to operate, with hoses on reels that can be easily rolled out, and which can be connected to any fire hydrant - a very efficient tool for fighting a limited fire. Again, it is important to have training on how to put the equipment into use at short notice.

Investigations have shown that in many engine room fires it has taken too long for a decision to release the fixed fire extinguishing system to be made, an average of more than 30 minutes since the fire has been discovered. Often that is much too long, because the fire may then have taken full control. As for the fixed fire extinguishing system, MSA surveyors see CO2 installation that require the operator to be most prudent more than any other system in use. Such a system requires all personnel out of the engine room before the gas is released.

A good reporting and head counting system is therefore essential in reducing the time needed for the release. Decisiveness in the use of the CO2 system and a full knowledge of how the system is operated are also key factors. It seems that the costs of refilling the CO2 system may sometimes also be a consideration, but it should not be. Once manual firefighting has been tried without success, use the main system before the fire turns catastrophic. However, do not release the fixed fire-fighting system in a panic, be aware of what you are doing, as the system can only be released once.

On many vessels, MSA surveyors find that the fire equipment is on board, still wrapped in its original packing. Obviously no one has ever tested it out and the equipment is not being used during fire exercises. It should of course be readily accessible and designated personnel should train in its use and also know its limitations.

it is the crew on board a vessel that will have to fight an eventual fire, and their success largely depends on dedication, knowledge and regular realistic exercises.

 

Fire / Explosion insurance claims frequency by vessel type:

Source: The Nordic Association of Marine Insurers (Cefor)

 

Fires on ro-ro vehicle decks 1994-2011:

Source: IMO-FSI Correspondence Group on Casualty Analysis, November 2012

 

 

 

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