Three main causes of fire on board
80 per cent of fires on board occur in three main cases: While cooking in the galley or through improper handling of flammable materials such as gas or paraffin. Cable fires, which are caused by a short circuit and quickly spread to surrounding objects. Or overheating, for example of the engine, which can lead to a sudden development of fire.
Even though it is possible to narrow down many of the causes of fire and take necessary precautionary measures to prevent them, at sea, predicting an emergency is an extremely difficult task. There are infinite scenarios, in which a multitude of different boats, each with their own equipment and crew, make every emergency a unique exceptional situation. All crew members should be familiar with the possible dangers and causes of fires, as well as the extinguishing methods available and how to use them. They should be trained well in advance.
In general, all fuels such as paraffin, gas, methylated spirits, petrol or diesel in cookers and grills, heaters or engine and tank installations pose a fire hazard. Other sources of danger are leaks in fuel and oil lines, filler necks, venting systems, shut-off valves or gas systems. Additional risks come from electrical devices and lines in cookers or engines: Short circuits (chafed wires), incorrect fuses, dangerous wiring (tangled cables), batteries without terminal covers and loose or oxidised connections easily lead to overheating. Open fires such as candles, cookers, grills, spirit or petrol lanterns and lighters are also prime causes of fire. Fires are less common when working with welding and soldering irons.
Take precautions to stay safe
Installing a smoke detector in each cabin should be first on the list of preventative measures for increased safety on board. They sound an alarm as soon as smoke is detected. Permanently live cables, such as the thick feed and discharge lines of batteries, should also be protected by conduit. Chafed insulation can be caused by repeatedly moving components, which in turn results in circuits shorting out. Each vessel also has a battery switch or main switch that immediately stops the flow of current if necessary. The diameter of all electrical cables must be appropriate to the electrical appliance and they must be protected by sufficient fuses. In plastic boats, only 2-core cables should be used. It is better to keep different cables for 12/24 V and 220 V separate and clearly marked. When it comes to fuses, the following points must be observed: fuse each appliance individually, use fuses of appropriate strength and overvoltage protection.
If cooking with gas on board, a specialist should check the system for leaks at least every two years. In some areas, this inspection is required by the authorities and some harbours demand proof of this for so-called "permanent berth holders". The NRW water police recommend that only tested and approved gas cylinders and connected devices such as pressure reducers be used (look for the stamp and GS mark). Boat owners should make sure that there is a safety shut-off valve and that gas cylinders are safely stored. A bottle case must be suitable for storing gas canisters and allow venting to the outside and away from the bilge area. Joints in copper pipes must be hard-soldered and pipes should also be fitted in such a way that they are protected from dynamic stress and mechanical damage. Spare cylinders should be stored with transport protection in suitable places and never in the engine room or ship interior. When not in use, gas cylinders must always be closed. A gas detector close to the bottom of the boat or in the bilge provides additional protection. Escaping gas is heavier than air and collects lower down on the bottom of the ship first.
Many fires develop during the refuelling process. Open fires, lights and smoking are generally prohibited during this procedure. Transportable tanks must be made of fuel-resistant materials and should only be filled on land. They should be firmly secured on board to prevent them from sliding around. In the case of built-in fuel tanks, tank venting should feed away from heat sources. Tanks should also be protected from static charge by earthing. A shut-off valve fitted in front of the tank, which can also be operated from the helm, is ideal. When refuelling, keep an eye on spillages. Overflowing fuel must be removed immediately and the bilge subsequently ventilated if necessary. When filling from canisters, it is essential to use a funnel to prevent fuel from spilling out of the canister opening.
General information on fire prevention
- Ventilate the engine compartment and bilge before and after your boat trip.
- Always empty the carburettor on an outboard motor.
- Open flames (paraffin lamps or candles) must be placed safely, away from flammable objects and in such a way that heat build-up is avoided.
- Heat build-up should also be avoided with electrical equipment. Do not cover devices with luggage or similar.
- Place oily rags in sealed containers, and no open flames in the engine room.
There are, of course, many possible causes of a fire on board. Therefore, every boat owner should be very familiar with their vessel and think about where preventive measures can be taken.
Firefighting and extinguishing agents
Every emergency at sea requires quick and resolute action with the right intervention. Not all fires are the same and each will require a different extinguishing agent, depending on its cause. But one thing is always true: every fire needs oxygen to burn. Cut off the oxygen supply and the flame goes out.
Some vessels have an engine room fire flap, through which an extinguisher can be directed straight into the engine room. This means that the bulkhead does not need to be opened in order to put out a fire in the engine room, which would result in a huge influx of oxygen and cause a backdraft explosion. In some boats, extinguishing systems are therefore permanently installed in the engine room, which automatically put out a fire. If the engine catches fire due to overheating or if leaking fuel has ignited, these devices are triggered immediately and extinguish the fire. Because fires in the engine compartment are often detected very late, such fire extinguishing systems offer a high degree of safety. (A later installation of such systems is usually possible in almost all cases.)
Extinguishing agents & accessories
Fire blankets should be provided as standard on board all boats. They are used to smother a flame, for example if fat ignites in a pan. The best place to keep them is next to the stove, and they should have a ribbon around the edge so that they can be unfolded quickly.
Caution: Do not try to use synthetic fibre blankets or sleeping bags to smother a fire, as they can quickly catch fire and stick to skin.
Fire extinguishers and fire blankets are essential on board a ship. They should be easily accessible, the right size and capacity appropriate to your vessel. On a small boat, where a fire can be discovered quickly and moving around the boat is quick and easy, a small fire extinguisher is sufficient. A smaller device will, of course, also save space. However, on larger boats experts recommend at least a 6-kilo extinguisher. Such devices spray extinguishing agent for ten seconds and will bring most fires under control.
Your fire extinguisher must also conform to relevant fire classes. So-called ABC extinguishers cover three fire classes at once: Solids (A), liquids (B) and gases (C). Almost one hundred percent of fires can be extinguished with such an ABC extinguisher. For the other fire classes D (metals) and F (fats), appropriate fire extinguishers are required, class F fires can be well contained with a fire blanket.
Caution: Under no circumstances should water be used to extinguish fires of the latter fire classes, as this will cause explosions and the fire to spread.
Advantages and disadvantages of the different agents used in fire extinguishers
Fire extinguishers can be filled with different extinguishing agents, which depend on the area of application and the expected cause of the fire. Extinguishing foam is used as an agent for fire classes A (e.g. textiles) and B (plastics, paints, oils). It works by forming an oxygen-impermeable foam blanket, which suffocates the fire. In addition, it has a cooling effect and causes only minor water damage.
Fire extinguisher with extinguishing foam
A special liquid extinguishing agent for fire class F was also developed for use in grease fires. However, this extinguishing agent is now also used in fire classes A and B.
Extinguishing powders have been developed for different applications. ABC extinguishing powder is a universal extinguishing agent for fire classes A, B and C (C = gas fires). When it melts, it forms a salt layer which cuts off the oxygen supply. It has a cooling, suffocating and anticatalytic extinguishing effect. BC extinguishing powder is used in fire classes B and C and is effective in flame fires. D extinguishing powder is used for metal fires.
Fire extinguisher with special liquid extinguishing agent
Carbon dioxide (CO2) is an extinguishing agent used in class B fires to extinguish fires involving flammable liquid substances and flammable gases. Carbon dioxide is a residue-free extinguishing agent and has a suffocating extinguishing effect.
Caution: The use of carbon dioxide as an extinguishing agent requires special caution, because when used in closed rooms, there is a risk of suffocation to any person present. Given the rapid onset of low oxygen levels, people in the room must be warned and evacuated in good time.
Aerosol, or dry mist fire extinguishers are small, potassium carbonate-based particle extinguishers with great extinguishing power. Initially developed for space travel, they are one hundred per cent pollutant-free and can be used everywhere. Because of their quick and easy operation, they can be used as soon as a fire is detected. This type of fire extinguisher is ideal for recreational boating, as they are small and handy and do not damage the sprayed surfaces. Aerosol fire extinguishers can be used for four years for fire classes B, C, F (twice as long as normal foam and water extinguishers). However, there are also significant disadvantages of aerosol fire extinguishers, as they are only suitable for small fires and produce a lot of smoke when used. Larger fires, such as in the engine compartment, cannot be stopped by using a hand-held aerosol fire extinguisher. By far the safest solution here is to install a fire extinguishing system directly in the engine compartment
What to do in the event of a fire
If a fire on board is detected at an early stage, the flames can usually easily be brought under control. However, to be sure that this is the case in an emergency, it is particularly important that the entire crew receive a fire safety briefing from the skipper before the start of the trip. Make sure roles are clearly assigned. In this way a fire can be extinguished quickly and panic on board prevented. The following fire points should be observed:
- If a major fire occurs, the crew must be alerted by calling "Fire on board!".
- The engine may need to be stopped and fuel lines closed.
- Electrical circuits must be disconnected from the on-board power supply to prevent short circuits (operate the main switch).
- All bulkheads and hatches must be closed.
- Move the boat to a heading where the wind will not blow flames and smoke across the deck.
- To put out the fire with a fire extinguisher, approach the fire with the wind behind you.
- Aim the extinguishing agent at the glowing parts of the fire, rather than at the flames.
- Any foam upholstery, i.e., cushions, must be thrown overboard immediately after extinguishing because they will continue to smoulder and are practically impossible to put out.
- Glass resin fires must be cooled with a large amount of water after extinguishing so that the resin can solidify again. Important: Make sure your bilge pump is running.
Experienced fire fighters recommend safety training where you can practise dealing with a fire - anyone who has had the experience of putting out a fire will be well prepared in an emergency.