Fire Safety. Many of our ship's rules have been instituted to prevent fires. Every seafarer is encouraged to learn as much as possible about fire prevention. To bum, a fire needs three elements which are known to be a fire triangle: fuel, heat and oxygen. We can extinguish fire, or prevent a fire, by removing one of 3 elements. You can prevent fires by maintaining equipment so there are no oil leaks and by storing flammable liquids and gases correctly. If the is consuming leaking fuel, we can extinguish the fire by valving out a section of piping so as to remove the fuel source. Most combustible materials can burn only when are warm enough to give of flammable vapors. Cool this materials and the fire will die. You can prevent fires by knowing and maintaining appropriate equipment temperatures and by storing combustible materials away from surfaces that get hot. A fire needs oxygen. If a small fire occurs in the galley, cover the fire with a pot lid. Or use carbon dioxide or dry powder fire extinguisher to smother the fire. Larger fires can be smothered with foam or sand. There are 4 types of flammable materials. Different fire-fighting equipment is used for each type. Class A. Class A materials are made from wood, natural fabrics or paper. Class A fires are fought with water. Class A fire extinguisher is filled with water under pressure. Class B involve such materials as oils, greases, paints, alcohol, flammable gases, and plastics. Class B fire may begin in the engine room, galley and cargo hold. There are 3 kinds of class B extinguishers: foam, dry chemical and carbon dioxide. Class C fires occur on or near live, energized electrical equipment, for electrical fires we must only use an extinguisher with no conducting agent. It must have the class C symbol. There are 3 kinds of class C fire extinguishers: dry chemical, carbon dioxide, and halon. Class D fires involve metals that can burn. These metals include magnesium, sodium, potassium, titanium and aluminum. When they burn, they produce extremely dangerous, high temperature fires that must be suffocated. Only 1 type of fire extinguisher can be used on a class D fire- a dry-powder type. SELF-CONTAINED BREATHING APPARATUS (SCBA) Self-contained breathing apparatus (SCBA) should be stored in a specially marked cabinet or locker. SCBA equipment is also stored near cargo holds containing toxic materials. You must have training in the proper use of this equipment. This training should include actual use of the SCBA equipment. You must know which respirator size correctly fits your clean-shaven face. To wear the SCBA equipment, you must be healthy. You cannot have any respiratory disease or heart ailment. SCBA equipment is used in places where there is not enough oxygen to support life or where there is a toxic material in the air. When worn correctly, the SCBA delivers clean air to your face mask so you can breathe. Improper use of SCBA equipment can cause serious injury or death. A SCBA air cylinder contains a 15- to 45-minute supply of air. Some models supply more than others. If you are working and breathing hard, you will use up the air faster than when you are breathing normally. The regulator, mounted on your belt, controls the airflow rate. An alarm sounds when about a seven-minute supply remains. When you hear that alarm, you must leave the dangerous environment and find fresh air immediately. After using a SCBA, follow your ship's procedures for replacing used air bottles and cleaning the respirator. The SCBA equipment is always stored ready for use, with full air bottles. An air-line breathing apparatus (ABA) is similar to a SCBA. It also supplies clean air to your respirator. The air line is a long hose connected to a bank of air cylinders and to a regulator on your belt. The ABA allows you to work in a dangerous environment for a longer period of time than the single -cylinder SCBA. Some SCBA systems are "dual-purpose," meaning that they work with either an air line or a portable air cylinder. Make sure you fully understand how your SCBA or ABA equipment operates before you use it. Be certain that you recognize the low-pressure alarm. Make sure you also know the procedure for bypassing the regulator in case it fails. FIXED FIREFIGHTING EQUIPMENT Water Sprinkler Systems Sprinkler systems are usually found in crew accommodations, passageways, public spaces, and vehicular decks on ro/ro vessels and ferries. Sprinklers can only extinguish Class A fires. They help limit the spread of all fires by cooling the fire, and they protect people who are using passageways as escape routes. Sprinkler systems are automatic. Each sprinkler head has a "fusible link" made of solder. It is designed to melt at a prescribed temperature and activate the sprinkler head. Note: Sprinkler heads should never be painted, as the paint can insulate the fusible links and interfere with their operation. Fire-Main System: Hoses and Nozzles Every vessel has a fire-main system. It supplies salt water for fire protection to every part of the ship. The fire-main system has pumps, piping, control valves, hoses, and nozzles. It also has a shore connection on each side of the ship. The fire-main system delivers water to fire stations throughout the ship. The fire stations each have a control valve, a hose connection and a hose rack with a fire hose and nozzle. The preferred nozzle is a combination nozzle. It is opened by pulling a lever toward your body after you are properly holding the hose. Never use the lever to pick up the hose. When you pull the lever halfway back, the nozzle delivers the water in a high-velocity fog. When you pull the nozzle all the way back, the water is delivered in a steady, continuous stream. A fire station may also contain a low velocity fog applicator. This applicator is used for Class C (electrical) fires and Class D (metal) fires. Do not use it unless you have been trained for it. Never use a regular water stream or a high-velocity fog on an electrical or metal fire. The wrong water stream could cause you to be electrocuted if you are fighting an electrical fire. The wrong water stream could cause hydrogen gas to be generated if you are fighting a metal fire. Foam Systems Foam systems are usually found in boiler rooms, machinery spaces, and pump rooms. Foam is excellent for fighting Class B fires. Foam is a conductor, however, and should not be used on Class C (electrical) fires. The foam floats on the surface of flammable liquids. It fights the fire four ways: - It smothers the fire, preventing air from mixing with fuel vapors. - It suppresses flammable vapors. - It separates existing flames from the fuel surface. - Because it is mostly water, the foam cools the fuel. There are several types of foam and there are several ways to mix each foam type. You need to receive special training for the foam systems found on your ship. The common foam types are: Aqueous film-forming foam (AFFF) Chemical foam Mechanical foam Each of these foams is made from a foam concentrate. Never combine different types of foam concentrate. Carbon Dioxide (CO²) Systems Carbon-dioxide systems are found in cargo spaces, pump rooms, generator rooms, storage spaces for paints and solvents, and galley ranges. CO² extinguishes a Class B or C lire quickly and leaves no residue. CO² is stored in cylinders as a liquid. It is discharged through very wide nozzles, where it expands into a gas. The CO² gas is heavier than air. It covers the fire and suffocates it. The CO² gas in the quantity delivered by a fixed system is dangerous to crew members. It displaces oxygen that you need to breathe and temporarily interferes with the way oxygen is normally absorbed in your lungs. A fixed CO² system has to be manually activated from a control station outside the compartment where the CO² will be released. The Carbon Dioxide Warning Alarm must be sounded first. If you hear this alarm, evacuate immediately. Halon Systems Halon systems can be found in many of the same shipboard locations as CO²: systems. This includes machinery spaces, turbine enclosures, and pump rooms. Halon is a colorless, odorless gas. When the halon reacts with the flames, it can turn toxic. Halon systems have audible alarms that warn crew members when the system is about to be discharged. When you hear a halon alarm, leave the compartment immediately. Halon is very effective for extinguishing fires. It extinguishes fires quicker than any other agent. There is no reason for you to try to fight a fire on equipment protected by a halon system. Most important is to evacuate immediately when you hear the alarm.