”Flame Out - Fighting fire on board your boat” ~ by Chris Caswell
When one engine
suddenly stalled on his 27-foot express cruiser
, Dave put the other engine
in neutral and stepped back to check the engine. As he started to lift
the engine hatch
, a sudden warning flashed through his mind and he leaned back as the hatch
opened, a move that saved him from severe burns as a raging fireball erupted into the cockpit
Slamming the hatch back down, he dove for the bridge and pulled the discharge handle for the Halon fire system that was installed in the engine compartment. With his other hand, he grabbed the VHF
mike and quickly broadcast a Mayday call to the U.S. Coast Guard. Well prepared by Power Squadron training classes
, he quickly gave his position, type of boat, number of people aboard and the information that he was fighting an engine room fire and would call them back when it was out.
He organized his wife to get their frightened children
into life jackets and onto the bow of the boat while he gathered up the two fire extinguishers. Cautiously cracking open the hatch again, it was readily apparent that the Halon had worked its magic: the fire was out. Opening the hatch fully to assess the damage, Dave was startled when, with a whuump, the fire burst out again. This time, however, there was no way to slam the hatch so he discharged first one and then the other extinguisher into the blaze. Neither extinguisher, which lasted only seconds, stifled the fire and Dave called to his family
to jump overboard
from the bow, while he did the same from the stern.
From the water
, they watched their boat burn from end to end but the story has a happy ending. When the Coast Guard didn't hear back from Dave, they scrambled a rescue
helicopter, which picked up the family
from the sea.
Dave did almost everything right, with a couple of exceptions. By slamming the hatch back down on the engine, he controlled the blaze and, when he pulled the Halon discharge, it provided the smothering gas that removed oxygen from the fire and extinguished it. Dave was smart to send the Mayday call and take care of his crew's safety
before dealing with the blaze.
But Dave had left one engine running, which, along with the bilge
blower, quickly sucked the Halon out of the compartment. By not waiting until the super hot engine metals had cooled down before opening the hatch a second time, he allowed a rush of oxygen back into the compartment which acted like a bucket of gasoline and the fire reignited.
In spite of being surrounded by fire-quenching water
, fire is one of a boat owner's biggest fears and accounts for hundreds of damaged or destroyed boats every year, not to mention the burns of those on board. Preparation is a key to not only preventing fires, but in quickly stopping them before they blossom out of control.
Start by identifying the potential fire areas aboard your boat. In general, the two most common fire sources are the engine and the galley
stove, so you'll be facing several potential types of fires. Class A fires involve solids (wood, cushions
, and even fiberglass), which can be fought with water. Class B fires are liquids and therefore include gasoline, stove alcohol, paints, solvents, and other volatile fluids which will flare up and spread if you use water. Class C fires involve electrical equipment
, and bring the added danger
shock as well as burns, so water is definitely out.
A fire needs three elements: oxygen, fuel, and heat. Remove any one, and you've put out the fire. Oxygen can be removed by a blanket of gas from a carbon dioxide fire extinguisher or by the layer of chemical powder from dry chemical extinguishers. In the case of a liquid fire, you can often remove the fuel by turning off the stove or fuel line valves, and you can cool down the heat of burning wood or fiberglass
The most common fire extinguisher aboard small boats is the dry chemical canister. With an ABC Tri-Class chemical, it can deal effectively with all three types of fires. Since a 5-pound dry chemical fire extinguisher is emptied in less than 15 seconds, use the U.S. Coast Guard requirements only as a starting point. Boats to 26 feet must carry one B-1 extinguisher, boats 26 to 40 feet must carry two B-1 or one B-11 extinguisher, but these are the minimums. Dave's two legal
extinguishers were useless in 30 seconds, which was far less time than he needed to combat his fire.
Remember that your fire extinguisher is only effective if you can get to it. Mounting a portable fire extinguisher above the stove or in the engine compartment is an invitation to disaster. Put one at the helm
, one in the cockpit
, and one in the cabin
away from the galley
. Since dry chemical extinguishers can be used to form a heat shield, you might also want one in the forward cabin
to help escape a fire that blocks other passages.
If you do have a fire, don't be afraid to use your extinguisher promptly. It's true that a dry chemical extinguisher causes a mess of powder and contaminates food
, but so does fire. Too many boats have been lost
because the crew thought they could put out a galley fire and still save dinner, only to end up eating with the Coast Guard.
It is well worth the investment to use an older fire extinguisher and practice on a beach bonfire to see how it works. Always aim at the base of the fire, and use a sweeping motion back and forth to dust the entire area. Your entire crew should not only know where each fire extinguisher is located, but how to remove it from the bracket, how to pull the locking pin, and how to trigger the chemical.
Alcohol galley stoves often flare during start-up, so keep a pan of water handy to set on the burner and control the flame beneath. This will allow the alcohol to burn out naturally without the risk of spreading to the curtains or padded ceiling materials.
Since the fumes from a cup of gasoline have the explosive power of 11 sticks of dynamite, don't try to be a hero if the fire starts to gain the upper hand. It's always better to be floating in the water watching the fireworks than getting a firsthand look at them.
Remember that it is far simpler to prevent a fire than to put it out but, if you do have a fire aboard, you should have the proper equipment
and knowledge to quickly extinguish it. Several good fire extinguishers will always be the cheapest insurance
you can buy.
by Chris Caswell
From BoatUS “SEAWORTHY” Magazine:
"Your Boat’s on Fire . . . Now What?"
Using the Wrong Type of Extinguisher to Fight a Fire is Like Trying to Dig a Hole With a Rake . . .
BoatUS Claim #9702081C:
The owner and his two friends were nearing the last leg of a long trip from Yorktown, Virginia to Watkins Glen, New York aboard a 46’ sportfisherman that he’d bought barely three weeks before. They were making good time across Oneida Lake when one of the crew left the flybridge to go below. He quickly reappeared on the flybridge: "We've got a problem," he informed the captain, " smoke!" The captain immediately brought the engines to idle and one of the crew tried very briefly to extinguish the fire. Within a minute or two, he was overwhelmed by fumes and had to abandon the effort. After trying unsuccessfully to send out a Mayday on the VHF, the captain ran to the foredeck, set an anchor, and hailed a passing boat by waving a life jacket. Meanwhile, a volunteer fireman saw the smoke from shore and dispatched a fireboat. By the time the fire was brought under control, the boat was destroyed.
Nowhere to hide but over the side. On board fires can quickly rage out of control if the crew doesn't respond immediately with the correct extinguisher. All hands had to abandon ship when this engine compartment fire became too intense for a portable dry chemical extinguisher to tame. Claim #9807387C
Later investigation determined that the electrical panel was the source of the fire. The captain's urgent Mayday call conveys the danger
of all fire outbreaks on boats. Unlike fires ashore, where there are usually several escape routes to safety
, there are few places on a burning boat to hide from the heat and noxious fumes. Add to that the anxiety of standing above many gallons of explosive fuel and the choice to stick or swim (literally) becomes even more, well, problematic.
Time is critical with any fire, but when one occurs in the confined spaces of a boat it is imperative that every move made by the crew be the correct move?there is rarely, if ever, a second chance. BoatU.S. Marine Insurance
claim files consistently confirm that a crew that reacts initially with confusion and indecision is likely to panic as the fire spreads.
Success and failure depends on understanding the fundamentals of fire classification, and providing the most efficient fire extinguishers in the locations where they are most likely be needed.
The Fundamentals: Learning
Your ABCs of Fire Classification
Not all fires should be treated alike. The source and location of a fire will determine which extinguishing agent should be used for maximum effect. Many people learn at home, for example, that throwing water on a stove-top grease fire (Class B) will cause a violent spattering reaction and spread the burning grease elsewhere. Matching the agent to the fire begins with an understanding of how fires are classified:
• Class A fires consist of all combustible solid materials, such as paper, wood, cloth, rubber, and many plastics including the fiberglass
reinforced plastic used for decks and hulls.
• Class B fires consist of all flammable liquids, including stove alcohol, grease, gasoline, diesel
, kerosene, oil
thinners, acetone, varnishes, and flammable gases or fumes.
• Class C fires consist of energized electrical equipment. Class C fires are identified for their potential to electrocute or shock personnel if conducting water-base extinguishing agents are applied. Turning off the electricity will change the status of a Class C fire to a Class A and/or B fire.
Note that Class A, B, and C categories are not subdivided any further, so it may be easier to think of them as (A) solids, (B) liquids, and (C) electrical fires; there's no need, for example, to waste time distinguishing between alcohol or kerosene when your stove’s on fire.
The In's & Out's of Portable Fire Extinguishers
All fire extinguishers are rated according to the extinguishing agent's effectiveness in controlling one or more classes
of fire. For example, ABC-rated extinguishers, commonly called multi-purpose or tri-class extinguishers, are capable of fighting all three classes of fire. Numbers preceding the letters (on portable units only) indicate an agent's relative effectiveness in extinguishing that particular class of fire. For instance, a 10 BC dry chemical extinguisher is twice as effective in putting out a fire as a 5 BC unit. Multi-purpose 1A-10 BC dry chemical extinguishers are becoming more popular as an alternative to the common 10 BC extinguishers because of the additional Class A rating, especially since the additional cost is minimal (less than $5).
In general, dry chemical extinguishers, which use a chemical powder to smother the source of the fire, are the favored choice in the boat’s cabin. Not only is a dry chemical extinguisher more effective, it is easier for an inexperienced user to direct the discharge plume to the base of the flame from a safe distance. Conversely, extinguishers with gaseous agents (CO2, Halon, and Halon replacements
FE-241 and FM-200), which react with the surrounding oxygen, aren’t as effective in a cabin because the gases are often dissipated before the fire is extinguished.
The ABC units have the drawback of often ruining equipment, but because the priority is on safety and the overall effectiveness of the extinguishing agent, the American Boat & Yacht Council (ABYC) recommends that ABC multi-purpose extinguishers be used in most instances on boats under 65'. The ABC extinguishers not only reduce confusion about what to use and where (saving time), but also cover the possibility that, for example, any Class B fire that spreads from the stove to the curtains (Class A) can be fought with the same extinguisher.
A Subtle, but Costly, Distinction
A 42' powerboat was cruising offshore
when a crewmember reported a strange smell coming from the engine compartment. The owner grabbed a dry chemical extinguisher from the galley on his way to the enclosed compartment, opened the access door, and was immediately driven back by smoke. He tried to direct the stream of dry chemical inside the compartment, but he could not see beyond the smoke to locate the source of the fire. By then the fumes had also engulfed the main saloon
and he was driven back. From the cockpit he saw flames coming out of the engine compartment's starboard ventilation ducts, so he directed another dry chemical extinguisher into the duct openings; the fire died momentarily but quickly resumed and grew rapidly. It soon became apparent that the vessel would have to be abandoned. It burned to the waterline. (Claim 9708770C.)
The same dry chemicals that are so effective in a boat’s cabin aren’t much use when a fire breaks out in the engine compartment. The reason has to do with how the two types of fires are fought.
Accounts of engine fires typically began with a warning?a burning smell, a loss of engine power, or even smoke trailing after the boat. If someone then opened the engine hatch to check out the trouble, he or she was usually overwhelmed immediately by flames and smoke. Fires need two things: fuel and oxygen. Opening an engine compartment hatch to look for a fire is like throwing gasoline on hot coals; it fans the fire with a rush of fresh oxygen.
The solution is to leave the hatch closed and fight the fire either with a fixed extinguisher in the engine compartment or with a portable extinguisher discharged through a Fire Port* (a small opening into the engine compartment), which is why dry chemical extinguishers of any class are inappropriate. Blindly spraying a chemical extinguisher through a fire port does little or nothing to stop an engine fire because the chemical isn’t being directed toward the base of the flames. A gaseous extinguisher, on the other hand, extinguishes the fire by affecting the oxygen supply. The same extinguisher that wasn’t effective in the wide-open spaces of a boat’s cabin will be much more effective in a cramped engine compartment.
For this reason, among others, the ABYC recommends that either a portable gaseous extinguisher be provided near (outside) the engine compartment or a fixed gaseous extinguisher be used inside the engine compartment. In the event of a fire, either option eliminates the need to open the hatch.
A few Words of Praise for Fixed Systems in the Engine Room
Overall, the most efficient fire protection system is the safest. Claim files show that the majority of fires begin in the engine compartment for numerous reasons: constant pounding and vibration loosens wiring
terminals and causes chafe, engine exhausts fail, water pumps fail, fuel leaks
?the list goes on. An automatic system, activated by a rise in temperature, can discharge and extinguish a fire long before any crew can detect a fire and react with a portable extinguisher, which is even more relevant if you sometimes cruise
shorthanded. The automatic system kills the fire earlier and minimizes damage. And since Halon and its replacements
will not damage internal engine parts
, it is often possible, after locating and correcting the problem, to restart the engine(s) after a fire and return to port.
Fire extinguishers are typically the last line of defense when a fire suddenly appears. The first line of defense is knowing how to prevent fires before they occur. In upcoming issues, Seaworthy
will take a look at how to prevent fires relating to engines, fuel, exhaust
systems, electrical systems, galleys, and other fire sources.
* Fire Port (under $10): http://cruisersforum.com/photopost//...php?photo=1782