The ideal answer is to prevent a fire in the first place, or barring that good fortune, have a quick-response plan ready so you'll be able to douse flames before they can spread. Many built-in fire suppression systems have a heat-melting auto discharge capability, but it takes either direct proximity, a very hot fire, or the ambient temperature to rise to 179 F for the system to auto deploy. By installing a manual-release cable, a crew can preempt the wait and choke off the flames before the fire builds.
Not only does opening a door or hatch to the engine compartment raise the risk of being scorched by flames; it also introduces more oxygen to a hungry fire. A built-in fire suppression system on even a modest-sized boat makes sense. It also keeps the crew from fighting an engine room fire with a dry chemical extinguisher, many of which are not very effective on Class A fires, and if the powdery, abrasive agent is ingested into a running diesel engine, it's usually fatal to the engine itself.
Take note: Though diesel fuel may be readily abundant, engine-room fires are often a Class C blaze, one that's linked to electrical ignition. Turning off the main battery bank switches is step one in combating this type of fire. If the current is not eliminated from the short circuit, the fire will continue despite the introduction of extinguisher agent. With this need in mind, it's always a good idea to make sure that the main switches are not hidden away in the engine room or placed in another area where they are likely to be quickly engulfed in flames.
Fighting a Fire
Responding to a fire aboard a sailboat is similar to coping with a large hole punched in the hull. Both require immediate action and neither is forgiving to an ineffective response. At the same time that the crew confronts the all-consuming challenge of stopping the blaze or significant leak, they need to be prepared to cut their losses and be able to instantaneously switch to an abandon-ship escape plan. Knowing when to make the call is both a tough decision and a reality that's shaped by the surroundings. One thing's sure: Waiting a little too long can be a big mistake.
A well-prepared crew understands the chaos factor that intrudes on such disasters. They realize that their best chance for success is already in place, and it includes the fire suppression system they installed months or years ago and the extra extinguishers waiting in easily accessible locations. Even more important has been the training that the skipper has done with the crew and how each person has tested her extinguisher operation skill. They are prepared to aim the suppression agent on the base of the flames. If there are enough crew on board, one member may be assigned to communicate a Mayday, set off the EPIRB, and ready the abandon-ship gear and life raft. Others head the boat downwind to keep flames from engulfing the cockpit and hindering raft deployment if the need arises. In short, a fire grows exponentially, and there's only a short window of time to get it under control. It takes quick response and gear at the ready to outwit the combustion triangle, and every second counts.
Take Stock on Your Boat
One of the best ways to determine how much of a fire hazard your own boat poses is to do a simple analysis of the combustible content of the boat. Tally up the major materials used to build the vessel. At first it may seem reassuring that glass fiber and lead won't burn, but the resin that makes up 50 percent of the FRP structure will self-ignite at about 880 degrees F and burn to a crisp, creating a toxic cloud of harmful gasses.
So will the core material and most of the wood and plastic liners that stylize the interior of your vessel. Add flammable diesel fuel, combustible sails, the dodger, and the bimini and one begins to get anxious over the fact that it's easier to list what won't burn than what will. Also note that just one candle produces a laminar diffusion flame that can reach 2,500 F, more than enough to instigate a roaring blaze.
The galley and the engine room are the two obvious concerns; it's why the A.B.Y.C. spends an inordinate amount of time on electrical-, fuel-, and propane-system specifications. By preventing fuel and L.P.G. leaks and lessening the chance of an electrical short, the potential for a fire goes way down.
The same consideration needs to be given to where flares and volatile chemicals like paint solvents and gas for the dinghy's outboard are secured. Using a large propane locker as a combined storage area for gasoline and solvents is just the type of situation to avoid. Commingling explosive and flammable products may seem like a sensible approach, but with electrical wires leading to the L.P.G. solenoid and the moist, salt-laden environment that's inside most propane lockers, these are anything but a sensible seagoing Hazmat container.
Many sailors see 12-volt DC batteries as a benign energy source with no electrocution worries. The latter is true, at least up until an inverter is wired into the system, but the former disregards the high-current and heavy-gauge circuits associated with low-voltage wiring that poses the potential for extreme heat generation if an unanticipated short circuit occurs.
Lastly, beware of the unexpected. A couple of years ago, a transatlantic passagemaker explained how a sheeting snafu turned into a fire on board. He said he'd been motorsailing in a light breeze and had trimmed the mainsheet using an electric cockpit winch, then went below to heat some water for tea. A malfunctioning solenoid switch connected to the self-tailing winch that held the mainsheet re-engaged on its own, and the noise of the engine prevented the skipper from hearing the sound of the winch coming to a stop under full load. The now non-rotating winch melted its motor-winding insulation and short circuited. A high-amperage fuse was able to carry more current than the wire that ran to the winch, which turned into a red-hot copper filament that set the liner on fire. The skipper responded, effectively switching off the current and dousing the flames with a fire extinguisher. He never expected such an incident to occur, but he knew how to effectively respond to a Class C fire. Would you?
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The U.S. Coast Guard is asking all boat owners and operators to help reduce fatalities, injuries, property damage, and associated healthcare costs related to recreational boating accidents by taking personal responsibility for their own safety and the safety of their passengers. Essential steps include: wearing a life jacket at all times and requiring passengers to do the same; never boating under the influence (BUI); successfully completing a boating safety course; and getting a Vessel Safety Check (VSC) annually from local U.S. Coast Guard Auxiliary, United States Power Squadrons(r), or your state boating agency's Vessel Examiners. The U.S. Coast Guard reminds all boaters to "Boat Responsibly!" For more tips on boating safety, visit www.uscgboating.org.