A fire on land is bad enough; at sea it can be disastrous. Since most fires start in the engine room, if you don't have an automatic fire-extinguishing system, it's time to install one. When fire breaks out, such a system will do the dangerous work for you, without anyone having to enter the compartment until the fire is out. (That's doubly important because opening a hatch introduces fresh air that will accelerate the fire and cause it to spread.) In fact, with luck, by the time you know you've got a fire, it'll already be out.
Unlike portable dry-chemical extinguishers, fixed systems use gaseous "clean agents" that quench the fire, then dissipate, leaving no residue. When the temperature in the protected compartment rises beyond a preset limit (usually 175 F), a valve opens and releases the extinguishant. Most systems use one of two agents: FE-241 is approved for use in the United States, but only in unoccupied spaces, e.g., engine rooms. European Union-approved HFC-227ea (or FM-200 or FE-227, which is the same stuff from a different manufacturer) is harmless to humans and therefore acceptable for occupied spaces; it's also used in portable extinguishers. According to Dave Blice, sales and marketing manager at Fireboy-Xintex, both are equally effective at firefighting, but HFC-227ea is more expensive; if discharged, it's also harmless to the ozone layer, while FE-241 has a minuscule impact.
For engine rooms of up to 1,500 cubic feet, the sensor and release valve sit atop the pressurized cylinder holding the agent, so installation basically means finding a suitable place to mount the cylinder. Fireboy-Xintex directions say to locate it as high as possible on a forward or aft bulkhead and as close to the centerline as possible. Aim the discharge toward the opposite bulkhead. Systems for larger engine rooms use two cylinders mounted at either end of the compartment, both connected to a remote temperature sensor. In either case U.S. Coast Guard regulations require a system-status indicator lamp at every helm station, which means running wires and making simple electrical hookups, too.
Larger engine rooms often require multiple cylinders to achieve proper coverage.
Diesel-powered boats also need automatic engine shutdown systems that are triggered by the system's temperature sensor, since a running diesel will consume the agent as fuel, lowering its concentration and making it less effective. This adds expense (shutdown systems aren't very costly, however) and complexity to the installation, so diesel folks might want to turn the job over to the boatyard.
Maintainance is simple. Coast Guard and National Fire Protection Agency rules both require checking the pressure gauge every six months and weighing the cylinder yearly; weighing is more accurate. (This is also true for handheld extinguishers.) Every 12 years you must pressure-test the cylinder or have it visually inspected by a qualified expert. Firefighting systems with multiple cylinders need the linkage between them pressure-tested every five years. The date and results of each check should be recorded on the cylinder tag.
Otherwise, install your fire system and forget it—at least until it saves your boat, and maybe your life.
Ask the Experts: Tom Guldner
The question: Although all boats carry required firefighting equipment, fortunately it's seldom used. But what if a fire does break out? What does a skipper need to know to fight it effectively?
For the answer, we turned to Tom Guldner, president of the Marine Firefighting Institute, who is a retired lieutenant in the New York City Fire Department. For ten of his 34 years with the FDNY, Guldner served as training officer for the Marine Division; he is currently consulting with the department on the design specifications for two new fireboats—the largest in the world. He serves on safety and technical committees of both the Society of Naval Architects and Marine Engineers and the National Fire Protection Association, is a nationally certified fire Instructor and a U.S. Coast Guard-licensed Ship's Master.
"Life is the first priority in any fire," says Guldner. "Generally it's a panic situation, so there should be a fire plan with an exit strategy, just like you have at home. Hold fire drills, too." Before attacking the fire, make sure everyone onboard is safe. Then break out the abandon-ship gear; you don't have to deploy the liferaft, but have it ready, he advises. Any boat with sleeping accommodations should be equipped with smoke detectors, carbon-monoxide detectors, and a high-water alarm, he adds. And don't forget to call for help immediately, "so at least someone—the Coast Guard, SeaTow, other boats, whoever—is on the way. At the very least they'll have more extinguishers."
How you fight a fire depends on what stage it's in, but in any case you need to be careful, Guldner says. There will be lots of heat and possibly poisonous byproducts of combustion. If the fire's in an enclosed compartment, never open the door and rush in: The fire can be intensified by the sudden flow of fresh air, "like in the movie Backdraft." But there's added danger, too: "The fire is consuming oxygen, so there might not be enough to breathe, although there's enough to keep the fire going," he says. Instead of entering, open the door a crack, shoot the extinguisher into the space, close the door, and see what happens. Repeat if necessary. "Never enter an enclosed compartment that's on fire," Guldner emphasizes. "And always have an escape route."
Even if the fire seems to be out, don't open the compartment right away. Unlike water, which extinguishes by cooling, dry chemical and Halon-substitute extinguishing agents work chemically to kill the fire. There's no cooling; since the fuel is still there, admitting more oxygen by opening the compartment can rejuvenate combustion in a smoldering fire. Let the extinguisher do its job, then give things time to cool down before going in.
When it comes to fire, the key thing, repeats Guldner, is to make sure everyone is heading for safety before beginning to attack it. "You can always get another boat," he says.
This article originally appeared in the April 2008 issue of Power & Motoryacht magazine.