New Rules of Fire Fighting on Boats

“It was like a fire-breathing dragon.” Fire on the water is no joke. Learn how to prevent, prepare for, and respond to, a worst-case scenario.

It was a matter of 15 seconds from the time we smelled the smoke to the time the flames were just billowing,” said Arthur “Kitt” Watson in an interview with NBC Boston after his 70-foot Marlow motoryacht, Elusive, burned on the Piscataqua River near New Castle, New Hampshire, on June 18, 2022. “It was the most frightening, harrowing experience we ever had.” Watson, his wife and the boat’s mate had to swim for their lives, along with the couple’s two dogs. The fire blocked access to the life vests, so the trio used pool noodles as substitute PFDs. All five abandoned ship via the stern platform and were rescued within 10 minutes by other boats, with no serious injuries. The boat, however, engulfed in flames and resisting firefighting efforts by the USCG and local authorities, drifted for two hours until sinking offshore of Kittery, Maine.

Later, Watson told a reporter from the Portsmouth, NH, Herald, “This didn’t come from the engine area, but it came out of our cabins. We could see a fireball coming up the companionway. It was like a fire-breathing dragon. Fiberglass burns so fast.”

Still think you don’t need automatic fire-suppression aboard your boat? A fire-suppression system will stand by 24/7 to detect and attack a fire early, before it has time to become an inferno; it’s alert even when you’re not, or if no one is aboard. The system’s sensors react to increased temperature—most are set to discharge at 175 degrees—and flood the protected space with gaseous fire-extinguishing agent in just a few seconds. An alarm at the helm warns that something’s amiss belowdecks while there’s still time to act; by the time the Watsons knew they had a fire, it was too late to do anything but abandon ship. (Every cabin should have a smoke and carbon monoxide detector as well, as they are excellent and inexpensive early-warning devices. Buy them with 10-year batteries, and replace the whole works when the battery goes dead.)

Most folks consider fire-suppression systems just for the engine room, but that’s not the only place they can be lifesavers. Given the propensity for petroleum-based fiberglass to burn (actually it’s the resin that burns), there should be systems in other spaces, especially staterooms, which are normally unoccupied when the yacht’s underway and the crew is on the bridge or lolling about in the cockpit. A fire that starts in a berth cushion, a locker or behind joinery can smolder for hours and then erupt into open flames. Once a fire gets a dose of fresh oxygen, there’s often no stopping it, unless you happen to be right there with an extinguisher. That’s the benefit of an automatic suppression system—it’s always there. No guarantee, but it gives you a chance.

Where Do Fires Start?

Fires can start in unexpected places and in unpredictable ways. Years ago, I reported on a blaze that destroyed an aluminum megayacht berthed in south Florida: Investigators surmised the cause was a cabin door left open, its top surface directly under a high-wattage overhead halogen light that was apparently left on day and night. In the interests of light weight, the door was built of wood veneers over honeycomb coring; the heat from the light eventually started a smoldering fire inside the door. When it finally burst out, the flames spread rapidly to other joinery, also honeycomb-cored, and from there, throughout the yacht. It spread so fast that workers on the flying bridge were trapped and had to jump overboard. Once the fire really got going, it was hot enough to ignite a classic wooden sailboat in the next berth. Both vessels were total losses, but thankfully, no one was badly injured.

According to GEICO/BoatUS insurance data from 2015 through 2019, 37 percent of onboard fires started in DC wiring, a bit more than half of them involving engine electrics, while another nine percent were due to faults in AC circuits, both shore power and genset. Thirty-three percent were caused by engine (19 percent) and fuel system (14 percent) malfunctions. That leaves 21 percent caused by other or unknown sources. Those “unknown sources” could be almost anything, and anywhere. Protecting against every one is impossible, but assuming every fire will start in the engine room is incorrect. Consult with a professional to determine how to protect against the most likely sources, especially in spaces like staterooms, that are usually unoccupied when the boat’s underway.

It’s important to protect battery and electrical compartments, too, something folks with outboard-powered boats often overlook. Boats today, especially multi-engine outboards, often carry lots of battery power, using stored 12-volt and an inverter to replace a genset. But if one of those high-amperage battery banks shorts, you’ll be lucky to escape without a fire. Robust fuses and an automatic firefighting system mounted in the battery compartment can be a boat-saver.

How Do You Fight a Fire?

When I was upgrading my seaman’s credentials to Tankerman, I had to study firefighting materials and methods before taking the USCG test. Lots of the material was targeted to sailors working on large ships—how to use foam to quench an oil fire, etc. But much of it was applicable to any fire, anywhere. You know the basics: Fire needs fuel, heat and oxygen; once ignited, fuel and oxygen combine to generate enough heat to keep the combustion chain reaction going, as well as produce byproducts, some of them toxic—carbon monoxide, for example. Extinguishing the fire requires breaking the chain by removing one of the three components, and doing so as soon as possible. Removing the fuel is seldom possible, since the boat and its contents become the fuel. Modern firefighting agents cool the fire (more precisely, they cool the fuel below its ignition temperature) and reduce the oxygen levels below what’s needed to support combustion. Cooling is the fastest way to kill a fire.

Unlike portable dry-chemical extinguishers, fixed systems use “clean agents” that quench the fire, then dissipate, leaving no residue behind. They are effective against all classes of fire that you’re likely to encounter on board, and won’t harm electronics like dry chemicals will. The firefighting agent is stored in a tank as a liquid. When the temperature in the protected compartment rises beyond a preset limit, a valve opens and a pressurized gas, often nitrogen, distributes the now-gaseous agent throughout the protected space within seconds. A small concentration of agent in the air, less than ten percent by volume, is sufficient, so it doesn’t take long for the system to distribute enough agent to be effective.

Until the early 1990s, Halon 1301 was the go-to agent in fire-suppression systems. It’s effective at fighting all classes of fires, and safe for folks caught in the protected compartments when the firefighting system discharged. Today’s firefighting systems use equally effective, although less environmentally harmful, firefighting agents, frequently HFC-227—or FM-200 or FE-227; same stuff, different manufacturers—a hydrofluorocarbon, or 3M’s Novec 1230, a fluoroketone. Chemists might appreciate the difference in composition of these materials, but the rest of us need only understand that both are effective firefighting agents that are harmless to humans, at least in the short term, and therefore acceptable for protecting occupied spaces. 3M says that Novec 1230 is safer to humans and to the environment than HFCs, but I’d venture that either one is way less damaging to the atmosphere than a burning boat. A third agent, FE-241, is USCG-approved in the U.S. for use only in normally unoccupied spaces, e.g., engine rooms, as it’s harmful to inhale. (The production of HFC-227 is being phased out due to provisions of the AIM Act enacted by Congress late in 2020. Manufacturers of marine firefighting equipment are still selling HFC-227 systems, but the future looks to be Novec 1230, and maybe other similar agents.)

Maintaining a sufficient concentration of a firefighting agent for as long as possible is essential to quenching a fire. Diesel engines will run happily on any of these clean agents, so the firefighting system in the engine room must include an automatic shutdown for all engines, including the genset. Otherwise the engine will both inhale the agent and blow it out the exhaust, while still drawing in fire feeding oxygen through the fresh-air vents. Intake fans should also be wired to shut down if the automatic system triggers; in the perfect scenario, the intake vents would be closed, too.

If a fire breaks out and the automatic system discharges, vacate the space ASAP. Close the door or hatch behind you to let the agent do its work, and don’t open it again until you’re positive the fire is out; I’d wait until there was a rescue vessel alongside, ideally crewed by folks experienced in firefighting. Never enter a compartment that’s smoldering—the oxygen that you allow in is just what the fire needs to rekindle. A clear fire port lets you monitor the situation, and shoot a handheld extinguisher into the space without opening the door if necessary.

Don’t expect too much from a portable extinguisher, especially if you carry just the minimum required dry-chemical types. Invest in clean agent Halotron portables at the helm, near the engine room and in the galley, with another one that’s easy to reach from the staterooms. They’re expensive, but if you’ve ever cleaned up dry-chemical residue, you’ll see why they’re worth it. And Halotron won’t damage electronics.

Save Your Life

Remember that the first rule of firefighting is to protect life. Don’t be a hero. Call for help; a Mayday is justified if your vessel is on fire. Start initiating your evacuation plan—the one you formulated when you got the boat, and ensure that you practice at least once a year (you do that already, don’t you?). Assemble all the crew in a safe place, and prepare your abandon-ship gear, in case the fire gets the upper hand. A boat engulfed in flames is a spectacle that you want to watch from a safe distance, even if it means treading water. Speaking of treading water, investing in a basic liferaft is a good move. An auto-inflating liferaft sufficient to keep you out of the water until help arrives is light enough that you can throw it overboard, just before you make the leap yourself. (Revere’s 6-person Coastal Compact life raft weighs just 24 pounds—easy to toss when motivated by fire licking at your Top-Siders.) And, as the Watsons learned, stow your rescue gear near your most likely evacuation point, to minimize the chance of flames making it inaccessible. On flying-bridge boats, keep another set of rescue gear there, in case you have to jump for it from the bridge. Engineering a fire-suppression network to protect all belowdecks spaces, not just the engine room, is a job for a professional, and can be complex and costly. With any luck, it’ll be money wasted, but if it saves your boat, or your life, it will seem cheap. Don’t wait until you smell smoke. Be prepared now.

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This article originally appeared in the October 2022 issue of Power & Motoryacht magazine.

Source: https://www.powerandmotoryacht.com/maintenance/new-rules-of-fire-fighting-on-boats