Fire Detection and Suppression

[Insequent]

I have a Fireboy automatic system (halon replacement gas), including the engine and exhaust fan shutdowns. The latter are crucial as pointed out above. Manual overide of the engines etc from the helm is possible (and also very important to have) should the boat be in an unsafe location at the time. I also have ER cameras, smoke and CO alarms and a bunch of handheld extinguishers of various size at various location in the boat.

My main concern in the ER is not one of the engines or fuel leaks, but a battery failing and going into thermal runaway. It would take me a little time to be able to disconnect and remove one, even though I have made some mods to expedite that process. Unless I caught it very early I probably could not get it out without running the risk of being overwhelmed by smoke etc. I shoot battery temps whenever running after a deep house bank discharge. My alternators total 400A and the solar 160A, so the batteries can get quite warm during charging. Of course an internal battery short could occur at other times as well......

The PO had a fireboy in the ER but no shutdown. It and numerous handhelds were all halon. I had them all serviced by a place that still has some halon, but then discovered I would have a big problem on entering Australia. Halon is banned here except for commercial aviation and the military. You can get a permit for a 'permanatly installed' halon system. But the cost of the permit exceeded the cost of replacement of all the halon units I had on board! Who says all bureaucrats are dumb! I sold all the halon units in the PNW before leaving, including a couple to TF members.

 

[sbu22]

Installed a Fireboy-Xintex FE 241 system and left the prior Halon system in place. Halon still servicable by all indications. F-X system is auto shutdown capable, but not hooked up. Both systems triggered by fusible links. Manual activation at upper helm for F-X. 6 x 5# dry chemical in spaces.

I'm obviously concerned about fuel fires, but from the research I've done, electrical ignition sources seem to predominate in rec boat fires. Bit the bullet and installed remote battery disconnects at the upper helm. On my boat, it's a long hot crawl (duckwalk) between engines to the manual disconnects.

In addition, half a dozen CO/smoke detectors, but not in the engine room. Two cameras in the engine room that will (hopefully) give me an indication of ER status.

As others have noted above, I've been through many USN and MARAD fire schools, all oriented to military and heavy commercial firefighting. With a GRP boat and zero compartment integrity, if I can't control a real fire within about a minute, it's ditch bag time.

Still debating about auto engine shutdown. Probably advisable, but having difficulty surrendering that control.

 

[psneeld]

Off Amazon...I got 2 smoke detectors that are wirelessly connected.

Put one over the engine and one in the saloon.

They have preformed flawlessly.....alerting me to the smallest bit of smoke from a prematurely failing damper plate and the friction caused smoke so thin it was hard to see.

 

[stubones99]

Most new fire control systems have FM-200 otherwise known as heptafluoropropane

It is colorless, odorless, and non-corrosive. You can breathe it and not die in the process.

All vents should be shut with dampers, fans cut off, and engines stopped for it to work.

 

[twistedtree]

Off Amazon...I got 2 smoke detectors that are wirelessly connected.

Put one over the engine and one in the saloon.

They have preformed flawlessly.....alerting me to the smallest bit of smoke from a prematurely failing damper plate and the friction caused smoke so thin it was hard to see.

Whirelessly connected to what? Each other so if one triggers they all sound? Or something else?

 

[psneeld]

Each other....when you by 2 or more, they discuss how to activate them to talk to one another.

Either one sets off the other....something like $49 for the pair.

I like them because a touch of smoke will set off both and the solo on one I can hear from the flybridge with no amplification or wiring.

 

[twistedtree]

Sounds like a good setup. Do you happen to know if they also have a contact closure to trigger an external alarm? I'd like to be able to generate an alert on my Marteron system, in addition to waking up me and everyone else within the sound radius.

 

[psneeld]

Sounds like a good setup. Do you happen to know if they also have a contact closure to trigger an external alarm? I'd like to be able to generate an alert on my Marteron system, in addition to waking up me and everyone else within the sound radius.

Doubt it, cheapo home style.

But a creative electronics guy might be able to...

Maybe a sound tripped relay externally?

 

[HopCar]

Before Halon fire systems were all CO2. The amount of CO2 required to put out the fire would also shut down the engine. This was also enough to kill a human pretty quickly.

Halon was much safer because a much smaller amount was needed to put out a fire. If the system was sized correctly it would put out a fire but not kill someone in the engine room. It also wouldn't shutdown the engine. Halon required that the engine be shutdown or the engine would just pump it out the exhaust.

I don't think the Halon replacements are as effective and safe as Halon. Does anybody know about the replacements?

Here is a Scientific American article that talks about how Halon ineterupts fire at concentrations that won't kill you. https://www.scientificamerican.com/article/what-chemicals-are-used-i/

 

[stubones99]

Hop, One of the problems with CO2 was that it froze everything, valves, pipes, and outlets, since rapid pressure drop makes dry ice snow, which can clog improperly designed systems. Before the bottle was empty, it had frozen over at the neck. Once it thawed out, it would repeat, until empty.

New systems with FM-200 work and don't have the problems of Halon or CO2, but are more expensive. It seems to odd to dump a modified propane on the fire

But the FM-200 heptafluoropropane has a carbon atom added between all the other atoms which makes it non-flammable. At concentrations up to 9%, you can still breathe enough to survive and escape. 6% concentration is enough to stop most fires.

After the fire is put out, vent the area and you're good to go back in. No cleanup necessary.

All the new fireboy suppression systems come with FM-200.

 

[HopCar]

Thanks for the update stubones99. I'm glad to know it is still safer than CO2.

I remember an incident, at the boat yard across the street from my store. Two men died in an engine room.They accidentally tripped the CO2 system as they were working on it.

You would think they could have just held their breath long enough to get out. There seems to be something about high concentrations of CO2 that kills quicker than it would take to just smother you.

 

[stubones99]

You would be surprised how fast you can go down, especially when you probably didn't know the situation was going to happen, and you didn't hold your breath.

I almost didn't make it out of a photo lab dark room when we had an anhydrous ammonia leak in a Diazo developer. You find out when your breath is taken away, your eyes are on fire, and once you figure out the problem, you then have to make it out of the dark room, which could be easier than a crowded engine room, climbing ladders and such.

I can still recall the taste and smell of anhydrous ammonia today, 45 years later.

 

[Spottsville]

Sounds like a good setup. Do you happen to know if they also have a contact closure to trigger an external alarm? I'd like to be able to generate an alert on my Marteron system, in addition to waking up me and everyone else within the sound radius.

You can add a maretron smoke detector to your N2K backbone and it will alarm the maretron system when smoke is detected.

 

[twistedtree]

You can add a maretron smoke detector to your N2K backbone and it will alarm the maretron system when smoke is detected.

Yes, and I am considering that approach. But their setup for smoke etc is expensive and is a wired solution. In general I prefer wired on a boat, but it is a giant pain in the butt to install, so I would consider a commercial wireless system where the devices are all supervised (continually monitored and checked to be sure they are responding, have good batteries, etc).

Also, I don't yet understand whether Maretron's fire system is dependent on one of their display products to actually alarm, or if a tripped sensor will cause one of their sounders to go off in the absence of a display relaying the alarm. This is a concern for me because I use their N2KView program as the sole display, and although I mostly like it very much, I have never been able to keep it running for more than 30-40 days without some sort of user intervention. For a fire system, I want something that will run indefinitely, like a commercial alarm system.

 

[koliver]

So far on this thread we have heard mostly from the well equipped.

For the rest, most meet the CG safety requirements, so have a 10BC at or near the entrance to the engine room and others throughout the boat.

In mine, I have 4 x 10BC located in: fwd cabin, galley, aft cabin entry, aft cabin rear entry, and a much larger 80BC? on the main cabin, near the ER hatches.I have also carried a trash pump equipped with a fire hose, but it sees little to no use, so is presently off the boat.

I once had a hydraulic hose go, spewing transmission fluid on everything nearby. When dry, the trans case was hot enough to ignite the oil coating, and the flames quickly consumed the plastic air cleaner housing and the air cleaner element, but all of the flames were consumed by the engine. Once the engine was shut down, the single 10BC then in the main cabin was enough to put out the fire, and the other 4 were kept close in case of reflash, but by then no new fuel was in danger of getting hot enough to burn.

The replacement for the exhausted 10BC is much larger.