Fire safety sticks

AntarcticPilot said:
Of course, but the problem isn't confined to engine-room fires. Given that many of us have engines that can draw air from the cabin, even letting one off in the cabin could result in powder getting into the engine space. Few engine spaces are sealed off from the cabin on sailing boats, at least not well enough to stop powder. The pervasive nature of powder extinguishers is well-documented - see the crash test boat videos, for one. If I let a powder extinguisher off below decks I couldn't be certain that powder hadn't got into the engine. And there are many circumstances where stopping the engine might not be a good idea; there are plenty of waters where not having steerage way could result in disaster, too.

If there is an engine-safe option (such as water mist extinguishers), then surely they are to be preferred to a type known to have the potential to cause damage - possibly fatal damage - to an engine? I will certainly not replace my existing powder extinguishers like for like when the time comes.
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I would think an engine fire is likely to be either electrical or fuel, neither of which water is a good idea. Not sure about the water mist thing though. Co2 would be the safest I would think....Are there any firemen on the forum to give a definitive answer ?
 
I was the OP of the recent extinguisher thread mentioned above...

Following that I went for a motorsport-spec AFFF extinguisher, as these are the only non-powder/non-CO2 I could find that aren’t affected by freezing.

We’ve also got a new water mist for the galley (but that’ll live at home during the winter) and mini-powder extinguishers for the aft cabins (to help crew/guests escape in a worse-case scenario).

Watch out for water (mist) and AFFF feezing and potentially damaging the canister and/or the additive separating. Not saying it will happen, but I couldn’t find a supplier who’d guarantee it wouldn’t for their regular-specced extinguishers.

Fire sticks?! On our offshore cruiser, where we potentially need to fight a fire and continue on our way... no thanks!
 
Water mist systems appear to be the most effective and safe and are widely used on ships.
It works on the principle of using the massive cooling area of millions of tiny droplets of water - the surface area of these drops is immense, especially so when compared to the surface area of the same volume of water in a bucket.
If you throw that bucket of water on a fire the odds are good that it might just put a dampener on the fire - release a water mist system with the same amount of water and the odds are good that the fire will be extinguished immediately (so long as the water mist is not blown away).
Here are two types that are used on ships -

Hi-Fog : Marioff.com | Fire Protection with HI-FOG Water Mist

Flexifog : FlexiFOG | Discovery Marine
 
I've got a 6kg automatic clean agent extinguisher in the engine room, not cheap but at least I don't need to verify there is a fire before it lets go and if it does whilst the engines or genset is running there shouldn't be any internal damage to them.

Still have four powder units distributed throughout the boat upstairs.
 
Jmc1764 said:
I would think an engine fire is likely to be either electrical or fuel, neither of which water is a good idea. Not sure about the water mist thing though. Co2 would be the safest I would think....Are there any firemen on the forum to give a definitive answer ?
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Water mist is safe on electrical and fuel fires, according to others. The droplets are separated, so there is no electrical conductivity, and it doesn't gather so that fuel can float on it.
 
penberth3 said:
The old chestnut. If I had an engine fire, first thing I'd do would be shut it down.
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If you have an engine fire on a light aircraft you (a) shut of the fuel and (b) open the throttle fully. That way you use up all the fuel between tap and cylinder, which leaves less to burn. Of course that's petrol, and accessible fuel taps don't seem to be a thing on boats.
 
My powder extinguishers would need to be replaced next year. I will replace them with the Water-Mist; they are equally as effective as the powder type and less messy but they are at least three times the price and from what I understand, they don't tolerate low temperatures.
 
AntarcticPilot said:
Water mist is safe on electrical and fuel fires, according to others. The droplets are separated, so there is no electrical conductivity, and it doesn't gather so that fuel can float on it.
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The reason they are safe for electrical fires is not that it is mist, it is that the water is deionized and thus not conductive. They MUST be filled with DI water. It is in the manual.

They can be used to put out fuel fires, but are not rated for it because they can make fuel fires worse both by spreading and increasing fuel evaporation. These are NOT the videos they share on you tube.

---

I don't think anyone is suggesting that pyrotechnic fire extinguishers should be the sole means, but there are valid suggestions that they can be a part of the tool kit. Having had a small fire offshore, I've thought about this. Don't forget...
  • Fire blanket. A big wool fire blanket many be best. The first choice for most galley fires.
  • Gloves suitable for grabbing hot stuff, such as leather.
  • Bucket with a rope. It never runs out!
 
CAPTAIN FANTASTIC said:
My powder extinguishers would need to be replaced next year. I will replace them with the Water-Mist; they are equally as effective as the powder type and less messy but they are at least three times the price and from what I understand, they don't tolerate low temperatures.
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Perhaps it is different in the UK, but in the US water mist extinguishers do NOT carry a fuel rating (A for wood and C for electrical only). Thus they are NOT as effective. Are they fuel rated in the UK?

Water mist ext.
 
thinwater said:
Perhaps it is different in the UK, but in the US water mist extinguishers do NOT carry a fuel rating (A for wood and C for electrical only). Thus they are NOT as effective. Are they fuel rated in the UK?

Water mist ext.
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There seems to be a general delay in independent research into water mist extinguishers, the Canadian research institute have conducted some tests and seem to conclude their effectiveness.
But they do seem to be gaining in popularity and have major 'clean-up' advantages over dry powder.
 
thinwater said:
Perhaps it is different in the UK, but in the US water mist extinguishers do NOT carry a fuel rating (A for wood and C for electrical only). Thus they are NOT as effective. Are they fuel rated in the UK?

Water mist ext.
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My understanding is that they are some water mists also safe for use on Class B fires involving flammable liquids;. But I need to get more clarity on their limitations.
 
CAPTAIN FANTASTIC said:
My understanding is that they are some water mists also safe for use on Class B fires involving flammable liquids;. But I need to get more clarity on their limitations.
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I don't mean to seem blunt, but this is the sort of thing we need to see in writing and with certifications. Also "flammable liquid" means different things in different jurisdictions. In the US, gasoline is flammable and diesel is combustible. For example, we might learn that water mist is useful on diesel but dangerous on gasoline (water mist can make the flame grow larger with fuels that vaporize readily).

I'm pretty sure we're going to learn that the effectiveness of water mist is so-so at best on fuel fires. That is what the chemistry and physics say. My opinion (not fact) is that water mist could and probably should be a part of the mix, but that I want something else on board too. And there is a very practical case for having multiple extinguishers.
 
dankilb said:
Looks pretty effective to me (inc on flammable liquid):
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Yes... and at the same time no, only so-so.

  • Dry chemical was much, much faster. The fire was out before the firefighter was even in the camera frame!
  • Notice how the flames actually spread first in the class F fire at the end. That is characteristic of water mist. In a bilge space, it may well have just moved it around.
  • These are simple, exposed fires. What of the actual cases, where the fire is hidden behind the engine?
  • I've done this test with a pyrotech extingusiher. It was more like the dry chemical in terms of speed, with a lot of smoke but little residue.
One down side of a pyrotechnic type is that you only have one go; the fire needs to be out within the burn time. There are pyrotechnic units with much longer burn time.

Maus. Look at 1:09, same standard petrol test

And look at the tiny size of the Maus, perhaps 10-20x less than the size water mist extinguisher we are comparing it to. It is batting way out of its weight class in this comparison.

Not sayin' I'm a Maus fan, or that I would sail with just a Maus (I would not), just trying to present something the group seems less aware of. The technology is just gaining traction, so the benefits, weaknesses, and best uses are still up in the air.
 
howardclark said:
I’ve got several powder extinguishers which are approaching the ends of their lives. I have in the past been on a fire course where I got to use extinguishers so feel I have some faint idea of what I would do if there were a fire on board, but these fire safety sticks are new to me.
Has anyone actually used one - in anger or as a trial?
pros and cons?
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What is the deficit with regular foam extinguishers, much tested and well understood, that sticks would solve?
Petrol fires are possibly one discriminator but otherwise, I see no advantage.

BTW. regular cylinder extinguishers run well past their printed date - a bit like best by stickers on grocery items. Any number of correspondents on this site have my experience - testing old cylinders and finding them effective well beyond stated dates.

Take care of course, but extinguisher dating is not the first consideration when inspecting a boat's gear.

PWG
 
peter gibbs said:
What is the deficit with regular foam extinguishers, much tested and well understood, that sticks would solve?
Petrol fires are possibly one discriminator but otherwise, I see no advantage.

BTW. regular cylinder extinguishers run well past their printed date - a bit like best by stickers on grocery items. Any number of correspondents on this site have my experience - testing old cylinders and finding them effective well beyond stated dates.

Take care of course, but extinguisher dating is not the first consideration when inspecting a boat's gear.

PWG
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Many off-the-shelf AFFFs don’t like freezing temperatures. At least according to their manufacturers.

But taking that into account, we’ve got (low-temp) 2.4L AFFF foam as our new main extinguisher.
 
peter gibbs said:
What is the deficit with regular foam extinguishers, much tested and well understood, that sticks would solve?
Petrol fires are possibly one discriminator but otherwise, I see no advantage.

BTW. regular cylinder extinguishers run well past their printed date - a bit like best by stickers on grocery items. Any number of correspondents on this site have my experience - testing old cylinders and finding them effective well beyond stated dates.

Take care of course, but extinguisher dating is not the first consideration when inspecting a boat's gear.

PWG
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one thing that can be useful with powder extinguishers is to regularly give them a shake upside down to avert powder compaction that can happen with engine vibration. ol'will
 
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