Replacement fire extinguisher for engine bay

[alt]

I have been told my auto fire extinguisher, HFC227EA, aka. FM-200 is not acceptable (Irish law for commercial boats) in the engine bay, so needs to be replaced.

The surveyor has recommended an auto CO2 fire extinguisher? My current one has a bulb on the top (well, it's placed up-side down on the vertical bulkhead forward of the engines) that blows once a certain temp reached.

Just checking that CO2 is OK to use in engine room? I'll have to shop local as think there's an issue delivering extinguishers.

Also, what is the concensus on 2 / 3 auto extinguishers vs. one big one? I was thinking 1 above each engine and then 1 on the vertical bulkhead would work well? Mainly because it'd mean i'd have a smaller one on the vertical bulkhead between the engines hence more space for moving about... the ones above the engine don't bother me cause they'll be out of the way when i've engine hatch lifted.

 

[sarabande]

I'm not sure that CO2 is the best extinguisher for an engine fire. You need something that reduces the temperature, displaces the oxygen (CO2 does that, but disperses rapidly), and preferably blankets hot fuel from contacting the air after the fire is out.

Perhaps a check with this company about water-mist ?

http://www.safelincs.co.uk/e-series-water-mist-fire-extinguishers/

And if it is interesting, can you report back please ?

 

[PCUK]

I use AFFF but I'm not sure if they do auto models. They blanket the flames and cool the area. I understand that a single extinguisher is considered better than several smaller ones.

 

[prv]

Is it specifically the FM200 that's not acceptable, or something else about the extinguisher? Because FM200 is surely superior to CO2, it chemically disrupts the fire rather than just trying to blanket it. Though if that's the law (even if stupid) then that's the law I suppose.

Multiple extinguishers is generally not recommended, especially gas-flood types, because they won't all go off at once. So the first one will go off, but is too small to displace all the oxygen in the space, so the fire doesn't go out. The gas leaks away, and then a bit later the next extinguisher goes off, same thing happens. So you're left with several empty extinguishers and a fire that's still burning. Unless you have a clever system that sets them all off together, you need one big extinguisher to fill the space in one go.

Pete

 

[prv]

I use AFFF but I'm not sure if they do auto models.

Certainly used to, we inherited one on our previous boat.

Active gas was a better fit for the new one, though, because it doesn't need to be mounted above everything where we don't have much space. As long as the operating head is high enough to get hot, once it goes off the gas will flow everywhere. Ours is mounted alongside the engine, above the electrics, as that seems like the most likely source of ignition.

All our manual ones are foam, no way I'd have powder after watching the Crash Test Boat video...

Pete

 

[alt]

Thanks guy's. OK so i'll stick with the 'one big extinguisher'.

The surveyor recommended CO2. He just stated that FM200 isin't allowed.

So what I need to look for is a similar size (will check the current size tomorrow) CO2 auto extinguisher.

Thanks for the help.

 

[prv]

So what I need to look for is a similar size (will check the current size tomorrow) CO2 auto extinguisher.

No, you need one that's rated to protect the same volume. Which, since CO2 is less effective than FM200, will probably be quite a bit larger physically

Pete

 

[alt]

No, you need one that's rated to protect the same volume. Which, since CO2 is less effective than FM200, will probably be quite a bit larger physically

Pete

That's a very good point. I'll measure the engine bay tomorrow. I know the width, just need to check depth & height.

-Edit- Looks like I have an engine room size of APPROX 12 sq. m

 

[PCUK]

I think I'd double check on the FE200 as surveyors are far from infallible.

 

[alt]

I think I'd double check on the FE200 as surveyors are far from infallible.

I will double check. This guy isin't an independent - He works for the Dept. of Transport (Marine Survey Office) and he is the guy that gives us our licence every 2 years. He knows his stuff. He didn't necessarily agree with it, just mentioned that FE200 isin't acceptable.

 

[jimmy_the_builder]

That's a very good point. I'll measure the engine bay tomorrow. I know the width, just need to check depth & height.

-Edit- Looks like I have an engine room size of APPROX 12 sq. m

Iirc you need volume, not area, when specifying an engine room extinguisher. The other thing to keep in your mind is acceptability of the replacement to your insurance company.

 

[Bandit]

I would be very surprised if FM200 as a type is not acceptable.

Perhaps your setup is not correctly specified perhaps?

Give Seafire a call http://www.sea-fire.com/technical-information/suppression/fm-200/

AFAIK you need one large bottle, mine is auto ( bursting glass vial) and manual ie when my feet start to smoulder you pull the handle on the wire on the way out of the boat. I would not like to have a fire and not be able to set it off manually.

On commercial boats you used to have to have a way of stopping the engines and shutting off the ventilation to the engine room before you set off the fire extinguisher .

Co2 is not nice as a gas it is heavier than air, if it leaks it gathers in spaces or hollows, ie a boats hull, you cant see it, smell it etc and it will kill you. Get another system if you can.

Halon its strange that the military can still use it but the public cant ?

 

[sarabande]

"Halon its strange that the military can still use it but the public cant ? "

Halon leaves no residue so doesn't affect complex electronic wiring, and is more effective than any other gas extinguishant. It happens to be a CFC, so not good for the environment, which is why it's generally proscribed.

 

[Piers]

I have been told my auto fire extinguisher, HFC227EA, aka. FM-200 is not acceptable (Irish law for commercial boats) in the engine bay, so needs to be replaced.

The surveyor has recommended an auto CO2 fire extinguisher? My current one has a bulb on the top (well, it's placed up-side down on the vertical bulkhead forward of the engines) that blows once a certain temp reached.

Just checking that CO2 is OK to use in engine room? I'll have to shop local as think there's an issue delivering extinguishers.

Also, what is the concensus on 2 / 3 auto extinguishers vs. one big one? I was thinking 1 above each engine and then 1 on the vertical bulkhead would work well? Mainly because it'd mean i'd have a smaller one on the vertical bulkhead between the engines hence more space for moving about... the ones above the engine don't bother me cause they'll be out of the way when i've engine hatch lifted.

I'd strongly suggest you check with your insurance company. I know that ours insists on a specific type and size and the ability for it to be able to be activated manually from a specific position ex-engine room.

Thereafter, you know what to look for.

 

[Bandit]

"Halon its strange that the military can still use it but the public cant ? "

Halon leaves no residue so doesn't affect complex electronic wiring, and is more effective than any other gas extinguishant. It happens to be a CFC, so not good for the environment, which is why it's generally proscribed.

Halon also is not a silent killer like Co2

 

[sarabande]

yes, I'm not certain how it works, but when triggered, the gas squishes out the fire, yet leaves enough oxygen in the air for people to breathe. CO2 is a total displacement system (initially at least).


There are also problems with CO2 that it leaves the extinguisher at a very cold temperature, and fired directly into a human face can freeze the surface of the eye, or into sensitive electronics can cause operational malfunctions.

 

[Bandit]

Co2 when there is a significant percentage in the air will not support burning but effectively a very high percentage is required to stop burning and flames.

However a modest increase in Co2 percentage will knock out a human and eventually kill them along with I assume Canary birds?

 

[prv]

yes, I'm not certain how it works, but when triggered, the gas squishes out the fire, yet leaves enough oxygen in the air for people to breathe. CO2 is a total displacement system (initially at least).

Fire is a chemical reaction happening quite fast. Halon (and the newer substitutes) work by disrupting that reaction, not by removing oxygen. I'm told you can still breathe perfectly well in a space where a correctly-sized halon extinguisher has been set off, though it's not recommended for health reasons (and will give you a headache afterwards).

CO2 itself does nothing to the fire except perhaps a bit of cooling at close range, so it's needed in much larger quantities to push aside all the oxygen.

Pete

 

[CLB]

Fire is a chemical reaction happening quite fast. Halon (and the newer substitutes) work by disrupting that reaction, not by removing oxygen. I'm told you can still breathe perfectly well in a space where a correctly-sized halon extinguisher has been set off, though it's not recommended for health reasons (and will give you a headache afterwards).

CO2 itself does nothing to the fire except perhaps a bit of cooling at close range, so it's needed in much larger quantities to push aside all the oxygen.

Pete

I think I would also want some form of auto engine room vent shut offs to ensure that the CO2 stayed in the engine room.

 

[MyMarine]

That is very strange that FM200 is not acceptable as it is recognised by many commercial bodies throughout the world. Including MCA, RNIA and Lloyds. If it is not accepted have you heard of 3M Novec 1230 it is the superior product to FM200 and would be a better solution than CO2.

If you would like any further info please just ask.

Regards
Peter