Engine Compartment Fire Extinguisher

**tuadhmumhan** · 25-02-10, 21:36

I'd like to install an automatic fire extinguisher in the engine compartment of my Malo 36.

What are the pros and cons of the various types (powder, CO2, foam, etc.)?

What is a "halon replacement" fire extinguisher and where can one be sourced (at a reasonable price)?

All advice welcome.

Martin.

**GrowingLad** · 26-02-10, 07:13

Originally Posted by tuadhmumhan

I'd like to install an automatic fire extinguisher in the engine compartment of my Malo 36.

What are the pros and cons of the various types (powder, CO2, foam, etc.)?

What is a "halon replacement" fire extinguisher and where can one be sourced (at a reasonable price)?

All advice welcome.

Martin.

Hi Martin,

I'm sure some people will be able to share some good info, in the past I've read quite a few posts on the subject (I seem to remember in the motor boat forum).

If you give the search option a go I think you'll probably find some good discussions on the subject.

cheers,
gl

**Chris_Robb** · 26-02-10, 08:40

Originally Posted by tuadhmumhan

I'd like to install an automatic fire extinguisher in the engine compartment of my Malo 36.

What are the pros and cons of the various types (powder, CO2, foam, etc.)?

What is a "halon replacement" fire extinguisher and where can one be sourced (at a reasonable price)?

All advice welcome.

Martin.

Powder is a disaster - as it will bugger your engine.

Halon replacement is the way to go.

But, if you have an automatic extinguisher, you must have some way of stopping the engine BEFORE the exstinguisher goes off, because when that happens the engine vents the extinguishant through the exhaust in seconds leaving nothing to tackle the fire!

You need to solve this problem, and I am not sure how without some very expensive systems.

I solve the problem by having an additional couple of manual extinghuisers which can be injected manually through a keyhole to the engine compartment, but this means going down below when there is a fire......

CO2 - very heavy canisters, also a large volume is needed, so I don't think it is really a practicle solution in small boats.

Also consider how you turn off your diesel tap if this is in the engine compartment.

**Rogershaw** · 26-02-10, 14:22

"But, if you have an automatic extinguisher, you must have some way of stopping the engine BEFORE the extinguisher goes off, because when that happens the engine vents the extinguishant through the exhaust in seconds leaving nothing to tackle the fire!"

What I did in the past and will do on my new boat is to fit a fire/smoke detector in my engine box with 2 remote operated extinguishers and a viewing port.

If the detector goes off I can check the engine box without opening it and if a fire is found, I can shut down the engine and operate the first extinguisher. If that does not kill the fire the second one can be used.

If I an in a place where I cannot shut off the engine due to safety reasons I can still monitor the fire until it is safe to shut down and deal with the fire.

**Ariadne** · 26-02-10, 15:18

Powder may bugger your engine but rather that than the boat burning down to the water line sinking! I would think in many cases unless you have a sealed engine compartment (which most yachts don't have) then halon/halon replacement would do more harm you than put out the fire. C02 would just get sucked into the engine and the fire would carry on.

I'm sure that most insurance companies would rather replace a buggered engine than a replace a whole boat, which is what they would have to do if you didn't stop the fire.

Me I've got an automatic 2Kg dry powder extinguisher, I'm happy as I know it will put out a fire. The rest I can deal with later, but I'll still be afloat and manoeuvrable.

**vyv_cox** · 26-02-10, 17:15

Originally Posted by Ariadne

Powder may bugger your engine but rather that than the boat burning down to the water line sinking! I would think in many cases unless you have a sealed engine compartment (which most yachts don't have) then halon/halon replacement would do more harm you than put out the fire. C02 would just get sucked into the engine and the fire would carry on.

I'm sure that most insurance companies would rather replace a buggered engine than a replace a whole boat, which is what they would have to do if you didn't stop the fire.

Me I've got an automatic 2Kg dry powder extinguisher, I'm happy as I know it will put out a fire. The rest I can deal with later, but I'll still be afloat and manoeuvrable.

The trouble with powder is that it puts out the fire but it doesn't either cool it (water) or smother it (foam). So with an engine fire, for example, there is a real risk that it will reignite. This happened to me in a fire after a carburettor leak on an Alfa Sud, of blessed memory. This negative property is widely reported.

Halon or its substitute extinguish the fire by chemical means and it will not reignite. Contrary to urban myths, halon is not poisonous. It is as unpleasant to breathe as the smoke is, but it will do no more harm. I assume the substitute is the same, although it was introduced after my fire-warden duties were over.

I carry all three: a large foam one for engine fires, halon substitute for something that really works when needed and powder as a last resort.

**rigman** · 26-02-10, 17:46

Originally Posted by Ariadne

Powder may bugger your engine but rather that than the boat burning down to the water line sinking! I would think in many cases unless you have a sealed engine compartment (which most yachts don't have) then halon/halon replacement would do more harm you than put out the fire. C02 would just get sucked into the engine and the fire would carry on.

I'm sure that most insurance companies would rather replace a buggered engine than a replace a whole boat, which is what they would have to do if you didn't stop the fire.

Me I've got an automatic 2Kg dry powder extinguisher, I'm happy as I know it will put out a fire. The rest I can deal with later, but I'll still be afloat and manoeuvrable.

What if it goes off in error, and trust me it does happen. (vibration, heat, someone burst the bulb when working in the engine etc) You have one almighty mess and it will probably happen at 3 am motoring in bad weather!!!!!

Halon or halon substitute is the way to go and as previously stated, reignition is a distinct possibility with dry powder.

**Chris_Robb** · 26-02-10, 17:51

Originally Posted by rigman

What if it goes off in error, and trust me it does happen. (vibration, heat, someone burst the bulb when working in the engine etc) You have one almighty mess and it will probably happen at 3 am motoring in bad weather!!!!!

Halon or halon substitute is the way to go and as previously stated, reignition is a distinct possibility with dry powder.

Who said halon - shhhhhssshshshs

**Sy-Revolution** · 27-02-10, 10:05

Surely and engine room full of CO2 would stop the engine too?

**emandvee44** · 27-02-10, 12:54

Halon replacement is the way to go. Without getting into arguments about stopping the engine, we have a 2Kg equivalent auto gas, bought from FIRE PROTECTION CENTRE LIMITED - very good prices and service (we also bought more extinguishers from them, including an auto gas one for the bow thruster compartment).
All approved by a surveyor for coding.

Cheers,

Michael.