Fire suppression

[BogMonster]

I have done a search on here, read all the posts discussing the subject and come to the conclusion that if I can find a suitable one I am going to get a plastic AFFF extinguisher.

But I didn't see any mention of alternative fire-suppression solutions.

What I'm thinking of is that on every domestic heating boiler there is a shutoff valve that when it gets above a certain temperature, a blob of solder melts (or something) and shuts off fuel flow into the unit so you don't keep pumping fuel into the flames...

Does any such thing exist for a RIB? It seems like a sensible idea (maybe the outboard has one fitted inside the cowl - but I haven't seen any mention of it in the book)

Mine - at the moment - doesn't even have a stopcock on the fuel tank, an odd oversight when it was screwed together, and that will be sorted before too long so that if the **** hits the fan I can whip the seat off and isolate fuel and battery in a few seconds. But I was just wondering about other ideas to reduce the risk or do you think it is overkill?

[codprawn]

The best extinguisher to carry is a green Halon one - of course they have now been banned except in certain cases - I am sure a burning RIB/Car will damage the environment a lot more than the Halon but of course the experts know far better!!! Failing Halon AFFF is the next choice as you say.

Inboards tend to have the protection you mention - outboards don't seem to - probably cos they are outboard. The most common cause of fire is electrical - make sure everything is fused that can be and you have a battery kill switch.

Failing that jump into the sea - my boat carries 500L of petrol - full I am not so worried by when the tanks are empty in hot weather it does get a bit worrying!!!

[Searider]

How is Halon going to be effective in an open space? It'll just blow away.
Gaseous extinguishers are only any good in enclosed spaces - plumbed into the engine cowling would be good.

Halon has been banned for use on boats for some time but there are "green" alternative gaseous extinguishers that can be used if appropriate

[havener]

AFF (acqueous filming foam) is a reasonable second best, now that Halon has been withdrawn. A second dry powder extinguisher is a useful idea, but be careful about contents becomign "packed" if it's not mounted properly.

The best system is well stored extinguishers and quick reactions - it's no good if you have to pull the contents of a locker out to find the extinguisher!

Mind you, we work with oil (and soon LPG) tankers so we tend to be a bit paranoid!

[BogMonster]

Sorry - I wasn't clear - I am going to get an AFFF extinguisher anyway - just wondering about this idea I had as additional protection?

My RIB has less than 100L Codders - so I'll be out of the burns unit before you

[codprawn]

Originally Posted by Searider

How is Halon going to be effective in an open space? It'll just blow away.
Gaseous extinguishers are only any good in enclosed spaces - plumbed into the engine cowling would be good.

Halon has been banned for use on boats for some time but there are "green" alternative gaseous extinguishers that can be used if appropriate

It all depends - obviously most electrical fires will occur in the console or in under deck spaces. Halon is very effective even if just aimed at the base of a fire - for example a car engine fire which becomes an openish space once the bonnet is lifted!!! On an outboard it would need to be directed into the cowl - as would any other medium.

[Poly]

Fire blanket? Or as suggested on my PB2 - when the fire ext. runs out a jacket dipped in the sea and wrung out placed over burning engine.

Cod - would rather use powder inside console than any gas, probably even halon. Might make a mess but it does work - and doesnt 'diffuse' away as easily.

Stephen - does your fuel tank have a 'quick' disconnect fitting on it like connects the fuel line to your engine? almost as good as a stop cock.

[BogMonster]

Originally Posted by Polwart

Stephen - does your fuel tank have a 'quick' disconnect fitting on it like connects the fuel line to your engine? almost as good as a stop cock.

Erm <slightly embarrassed pause> no I don't think so ... I think it is securely attached at the tank end then there is just the primer bulb and a hose straight to the engine. I don't think there is one at the motor end either, unless it is inside the motor cowling - I am pretty sure the whole lot goes in through a big sort of grommet thing together. I know the fitting you mean though, as I just bought one while I was on holiday, for the 6hp aux that arrives next week so I can use an external tank with that.

Good idea though - will look into it

[Jeff Pike]

Steve, have you looked at Boat Save Cannisters? Got 2 on my RIB to supplement the usual ABC extinguisher. Supposed to be a suppressing foam to smother fire & prevent re ignition. Never used them & hope never have to but sounded a good idea - but I'm a sucker for sales talk

[codprawn]

Originally Posted by Polwart

Fire blanket? Or as suggested on my PB2 - when the fire ext. runs out a jacket dipped in the sea and wrung out placed over burning engine.

Cod - would rather use powder inside console than any gas, probably even halon. Might make a mess but it does work - and doesnt 'diffuse' away as easily.

Stephen - does your fuel tank have a 'quick' disconnect fitting on it like connects the fuel line to your engine? almost as good as a stop cock.

A console is a lot more enclosed than a car engine compartment with the bonnet up - Halon works fine - I have used it several times. Unlike CO2 it doesn't just smother - it actually interupts the combustion process. 1kg of Halon is equiv to 10kgs of CO2. You do NOT need to flood totally with Halon.

[Poly]

Originally Posted by codprawn

A console is a lot more enclosed than a car engine compartment with the bonnet up - Halon works fine - I have used it several times. Unlike CO2 it doesn't just smother - it actually interupts the combustion process. 1kg of Halon is equiv to 10kgs of CO2. You do NOT need to flood totally with Halon.

Both my (and I believe BogMonster's) consoles are alot smaller than a car engine bay with a lot less gubbins in there to (1) catch fire (2) get in the way of the extinguishant (I think I invented that word). Perhaps on the Codship you "need" Halon but not on ours. We also have (i believe) pretty basic electrics so I think an engine fire is much more likely.

Halon was banned for a reason (you might not agree with it - but get over it).

I don't think CO2 is a realistic proposition on an open boat (or possibly any boat as its an asphyxiant - so not ideal in an enclosed space). So you are looking at foam or powder. Both work. Both make a bloody mess. But burnt boats aren't too pretty either.

[wavelength]

Stephen - does your fuel tank have a 'quick' disconnect fitting on it like connects the fuel line to your engine? almost as good as a stop cock.

dont disconnect at the engine end if its on fire-you could end up holding a burning fuel line when it spurts on disconnecting.

[Poly]

Originally Posted by wavelength

dont disconnect at the engine end if its on fire-you could end up holding a burning fuel line when it spurts on disconnecting.

Appologies if that is what you thought I was suggesting. I wasn't. If the engine is on fire then you wont find me trying to pull that tricky plug off the front. I was simply trying to describe the connector - as I don't know the correct name.

[jwalker]

Stephen, I think your idea of using a central heating valve is a good one. Obviously, the sensing bulb would need to be where the fire is. In an open boat I guess you would need to give the valve a good coat of paint to protect it but, on my central heating, the capillary tube and the bulb are both copper so they would last a good while.

On my boat, I have a 2kg hand CO2 extighisher in the cabin and two of these under the engine hood. http://www.magicmarine.co.uk/fire/Ex...herOrders.html

I do believe the CO2 is useful. If the fire is large enough I feel you are unlikely to win with any smallish hand held extinguisher. I know CO2 is not recommended for materials that one might imagine may burn on a boat but I've used CO2 on smallish fires for which they are not recommended and the dousing was pretty well instant. In a fire situation that is recoverable, I'd expect the CO2 to cool it and I'd rather not have to clear up the mess of powder. In an engine compartment, filling your engine with dry powder while it is running with surely do damage.
I do think that if you get a real petrol fire it will simply be a whoomph and your best bet would be the sea, if you are able.

My understanding of C02 and Halon replacement is that they mainly work by absorbing the heat of the fire rather than by smothering it.

[CJL]

Halon and CO2 fire extinguishers work by removing oxygen from the local environment around the fire. They don`t cool the fire. Basically all fires have 3 ingredients, ignition source, fuel and oxygen. If you remove any ingredient you won't get a fire.

Codprawn, why the obsession with halon fire extinguishers ? Move with the times. The replacements 4 halon are just as good, if not better.

Chris

[BogMonster]

Originally Posted by Polwart

Both my (and I believe BogMonster's) consoles are alot smaller than a car engine bay with a lot less gubbins in there to (1) catch fire (2) get in the way of the extinguishant (I think I invented that word). Perhaps on the Codship you "need" Halon but not on ours. We also have (i believe) pretty basic electrics so I think an engine fire is much more likely

Pretty much right - there is not a lot in mine really. If the whole thing goes boom then I guess I am swimming, but the real point of the exercise is that I'd hate to see it go up in smoke for the sake of a teeny little fire that could easily have been put out. Even if I lost the engine, if the rest of the boat was saved it would be worthwhile. Also, the sea isn't that hot here...

[codprawn]

Originally Posted by CJL

Codprawn, why the obsession with halon fire extinguishers ? Move with the times. The replacements 4 halon are just as good, if not better.

Chris

But that is the whole point - they are NOT better - or even as good for the purpose.

Or have Boeing and all other aircraft makers got it wrong? Halon is still exempt for critical use applications such as aircraft cargo holds etc.

http://www.fire.nist.gov/bfrlpubs/fire05/PDF/f05068.pdf

Many things that have been forced on us aren't always for the best.

[jwalker]

Originally Posted by CJL

Halon and CO2 fire extinguishers work by removing oxygen from the local environment around the fire. They don`t cool the fire.

I think that is true for Co2 but at close quarters, as might be the case in a rib, the cooling effect is substantial and if you release Co2 into a small fire there is often ice on the surface where the flames have been extinguished. Whilst displacing the air (hence oxygen) is a benefit, if you do a bit of research on the Halon replacement gasses, I think you'll find they do absorb heat. If they just displaced the oxygen, it wouldn't matter which inert gas was used.

I would guess that they initially remove heat to below a point of ignition then they prevent reignition by hanging around excluding the oxygen. As I said, just guessing.

[jwalker]

I'm a bit bored this morning so did a bit of googling for ya.

[jwalker]

Anyway, I think Stephen's idea of shutting off the fuel supply to prevent a small fire turning into an inferno is cool. It could be especially effective for a diesel boat and it might not be long before a boat I know has a valve fitted.