Engine Fire - what is the likelihood?

[Ricd]

Thinking of installing an auto fire extinguisher in engine compartment. Doing a risk assessment I know the consequences of a fire at sea is severe but what is the likelihood of a modern marine diesel engine of catching fire? What might cause a fire in the engine?

 

[pyrojames]

Electrical fault, chafed wire, resitive heating, high output alternator, etc.
Oil leak onto turbo.
Coolant leak onto turbo.
Catastrophic engine failure (piston through side of block)

 

[maby]

Most likely cause has got to be a leak in the fuel or lubrication system resulting in a mist of inflammable fluid - recipe for a significant fire. Assuming it's diesel, there's little risk of a fire from a non-atomised spray - diesel and lubricating oil are not very inflammable in bulk.

Electrical is obviously a potential issue too. I've not bothered with an automatic extinguisher yet, but I'm planning to put a small tube heater in the engine bay to protect against frost damage in the depths of winter and I'll add an automatic at the same time just in case!

 

[ValleyForge]

Isn't it a requirement by your insurers ? It certainly was on the inboard powerboats we have had in the past.

 

[Ricd]

Isn't it a requirement by your insurers ? It certainly was on the inboard powerboats we have had in the past.

No..never has been.

 

[PetiteFleur]

I fitted an auto extinguisher when I re-engined. The Halon replacement type not dry powder. It was on special offer at the boat show so I bought it immediately.

 

[sailorman]

Most likely cause has got to be a leak in the fuel or lubrication system resulting in a mist of inflammable fluid - recipe for a significant fire. Assuming it's diesel, there's little risk of a fire from a non-atomised spray - diesel and lubricating oil are not very inflammable in bulk.

Electrical is obviously a potential issue too. I've not bothered with an automatic extinguisher yet, but I'm planning to put a small tube heater in the engine bay to protect against frost damage in the depths of winter and I'll add an automatic at the same time just in case!

Make sure its not a powder one then

 

[Searush]

You could ask Take5 if he was still on the forum.

His sportboat caught fire just off Caernarfon Bar on te way back from a NW Mob barbie at Port Dinllaen. Frightened him & SWMBO so much that they packed in boating. It was a petrol engined boat, but they were damned glad they were in convoy with people who could take them off, help put it out & get them home.

 

[fishermantwo]

I fitted an auto extinguisher when I re-engined. The Halon replacement type not dry powder. It was on special offer at the boat show so I bought it immediately.

Halon not banned in Britain yet?

 

[VicS]

Halon not banned in Britain yet?

Yep! He said, "Halon replacement"

 

[trapezeartist]

Electrical fault, chafed wire, resitive heating, high output alternator, etc.
Oil leak onto turbo.
Coolant leak onto turbo.
Catastrophic engine failure (piston through side of block)

Which is to say: not very likely at all.

Electrical faults no more likely to cause a fire in the engine bay than anywhere else.
Oil leak onto turbo; not many boats have a turbo.
Coolant leak onto turbo; not many boats have flammable coolant!
Catastrophic engine failure; I don't see why that is likely to cause a fire. It tends to be prevalent in racing cars (Martin Brundle, McLaren-Peugeot, Silverstone springs to mind) but racing cars have red hot exhausts. Boats have very cool exhausts.

 

[trapezeartist]

Make sure its not a powder one then

Why aren't CO2 extinguishers universal in engine bays? The thought of cleaning up an engine bay after a powder extinguisher has gone off (possibly unnecessarily) does not fill me with enthusiasm.

 

[sailorman]

Which is to say: not very likely at all.

Electrical faults no more likely to cause a fire in the engine bay than anywhere else.
Oil leak onto turbo; not many boats have a turbo.
Coolant leak onto turbo; not many boats have flammable coolant!
Catastrophic engine failure; I don't see why that is likely to cause a fire. It tends to be prevalent in racing cars (Martin Brundle, McLaren-Peugeot, Silverstone springs to mind) but racing cars have red hot exhausts. Boats have very cool exhausts.

Its all in the name
Guess WOT James does to earn boat vouchers

 

[Csail]

Not sure on the law but we still have halon (military)
Anyway after my research we fitted two Firetrace systems in the boat.
http://www.firetrace.co.uk/boats.html

 

[Deleted member 36384]

Why aren't CO2 extinguishers universal in engine bays? The thought of cleaning up an engine bay after a powder extinguisher has gone off (possibly unnecessarily) does not fill me with enthusiasm.

A couple of reasons: CO2 bottles tend to be heavier and larger as they work by displacing the oxygen from the space and therefore need a large volume to do this, they also tend not to cool ignition sources which can cause re-ignition after the C02 depletes. This also makes C02 potentially harmful to humans as well.

The new fire extinguishing gases like Inergen or FE36 work by cooling the ignition source and by a chemical reaction which inhibits combustion. In addition they are clean products and offer no environmental damage.

Approximately £90 for this 1 kg FE36 extinguisher. Far better than C02.

 

[snowleopard]

Boats have very cool exhausts.

Until your impeller packs up. Then you have dry gases going into rubber hose and plastic water locks. Result: melted exhaust system and hot gases discharged into GRP compartment.

When I built my boat I lined the engine bays with a layer of fire-resistant resin but I doubt many production builders bother.

 

[Evadne]

Having, by today's standards, a small sailing boat (29 foot) I am reluctant to install a device that could fill the accommodation with CO2 without any human intervention, at any time, day or night. A manual system might have some attraction, though.

 

[Ricd]

Which is to say: not very likely at all.

Electrical faults no more likely to cause a fire in the engine bay than anywhere else.
Oil leak onto turbo; not many boats have a turbo.
Coolant leak onto turbo; not many boats have flammable coolant!
Catastrophic engine failure; I don't see why that is likely to cause a fire. It tends to be prevalent in racing cars (Martin Brundle, McLaren-Peugeot, Silverstone springs to mind) but racing cars have red hot exhausts. Boats have very cool exhausts.

That's roughly he square I got to. Top that with the engine has a over temp alarm and is well maintained so cannot see hoses melting as described by snow lep. If I do a normal risk assessment I get likelihood very very low (1 out of 3)x consequences severe (3 out of 3) giving product do nothing more than maintain engine (3). So why fit one?

 

[Robin]

A friend's yacht years ago caught fire in the engine room on launch day after an electrical fault when a battery cable chafed through and shorted out. After the mess was sorted he fitted high amp fuses in the battery leads, something rarely seen over here but which I believe is common, if not obligatory, on boats in the USA.

 

[snowleopard]

That's roughly he square I got to. Top that with the engine has a over temp alarm and is well maintained so cannot see hoses melting as described by snow lep. If I do a normal risk assessment I get likelihood very very low (1 out of 3)x consequences severe (3 out of 3) giving product do nothing more than maintain engine (3). So why fit one?

A well-maintained and run boat is very unlikely to sink. Do you carry a liferaft?