Gas Explosion

[a64pilot]

My RV has a propane / carbon monoxide detector. That's not common in the marine world?

[Delancey]

Yachting Monthly's Crash Test Boat - Explosion! - YouTube

[GordMay]

Originally Posted by Tony B

Overall, it's pretty hard to create a propane explosion. ...

The Flammable Range (Explosive Range) is the range of a concentration (% of propane that must be present in an propane/air mixture) of a gas or vapour that will burn (or explode) if an ignition source is introduced. The limits are commonly called the "Lower Explosive or Flammable Limit" (LEL/LFL) and the "Upper Explosive or Flammable Limit" (UEL/UFL).

Propane’s approximate Explosive Range is between 2.1% (LEL) to 9.6% (UEL).

The gas mixture from a leakage will not be homogeneous; as a light gas concentrates along the ceiling, and a heavy gas (like propane) concentrates along the floor.

Propane has a Specific Gravity of 1.52 - 1.55 (± 1.5 times as heavy as air).

Everyone handling or using LP-Gas should realize that the odourant (typically ethyl mercaptan) used to give propane a distinctive smell may not be detected by all people, under all circumstances.
The strongest odour may be near the floor, and the odourized gas may be masked or covered up by other odours such as musty bilges, cooking odours and certain foods, etc.
High concentrations of odour can shock or diminish the sense of smell, which can also occur from prolonged exposure to the odour of LP-Gas (odour fatigue & odour fade).

[skipperr100]

I was in San Juan, PR, a few years back, the boat two slips over was drilling a hole in the gasoline tanks, converting them to diesel, and the spark made him a Darwin statistic. no dagage to my boat.

[Tony B]

Gord

If you have a propane leak, you can smell it way before it hits it's LEL.
Today's equipment is made very, very safe. The probability of anything going wrong with reasonable maintained equipment such as tanks, hoses. appliances, gas sniffers with remote tank shut-off etc. , is extremely remote.
If these were not extreme cases we wouldn't be hearing about it.
Anyway, not knowing the details from the OP, everything here is speculation.
I have been in many boats where a major disaster is waiting to happen, fortunately, a hurricane usually takes it out of commission first.

[tamicatana]

Originally Posted by a64pilot

My RV has a propane / carbon monoxide detector. That's not common in the marine world?

Our surveyor made a CO detector a requirement of purchase, but there's no controlling the jackwagon factor

[GordMay]

Originally Posted by Tony B

... If you have a propane leak, you can smell it way before it hits it's LEL.
Today's equipment is made very, very safe. The probability of anything going wrong with reasonable maintained equipment such as tanks, hoses. appliances, gas sniffers with remote tank shut-off etc. , is extremely remote...

There's numerous circumstances under which one might not smell propane at it's local LEL; some of which I previously enumerated.
The human nose is an UNRELIABLE gas detector!
I agree that propane (equipment & installations) can be very, very safe.

[S/V Alchemy]

Originally Posted by a64pilot

My RV has a propane / carbon monoxide detector. That's not common in the marine world?

My boat has a propane/gasoline detector...a good idea with an old Atomic 4 inboard gasoline auxiliary.

I also habitually sniff the compartment and feel beneath the fuel pump and carb when I switch on the seawater intake and the fuel line. This is before I run the blower. I NEVER simply switch on the engine. That's the way to become a meat bomb.

[Richard_W]

Was it a gasoline/petrol or LPG powered stove?

Assuming that the "gas" stove reported in OP post meant gasoline/petrol stove ("gas" is a North American moniker for gasoline) ... no wonder the thing got poof as the gasoline/petrol vapors have significantly lower point of ignition. The LPG powered devices are relatively safer that the gasoline/petrol powered counterparts.

[Cheechako]

using a camp stove inside the boat is well... not a good thing. Last I heard electrical fires are more prevalent than propane fires on boats. So if you dont like propane better remove all that wiring also!

[Ocean Girl]

Reading this LEL stuff, I believe the placement of out propane sniffer is too high. Mounting near cabin sole seems more logical.

[SVRapture40]

The Mythbusters did an episode a few years ago trying to blow a room up with methane. They found that it is VERY difficult to get a room (boat) to blow up with methane (propane). That was confirmed in the youtube video that 2 people posted here - it took 2 tries to get it to blow, even with measurement instruments. So as the last post just said - don't know the exact details of the original post, but it is very difficult to get this to happen.

[MarkSF]

Originally Posted by a64pilot

My RV has a propane / carbon monoxide detector. That's not common in the marine world?

Propane detectors, and CO detectors, are completely different things.

A propane detector works on the basis of detecting hydrocarbons, so they usually work on gasoline, propane, butane, etc. You can test one with the vapour from an unlit lighter. The best practice is one that is connected to a solenoid that will cut the propane off at the bottle, in case of a leak.

A CO detector does not detect hydrocarbons, it detects the toxic carbon monoxide produced by a flame.

A CO detector will give you no protection whatsoever from a gas leak, just like a propane detector will give you no protection at all from the fumes from a lit stove.

A marine CO detector :

Xintex CMD-4MR CO Sentinel Carbon Monoxide Detector*-*Fireboy-Xintex*CMD-4MR*-*Gas Fume/CO Detectors*-*Marine Instruments*-*Boatersland Marine

Marine propane detector :

Xintex 2" S-1A Propane & CNG Fume Detector*-*Fireboy-Xintex*S-1A-NV*-*Gas Fume/CO Detectors*-*Marine Instruments*-*Boatersland Marine

[boatman61]

If your worried about gas in your bilges crank your manual bilge pump a coupla dozen times and it'll clear anything down there.. don't use your electric pump...

[MarkSF]

Originally Posted by GordMay

There's numerous circumstances under which one might not smell propane at it's local LEL; some of which I previously enumerated.
The human nose is an UNRELIABLE gas detector!
I agree that propane (equipment & installations) can be very, very safe.

I wanted to mention another issue with the methyl mercaptan in propane - it can be oxidised if there is any oxygen present. A common reason for this is not properly evacuating new propane cylinders before filling, so air (oxygen) is present, which attacks the mercaptan. You then have propane with no smell.