Propane, the kiss of death

[Pelagic]

Originally Posted by belizesailor

Liquid propane has an expansion factor, when it converts to gas, of about 270:1. Imaging a mass of propane gas below decks equal to 270 of those little tanks!

Being in a locker or the bilges is contained enough to make a powerful explosion.

The small tanks are steel so will eventually rust in a marine environment. Bad idea on a boat.

But yes in the end its human error: storing steel propane tanks below deck, ot having them on a boat at all, is a recipe for disaster.

Exactly and a good reminder to all of the insidious nature of Propane inside boats, whether it be a portable canister or a hidden hose penetration or connection.

For those who blame the skipper, even smart people can have bad days of forgetfulness, or Murphy decides to send you a clumsy contractor.

The bottom line is that propane is not forgiving of mistakes or damages !

When I remodeled my gallery to have built in top loading Fridge and freezer, it meant that I had to reroute my Propane line down an extra level then back up.

Once the refer compressors were in, Propane line would be inaccessible, which was enough to make me switch to induction.

So glad I did and while I still carry Propane for BBQ, they are outside, open for inspection and easily jettisoned in a Fire.

https://www.envinsci.co.uk/dangers-g...losions-boats/

According to Consumer Product Safety Commission estimates, roughly 600 propane tank explosions occur each year. Every accident is different and is the product of the attendant circumstances, so one cannot accurately predict without examining the circumstances present at the accident.

[Jammer]

YHBT. YHL. HAND.

[Don C L]

Originally Posted by Pelagic

Exactly and a good reminder to all of the insidious nature of Propane inside boats, whether it be a portable canister or a hidden hose penetration or connection.



Attachment 246383

This reminded me of a friend who found a leak in a connection in a line in cabinetry behind the stove many years ago. There was no explosion and the smell tipped him off, but that tends to be one of those things you remember.

[boatpoker]

Originally Posted by Don C L

This reminded me of a friend who found a leak in a connection in a line in cabinetry behind the stove many years ago. There was no explosion and the smell tipped him off, but that tends to be one of those things you remember.

A fume detector under the stove would have alerted him much sooner.

[Pelagic]

Originally Posted by boatpoker

A fume detector under the stove would have alerted him much sooner.

The fume detector is normally installed low, in the vicinity of the stove in case of a flame out, so doesn't cover the whole area.

The insidiousness of a leak is that it could be elsewhere, very small and if you are in the good habit of switching on and off the propane tank solenoid every time you cook..... and purge the line when finished, you may never even smell it until Murphy comes along
Someone else is cooking, forgets to switch off solenoid, or it is faulty and they forget to manually turn off tank.
You close up boat and go ashore... then boom!

[Dockhead]

Originally Posted by Adelie

Propane has 50.3 MJ/kg
1lb would have 22.9 MJ
A stick of dynamite has about 1 MJ. more or less according to Wikipedia.
A very small amount of propane mixed in the air near the proper ratio will give a nice bang. It probably would be a low order detonation, but plenty to do a boat from the inside.

Beat me to it, and better than I could have done


Propane is extremely dangerous. Someone gets killed or maimed almost every year in the UK in an LPG explosion on a boat.



Yes, gasoline/petrol is dangerous too.


A boat with neither on board would suit me much better.


Propane containers, and ESPECIALLY those flimsy portable cans, should NEVER be brought inside the main hull volume. Thanks to the OP for posting this.

[boatpoker]

Originally Posted by Pelagic

The fume detector is normally installed low, in the vicinity of the stove in case of a flame out, so doesn't cover the whole area.

The insidiousness of a leak is that it could be elsewhere, very small and if you are in the good habit of switching on and off the propane tank solenoid every time you cook..... and purge the line when finished, you may never even smell it until Murphy comes along
Someone else is cooking, forgets to switch off solenoid, or it is faulty and they forget to manually turn off tank.
You close up boat and go ashore... then boom!

Yes, low under the stove as I said.
Yes, you will smell it. The add odourants to the propane for that very purpose.
Has nothing to do with a flame out. A flame out is handled by the thermocouple shutting off the propane.

[Dockhead]

Originally Posted by boatpoker

Absolutely nothing wrong with propane if one has an IQ slightly higher than a cumquat.

I daresay plenty of people blown up in propane explosions have higher IQ than you or me.


It is a dangerous, arrogant assumption that an accident can't happen to me because I'm just so damned smart.

[AKA-None]

Reminds me of a case where a burner was working on a barge and lowered his torch down then went for lunch
After lunch they struck an arc (so is is supposed) both died
This was in Norfolk va back in the 70’s
No link to story sorry it was long ago

[Na Mara]

I’m with Billkny. We are all so aware of the dangers of propane that we take serious precautions with it and thus it is very rare that accidents occur. For instance, I am rebuilding a cockpit locker (I have three) to be a gas locker as where the gas is now isn’t up to code. It’s not a question of if that money has to be spent or whether I can live with the present system, which works fine by the way, it’s simply a fact. What I have at present isn’t as safe as it should be and you don’t f***. around with propane aboard, period. Contrast that with all the hobbyist electrical installations you see afloat.

The nearest I have come to meeting my maker was a very near miss with a boat fire in the middle of the North Sea in a gale. My batteries failed, resulting in my alternator sending too much charge to them to bring up their voltage, which should have blown fuses which, due to improper installation by the PO, instead of blowing melted and burned. Only the absence of flammable material nearby saved us and the boat. I am now as careful with my DC electrical installations as with my propane installation.

[Tortuga's Lie]

Every time I swap out my tanks, I conduct a leak down test on my propane lines (2X a year), I should probably do it more often though, once a month would be best I would think. I also have a sensor alarm with two sensor modules, one down low in the bilge, the other under the stove.

[thinwater]

a. Store in a vented locker. I always do. Not hard to figure something out.


b. the cause was a leaking valve. Common, I've had it happen to me twice. The solution is cheap and simple; use a proper storage cap. I use these AT HOME too! about $2 each through Amazon.

http://data:image/jpeg;base64,/9j/4A...UUAFFFFAD/2Q==

[hpeer]

Originally Posted by Dockhead

I daresay plenty of people blown up in propane explosions have higher IQ than you or me.


It is a dangerous, arrogant assumption that an accident can't happen to me because I'm just so damned smart.

Yup, exactly.

Some people cope with adding on gizmos like solenoid switches and alarms.
Some folks turn to electricity.
Some folks use kerosene.

And some folks blissfully exist in ignorance until they don’t.

When we bought our big boat the cooker was rusted out, the controls shot, the solenoid corroded, the tanks a mess, and the copper tubing behind 23’ of wall kinked and inaccessible. The only good thing was the locker, which was itself proper. It was a “no brainer” to install a kero cooker and avoid all that expense and effort to do propane. I now keep the 1 pound cylinders in that locker.

It takes vigilance to keep the boat systems up and safe. The simpler and more inherently safe the better.

I have been thinking of a thread about inherently safe(er) design features.

[rslifkin]

Originally Posted by hpeer

It takes vigilance to keep the boat systems up and safe. The simpler and more inherently safe the better.

I have been thinking of a thread about inherently safe(er) design features.

That idea is part of why I like electric galleys. Electrical systems have their dangers, but you're likely to have one of those regardless of cooking fuel. So enlarging it a little to add electric cooking to the mix still means 1 less system to maintain, making it easier to keep everything safe and happy.



Plus, even though I own a boat with gas engines, propane concerns me. Non-pressurized flammable liquid is bad enough, but pressurized flammable stuff is absolutely a bigger concern in my mind (takes a smaller problem to leak enough to go bad quickly, possibly before you even detect the problem).

[Chotu]

I mitigated the risk with an outdoor deck locker with about 1sqft of holes in the bottom of it directly over the open water. All propane tanks, valves and accessories are in this locker (same for all gasoline plumbing connections). I call this my “explosives box.”

Copper lines run from inside this locker directly to each appliance (one for each appliance) without any interruption and are connected directly to the appliance with flare/compression fittings that came with the appliances.

All copper lines that pass through this box are sealed off air right where they pass through.

All appliances have flameout mechanical gas shot offs installed by the manufacturer in accordance with all UL/CE regulations and codes.

In short, there is practically no way propane can leak at all in my boat.

My point is this is a good way to do it and that propane is hardly dangerous if carefully installed.