Propane, the kiss of death

[gonesail]

Originally Posted by Dockhead

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

depends on your definition of smart. if you follow the rules and have the proper safety equipment for using propane then I would say that qualifies as smart

[boatpoker]

Tell me the examples shown in this article are intelligent people ...
Safe Boat Propane System Installation

[Dockhead]

Originally Posted by boatpoker

Tell me the examples shown in this article are intelligent people ...
Safe Boat Propane System Installation

You can find stupid people killing themselves anywhere. Doing good to the gene pool. That doesn't prove that you and I are immune to blowing ourselves up.

Much more relevant reading is the above linked report on the Lord Trenchard incident. I guarantee you their procedures were better than yours or mine. Do you manually pump your bilge every day to get out any possibily spilled gas? They blew themselves up exactly the way you and I will, if it happens - unfortunate coincidence of couple of failures which went unnoticed despite regular inspection.

I say again - complacency with stuff like propane, arrogance, is a bloody good way to get yourself killed.

[Jammer]

Originally Posted by Dockhead

Much more relevant reading is the above linked report on the Lord Trenchard incident. I guarantee you their procedures were better than yours or mine.

They were using cylinders with prestolite connections on the valves. The USA version is CGA-510 and I guess the UK version has very slightly larger threads which has nothing to do with the accident. The connection was the immediate cause of the accident because it was loose and it leaked.


There is absolutely no reason why this sort of thing should still happen.


The USA switched to valves that have seals on the connection and a safety valve that will not allow gas to flow unless a hose is connected. This happend about 20 years ago as part of the switch to OPD valves. With these valves if the hose isn't tight enough that it won't leak then the valve won't open. There has also been a switch to ACME-threaded connectors (the cylinders have both those and the old CGA-510 to ease the transition) that incorporate an excess flow check and a thermal shutoff.



Some boats still have the old connectors on the boat side but you can get new ones for $11 including a new hose.


There are far more propane explosions on boats in the UK than in the USA despite the UK having the "boat safety scheme" which has a propane system inspection as a major item. I don't understand it completely but believe that, in addition to the tank valve connection, differences in tubing/hose connection standards must play a role. USA propane connections mostly use flare connections which are more reliable than the compression connectors used in the UK. USA standards (ABYC) require all Ts and valves to be in the propane locker while UK standards allow them anywhere.

[CMO Tashina]

Originally Posted by Tayana42

It’s a bad combination of molecular chemistry that leads to propane explosions. It’s all those protons, electrons and morons mixed together.

Agree totally!

[senormechanico]

Originally Posted by 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.”

How rusty are the bottoms of the tanks now that they are subject to salt spray? It seems to me that would be an open invitation to corrosion.

[hpeer]

Look, if I were looking for a new boat I would not reject one because it had propane. That is reality, the world we live in.

Yet, when you read through the above posts it becomes clear that propane requires a fair amount of vigilance and an understanding most boat owners do not have. Propane is safe “IF” you;
Have vented lockers
Gas detectors
Solid copper tubing
Solenoids
Do regular inspections
Have the right connectors
Etc.

Every “IF” statement is a point of potential failure. All systems have “IF” statements, but the fewer the better.

Then there are the PERSONAL “IF” statements.
And those are myriad.

Who was the writer (Gerr?) who wrote about putting allegorical money in a box so that when stuff happens you have some balance left?

[Shrew]

I'm going to guess there is more to the story than has been presented by the OP. Since we're talking about a propane lantern, my guess is these are the 1 lb bottles. They have a spring loaded valve on the inside. If anything, if subject to corrosion, the default would be to be frozen CLOSED. Corroding won't make the valve, creep open.

What I have seen on MANY occasions is, when you remove the regulator, the needle should slide out and the spring loaded valve should close and seal the bottle. However, what happens is, you remove the regulator and the valve fails to close all the way, causing a leak. I've seen this happen where the valve remains wide open and the decompression from discharge creates a huge white cloud of propane. More common is to hold it close to your ear to hear a very faint hiss.

Our solution is to not remove the regulator until the tank is empty.

[ikanode]

I use my Foodsaver to vacuum seal 1lb propane canisters along with a desiccant after having problems with the threads rusting. Since then, I check the threads at the store and have found some that are already rusty.

An unexpected benefit was finding one vacuum sealed bag that was swollen due to slow leakage from the canister.

[Greg Mason]

No wonder I paid the bucks t get a fiberglass tank.

[waterman46]

I always thought it was a bad idea using those little portable tanks for a rail mounted barbeque, due to storage issues. But it never occurred to me that my propane torch which I have stored on my workbench below deck, was basically the same situation. I am definitely going to move that bottle to the propane locker now and liberally coated with Boeshield for rust protection.

[Pelagic]

My take away logic for this discussion is that there are dangers everywhere and a good skipper will be aware of and monitor/test for those dangers.

Improvements in Propane fittings, safety devices and guidance on installation have certainly helped with new propane installations, but on older boats with hidden gas lines, you just hope it was done properly.

Most of us are equipped to deal with Fires, be it from electrical or cooking, but none of us are equipped to deal with an explosion of the scale that a propane leak into the bilge can cause.

If everything is done properly, that is very rare, but maybe a rat chewing on a hose line coupled with a late night dinner and too much wine, made you forget to switch off the gas solenoid and then that risk is both real and human.

In the past, we had no choice but to carry cooking fuels.

Propane, despite it's explosive danger, became the favorite.

But today with Solar and Induction, we have a flame free and explosion free choice .

I'm not saying that everyone should rip out their propane system, but if building new or if you have an older system with propane hoses and copper pipe sections you have never been able to inspect, .....
.. remember, with Solar and Inverter, you now have a safer choice!

[Jammer]

I don't think there is enough evidence to conclude that propane cooking systems are less safe than electric cooking systems aboard. Each has inherent dangers that can be mitigated through careful installation, maintenance, and use.


Large studies of residential cooking (on land) have consistently shown that the overall safety risk (gas vs. electric) is about the same. Not enough data on cooking on boats but as a thought exercise both systems pose additional risks aboard with the fire risk from the solar panels themselves as well as the battery and inverter system adding risk not present on land, and the greater problems with propane accumulating in the bilge.

[Chotu]

Originally Posted by senormechanico

How rusty are the bottoms of the tanks now that they are subject to salt spray? It seems to me that would be an open invitation to corrosion.

Doesn’t even matter.

First, they are not filled if too rusty. No place fills rusty tanks.

Second, they have a ring on the bottom (don’t all tanks?) to keep the tank off the ground. That keeps the tank dry and rust free while the sacrificial ring takes rust from any condensation.

Third, if they leak it doesn’t even mater. Propane just falls harmlessly overboard.

[Thumbs Up]

Originally Posted by belizesailor

I knew someone who died in a propane explosion...same basic result, blew the deck off the boat. He survived a few more excruciating days after the explosion. Boat sunk.

Assuming that you mean Richard Muntzing of s/v Panacea. The explosion was loud where I was 2 miles down river. Blew the windows out of a neighboring boat. Another boat may have got dismasted (trying to remember). When salvaging the bits and pieces they found his stove with a rubber propane line that had been chewed by a rat. He had been complaining about a rat on board. I upgraded my propane system after that.

Warning. Some places (Guatemala) don't put much, if any smell ( Ethyl Mercaptan), in their gas.

Propane is heavier than air which makes it problematic. There are combustable gas detectors that you can install. I don't know how reliable they are nor which one is best. Here is an example of one: https://www.amazon.com/PANGAEA-Digit..._t3_B08MDXKRVK