Check Your Gas Locker Drain!

[leftbrainstuff]

It wasn't lpg that caused your issue. Why blame it.

I check our gas locker drain as part of our monthly checks. I pour a bucket of water in the gas locker and watch it drain out the transom.

I'd rather have lpg than lion batteries. They are a hideous fire hazard. You'll need lots of them with your all elec stove.

[44'cruisingcat]

I'd be looking to relocate the gas locker to somewhere it doesn't need a hose to drain overboard, but can drain directly.

Possibly easier on a cat, but our gas locker has2 X 2 inch drains.

[buzzstar]

Originally Posted by Dockhead

So as far as I can tell, my boat has NEVER had a working gas locker drain

The important part is you caught it before something really bad occurred. One more area to affirmatively check rather than just a quick visual, and it looks OK. Your experience is a warning to us all, and because of it we may live to find something else to disagree about. THANK YOU!

[buzzstar]

Originally Posted by leftbrainstuff

It wasn't lpg that caused your issue. Why blame it.

I check our gas locker drain as part of our monthly checks. I pour a bucket of water in the gas locker and watch it drain out the transom.

I'd rather have lpg than lion batteries. They are a hideous fire hazard. You'll need lots of them with your all elec stove.

Is that sort of check adequate? The water may just displace other water, with both the new and the old water forming an effective block to the drainage of gas. I had not properly considered how incompetently a gas bottle locker drain could be installed until Dockhead's discovery and revelation. We all have a debt of gratitude owed to him.

[Terra Nova]

Originally Posted by buzzstar

...We all have a debt of gratitude owed to him.

Gush!

I wouldn't go that far.

[buzzstar]

Originally Posted by Terra Nova

Gush!

I wouldn't go that far.

I've made a payment. Have you?

[nautitrix]

I feel your pain but agree with the poster that the propane is not the problem so why blame it. The problem is the installation. I am refitting a boat right now that had a 2 cylinder internal propane locker. My survey said "crimp in propane locker vent hose". I was not too concerned as I would never personally put propane in a locker inside the hull of a boat. I am moving the propane to the stern rail, but when I removed the propane locker I got out a screw driver to undo the ring clamps and the hose fell off in my hand. The nylon spigot had separated from the thru-hull and had been reattached with a polysulfide type adhesive. The spigot broke off because there simply was no room to move the locker or the tanks around in the starboard cockpit locker. As infuriating as it is that a PO would sleaze that fix, it is exactly why I will have my propane system on the rail. I know that it is not pleasing to the eye but I see it as a safer way to do things. If your boat is big enough to have a real, built-in, propane locker go with it. For my own part I have never heard of an outboard propane installation going boom!

[Terra Nova]

Terra Nova came to me with two 6-lb propane cylinders installed in tubular fiberglass lockers let into the cockpit seats. As part of the refit I removed these and glassed in a proper locker at the very aft end of the boat, creating a space which drains directly overboard through scuppers, and houses three 10-lb cylinders, which are accessed through a large, round, aluminum deck hatch normally found on commercial fishing boats.

You can see the drain holes in the topsides, aft, below the A in San.

[Dockhead]

Originally Posted by nautitrix

I feel your pain but agree with the poster that the propane is not the problem so why blame it. The problem is the installation. I am refitting a boat right now that had a 2 cylinder internal propane locker. My survey said "crimp in propane locker vent hose". I was not too concerned as I would never personally put propane in a locker inside the hull of a boat. I am moving the propane to the stern rail, but when I removed the propane locker I got out a screw driver to undo the ring clamps and the hose fell off in my hand. The nylon spigot had separated from the thru-hull and had been reattached with a polysulfide type adhesive. The spigot broke off because there simply was no room to move the locker or the tanks around in the starboard cockpit locker. As infuriating as it is that a PO would sleaze that fix, it is exactly why I will have my propane system on the rail. I know that it is not pleasing to the eye but I see it as a safer way to do things. If your boat is big enough to have a real, built-in, propane locker go with it. For my own part I have never heard of an outboard propane installation going boom!

Propane IS the problem. It is inherently dangerous on a boat because it is heavier than air, which means it will accumulate in the bilge if leaked inside the hull volume, and it is extremely explosive (several times more so than TNT).

It is possible to mitigate these risks by taking a lot of care, but still boaters are killed every year in gas explosions. It's one of the main risks of boating, statistically.

Like others, I use gas for cooking, because there doesn't seem to be any good alternative, but my next boat will not have propane on board at all.


Your rail mounted system is elegantly simple, and simplicity adds to safety by reducing points of potential failure. But by no means solves everything. You can still have a propane leak at the stove or in the gas line or connections inside the hull volume.

And gas lockers don't solve everything, as my case shows. A particularly bad case was the explosion of the Royal Navy training yacht Lord Trenchard. See: https://assets.publishing.service.go..._trenchard.pdf. Despite extremely thorough procedures (it's the Royal Navy!!), they managed to blow themselves up. The fault was a leak between the gas locker and the hull volume.

Do you pressure test your gas locker? No, I didn't think so. Neither do I. And I just accidentally found a hole where a screw had been, last year, and sealed it up. It seems like there's always something else you can miss.

[lonesoldier0408]

Originally Posted by LoudMusic

Speaking of taking water into your gas locker, I recently saw pictures of a boat for sale with an air tight gas locker lid. The thought is good - you won't get anything into the gas locker to mess up your tanks or pipes. But it also means that even with a working drain, it won't drain because air can't get in to let the gas out.

So, run a smaller line inside the drain pipe, with the locker end terminating at the top opposite corner of the locker.

[Dockhead]

Originally Posted by Terra Nova

Terra Nova came to me with two 6-lb propane cylinders installed in tubular fiberglass lockers let into the cockpit seats. As part of the refit I removed these and glassed in a proper locker at the very aft end of the boat, creating a space which drains directly overboard through scuppers, and houses three 10-lb cylinders, which are accessed through a large, round, aluminum deck hatch normally found on commercial fishing boats.

You can see the drain holes in the topsides, aft, below the A in San.

Sounds like a well-designed system

[Cadence]

Originally Posted by buzzstar

Is that sort of check adequate? The water may just displace other water, with both the new and the old water forming an effective block to the drainage of gas. I had not properly considered how incompetently a gas bottle locker drain could be installed until Dockhead's discovery and revelation. We all have a debt of gratitude owed to him.

All the water is doing is checking the P/J trap of a design flaw.

[nautitrix]

Originally Posted by Dockhead

Propane IS the problem. It is inherently dangerous on a boat because it is heavier than air, which means it will accumulate in the bilge if leaked inside the hull volume, and it is extremely explosive (several times more so than TNT).

It is possible to mitigate these risks by taking a lot of care, but still boaters are killed every year in gas explosions. It's one of the main risks of boating, statistically.

Like others, I use gas for cooking, because there doesn't seem to be any good alternative, but my next boat will not have propane on board at all.


Your rail mounted system is elegantly simple, and simplicity adds to safety by reducing points of potential failure. But by no means solves everything. You can still have a propane leak at the stove or in the gas line or connections inside the hull volume.

And gas lockers don't solve everything, as my case shows. A particularly bad case was the explosion of the Royal Navy training yacht Lord Trenchard. See: https://assets.publishing.service.go..._trenchard.pdf. Despite extremely thorough procedures (it's the Royal Navy!!), they managed to blow themselves up. The fault was a leak between the gas locker and the hull volume.

Do you pressure test your gas locker? No, I didn't think so. Neither do I. And I just accidentally found a hole where a screw had been, last year, and sealed it up. It seems like there's always something else you can miss.

Thank you for your thoughts Dockhead. I agree that there is an inherent risk with propane or any fuel for that matter. I believe the safety aspect is all about mitigating risk. The ABYC standard calls for a single line connected from the propane shut-off to the appliance. In my case there will be one connection inside the hull and it will be to the stove in my case. I have used propane on boats and at home for 15 years now and agree that it represents a serious hazard on a boat. As you also agree it is a very good cooking fuel. A bilge blower on a diesel powered boat is a great option. We are looking into induction cooking which may be efficient enough along with the microwave to eliminate the propane but the energy budget is not finished being drawn up yet.
Not to hi-jack the thread but, I have removed the oil lamps, one of which is an Aladdin and something I see as far more hazardous to my health. Atomized diesel fuel spraying against a hot exhaust is also more likely to be disastrous. I have done everything I can to eliminate open flame and fuel-fed fire, installed gas, smoke, o2, monoxide, and propane detection.
I am wondering what the real numbers are on propane caused injury and death in sailboats around the world.

[Dockhead]

Originally Posted by nautitrix

Thank you for your thoughts Dockhead. I agree that there is an inherent risk with propane or any fuel for that matter. I believe the safety aspect is all about mitigating risk. The ABYC standard calls for a single line connected from the propane shut-off to the appliance. In my case there will be one connection inside the hull and it will be to the stove in my case. I have used propane on boats and at home for 15 years now and agree that it represents a serious hazard on a boat. As you also agree it is a very good cooking fuel. A bilge blower on a diesel powered boat is a great option. We are looking into induction cooking which may be efficient enough along with the microwave to eliminate the propane but the energy budget is not finished being drawn up yet.
Not to hi-jack the thread but, I have removed the oil lamps, one of which is an Aladdin and something I see as far more hazardous to my health. Atomized diesel fuel spraying against a hot exhaust is also more likely to be disastrous. I have done everything I can to eliminate open flame and fuel-fed fire, installed gas, smoke, o2, monoxide, and propane detection.
I am wondering what the real numbers are on propane caused injury and death in sailboats around the world.

Natural thread evolution, not hijack!

I agree with all of this. A really good propane system following well thought out standards, and then operated and maintained with great care, of course dramatically reduces risks. The problem is how many possible points of failure there are and how really difficult it is to be sure you've covered all of them. Besides the risk (small risk of a really catastrophic event), it is just big PITA to really stay on top of.

Once upon a time I looked for statistics on gas explosions on boats. Naturally there are no worldwide stats, but there are different things online if you want to look. They are often mixed up with fire casualties so not always that transparent. In any case, however, it is clearly seen that several people die every year in gas explosions on boats, which is a lot considering the population. IIRC one year I looked at (2015?), more people died in gas explosions on boats in the UK than drowned by falling overboard or any other cause except carbon monoxide inhalation (which was #1 IIRC). So even if we can't find exact statistics, it is at least obvious that gas explosion is a risk in the first rank of boating risks.

Kudos to all of your work on other risks. That's a fundamental part of designing or even specifying a new boat. Fuel sprayed on a hot exhaust is a serious question (fuel hose routing is implicated in this), also overheated exhaust from stoppage of water injection -- it goes on and on. In our sport, we have to manage a lot of risks. Eliminating gas as one of them would really be nice -- leaving more time to worry about other stuff which is less easy to get rid of, like falling overboard, carbon monoxide, etc.

[Dockhead]

Originally Posted by leftbrainstuff

It wasn't lpg that caused your issue. Why blame it.

I didn't blame it. I blamed my own stupidity. Nevertheless, LPG on a boat is a very bad compromise if there are other options.

Originally Posted by leftbrainstuff

I check our gas locker drain as part of our monthly checks. I pour a bucket of water in the gas locker and watch it drain out the transom.

That's what I used to do, and as others have pointed out, and as I explained in the original post, it tells you nothing about the system's ability to drain away leaked gas. Going through this test merely gives you a false sense of security just like the Lord Trenchard crew's procedure of pumping the bilges before starting up engines.

Originally Posted by leftbrainstuff

I'd rather have lpg than lion batteries. They are a hideous fire hazard. You'll need lots of them with your all elec stove.

I agree that LiFePo4 batteries are a really serious fire hazard and another serious risk to manage. For that matter, a large bank of lead-acid batteries is also a big fire risk.

But using gas for cooking doesn't allow you to eliminate battery banks -- you're stuck with that problem no matter what. It is rational systems design to use a single system for both cooking and electrical needs, and then concentrate effort on making that system as robust and safe as possible, rather than dividing your resources and attention between two dangerous systems. It allows you to concentrate resources better.

Electric cooking would not necessarily require additional battery capacity. It depends on the other parameters of the system. My present boat wouldn't need more capacity, for example, if I were to drop in electric cooking. I've got a 6.5kW heavy duty generator PLUS a heavy duty alternator which will put out realistic 2.5kW at slow cruising speed, and 420A/h @24v of batts, and a 3kW inverter. My system includes a lot of electrical equipment already including washer/dryer etc., so adding electric cooking would hardly be noticed. I'd just do the heavy cooking while doing generator runs or while motoring, just like I already do with the washer/dryer. And obviously at the dock this is no problem at all. Induction cooking is remarkably efficient and doesn't need all that much power.