Gas

[pmagowan]

Just reading through the boat safety scheme regarding how one would best design a gas system for a sailing boat. I know lots of you don't like gas but I personally think the risk is low and you can't cook properly on electric. I was simply wondering what would be the ideal layout for a gas installation.

The BSS suggests a bubble valve at the gas locker but then how many people sit there watching for bubles? Is it not just another connection to go wrong? They are also very keen on solid pipe which I would have thought was more likely to fracture with the twisting and movement of a sailing boat over time.

I think it is sensible to have a draining locker, a gas alarm and a good way to shut it off. I also think that the idea of protective grommets is a good one. In my current boat I am going to take the deck off and may have to explore the possibility of making a proper gas locker. It is problematic due to the size of the boat and getting any drains to go above the waterline but I am sure I will think of something. With my next boat I can design the 'perfect' system with your help.

 

[Eyore]

Gas is perfectly safe with a few sensible precautions. This is my setup.
Gas locker draining overboard. Flexi pipe into copper where is goes through bulkhead followed by gas tap on copper which is turned off every time cooking is finished. Flexi pipe to cooker. Apart from turning off gas tap after use every time, the bottle is shut off when the boat is left. I have also got a gas alarm with a sensor below the cooker and one in the bilge.

 

[Rigger Mortice]

If your boat is flexing so much that a properly mounted metal gas pipe fractures then you have a much bigger problem to worry about than a gas pipe.

 

[AntarcticPilot]

Just reading through the boat safety scheme regarding how one would best design a gas system for a sailing boat. I know lots of you don't like gas but I personally think the risk is low and you can't cook properly on electric. I was simply wondering what would be the ideal layout for a gas installation.

The BSS suggests a bubble valve at the gas locker but then how many people sit there watching for bubles? Is it not just another connection to go wrong? They are also very keen on solid pipe which I would have thought was more likely to fracture with the twisting and movement of a sailing boat over time.

I think it is sensible to have a draining locker, a gas alarm and a good way to shut it off. I also think that the idea of protective grommets is a good one. In my current boat I am going to take the deck off and may have to explore the possibility of making a proper gas locker. It is problematic due to the size of the boat and getting any drains to go above the waterline but I am sure I will think of something. With my next boat I can design the 'perfect' system with your help.

It's hardly "lots" - probably the vast majority of us cook with gas! And you are quite right to say that the risk is low as long as the installation is properly done.

Electricity is rarely used as the primary means of cooking on boats, except for occasional use in marinas; few boats have the generating capacity to keep up with an electric cooker. The primary alternatives are paraffin (kerosene if you're in the States) and methylated spirit. Diesel stoves are available, but costly and rarely used.

All are regarded as safer than gas from a fire hazard point of view, but you should be aware that the primary danger for any cooking using a flame isn't fire or explosion; it's carbon monoxide poisoning. There have been several deaths from this cause reported on here (search for "carbon monoxide"), and a badly adjusted cooker can kill you pretty quickly. Paraffin with a vapourizing "roaring" burner is probably the most hazardous in this regard, though I've had a CO alarm go off with a gas cooker on my boat.

I'd suggest that an important safety feature is a carbon monoxide alarm, cheaply available from most hardware stores.

Otherwise, the BSS is widely regarded as sensible advice; if you intend to take your boat on a canal for any length of time, it becomes mandatory. Flexible pipes are subject to wear and deterioration with age. If armoured, they can't readily be inspected; that's why they are deprecated. Rigid pipes should be secured sufficiently frequently to avoid vibration etc.

 

[sarabande]

on the basis that the riskiest boating sector for gas installations is our canal brethren, it's worth considering the details of the BSS Gas Installation protocols.

If you install to these standards, you have only operator error to worry about afterwards.

http://www.boatsafetyscheme.org/boat-examination/boats-with-gas/

 

[pmagowan]

If your boat is flexing so much that a properly mounted metal gas pipe fractures then you have a much bigger problem to worry about than a gas pipe.

I don't think so. The BSS suggests that the pipes should be securely attached. Copper is not very resistant to fracture and even minor movement repeatedly can cause fractures. It is not a case of flexing enough to bend the pipe 30 degrees each way! Uri Gellar could maybe explain more!

 

[sarabande]

work hardening by vibration of pipes contiguous to an engine or a resonating panel is a possibility, but unlikely. I'd go for copper pipes and fixing which reduces vibration*, e.g. closed cell dense PU. Ideally, though you should have multiple layers of vibration absorbing material to account for varying frequencies.


Can't see it being necessary, though.


* I've seen small coils of fuel pipe near engines, about 2 - 3 inches diameter, to absorb any movement.

 

[Rigger Mortice]

All are regarded as safer than gas from a fire hazard point of view, but you should be aware that the primary danger for any cooking using a flame isn't fire or explosion; it's carbon monoxide poisoning. There have been several deaths from this cause reported on here (search for "carbon monoxide"), and a badly adjusted cooker can kill you pretty quickly. Paraffin with a vapourizing "roaring" burner is probably the most hazardous in this regard, though I've had a CO alarm go off with a gas cooker on my boat.

Is that quite accurate? Whilst I agree that cookers have been involved in cases of CO poisoning, I've always understood that it was when people were using them as cabin heaters rather than for the relatively short time that they are used for cooking.

 

[vyv_cox]

I don't think so. The BSS suggests that the pipes should be securely attached. Copper is not very resistant to fracture and even minor movement repeatedly can cause fractures. It is not a case of flexing enough to bend the pipe 30 degrees each way! Uri Gellar could maybe explain more!

Copper has reasonable fatigue resistance, if it didn't there would be far more electric cable failures that in fact there are. The gas piping in my boat is copper, supported at about two foot intervals by short pieces of hose sikaflexed to the hull. It has been like that for 30 years, no sign of any fractures.

 

[pmagowan]

Copper has reasonable fatigue resistance, if it didn't there would be far more electric cable failures that in fact there are. The gas piping in my boat is copper, supported at about two foot intervals by short pieces of hose sikaflexed to the hull. It has been like that for 30 years, no sign of any fractures.

OK so soild pipe it is, as long as it is reasonably secured especially if by some vibration damping fixings. What about copper in the context of corrosion etc on a boat. I presume the copper in gas fittings would not come into electrical contact with any other metal so no problems here??

Do we all replace our regulators every 10 years? Or our hose?

I presume at the end of the day we should simply follow the BSS word for word unless htere is anything particular about sailing boats that their scheme is not designed to cover.

 

[Rigger Mortice]

I don't think so. The BSS suggests that the pipes should be securely attached. Copper is not very resistant to fracture and even minor movement repeatedly can cause fractures. It is not a case of flexing enough to bend the pipe 30 degrees each way! Uri Gellar could maybe explain more!

I suspect that the answer is that experience shows that metal pipes are more reliable than flexible pipes. If you are worried about copper then there are other options, stainless being one, but, personally, I would just stick with copper.

I think it is more important to ensure that the pipe is routed in such a way that it cannot be damaged by things bashing about in lockers.

 

[sarabande]

I suspect that the answer is that experience shows that metal pipes are more reliable than flexible pipes. If you are worried about copper then there are other options, stainless being one, but, personally, I would just stick with copper.

I think it is more important to ensure that the pipe is routed in such a way that it cannot be damaged by things bashing about in lockers.

Stainless is more brittle (less ductile) than copper.


Good point about protecting the pipes from adventitious damage. What do you think about slitting some hosepipe lengthwise, and 'clipping' it onto the pipe in sections ? It could then be removed easily if you want to inspect the pipe.

 

[Tranona]

I don't think so. The BSS suggests that the pipes should be securely attached. Copper is not very resistant to fracture and even minor movement repeatedly can cause fractures. It is not a case of flexing enough to bend the pipe 30 degrees each way! Uri Gellar could maybe explain more!

Securely attached does not mean rigid. My copper pipe runs in plastic hose which is clipped at 300mm centres.

There is nothing difficult about basic gas installations as it is well proven technology. As noted already the BSS regulations are good and easy to follow. For most people with smaller boats the gas tight vented locker is the biggest problem owing to lack of depth in the stern to get it above the waterline. Problem gets easier as boat size increases and provision is made in the original design.

Doubt forget the gas and CO sensors.

 

[pmagowan]

I suspect that the answer is that experience shows that metal pipes are more reliable than flexible pipes. If you are worried about copper then there are other options, stainless being one, but, personally, I would just stick with copper.

I think it is more important to ensure that the pipe is routed in such a way that it cannot be damaged by things bashing about in lockers.

That is a good point and is quite difficult to achieve. The BSS says that the pipe should be able to be inspected along its entire length yet to protect it you would think covering it up would be better. Perhaps if it is routed right along the top of lockers above anything that would likely hit it.

 

[pmagowan]

Stainless is more brittle (less ductile) than copper.


Good point about protecting the pipes from adventitious damage. What do you think about slitting some hosepipe lengthwise, and 'clipping' it onto the pipe in sections ? It could then be removed easily if you want to inspect the pipe.

I think SS work hardens also so any movement in it would make it more and more brittle. The hose pipe protection might be worth a thought. Would it risk trapping moisture next to the copper and promoting corrosion?

 

[pmagowan]

Securely attached does not mean rigid. My copper pipe runs in plastic hose which is clipped at 300mm centres.

There is nothing difficult about basic gas installations as it is well proven technology. As noted already the BSS regulations are good and easy to follow. For most people with smaller boats the gas tight vented locker is the biggest problem owing to lack of depth in the stern to get it above the waterline. Problem gets easier as boat size increases and provision is made in the original design.

Doubt forget the gas and CO sensors.

Can you vent it from high up in the locker as long as and route to the bilges is above the vent?

 

[NickTrevethan]

Just reading through the boat safety scheme regarding how one would best design a gas system for a sailing boat. I know lots of you don't like gas but I personally think the risk is low and you can't cook properly on electric. I was simply wondering what would be the ideal layout for a gas installation.

The BSS suggests a bubble valve at the gas locker but then how many people sit there watching for bubles? Is it not just another connection to go wrong? They are also very keen on solid pipe which I would have thought was more likely to fracture with the twisting and movement of a sailing boat over time.

I think it is sensible to have a draining locker, a gas alarm and a good way to shut it off. I also think that the idea of protective grommets is a good one. In my current boat I am going to take the deck off and may have to explore the possibility of making a proper gas locker. It is problematic due to the size of the boat and getting any drains to go above the waterline but I am sure I will think of something. With my next boat I can design the 'perfect' system with your help.

Electric induction is as good or better than gas - just as responsive, super efficient, no CO risks, doesn't generate wet heat, indeed only generates heat in teh cookware

Just saying... and I am one of those who are not a gas fan, I have it but looking to get rid of it from a safety perspective.
I want to cut risks and while the risk of a gas leak in a properly installed system is low, the consequences are very significant.

Other factors - availabilty of your type of gas - I use camping gaz 907 bottles, which I have to order at 27 quid each (delivered). Nowhere nearby seems to sell them.
Will the cylinder type you choose be available in your cruising grounds. The liveaboard forum is replete with requests from people who want to know where to get gas. You mentioned heading up to Norway and cruising other cooler climes so you want to know you can get your refills!

Check out induction cooking. To me its a great solution for a bigger boat. No connection - well maybe a small one - I write about coal for a living so I guess I have a very slight vested interest ins eeing people use more electricity

 

[Rigger Mortice]

That is a good point and is quite difficult to achieve. The BSS says that the pipe should be able to be inspected along its entire length yet to protect it you would think covering it up would be better. Perhaps if it is routed right along the top of lockers above anything that would likely hit it.

The problem with that is that when a boat is heeled hard over and bouncing off waves the top of a locker suddenly becomes vulnerable, so I'm not sure what the best answer is. The BSS isn't really concerned about boats that tip over and go on bumpy water.
On my boat the copper pipe was glassed in when it was made. I think that is frowned upon nowadays.

Interestingly, the BSS doesn't appear to make any recommendations on the distance between pipe fixings. It just says that the pipe shouldn't move.

 

[Seajet]

As my boat has a big cockpit for 22' and I almost always sail with 1 crew, I made a ' gas box ' extension to the bridgedeck.

This consists of 2 pieces of marine ply, making the front and top ( which has antislip tape strips ).

The sides are open and the bottom doensnt reach the cockpit sole, so there's plenty of ventilation, and I can reach out of the companionway to turn the regulator on while cooking, then immediately off again.

It also makes a handy seat, and as I do less cooking aboard than I used to, the second bottle space is used for stowing a bucket, along with winch handles & breadkife for fouled prop' etc.

Flexible hose ( replaced every winter as part of the refit ) at the gas bottle & gymballed cooker, with a one-piece length of copper tube inbetween, I have gas & CO2 alarms as they're cheap compared to having myself re-made a la Six Million dollar man !

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[AntarcticPilot]

Is that quite accurate? Whilst I agree that cookers have been involved in cases of CO poisoning, I've always understood that it was when people were using them as cabin heaters rather than for the relatively short time that they are used for cooking.

The most dangerous use of a flame-based cooker is to heat a cold pan with inadequate space between pan and flame. This maximizes the production of CO, even with a well-adjusted flame. The incident where we set off a CO alarm happened when a poorly adjusted burner was being used to boil a kettle of cold water; if we hadn't had a CO alarm, we might well have been another statistic. It is a well-known hazard in polar exploration, where water has to be obtained by melting snow!

People should be aware that paraffin pressure stoves produce significant CO even when working properly; even small deviations from correct operation can be fatal - this has been the cause of fatalities in Antarctica. In this regard, gas is safer than paraffin (though drip-fed or wick based paraffin is safer).

Of course, any misuse of a cooker increases the chances of CO production; using one as a heater may well do so. But normal cooking operations can switch a marginally safe cooker to unsafe operation