A Close Call

[Wussername]

http://www.edp24.co.uk/news/somerleyton-carbon-monoxide-poisoning-1-5545579

[Guest]

Speaking as an eye witness to the incident it was a very big presence by the emergency services , 2x fire engines, 2 x coastguard , 2x ambulance's 1x first responder a fire department boat  and several unmarked cars etc , I was walking team dog at the time and obviously had to obey the area blocked off for as long as it took ( team dog enjoyed meeting fire men etc n nearly got in one fire engine !  ) .

All in all a very sad situation I saw them leave all happy in the morning n then in the evening that happened , trust me I was pretty shaken up by it as it brought so many memory's flooding back of when I lost someone very close to me at reedham just over 5 yrs ago due to a heart attack.

Incidentally that vessel is very similar to the one in the incident at wroxham where there were fatalities and also petrol powered .

I truly hope everyone recovers from this cos trust me it was pretty scary to witness .

 

[dnks34]

30 minutes ago, Ricardo said:

Incidentally that vessel is very similar to the one in the incident at wroxham where there were fatalities and also petrol powered .

I truly hope everyone recovers from this cos trust me it was pretty scary to witness .

 

I immediately thought the very same thing.

[ChrisB]

And me, no true transom allowing the flow up under the canopy. Sorry to hear that it sparked unhappy memories Ricardo. I remember your loss, tragic.

[dnks34]

Comparing the pictures for both incidents it could almost be the same boat. 

[BSS]

We issued some blunt non-nonsense advice a few weeks ago. The nub is this, any boater using a petrol engine needs to keep their senses open, because if they can smell petrol-engine exhaust fume in the cabin space, turn off the engines and get out immediately. https://www.boatsafetyscheme.org/about-us/news-and-press-releases/news-releases/nr18-002-blunt-co-warning-for-petrol-engine-users/

This applies to all petrol engine users, but especially anyone with a large capacity inboard. Love For Lydia at Wroxham was followed by Vasquez in Cardiff Harbour and Mais Ouis in Jersey all in two years, four boaters dead - all running big petrol engines on cruisers with canopies over the back deck.

During the MAIB investigation, the engines on Love For Lydia filled the cabin with thousands of ppm of CO in seconds. So the formula is simple 'smell petrol engine exhaust fumes inside = get out now action', end of. It can't be assumed it'll be ok - done it lots of times, I'll know the difference etc, etc, etc.

Last week it was two boaters in Georgia, North America who died. This week its four Broads boaters in hospital. Keep your wits about you folks.

[JennyMorgan]

There was also very little wind to blow fumes and gas build-ups away. 

[Guest]

Fact is these sports cruisers were not designed to have engines running with canopies up but open at the back, thankfully no deaths this time but I don't understand why C02 detectors are not mandatory for the BSS  

[MauriceMynah]

It depends where you draw the line 40something. Perhaps banning the canopies is the way forwards (and you all know I say that tongue in cheek) No, Until there is fixed advice as to what action to take if your Co alarm goes off where you can't make out any source, their compulsory fitting would be inappropriate.

I had one go off at home a couple of years ago. It was 1am on a rainy winters night. Neither my sister nor I could find any reason. Question, What action should I have taken? 

Now place yourself on a boat at the Berney Arms mooring. it is a cold spring night. It is 1am and your Co alarm goes off. You can find no reason for this. What do you do, and for how long do you do it? 

[Malanka]

You flush out the top layers of the inside air as quickly as possible whilst staying outside as CO effectively fills up from the top down. That's why it's so pernicious when you are sleeping so by the time you wake up and sit up you have already been poisoned and short of a High pressure oygen chamber you are a gonner no matter what. And you do "it" until the detector stops detecting. And again yes this will be a long time.

Remember Fiona and I had the electrical fire in Malanka, we were sitting and only felt something was wrong when we stood up, at that point the impact and effect is instantaneous and dramatic. We then saw smoke and had to deal with it or watch the boat burn down, so I dealt with it after getting Fiona the heck off the boat. All done whilst holding my breath as I knew what would happen if I took more breaths. I already had the roaring in the ears plus the inability to actually take a BREATH that did anything which is very very scary. (if you've ever been put under in a choke hold that's what it feels like) Smoke plus CO is a nightmare that still sometimes wakes me up.

It was only my Royal Borough of Windsor and Maidenhead Fire service (Rire Responsible Person) training that kicked in and gave me the confidence to get the extinguisher out and deal with it again holding my breath. Oh and I am not a fan of powder fire extinguishers, Tripple F for me all the way now when possible.  

The stink and clean up afterwards was horrednous. Thank you Mr Dyson..

The day after the fire the newly purchased CO alarm kept pinging every now and then as we disloged a patch of CO in the ceiling of the boat. We didn't have any detectors before the fire and now use the CO detector which still detected CO the next day in the highest part of the boat and its very sensitive.

M

 

 

[MauriceMynah]

This is where I get confused Martin. Is Co heavier or lighter than air? from what you say it's lighter, which makes sense given that we are supposed to place the detectors high. But if lighter than air, why doesn't it escape through the ceiling vents?

[Vaughan]

It is most important, in these discussions, not to confuse CO2 with CO.

CO2 always exists in the atmosphere and is more present in a small boat cabin simply because we are sitting in there, breathing it out! This is why boat accommodation must have fixed ventilation, by law. A gas appliance such as a cooker gives off nothing but CO2 and water, so this requires even more ventilation. CO2 is not a poisonous gas but it can suffocate you, by cutting out oxygen in the living space.

CO is usually the result of incomplete combustion and it is a colourless, odourless and poisonous gas. A gas cooker burning with white tips on the flames is very dangerous in this respect.

Petrol engines give off enormously more CO than diesel (this is why the Americans insist on cars with catalytic converters) but the exhaust from a diesel contains such a tiny amount of CO that it is negligible.

As to what actually happened in this case, we are best not to speculate.

[Paul]

1 hour ago, MauriceMynah said:

Until there is fixed advice as to what action to take if your Co alarm goes off where you can't make out any source, their compulsory fitting would be inappropriate.

I can't agree with that, there is pretty clear advice on what to do, get out. 

1 hour ago, MauriceMynah said:

I had one go off at home a couple of years ago. It was 1am on a rainy winters night. Neither my sister nor I could find any reason. Question, What action should I have taken? 

Get out, and then be thankful that you had one fitted so you could be with us today to recite the story. 

1 hour ago, MauriceMynah said:

Now place yourself on a boat at the Berney Arms mooring. it is a cold spring night. It is 1am and your Co alarm goes off. You can find no reason for this. What do you do, and for how long do you do it? 

Get off, and stay off until the alarm says it is safe to return. Cold and wet is better than dead.

Carbon monoxide kills. You don't have to be asleep, it catches you unaware, makes you drowsy and puts you to sleep. A sleep you will never wake up from. I have lost a close friend to CO poisoning and would not be without proper detectors. Good quality ones with display to show ppm. It should be law that every habitable building has them, every boat, every caravan, every tent. There is no excuse.

[Malanka]

Hi John,

It's simple, Carbon (14) weighs less atomically than an atom of oxygen (16) does. Oxygen appears in the atmosphere as 02 which is 2x16 (32), CO is one of each which is 14+16 (30) Scientifically this is referred to as the Molecular weight i.e. how much does a molecule of X weigh when molecules are made up of individual atoms. (its more technical than that but we don't need to start discussing ideal gasses and Moles) CO2 is one carbon two oxygens so a molecular weight of 46. and so an oxygen rich 2x16 filled atmosphere with lots of Nitrogen 2x15 (as a molecule its N2) is 30. Has oxygen, nitrogen, carbon dioxide C02, and Carbon Monoxide CO. When there is a roof it is trapped and so fills up from the top down.  Of these Nitrogen which doesn't help with respiration and CO are the lightest.

Remember respiration is what goes on after the breathing bit which is just physical gas in gas out forced by Diaphragm movements and intercostal muscle movements. If you are not breathing in respirable gasses you are doomed after only a few breaths.

The issue is that under normal circumstances CO binds irreversibly to the haemoglobin molecule and so an oxygen molecule cannot displace it (unless we increase what's called the partial pressure of the gas mix by increasing the external atmospheric pressure in a chamber and then sometimes the CO can be displaced), simply giving pure oxygen just allows the Haemoglobin molecules not yet bound to CO to be saturated with O2, it does not displace the CO unless at elevated partial pressure.

So CO will "tend to be" at a physically higher level in undisturbed atmosphere than 02 as it weighs less. CO mixes freely with the Nitrogen (also molecular weight 30) you cannot utilise Nitrogen in respiratory processes either.

 

CO2 is a bit of a red herring as all Co2 does is exchange with O2 under normal gaseous exchange in the lungs, roughly 400ppm in and up to 35000 ppm out. What CO2 does is act as a trigger for breathing when the level in the bloodstream rises to a threshold value which is quite low, there is another trigger which is lack of O2 but this is way lower and normally CO2 is the trigger. 

You can prove this to yourself by hyperventillating for two minutes (if you try sit down to do it or you'll fall down) and then wait until you need to take a breath, this is why you breathe faster and deeper during exercise, CO2 build up prompts you to. 

When you hyperventillate you purge the CO2 and so until the low O2 level trigger is initiated or the CO2 builds up to the threshold value you'll not need to take a breath. Feels quite wierd actually, when I was younger I could quite easily do this for nearly three minutes, if I did it now I'd collapse or pass out after 30 seconds of hyperventillating, as I did when I went for a lung function test last June. 

 

All good stuff. Hope this helps.

When you sit in a human physiology exam and they ask you to discuss respiration the number of people you can see holding their ribs to decide internal or external intercostal muscle use is hilarious or it was for me 33 years ago.

One more scientific thing to leave you with. The level of CO2 required to place most humans in respiratory distress is 5000 ppm. With only 400 ppm in the atmosphere at the moment how did evolution give us a stress level of 5000 ppm? I'll help by adding that stress is what prompts evolution, i.e. we can't evolve systems that respond to 5000ppm without being exposed to 5000 ppm.

As far as I know the PPM meter on nuclear subs is /can be, set to 3000 / 3500 ppm, so the military know this physiological glitch and have done for decades. The submariners routinely breathe air with many times the normal level of CO2 than is present in the atmosphere and these guys have the nuclear button in their hands...LOL

M

 

 

Edited June 4, 2018 by Malanka

[Malanka]

I will now go and have a lie down.....

[Hylander]

41 minutes ago, Malanka said:

Hi John,

It's simple, Carbon (14) weighs less atomically than an atom of oxygen (16) does. Oxygen appears in the atmosphere as 02 which is 2x16 (32), CO is one of each which is 14+16 (30) Scientifically this is referred to as the Molecular weight i.e. how much does a molecule of X weigh when molecules are made up of individual atoms. (its more technical than that but we don't need to start discussing ideal gasses and Moles) CO2 is one carbon two oxygens so a molecular weight of 46. and so an oxygen rich 2x16 filled atmosphere with lots of Nitrogen 2x15 (as a molecule its N2) is 30. Has oxygen, nitrogen, carbon dioxide C02, and Carbon Monoxide CO. When there is a roof it is trapped and so fills up from the top down.  Of these Nitrogen which doesn't help with respiration and CO are the lightest.

Remember respiration is what goes on after the breathing bit which is just physical gas in gas out forced by Diaphragm movements and intercostal muscle movements. If you are not breathing in respirable gasses you are doomed after only a few breaths.

The issue is that under normal circumstances CO binds irreversibly to the haemoglobin molecule and so an oxygen molecule cannot displace it (unless we increase what's called the partial pressure of the gas mix by increasing the external atmospheric pressure in a chamber and then sometimes the CO can be displaced), simply giving pure oxygen just allows the Haemoglobin molecules not yet bound to CO to be saturated with O2, it does not displace the CO unless at elevated partial pressure.

So CO will "tend to be" at a physically higher level in undisturbed atmosphere than 02 as it weighs less. CO mixes freely with the Nitrogen (also molecular weight 30) you cannot utilise Nitrogen in respiratory processes either.

 

CO2 is a bit of a red herring as all Co2 does is exchange with O2 under normal gaseous exchange in the lungs, roughly 400ppm in and up to 35000 ppm out. What CO2 does is act as a trigger for breathing when the level in the bloodstream rises to a threshold value which is quite low, there is another trigger which is lack of O2 but this is way lower and normally CO2 is the trigger. 

You can prove this to yourself by hyperventillating for two minutes (if you try sit down to do it or you'll fall down) and then wait until you need to take a breath, this is why you breathe faster and deeper during exercise, CO2 build up prompts you to. 

When you hyperventillate you purge the CO2 and so until the low O2 level trigger is initiated or the CO2 builds up to the threshold value you'll not need to take a breath. Feels quite wierd actually, when I was younger I could quite easily do this for nearly three minutes, if I did it now I'd collapse or pass out after 30 seconds of hyperventillating, as I did when I went for a lung function test last June. 

 

All good stuff. Hope this helps.

When you sit in a human physiology exam and they ask you to discuss respiration the number of people you can see holding their ribs to decide internal or external intercostal muscle use is hilarious or it was for me 33 years ago.

One more scientific thing to leave you with. The level of CO2 required to place most humans in respiratory distress is 5000 ppm. With only 400 ppm in the atmosphere at the moment how did evolution give us a stress level of 5000 ppm? I'll help by adding that stress is what prompts evolution, i.e. we can't evolve systems that respond to 5000ppm without being exposed to 5000 ppm.

As far as I know the PPM meter on nuclear subs is /can be, set to 3000 / 3500 ppm, so the military know this physiological glitch and have done for decades. The submariners routinely breathe air with many times the normal level of CO2 than is present in the atmosphere and these guys have the nuclear button in their hands...LOL

M

 

 

And to quote Trigger from Only Fools and Horses,   "so what are you saying".    Only joking.    It is all very complex and I agree with the sentiments above about better to be wet and cold than dead.    One thing I was concerned about with the Broom's Captain is that they are all sealed windows, unless of course you have fabulous weather and can open the roof top in the front cabin.  However I did notice that there is a Co2 alarm in the galley.

[MauriceMynah]

Martin, My question was very much simpler than your answer. As we both know "air" isn't an element, it's a right old cocktail and as such will have a different weight from that of it's two major ingredients (Nitrogen and oxygen) but what do those other ingredients do to the air when comparing it with the weight of Co.

As you say, lets not bring Co2 into the frame except in that it is an ingredient of air. Frequently I hear/read people saying/writing Co2 when they mean Co, so lets take it as read, they mean Co.

So, my question remains. Is Co (normally) heavier or lighter than air for all practical purposes? As questions go... It's kinda important.

If I take it from one of your earlier posts it seems to be lighter, so my other question becomes more relevant... Why don't ceiling vents allow it's escape?

Paul, Sorry but "get out" isn't where the story ends. Get out and do what? Who should I call? The emergency services?  How far "out" do I need to be?  Would standing in the cockpit with the sides off be enough?  If not, how far from the boat would be safe for me?

The one that went off at home had either detected something other than Co that had triggered it or the unit was faulty. We came to that conclusion when it didn't shut off even when there seemed to be no possible Co source. We went back to bed.

My instructions to someone who's Co alarm has gone off seems to be different from yours.. Get everyone off the boat, and assuming there is no apparent source, after having had some fresh air, hold your breath and return to the boat opening all windows and doors. Retreat and wait for the alarm to stop. If the alarm hasn't stopped after at least10 minutes with full ventilation. remove alarm. It's faulty (as I believe ours was.). 

Monica, It is a Co alarm not a Co2 alarm. A frequent mistake made.

  

[CambridgeCabby]

CO is lighter than air , CO2 is heavier .

 

we have a detector in our cabin which we test every time we go aboard , it doesn’t make sense to have one fitted if you don’t regularly test it ,please check yours are still functioning fellow forumites they save lives .

[Bound2Please]

[grendel]

I think (looking at martins figures) that the problem is that co is lighter than oxygen, but not lighter than the nitrogen in the air, since the nitrogen makes up the bulk of the air (78%), and since it and the co are the same weight, it doesnt rise comparative to most of the atmosphere, but builds up at the higher elevations (or more to the point the oxygen sinks down to be just above the carbon dioxide)

without air circulation (ventilation) therefore the co builds up in the nitrogen and displaces the oxygen we need. on convection alone if the co levels are increasing, then it wont flow out of the ceiling vents as its mixed in with the nitrogen, but is slowly displacing the heavier oxygen. so stirring the air about will help, but the co will get you as its  mixing with the nitrogen faster than it can flow though the ceiling vents. that and if the incoming air contains the co, then its not refreshing the oxygen.

[Guest]

A bit of good news on this incident , BA visited the marina this morning and I'm happy to report that all 4 persons are OK , I also spoke to the boats owner at lunch time n they fully realise how lucky they were , there are apparently CO alarms onboard but they are in the forward cabin but additional alarms are being fitted in the aft cockpit area .

[MauriceMynah]

That is good news Ricardo, and thanks Grendel, that I understand. Now, Why do petrol engines produce more Co than Diesel ones?

[Paul]

1 hour ago, MauriceMynah said:

Why do petrol engines produce more Co than Diesel ones

The Nitrogen found in diesel forms NOx, which is the stuff that gives diesel it's bad name. The lack of Nitrogen in Petrol means the Oxygen molecules bind with Carbon to produce CO

Or so I understand. I'm sure somebody will be along with Chemistry 2.2 sometime soon.

 

[Guest]

1 hour ago, MauriceMynah said:

That is good news Ricardo, and thanks Grendel, that I understand. Now, Why do petrol engines produce more Co than Diesel ones?

I recall it is because diesel engines have better combustion due to the excess of air in the mixture even at full load. 

[Malanka]

Petrol engines can be tuned to reduce both CO and CO2 produced. So called lean burn technology has been available for many years. If folks remember the eutrophication scandal of the 70s and 80s  ( acid rain killing fish and Forrests in Scandinavia) 

More modern research has shown that CO from cars was NOT the culprit and farming practices had way more influence. So we then fit cats to cars to turn the non problem CO into CO2 which we of course now tax, wonder why that happened.

to answer your question John Grendel said it in that yes CO per volume weighs less than what we call air. Remember I mentioned respiration as we respire with oxygen not air and we breathe air not pure oxygen. So my answer was not more complicated than the question my answer is what’s Necessary to understand to fully understand why as you put it the CO doesn’t escape out the vents. Movement of air inside rooms is not like balloons rising or not depending on weight. The answer involves basic thermodynamics I.e. excited molecules ( warmer) occupy a larger volume therefore they are relatively lighter than the same gas with a lower temperature in the same volume. I said I didn’t want to explain ideal gasses and physics but think about this . P1x V1 divided by T1 is always equal to P2xV2 divided by T2. The individual values my change but the sum of the energy equation is ALWAYS equal.

p is pressure 

v is volume

t is temperature

decrease volume increase pressure and thus increase temperature. It’s how fridges work actually.

so it can’t escape because it’s not a balloon it’s distributed in the other non oxygen parts of the total volume. Some will but it doesn’t take much once bound to the haemoglobin it’s bound and going nowhere. Remember this is all at the molecular level.

if the air in your boat is at a lower temperature than the CO then yes most will escape. If they are the same then the CO will SLOWLY move to the top. This is a very slow process which is why defective boilers kill people when they are asleep not when they are moving about.

i will tell you all about the myth that is temperature over a beer sometime.

 

CO is LIGHTER than the weight of air at the same temperature but not all gasses in the air are at the same temperature all the time. You’re really asking a question about mass and temperature not lighter or heavier.