Co Gas Detection

[teadaemon]

4 hours ago, ChrisB said:

Both the Kidde and Fire angel combined smoke/CO are very good products. I only have a very small boat but if I wished to protect a large 30ft+ boat my preference would be a Heat Enhanced Optical smoke detector and a dedicated CO detector. My reason for this choice  is with the low head room in boats ionisation as combined usually are, employ a radioactive source, today this is usually Americium 241 which is pretty tame by the old radium standards but are designed assuming a ceiling height of 8ft.  Ionisation should certainly not be fitted above your head where you my be for a long period ie above your bunk.

Considering that the isotope in question (Americium 241) produces alpha particles that are stopped by human skin, is a sealed source, and there's only about 0.3 micrograms of it in a modern smoke/CO detector (with an activity of approx. 1 microcurie), that would seem to be somewhat over cautious. You'd probably take in more radiation eating a banana than you would sleeping under an ionisation smoke/CO detector.

[Vaughan]

22 minutes ago, teadaemon said:

4 hours ago, ChrisB said:

Both the Kidde and Fire angel combined smoke/CO are very good products. I only have a very small boat but if I wished to protect a large 30ft+ boat my preference would be a Heat Enhanced Optical smoke detector and a dedicated CO detector. My reason for this choice  is with the low head room in boats ionisation as combined usually are, employ a radioactive source, today this is usually Americium 241 which is pretty tame by the old radium standards but are designed assuming a ceiling height of 8ft.  Ionisation should certainly not be fitted above your head where you my be for a long period ie above your bunk.

Considering that the isotope in question (Americium 241) produces alpha particles that are stopped by human skin, is a sealed source, and there's only about 0.3 micrograms of it in a modern smoke/CO detector (with an activity of approx. 1 microcurie), that would seem to be somewhat over cautious. You'd probably take in more radiation eating a banana than you would sleeping under an ionisation smoke/CO detector.

Phew!

Me, I shall still "prioritise" on adequate fixed ventilation.

[MauriceMynah]

I'm going to fit a banana to my boat's ceiling, well better safe than sorry.

[ChrisB]

Actually the Alpha particles are absorbed within the detector, the gammas escape and are considered harmless in the concentration given off. 

Within the industry it is still advised not to site any product produced from source Plutonium 241(Americium 241 is produced in a reactor from Plutonium 241) close to bed heads or over school desks etc. That is why the industry standard is now optical, heat or combined optical/heat. They cost more but are not prone to going of if you make a bit of toast!  (Hence folk remove the battery)

Recently there has been alot of discussion about disposal. It was always considered safe to put in household rubbish, but the vry low cost of ionisation makes people change them every time they decorate. And with landfill becoming concentrated in fewer sites! Talk has been of having dedicated skips for them at recyle centres for incineration.

Any detector is better than none but I still would recommend Optical for the few extra pounds. You will make toast, grill pork chops and not have to fan the detector of heavens forbid remove the battery!

 

 

[ChrisB]

Don't know why it posted and would not let me say:

Ionisation are good at small airbourne particles hence going off with toast and grilled bacon but Optical are much better at the slow smouldering of electrical wiring, foam etc. Given the nature of the dc electrics in boats I would always go the optical route.

But there are other forms of protection, We fitted linear to the engine rooms of superyachts in the past.

[Mowjo]

21 hours ago, stumpy said:

The first thing we fitted to No Worries was a Fireangel CO detector. It's a sealed unit with a life of 7 years,it has a green flashing LED to show its functioning which goes amber when it's time to bin it and start again. We know it works as a hire boat set it off with its exhaust while moored at Womack last year -apparently they had to run their engine because a light on the dashboard told them to. £20-odd didn't seem a lot for peace of mind! We 

Well! Thats exactly what I just bought to replace my other one, I went for it because it's a sealed unit and know that if my grandkids or anyone else uses my boat there's no chance of them removing the battery, the reason I changed to the digital is that the little green light on my other one is hard to see, but I do check it everytime I'm on theboat, at least now with the digital PPM screen I can see at a glance, I got mine from Wick's for £29.00 but if anyone is interested I just found this on Amazon for £18.00,, FIREANGEL

[StillCruising]

Possibly a stupid question but are these units best mounted on the ceiling (cabin roof) on an upright surface.

Regards

Bob

[BroadAmbition]

As per the manufactures instructions would be the sensible answer.  We have the aft one mounted vertical on a bulkhead and the fwd one horizontal on the deckhead

Griff

 

[ChrisB]

As a general rule smoke detectors should be ceiling mounted making sure that no hanging bulkheads or beams mask them or stop smoke reaching them.

CO detectors should be vertical mounted about  200mm below the ceiling except when the area is used for sleeping in and then about 400mm above pillow height would be about right.

CO is very slightly lighter than air and if it can not escape upwards the build up comes lower and lower with tragic consequences for those lay prone asleep.

[ChrisB]

Griff's answer is absolutely correct, but manufacturers instructions tend to assume a cube. You may have to interpret them as a near as possible solution in boats where the configuration of galleys, berths and cabins is endless.

[ChrisB]

PS.

As I said before dont mount CO detection too close to your appliance as many do emit CO on start up, this is especially true of some of the more traditional "Taylors" type stoves where pre-heating with meths is used before the parafin will fully vaporise. Difficult on a small craft but a min of one metre from hob or oven should suffice.

[StillCruising]

Chris B.

Thanks for the general info on the CO alarm mounting, of course I would follow the manufactures instruction if I had bought a unit. Your comment about the manufactures  'cube' assumption is well made it was an issue with the placement of a smoke alarm when we had our loft extension done.

As well as an Ebber our boat also has Thermx gas heaters which we tend to use if moored close to others because of the exhaust noise and the possibility our fumes drifting, so the positioning will probably be fairly critical. We have lots of fixed vents in the roof and cabin doors but for the cost of them the alarms will be a good addition to our safety.

Regards

Bob

[webntweb]

We have a Kiddie CO detector which you can lift off its backplate.

In winter we sometimes run the Webasto on low all night if there are no boats nearby.

I unmount the detector and take it into the bedroom and place it on a shelf about 18 inches above my head when sleeping.

The reason I do this is because the Webasto is between the detectors normal position and the bedroom.

Don't know if I am doing the right thing - anybody any thoughts.

Roy

[ChrisB]

18 inches above your head is spot on. But for the sake of a few quid why not leave it where it is and have an additional one above your berth.

[BroadScot]

12 minutes ago, ChrisB said:

18 inches above your head is spot on. But for the sake of a few quid why not leave it where it is and have an additional one above your berth.

Wise words Chris. Or put another way, money well spent !

Iain

[ChrisB]

21 minutes ago, StillCruising said:

Chris B.

Thanks for the general info on the CO alarm mounting, of course I would follow the manufactures instruction if I had bought a unit. Your comment about the manufactures  'cube' assumption is well made it was an issue with the placement of a smoke alarm when we had our loft extension done.

As well as an Ebber our boat also has Thermx gas heaters which we tend to use if moored close to others because of the exhaust noise and the possibility our fumes drifting, so the positioning will probably be fairly critical. We have lots of fixed vents in the roof and cabin doors but for the cost of them the alarms will be a good addition to our safety.

Regards

Bob

Bob has raised a very important issue here.

When you do not have a flat ceiling, but, say an apex, like in many loft conversions you can get something called "heat shielding" 

Hot air from central heating goes right up into the apex and smoke rising from combustion may not penetrate this layer of hot air but run along it as though it were a glass ceiling. Smoke detectors, especially ionisation types should not be placed high up in an apex for this reason.

There used to be a test rig at the Fire Training College, Morton-in-Marsh that demonstrated this brilliantly.

[Viking23]

1 hour ago, webntweb said:

...I unmount the detector and take it into the bedroom and place it on a shelf about 18 inches above my head when sleeping...

Roy

If you do unmount the detector, be aware there is often a mechanical interlock, that stops it remounting if no battery is fitted, unless you compress the battery, before it can remount.

So do check if by demounting, that you haven't disconnected the battery, or allow the battery to fall out. I have seen this on smoke alarms a lot, so I assume CO detectors could be the same.

Use the test button, now, and again a few hours later.

 

 

[webntweb]

40 minutes ago, Viking23 said:

 

It has a light that flashes occasionally when working. I am pretty sure I checked that when I demounted it in March.

Thanks for the warning and I will definitely check it next time I am board.

[LondonRascal]

I did not see there was a thread on this topic but there is a post that was made on one of the Norfolk Broads Facebook Groups which covered the topic of Carbon Monoxide and alarms, since there has been someone talking of how a hire boat they had did not have an alarm fitted and finding this worrying. 

This sort of topic pops up every now and then usually when there has been attention in the news about a suspected or confirmed tragedy that involved Carbon Monoxide. 

Frankly to my mind things have got a lot better and not just because of awareness and alarms but because there is far less gas being used on boats generally.  Think back to the days of catalyst gas heaters in every cabin. 

That said, there is confusion on the subject where some may assume that Carbon Dioxide (CO₂) and Carbon Monoxide (CO) are the same. They are not but both are produced when you burn fuels – like gas or diesel. 

The thing is, we as humans can stand quite high concentrations of Carbon Dioxide and just feel a bit dizzy or not quite right – it is only when things get stupidly concentrated that it becomes life threatening.  Not so with Carbon Monoxide where just a small concentration can build up in your blood stream and cause unconsciousness and eventual suffocation. 

Air can be about 5 percent CO₂, from a stuffy room, before to u may feel a little uncomfortable. From reading on Wikipedia, amounts above 800 Parts Per Million (ppm) are considered unhealthy, amounts above 5,000 ppm are considered very unhealthy, and those above about 50,000 ppm are considered dangerous to animal life.

Carbon monoxide CO, unlike CO₂, is a bad poison. CO is produced by incomplete combustion, for example when there isn't enough Oxygen to make CO₂, you get CO and that is why one is often drawn to the attention of faulty gas appliances afloat or in the home not burning with a clean, blue flame.  Sure, you still get some CO and CO₂ but with adequate ventilation it will not provide a health hazard. 

Carbon monoxide binds in a very strong manner the Iron in the Haemoglobin in the blood stream. Once Carbon Monoxide attaches, it is very difficult to release. So if you breathe in Carbon Monoxide, it sticks to your Haemoglobin and takes up all of the Oxygen binding sites. Your blood loses all of its ability to transport Oxygen, and you suffocate.

Because Carbon Monoxide binds to Haemoglobin so strongly, you can be poisoned by Carbon Monoxide even at very low concentrations - if you are exposed for a long period of time. 

Concentrations as low as 20 or 30 ppm can be harmful if you are exposed for several hours. Exposure at 2,000 ppm for about an hour will cause unconsciousness.

The thing is despite all this, as I said to begin in the main things are perfectly safe – using a cooker on a boat is fine so long as the ventilation space has not been blocked up and that space is not just a guess, it is all about volume and number of people on board and so on and you may find even when a lot of guest are on a boat you get that ‘stuffy feeling’ which is not Carbon Monoxide but Carbon Dioxide, an opening a window will rapidly help things improve.

However, should you ever suspect that your suffering signs of Carbon Monoxide poisoning commonly referred to as if suffering for ‘flu like’ symptoms like a headache, dizziness, weakness, an upset stomach or vomiting, chest pain, and confusion – get outside right away and seek medical help because as I said above the molecules that have attached to the Haemoglobin are not just going to ‘let go’ and you return back to normal health in a few minutes – despite being outside breathing normally, your body will just not be getting as much Oxygen as it usually would be. 

The only thing that will show up how much you’ve been poised is a blood test and as a result of high levels you’d likely have 100% Oxygen delivered by a tight fitting face mask – normal air is roughly made up of just 24% Oxygen. Breathing in concentrated Oxygen enables your body to quickly replace Carboxyhaemoglobin. Therapy will continue until your Carboxyhaemoglobin levels decrease to under 10%.

So now you know about that Carbon Monoxide can do to you what do you do to help stop it?  Well there are on the average boat not many sources of it but would include the engine, a diesel heater and the hob, oven and grill. I think it is a good idea at least once a year, but perhaps twice yearly to have a good check about the exhaust of your diesel heater  to ensure there are no leaks – the same goes for your engine from the actual exhaust elbow right down through water lock/silencer to exit from boat. 

How does your hob, grill and oven burn? Are vents clear of dust and spider webs? It is simple things that could make all the difference – not to mention the fitting and regular testing of a Carbon Monoxide alarm (or 2).

Of course some boats might have more things that may produce Carbon Monoxide like a built in generator – and it goes without saying should you have a portable generator don’t run the thing on the boat.  Don’t have a BBQ inside – or under an awning that is not open sided (yes some have done such things) don’t use portable gas heaters in a boat – and remember when you burn fuel it burns Oxygen, that Oxygen needs replacing from outside (you also consume Oxygen when breathing) so it is vital there is air coming into the boat.

Ok pleased I let all that out because this is an important issue.

[Bob48]

we always have at least one window open on any of those that we have hired , the last one we went on had 4 in the cabin ( all open when the hob was on ) and the door open too , better safe than sorry , she also had a roof vent or maybe an escape hatch  in the forward end ,which i had open during the day for airing purposes , i think that as long as you are sensible this sort of thing shouldn't happen , as i said at the beginning always have a window open we had the " down wind" side open every night ,there is always an extra blanket should you need one .

 

[Movic]

Well done Robin, I agree with every thing you have said.

I work as a Paramedic with the London Ambulance Service and have attended many calls involving this stuff some with fatal  consequences. We now have specialist teams that deals with this type of incident with some people requiring Hyperbaric Oxygen Therapy which is the same that divers  suffering with the " Bends" receive. There is only a few chambers in the country , one being at whipps cross. However the Jury is still out on how effective the treatment really is.

We keep hearing that Co monitors etc are not expensive, and they are not. So why do people still not have them. More to the point why are they not mandatory, particularly on hire craft ?

All boats on the broads network are subject of a Boat Safety Check . No safety check Cert, no registration !

These should be part of that check. fitted and in working order. Yes people could fit one for the check and then remove it after buy why would they? after all we are not talking hundreds of pounds here.

My family and kids lives are not up for debate !

 
.

[JawsOrca]

Do hireboats still not have alarms and monitors?!

Geez this is surely a perfect example were the BSC is flawed?? I suspect the BSC aim is prevention is better although evenso they should be fitted without discussion. 

I wouldn't sleep on our boat without alarms and have both smoke and CO in all cabins.

The BSC scheme needs to get on top of this and make these mandatory even for boats with current certificates. 

If I was hiring I'd certainly take a couple of alarms with me.. (Exhaust fumes give off CO as does heating fumes so when moored stern on surely there's a great risk).

[BroadScot]

Any hire craft I have been on in the past 10 years or so have a fixed locked open window very close to the cooker in the galley. This does not mean to say that somebody on a hire boat may attempt to block such a draft!. Also, last thing at night before retiring to bed, I turn the gas tap at the cooker off !

Iain

[Vaughan]

Let's look at this chemically for a moment. The composition of butane gas is C4 H10.

One part butane needs just over 6 parts oxygen when burning. This means you need 31 parts of air, since oxygen only forms a small percentage of the air that we breathe.

So "complete" combustion of the gas will mix 4 parts carbon, 10 parts hydrogen and 13 parts oxygen.

When combustion is "complete" you end up with 4 parts CO2 and 5 parts H2O (water). Do the maths if you don't believe me!

If the primary air ports to the cooker are blocked, or if there is not enough ambient air to mix enough oxygen, you still get H2O but the some of the CO2 becomes CO. This is called incomplete combustion and you can immediately see it, if the burner flame has a white tip.

If it has a white tip, you are in danger! Conversely, if it has a perfect blue flame then you are NOT releasing CO into the boat.

Three other things can be noticed from this calculation.

1/. LPG exhaust when burning perfectly, consists ONLY of CO2 and water. There are no other pollutants.

2/. One cubic metre of butane burned on a cooker will release two and a half litres of water into the air in your cabin. No wonder the windows are running in the morning! Another good reason for ADEQUATE VENTILATION.

3/. By the way, it may now occur to you that the lovely "living flame" gas fires that you can buy for your house are a prime example of incomplete combustion and are VERY dangerous.

 

VENTILATION is the key to all this for me. I am not disparaging the fitting of CO detectors but please don't forget that by doing so you are just attacking the symptoms, but not the disease itself.

You can never have enough VENTILATION.

 

 

 

 

[Siddy]

Well some good points shared on this including mounting locations etc.

The poll I wanted to run one of the question was do you have a detector install then at the end of the season the same question to see if results had improved. Also what testing happens.

" Do hireboats still not have alarms and monitors?! " This would have to be tested on handover before the kids have swapped the batteries for there mp3 player. It happens same as tv remotes even in our conf rooms the batteries get swapped/nicked. They'd have to glue the cover inplace.