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wetfoot

Information on water cooled exhaust manifold please

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My son has bought a broad beam canal boat fitted with a Yanmar 4JH4AE engine.

The engine had what appeared to be a home made, aluminium, water cooled exhaust manifold with the exhaust gas going straight through an aluminium box about the size of a shoe box. The 'shoebox' had a radiator style filler cap on top and two connections about 30mm diameter for the engine cooling water/antifreeze to circulate in and out on its way to the skin tank.

That's it, no connection to the canal water or the 'elbow' I've heard so much about. (I've found a picture of something very similar at attach it here as I don't have access to the real thing at the moment)

 

Due to its size and weight the exhaust inlet pipes  have cracked several times in spite of being re-welded, so I'm looking to replace the whole thing.

 

First of all, can someone tell me the point of it? is it simply to keep the engine bay a little cooler? It realise it will cool the exhaust gasses but they leave the boat after about 1.5m so why should I care if they are hot?

 

Secondly can anyone tell me where I might be able to get a replacement or even what the correct name is of the thing I should look for?

 

All my searches for 'water cooled exhaust' or 'manicooler' come up with loads of stuff about an elbow that corrodes and directly injecting sea water into the exhaust gas which this doesn't do.

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Try Bowmans e.g.

https://www.ejbowman.co.uk/products/MarineHeatExchangers.htm

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The water jacket is not there to cool the exhaust gasses, its there to prevent the manifold glowing red hot as it might if a water jacket was not in use.

 

The major UK mariniser of Yanmar engines introduced a cheap range of non-Yanmar units and they kept their automotive the manifold that was just wrapped in glass fibre thermal insulation.

 

In fact it looks rather like a "Fred in a shed" DIY bit of kit to me.

 

Its just a water cooled exhaust manifold for a Yanmar 4JH4AE.

 

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4 hours ago, Tony Brooks said:

The water jacket is not there to cool the exhaust gasses, its there to prevent the manifold glowing red hot as it might if a water jacket was not in use.

Why does the exhaust manifold in a boat 'glow red hot' when the same manifold in my 2 litre diesel car sitting at 1500 rpm doesn't? From what I have researched it is unlikely to get more than around 900 Dec C.

 

4 hours ago, Tony Brooks said:

 

The major UK mariniser of Yanmar engines introduced a cheap range of non-Yanmar units and they kept their automotive the manifold that was just wrapped in glass fibre thermal insulation.

Yes I heard about that, hence my question about whether the water cooled manifold was really necessary

4 hours ago, Tony Brooks said:

 

In fact it looks rather like a "Fred in a shed" DIY bit of kit to me.

 

What does? the picture I uploaded? I thought that was a genuine yanmar component

 

Its just a water cooled exhaust manifold for a Yanmar 4JH4AE.

iI it? That would be good to know. If that is a picture of a water cooled manifold for the 4JH4AE engine then my problem is solved. I can simply buy that one. However as I do not really know much about these things I am relying on all you experts to help me out.

4 hours ago, Tony Brooks said:

 

 

4 hours ago, Onewheeler said:

Try Bowmans e.g.


https://www.ejbowman.co.uk/products/MarineHeatExchangers.htm

Thanks, I did look there but all their products seem to assume you are using sea water to cool the manifold, not the ordinary engine coolant - unless I am looking at the wrong thing.

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8 hours ago, wetfoot said:

Thanks, I did look there but all their products seem to assume you are using sea water to cool the manifold, not the ordinary engine coolant - unless I am looking at the wrong thing.

The heat exchanger couldn’t care less where the water comes from. It’s designed to operate in a closed loop system anyway. It’s ‘just’ a water jacket surrounding the manifold. 

8 hours ago, wetfoot said:

In fact it looks rather like a "Fred in a shed" DIY bit of kit to me.

 

What does? the picture I uploaded? I thought that was a genuine yanmar component

Yanmar do not I believe manufacture any marinising components - those are manufactured by the mariniser. Tony was making the point that the mariniser made a pretty much DIY job of it. 

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8 hours ago, wetfoot said:

Why does the exhaust manifold in a boat 'glow red hot' when the same manifold in my 2 litre diesel car sitting at 1500 rpm doesn't? From what I have researched it is unlikely to get more than around 900 Dec C.

 

Yes I heard about that, hence my question about whether the water cooled manifold was really necessary 

iI it? That would be good to know. If that is a picture of a water cooled manifold for the 4JH4AE engine then my problem is solved. I can simply buy that one. However as I do not really know much about these things I am relying on all you experts to help me out.

 

 

1. So you have had a look after an hour or so flat out while still running fast? Anyway the faster the car goes the more cool air is rushing around and about the engine, unlike your boat where there is virtually no air flow around the engine.

 

2. I gave you an example of where a water jacketed manifold is not used. Some Ford XLD marinistaions don't have a water jacket around the exhaust manifold. I would have thought that you could draw your own conclusions but if you can't then I am unwilling to say its not necessary because then if by some chance something goes wrong you might sue me.

 

3. You normally pay for expert help. Are you saying that the photo is a commercially available manifold? If so you need to contact the vendor and get the plans/dimensions so you can take measurements and check it will fit your engine. You need to ensure the manifold will not foul any marine or base engine parts, that the ports are in the correct place and the fixing stud holes are correctly placed.

 

I got the impression that the photo was of your manifold, not one offered for sale.

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Thank you Tony, I'm not sure why you seem to have taken offence at my queries. I don't know anything about boats or boat engines (I'd never even heard the term marinisation until now). I was simply hoping that someone on this forum was an 'expert' relative to me. My activity as an expert on forums for other topics usually consists of knowledgeable people helping out those less knowledgeable, if necessary in simple terms, without sarcasm and without expecting to be paid.

 

The picture was simply one I got from Google images but it is for a different engine. It's the only picture I could find that looks like my son's one. All the others have an elbow that seems to actually inject the water into the exhaust gas, not simply surround the exhaust pipe.

 

Are you able to tell me who the major UK mariniser of Yanmar engines is so maybe I could contact them?

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Many years ago I bench tested a new Ford diesel engine intended for road use.  I can confirm that stationary on the tdyno the uncooled  exhaust manifold did indeed get any where beween dull red and bright red, depending on the power demanded.  At full chat we were quite worried about the long term integrity of the manifold.

In a car, but not in a boat engine space, there is a howling gale rushing through the engine space once the vehicle is moving at normal speeds.  There is also a fan to assist at low speed.

N

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12 minutes ago, wetfoot said:

Thank you Tony, I'm not sure why you seem to have taken offence at my queries. I don't know anything about boats or boat engines (I'd never even heard the term marinisation until now). I was simply hoping that someone on this forum was an 'expert' relative to me. My activity as an expert on forums for other topics usually consists of knowledgeable people helping out those less knowledgeable, if necessary in simple terms, without sarcasm and without expecting to be paid.

 

The picture was simply one I got from Google images but it is for a different engine. It's the only picture I could find that looks like my son's one. All the others have an elbow that seems to actually inject the water into the exhaust gas, not simply surround the exhaust pipe.

 

Are you able to tell me who the major UK mariniser of Yanmar engines is so maybe I could contact them?

The reason I am not feeling particularly good towards you is because  your second post I replied to seemed to imply those forum members with a  degree of expertise were not trying to help you when I was. You also questioned my assertion from a degree of expertise that exhaust manifolds glow red hot at times.

 

You do not need an exhaust mixing elbow on a dry exhaust boat but you ma have to buy a manifold wit one already fitted, remove it and fabricate a suitable flange  fitting to connect the exhaust pipe.

 

E P Barrus of Bicester marinise some Yanamar engines in their Shire range but how willing they will be to sell you a manifold for your own marinisation is open to question.

 

You say the exhaust pipe keeps breaking. This suggest it may not be well enough supported, it may not have a flexible section if the engine is on flexible mounts, or the flexible section is aligned so it does not allow for sufficient engine movement. If its on flexible mounts it may also be the mounts are broken/worn out or they are not adequate for that engine.

 

You do not need a heat exchanger core in your manifold but you may ave to buy one with it. If so you just need to ignore or block the holes that feed the heat exchanger core. NOT the  ones that allow water to circulate around the core. Those are the ones you connect to.

 

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OK, thank you for the information, very useful. I'll contact E P Barrus to see what they can do. 

 

Thanks also for the info about blanking the manifold core pipes. That makes sense as nearly all of the images I looked at had such a core so I assumed they were not what I was looking for. Simply blanking those pipes would convert the manifold into something similar to what my son has.

 

You are correct that when my son bought the boat a month ago the only way the large, heavy, manifold was supported was simply by the exhaust inlet pipes so it is not surprising that the aluminium pipes had suffered stress fractures and were broken. I could also see that they had been repaired more than once in the past due to similar fractures.

 

I got the manifold repaired at a local agricultural engine repairers who were familiar with yanmar and did aluminum welding. Then I fabricated a steel support shelf for the manifold which attached both to the engine block sideways and to the engine mounts downwards (on the engine side of the flexible mount so it vibrated with the engine). However after moving the boat 21 miles my son says the pipes have broken yet again so its now time to look for an alternative. I'm even considering buying a TIG welder and making one myself!

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The manifold should be supported by the bolts which hold it to the cylinder head and there should be a flexible part between the manifold and the rest of the pipework.  In a water injected exhaust this is normally a bit of rubber hose after the water injection point.  Yours is a dry exhaust so you should be able to get a suitable piece of flexible metallic exhaust pipe to go between the manifold and the fixed-to-the-hull pipework.    One sort , though not my preference,  is here:  https://www.asap-supplies.com/exhaust/flexible-dry-exhaust-pipe

 

Mine came from Uxbridge Boat Centre but there are other chandlers.  There are weld-in and screw types  e.g..  https://www.limekilnchandlers.co.uk/exhaust-flex.html If you go for the weld-in type you need to think about how it might be got apart again if ,say, a decoke was needed.

 

N

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2 hours ago, BEngo said:

Many years ago I bench tested a new Ford diesel engine intended for road use.  I can confirm that stationary on the tdyno the uncooled  exhaust manifold did indeed get any where beween dull red and bright red, depending on the power demanded.  At full chat we were quite worried about the long term integrity of the manifold.

In a car, but not in a boat engine space, there is a howling gale rushing through the engine space once the vehicle is moving at normal speeds.  There is also a fan to assist at low speed.

N

I have had the pleasure of testing a big v8 petrol on a dyno outdoors late evening. The manifold got more than red hot and took on a very strange almost translucent appearance, It looked as if I could actually see the pulsations of hot gas going through it but maybe that was my imagination.

 

Our JD3 does not have a watercooled manifold. I will try to estimate its temperature next time I run without the heatshield.

 

.................Dave

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@BEngo

 

Yes there is a flexible, insulated, exhaust pipe bolted to the outlet pipe of the manifold, which then goes out of the side of the boat. From the bit I can see before the insulation starts it looks the same type as the one you got from Uxbridge Boat Centre. Although that 1.3 m of pipe is not supported so probably added to the weight and vibration on the exhaust manifiold, which is then transmitted to the welds on the flange.

 

I guess ideally there should be short flexible pipes between the manifold flange and the water cooling part to prevent stress fractures, although I suppose having solid aluminium pipes would aid in the cooling of the bits of pipe between the flange and where the exhaust is being cooled by allowing heat to travel quickly towards the cooler parts.

 

I'm certainly learning a lot about marine engineering. It's a whole new world!

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If you are saying its the exhaust stub pipes that  attach the mounting flange to the cylinder head that smap then that suggests they are too long or too thin. It may also suggest the engine as excessive and large vibration (back to a mount problem, misfiring, or the shaft being out of alignment. As we can not see your manifold we do not know and cannot guess.

 

Ideally when the exhaust system is disconnected from the manifold the flange (if it as one) then the exhaust flange should just sit there more or less in line with te manifold. If it drops more than half an inch or more UNLESS its just the flexible flexing then you know the manifold is trying to support the exhaust and the extra weight may well damage the manifold.

 

No wet exhaust manifold I have seen has flexibles between the manifold and exhaust flange. Those sort lengths need to be as short as possible so  engine vibrations do not try to make them flex. The manifold and engine should move as one great big lump. If you look at Beta exhaust manifolds on their range of marinised Kubota engines you will see they have no stub pipes . The manifold bolts go right through the manifold so the engine face of the water jacket goes straight against the cylinder head.

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I hope it helps to add a couple of photos of end caps. Here is the Bowman exhaust manifold on my boat with the primary water going through it on its way to the skin tank.  after I had upgraded it to create a separate circuit feeding a couple of radiators in the boat.  (second photo is of the rather expensive tubestack I had to add.

 

Always good to have spare end caps and jubilee clips on board, as they can split.

 

dscf3154.jpg

 

896191148b60149d6fe20a3d797bb2f625af568a

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21 minutes ago, Scholar Gypsy said:

I hope it helps to add a couple of photos of end caps.

And here is mine :

And then the exhaust just below the end cap.

 

IMG_20151219_085335.jpg

Versatility-35-1.jpg

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Thanks for the pictures. That helps a lot.

In the end I have contact the person who had the cooler in my original pic and arranged to buy that from them as I think it will fit. It still has stub pipes but the cooler itself is smaller, rather like the picture from Scholar Gypsy so will not create such a large bending moment on the welds.

 

I don't have a very useful picture of the original, broken one from my son's boat but you can see it in the attached picture. It's the big black black box with the car radiator cap on the left of the rocker box cover. (I painted it black after the repair and added the strap down to the support that I fabricated)

 

The depth is almost the same as the width, ie from the side it is almost square. I'd estimate when full it would hold about 6 litres of coolant, about 6Kg, plus about 5Kg for the cooler itself, plus some weight from the exhaust pipe, means the pipes are (were) supporting over 11 Kg of vibrating mass. The other photo shows the support frame that I fabricated before the repaired cooler was fitted, with legs down to the engine side of the engine mounts and also across to the flywheel cover. It's made from 5mm thick steel strapping with a thin layer of closed foam padding on top, apart from the top strap which is only 1.5 mm thick.

 

However I've just driven down to my son's boat in London and all the flange welds have failed again and the cooler, complete with all four pipes can be pulled completely out of the flange bolted to the engine block.

 

Good job I bought the other one as they seem hard to come by and very expensive. But if it doesn't quite fit it will be simpler to make a flange converter than a whole new cooler. But I think it will fit as the engine it comes from is the same make, bore and stroke as my son's, just a slightly smaller HP so I'm guessing it's the same engine block.

 

@Alan de Enfield

One day my son's engine bay will be as clean and pretty as yours !

 

Priority at the moment though is to get the engine working nicely, then get the solar panels working to charge the new Lithium batteries and strip out  and remove a full size, ceramic, pump out toilet, its collection tank tank and two macerator pumps that have been sitting unused, full of sewage, for two years and then replace the whole lot with a compost system. 

 

 

 

 

Capture.JPG

IMG_20180704_150349.jpg

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I really don't want to get sidetracked from a helpful, technical discussion on marine engines into an emotive discussion on waste disposal. 

However I feel I must respond by saying 'who wants to go to a marina, park nose to tail with your neighbours, pay through the nose for everything they offer, then hook up to mains water, electricity and (pump out) sewers'? Might as well live in a terraced house.

 

Composting toilets are very widely used and can be clean and environmentally friendly - if used properly ie not simply emptied into a 'normal' toilet or elsan point as that rather defeats the purpose. Dumping it in an elsan point uses a lot of water and effectively gives your sewage to someone else to deal with instead.  I can see why marinas would object to having a large quantity of waste disposed of at once at such a point, especially if those doing so were irresponsible and made a mess. 

 

But apart from the plastic in a nappy, the solid contents of a compost toilet consist of practically the same chemicals, bacteria and other substances as a baby's nappy or adult's incontinence pads, except that being dry it does not smell and is easier to handle. I understand it falls under the same disposal regulations as such items as nappies (except, as you pointed out, those regulations made up by private land owners such as marina owners) although as it can be classed as dry sludge it is more suitable for direct land use, further composting or landfill via the normal waste collection systems.

 

Personally I'd rather have dry poop in a sealed container (not under my bed) for a couple of months than 300 litres of mixed up urine and poop slurry sloshing around in a tank that I can't do anything with without going to a marina and paying someone to waste another 300 litres of fresh water to dispose of it down the severs.  

 

But each to their own. 

 

(BTW the comment about your engine bay was intended as a compliment.)

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1 hour ago, wetfoot said:

(BTW the comment about your engine bay was intended as a compliment.)

It was taken that way, and I thank you.

 

Toilets are the ongoing 'big-issue', they are required for something that all of us do every day, but there are very entrenched views from those who have whatever 'type' and few are rarely convinced to move to something else.

 

My post was supposed to be a very mild introduction to what you will get in the forthcoming months.

 

Everyone has the right to use whatever they wish - but in all seriousness read the thread I linked to as it appears that the waste produced may / does not comply with waste transfer laws.

The waste transfer laws are not 'made up by private marina owners', they are Government acts of Parliament (Laws) and marinas are contravening the regulations by allowing the 'composted' (or in many cases partly-composted) waste to go into the waste disposal 'chain'. Our business produces waste and we have to make a declaration as to exactly what goes into the bins - anything they find which we have not declared (and given them the opportunity to refuse) and we are in serious trouble.

The point about "they can impose whatever rules they wish" was meant to be with regard to refusing boats with composting toilets entry into the marina - not - anything regarding the waste transfer legislation..

 

Good luck with the whole project. (said with sincerity)

Edited by Alan de Enfield

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17 minutes ago, Alan de Enfield said:

... it appears that the waste produced may / does not comply with waste transfer laws.

The waste transfer laws are not 'made up by private marina owners', they are Government acts of Parliament (Laws)

I know that's what your notice from BWML said, but I don't believe them.

 

If you can find something to support their theory I would be grateful - because as I said in the other thread, disposable nappies are *supposed* to be put in general waste. 

 

Are there age limits at which human waste becomes illegal?

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8 hours ago, TheBiscuits said:

I know that's what your notice from BWML said, but I don't believe them.

 

If you can find something to support their theory I would be grateful - because as I said in the other thread, disposable nappies are *supposed* to be put in general waste. 

 

Are there age limits at which human waste becomes illegal?

A quick Google search brings up loads of interesting stuff - building regs (obviously not boat relevant) and EA requirements - if you want to know any specific 'stuff' then I suggest DYOR

 

1) EA Requirements

If the toilet is connected with a householder (i.e. located on a domestic premise), and the waste it generates is kept within the premises (e.g. spread onto a garden), it is not subject to control under the Environmental Permitting Regulations 2007 or Sludge (Use in Agriculture) Regulations 1989. If the waste leaves the premises (e.g. to be spread onto other land) the situations described below may apply. However, in all cases the site specific nature of the operation must be individually assessed.

If the toilet is connected with a business, and not a private individual, the composting operation may be subject to controls under Environmental Permitting Regulations 2007. For example, the Para. 12 Exemption, Schedule 3 of the Environmental Permitting Regulations 2007 may be applicable.

Any further treatment of the waste from the composting toilet (before it is disposed or recovered/recycled) may be subject to controls under the Environmental Permitting Regulations 2007. For example, if the waste is subjected to secondary composting before its disposal or recovery the Para. 12 Exemption, Schedule 3 of the Environmental Permitting Regulations 2007 may be applicable. Alternatively, the waste may be sent to a sludge treatment centre for treatment in accordance with the Sludge (Use in Agriculture) Regulations 1989.

 

2) Building regulations

Part G 4.19 states (as of Jan 2018) “Chemical toilets or composting toilets may be used where: a. suitable arrangements can be made for the disposal of the waste either on or off the site; and b. the waste can be removed from the premises without carrying it through any living space or food preparation areas (including a kitchen); and c. no part of the installation would be installed in any places where it might be rendered ineffective by the entry of flood water.”

Part G 4.21 goes on to say: “Composting toilets should not be connected to an energy source other than for purposes of ventilation or sustaining the composting process.” In other words, dehydrating and incinerating toilets which use energy (gas or electricity) to dry the contents (beyond the natural composting process) will probably not pass building regulations.

 

So, all these super 'gas or electric incinerating drying toilets' cannot be used in a house.

 

3) The waste transfer regulations are not easy to follow and pretty much anything is banned depending on how you read it - read them for yourself and decide if sewage is allowed in a waste bin.

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2 hours ago, Alan de Enfield said:

3) The waste transfer regulations are not easy to follow and pretty much anything is banned depending on how you read it - read them for yourself and decide if sewage is allowed in a waste bin.

 

^^^This^^^

 

The plumbing forums are full of threads about how these regulations stop us tradesmen taking our lunchtime fish and chip wrappers home in our vans without a Level Two Waste Carriers Licence which costs £156 (approx) every two years. 'Trade waste' apparently, as eating our lunch counts as trade associated activity. The best solution to this problem seems to be for us to chuck the wrappers out of the window rather than risk driving along with it in the van. Putting the wrappers in the bin at home is another offence, apparently.

 

The world's gorn MAD, I tell you!

 

 

Edited by Mike the Boilerman
Add a bit.

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10 hours ago, TheBiscuits said:

If you can find something to support their theory I would be grateful

I did find this, suggesting that the contents of a composting toilet are treated the same as the contents of a septic tank.

From the "Little House" company (suppliers of composting toilet systems)

 

"......a composting toilet generates sludge which, depending on its treatment and disposal or recovery is subject to a range of regulatory controls. Within the context of the Sludge (Use in Agriculture) Regulations sludge from a composting toilet is, unless site specific reasons require otherwise, regarded as septic tank sludge, i.e. ‘residual sludge from septic tanks and other similar installations for the treatment of sewage’." 

 

 

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49 minutes ago, TheBiscuits said:

I stand corrected. 

 

It's not the age of the person, it's the weight of the poo - 7kg is the limit for disposal of non-hazardous offensive waste (ie nappies) in a commercial general waste bin. 

 

https://www.gov.uk/how-to-classify-different-types-of-waste/healthcare-and-related-wastes

 

 

It also says that it must be separated from other waste :

 

Municipal offensive waste, eg hygiene waste and sanitary protection like nappies and incontinence pads.

You must segregate healthcare offensive waste from both clinical and mixed municipal wastes.

 

But this is for 'hospital' guidance where it is expected that there will be such "offensive waste" and their waste transfer agreements will have listed it.

 

A Marina (or I'd suggest any other 'place') would not have an agreement in place with their waste carrier to allow such 'offensive waste' to be placed in the bin, irrespective of quantity.

 

I guess it now needs someone to prove that :

1) Properly composted sewage is 'non-offensive'

2) Partially composted sewage is 'non-offensive'

3) Boaters NEVER put partially composted sewage into the bins. 

 

 

 

17 Offensive/hygiene waste (yellow bag with black stripe) will require disposal at a suitably permitted or licensed landfill, incinerator or other permitted or licensed alternative treatment facility. This waste should not be compacted unless in accordance with the conditions of an environmental permit/waste management licence. Where compaction is authorised the operator should have procedures in place to contain, minimise, and monitor potential bio­aerosol releases

 

Image result for yellow bag with black stripe tiger bag

Edited by Alan de Enfield

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