Adding a second bilge pump?

[magnetman]

2 minutes ago, Tony1 said:

 

The main bilge pump is automatic, but the problem with any bilge pump is that the water has be at least few mm deep before it will kick into action, and it never removes all the water- there is always a few mm of water hanging around that it leaves behind. And ideally I'm trying to keep the bilge dry for as long as possible.

My goal is to minimise long term rust by not allowing water to collect in the bilge at all, as a general rule (and also painting with vactan etc). 

 

The main bilge pump does sit in a small vertically recessed square, about 15mm deep and maybe 30cm along each side. So in theory it should suck out any water that I tip into that little recess (from the other bilge pump), and it should suck it out before it overspills from the recess and starts running along the engine bay floor. In theory.

But yes, your idea could work, and it might be worth a try before cutting holes in the hull. So I would route the waste pipe from the second bilge pump so it drains into the small square recess where the main bilge pump is,, and let the main bilge pump suck it out.

 

It means that that the little recess for the main bilge pump will have a more or less permanent layer of a few mm of water in it, but at least the thin layer of water is contained in one small area, so any potential rust is limited to a small spot. 

 

 

 

 

It would need experimenting with. Don't forget that a bilge pump is a non positive displacement pump so you can restrict the outlet size and slow down the transfer rate without causing any problems. 

 

I think if you got a small bilge pump and plumbed it using 15mm speedfit pipe you could consider putting a valve in the pipe and arrange it so that the discharge was not capable of overloading the existing bilge pump space. 

 

You could alternatively wire the new bilge pump through a small PWM speed controller and have endlessly adjustable flow rate. 

 

Great for tinkering with ! 

[Momac]

Just now, matty40s said:

No, as I explained on the other thread, it's down to the insurance companies insisting on it at the annual conference with the surveyors.

But not universally applied to all types of boat

[Tony1]

15 minutes ago, Alan de Enfield said:

 

Surveyors report :

 

The forward deck drained via openings in the hull sides, these were of adequate size and found satisfactory. The forward deck drains were a satisfactory height above the waterline (especially when considering the front door cill) however it is very easy to overload a small vessel such as this. With full water and fuel tanks and many persons and gear onboard, freeboard heights will be greatly reduced and this must be considered at all times and outlets/drains monitored regularly. If freeboard heights become much reduced then they will need revising.  
    
Essential Repairs * Ensure freeboard height of the weed hatch is at least 15cm.
    
Essential Repairs * The bilge pump outlet must be raised to above the upper full length ‘D’ bar and the current opening plated over, using 6mm plate.
    
Four skin fittings, located starboard side, were far too close to the waterline. The bilge pump outlet must be raised to above the upper full length ‘D’ bar and the current opening plated over, using 6mm plate.
    
Essential Repairs * The galley and heads sink outlet skin fittings must be fitted with isolators as these cannot be raised as they rely on gravity drainage. These isolators must be easily accessible and clearly marked and turned off on certain waters/weather conditions.
    
The galley and heads sink outlet skin fittings must be fitted with isolators as these cannot be raised as they rely on gravity drainage. These isolators must be easily accessible and clearly marked and turned off on certain waters/weather conditions.
    
Essential Repairs * The shower pump outlet must be raised to at least 25cm above the waterline and the current opening plated over, using 6mm plate.

 

Owners comments :

 

I have studied the RCD  DIRECTIVE  2013/53/EU   and also Small craft - Seacocks and through-hull fittings - Part 1: Metallic (ISO 9093-1:1994)Publication date:Feb 14, 2019 and can find no heights specified for hull outlets, only a requirement for seacocks for underwater fittings.   There is this in the BSS https://www.boatsafetyscheme.org/requirements-examinations-certification/non-private-boat-standards/part-10-non-private-boats-safety-features/hull-openings/ but only as a suggestion of 250mm height for private boats.

The lowest of these outlets is the bilge pump 0nly 9cm above the waterline with the secured hose rising well above it and the shower outlet is 13mm.

The builder says the boat conforms with the RCD and there is nothing wrong with it as it is the same as all the 200+ boats they have built, however at my request they reballasted the boat for me as it was too low in the water at the stern.     I asked the marina to get the surveyor to recheck the boat as he was due to inspect another one, I had to pay for that in advance!   The surveyor refused to alter the survey and the marina still refused to sell the boat.  

 

Thread discussing it :

 

 

 

I honestly don't know what to make of that. My guess is that hundreds of Liverpool boats, and probably a lot of others, will be non-compliant overnight if that assessment of the surveyor becomes a generally accepted principle or rule. 

But to clear, that was not a BSS survey, right?

It was a pre-sale survey?

 

 

[magnetman]

 

 

On a GRP or wooden boat you would not have a lot of choice. If you want a sea heads outlet or engine cooling intake it would have to be a fitting of some sort. 

 

Steel boats do introduce the option of having the ideal system which is a welded in fitting. 

 

Of course there are dissimilar metals discussions to be had if the thing is underwater. 

 

I don't like underwater hull penetrations at all. They seem wrong to me and usually (not always) there is a way to avoid such things. 

 

My seagoing trawler style boat with twin diesels and optional overboard lavatory discharge has no underwater hull penetrations because it is a steel boat. 

Edited January 12, 2023 by magnetman

[matty40s]

It's NOT a BSS/BSC fail, it's a survey on a boat up for sale, where the new owner will need to insure it, and the insurers have decided and told surveyors that this is their new risk area that needs addressing by these new rules.

[Tony1]

13 minutes ago, magnetman said:

It would need experimenting with. Don't forget that a bilge pump is a non positive displacement pump so you can restrict the outlet size and slow down the transfer rate without causing any problems. 

 

I think if you got a small bilge pump and plumbed it using 15mm speedfit pipe you could consider putting a valve in the pipe and arrange it so that the discharge was not capable of overloading the existing bilge pump space. 

 

You could alternatively wire the new bilge pump through a small PWM speed controller and have endlessly adjustable flow rate. 

 

Great for tinkering with ! 

 

My problem is that I'm not much of a tinkerer, I like to get the thing done and forget about it. 

My current obsession is dry bilges, and even having a small standing pool of water in the main bilge recess square is not ideal- because that recess will rust and eventually need remedial work. 

Ideally I want the bilge to be totally dry as the normal situation for 90% of the time. I want water to be the exception- and when I do see water, I will dry it out before it causes rust. 

So I'll probably fit a skin fitting for the second bilge pump, so that it goes straight out. 

That way, when I do see water in the main bilge pump recess, I'll know its a genuine ingress from somewhere. I'd rather water in there be the exception than the rule, is my thinking.

 

Edited January 12, 2023 by Tony1

[Tony1]

12 minutes ago, matty40s said:

It's NOT a BSS/BSC fail, it's a survey on a boat up for sale, where the new owner will need to insure it, and the insurers have decided and told surveyors that this is their new risk area that needs addressing by these new rules.

 

It sounds a bit daft to me. So that particular insurance company are no longer going to insure Liverpool boats that have been surveyed as per their new guidelines?

Despite the fact that a customer could call them up looking for insurance on a 7 year old Liverpool boat that has not been surveyed to these new rules, and that customer can get insurance no problem, even though their boat has these same 'problematic' skin fittings?

 

 

Edited January 12, 2023 by Tony1

[Momac]

7 minutes ago, matty40s said:

It's NOT a BSS/BSC fail, it's a survey on a boat up for sale, where the new owner will need to insure it, and the insurers have decided and told surveyors that this is their new risk area that needs addressing by these new rules.

 

Perhaps the design of narrowboats prevents the same arrangements that are common  on sea boats 

 

 

[Alan de Enfield]

10 minutes ago, MartynG said:

 

Perhaps the design of narrowboats prevents the same arrangements that are common  on sea boats 

 

 

 

But the BSS does demand this for narrowboats with a commercial licence - eg hire boats etc.

 

So NB's can be made to meet the requirements.

[magnetman]

10 minutes ago, MartynG said:

 

Perhaps the design of narrowboats prevents the same arrangements that are common  on sea boats 

 

 

Material vessel is made from is a big consideration as well. 

 

Also sea boats will be more likely to have engine cooling taken from the waterway. Sea boats have keels which will prevent grounding damage to hull penetrations. Sea boats tend not to have long straight sides.  Sea boats often have direct discharge lavatory arrangements. 

 

There are a lot of differences but the main one is straight sided boats regularly going through limited width structures like locks and bridgeholes. 

[Alan de Enfield]

From another post (in 2021)

 

 

 

Hi Guys

I am selling my beautiful boat which is just over 2 years old ( i bought it brand new), it still has a valid RCD conformity certificate, however, the potential buyers surveyor has highlighted that the "outs" are too low to the water, i presume he's referring to the exhaust outlet which sits virtually on the water line but has a swan neck internally. My question is, What recourse do i have against the builders of my boat or the RCD issuing body themselves if my buyers pull out and i loose the sale because of this?. I did query these "outs" levels before i purchased my boat, which i can prove in an email trail. 

 

He went back to the builder who accepted responsibility and agreed to the rectification work ...........................

 

hi all

i thought i would update you all regards the sale of my boat.

when i purchased my boat brand new it came with all the usual legal paperwork including a certificate of conformity which is valid for it's 1st 4 years. i'm presuming this is the initial builders certification that is basically its initial BSS certificate. 

as you can probably imagine that when i had to sell my beautiful boat because of a breakdown of a relationship after owning it for just over 2 years i was somewhat shocked and horrified that the potential buyers surveyor picked up on the "outs" being too close to the water. Thankfully the builder has realized  that they could be on a very sticky wicket if it was proven that they had sold a boat with a legal certificate of safety which was indeed not to the regulatory requirement and have made good the problem by removing ballast from the rear of the boat and have also provided a written affidavit that they will attend to raising the exhaust outlet in the new year  for the new owners. my boat is now in the loving arms of it's new owners with all issues sorted. my warning from hindsight is this. No matter what age of a boat you intend to buy, even if it's brand new off the production line, get it fully surveyed. 

 

[Momac]

33 minutes ago, magnetman said:

Material vessel is made from is a big consideration as well. 

 

Also sea boats will be more likely to have engine cooling taken from the waterway. Sea boats have keels which will prevent grounding damage to hull penetrations. Sea boats tend not to have long straight sides.  Sea boats often have direct discharge lavatory arrangements. 

 

There are a lot of differences but the main one is straight sided boats regularly going through limited width structures like locks and bridgeholes. 

Yes I get it - you hit a lot of stuff with a narrowboat..

 

 

Edited January 12, 2023 by MartynG

[robtheplod]

Would it not be easier/cheaper possibly to focus on stopping the water getting in?

[Tony1]

29 minutes ago, robtheplod said:

Would it not be easier/cheaper possibly to focus on stopping the water getting in?

 

Yes, and I've been identifying all the routes for water to get into the engine bilge. 

The problem with the drain hole on the lowest step is that it is at or below the water line, so it can't be drained to the outside of the hull by gravity alone. I could put a bilge pump on the lower step, but if that pump fails the step will fill after 3 or 4days of proper rain, and will overflow- and that means it goes over the porch of the door and into the cabin area. 

Also, it would need a cage or something to protect it from being constantly stood on, and all this would reduce the amount of area to place your feet on that step. 

 

I feel my solution is the next best thing, which is to allow the water to drain from the step into the engine bay, but catch it in a plastic tray before it hits the floor.

If water is allowed to drain freely into the bilge, then from that location the water will slosh around until it gets to the back of the engine bay, where the bilge pump will eventually remove it, once it gets to say 10mmmm depth. But that approach means there is a constant presence of a few mm of water on that floor. The fact that it's never 100% dry will I think will give rise to rust in the longer term, in fact there are already signs of that developing, so I need to stop it asap.

 

My second bilge pump idea will also allow the main bilge pump to act as a back up system. 

For long periods away from the boat, the real solution to rain ingress would be to cover the stern area (or at least the steps) with a tarp of some sort. I'd also like to route some solar power back into the lead acid batteries to help them stay fully charged and able to work (as it all goes to the lithiums at the moment), but that's probably a summer project.    

 

 

Edited January 13, 2023 by Tony1

[magnetman]

Where does other bilge water come from? 

 

If it is only the stern tube then you could maybe cut something out of a 20 litre plastic drum to put under it as a sump. 

 

Perhaps if it is a cruiser stern you also get a bit of water in through the decks as well. 

 

What about a great big umbrella over the stern doors? Fisherman umbrella. 

[Tony1]

Just now, magnetman said:

Where does other bilge water come from? 

 

If it is only the stern tube then you could maybe cut something out of a 20 litre plastic drum to put under it as a sump. 

 

Perhaps if it is a cruiser stern you also get a bit of water in through the decks as well. 

 

What about a great big umbrella over the stern doors? Fisherman umbrella. 

 

The radiator overflow hose can produce a small amount of water, and there is another hose on that side that I think it related to the diesel CH which produces a little bit.

Its small amounts, but its very slow to evaporate if not caught, so it forms a thin film on the floor under the engine, which is the worst place I want to see rust developing. That was easily dealt with using a plastic container which I drain every week or two. 

The stern locker can get a lot of rain ingress (draining down the rear cabin wall), and that also had two drain holes into the engine bay, so I've sealed those for now until I can think of a better catchment idea. 

The deck drain channels around the engine cover board normally drain through exit tubes at each side, but they are sometimes temporarily overwhelmed during a heavy downpour, so there is some overflow directly into the engine bay from those, but that isn't very common. 

Its not possible to entirely catch, block or divert all of the water ingress, but I would like to see a dry floor most of the times when I look in there, whereas last year it was wet almost all the time.

 

There may be a small leak from the stern tube, I'm not sure yet. It feels dry, and the recent rain is so persistent that when I do see a few mm of water around the bilge pump, I can't yet be sure that its not more rain ingress from somewhere I havent spotted.

Certainly there's more messing about to be done before I get it totally dry.  

 

 

[magnetman]

I think some of this floor protector covering the stern deck might be an interesting way to slow down the flow of water after heavy rain. 

 

Don't know what it's like for durability but it seems interesting. Would need some rubber tape or something under to stop it moving around. 

https://www.wickes.co.uk/Proplex-Black-Surface-Protection-Sheet-2400-x-1200-x-2mm/p/118670

 

[Tony1]

4 minutes ago, magnetman said:

I think some of this floor protector covering the stern deck might be an interesting way to slow down the flow of water after heavy rain. 

 

Don't know what it's like for durability but it seems interesting. Would need some rubber tape or something under to stop it moving around. 

https://www.wickes.co.uk/Proplex-Black-Surface-Protection-Sheet-2400-x-1200-x-2mm/p/118670

 

 

Thing is, I already have fittings on the roof edge for straps- and on the stern rail for popper fittings. So a tarp could be made and fastenings added with not too much effort. 

It doesnt have to be totally watertight, just to keep out most of the rain. 

I do like the look of that floor protector, but apart from the issue of fixing it in place against occasional high winds etc, the water collecting in it has to be routed somewhere via gravity, and my deck has a sort of lip around it that is about 8 inches high.

If you placed an upright pole in the middle, the water would drain down and off it. But to drain over the lip of the deck, it would need slits made at the edges, so that it would fit around and in between the legs of the stern rail. Not to mention something to fasten it to the outer edges of the deck. 

I like the idea of a lower level deck covering, because it might get less stress during high winds, but there are some complications.  

 

 

[magnetman]

I meant put the cover flat over the deck. This could have the effect of "filtering" the rain so it didn't get into the drains too quickly. 

 

Might not work but if for example the problem area is where two deck boards but together over a drain channel it might be useful to cover than particular area.

 

Worth studying exactly how the deck drains behave. 

[ditchcrawler]

1 hour ago, Tony1 said:

 

 

I feel my solution is the next best thing, which is to allow the water to drain from the step into the engine bay,

 

 

For long periods away from the boat, the real solution to rain ingress would be to cover the stern area (or at least the steps) with a tarp of some sort. I'd also like to route some solar power back into the lead acid batteries to help them stay fully charged and able to work (as it all goes to the lithiums at the moment), but that's probably a summer project.    

 

 

Could you not pipe it from the bottom of the step back,  Do you have your Lithium's as a hybrid system, if so doesn't your solar connect to both or is your pump on you engine start battery?

[Tony Brooks]

I think Tony has identified the problem and the most cost effective solution. It is the one drawback of a cruiser stern with the steps set back into the deck area so  you gain a little more interior space and avoid the need for a slide.  I kept an old washing up bowl under the bottom step on JennyB for the same reason and always intended to fit  a bilge pump as tony intends. What i did find is that  the said bowl did collect a lot of mess that fell or was washed down the hole.

 

Two points Tony

 

1. It sounds as if you are overfilling the cooling system. Any marks on a header tank or height of air gap you read on line/in a book will almost certainly be too full for a tank cooled boat. Fill to brim once, get engine right up to temperature, allow to cool right down and whatever the level is will be the correct topping up level.

 

2. The second source of water you think may be something to do with the central heating system. Follow the pipe back because I think it might be the domestic water PRV vent if you have a calorifier. If so it tells us one of:

 

you don't have an expansion vessel on your system, and if you do it is incorrectly pressurised

the PRV is not sealing (try twisting the plastic knob on to a few times with the pump on and taps closed).

the domestic water pump cut out pressure is, for some reason, too close to the PRV setting.

[Ewan123]

Would it not be easier to just run a pipe from the steps drain hole straight to the main bilge sump? Perhaps fixed at a few points on its way around the engine bay to maintain a reasonable angle to drain. I've got the same sump at the stern in our Liverpool Boat and just accept that it will never really be fully dry, but at least it's only a very small section that remains wet. A plastic tub sat on the engine bay floor might well just hold enough moisture under it to maintain a rusty patch anyway.

[Tony Brooks]

1 minute ago, Ewan123 said:

Would it not be easier to just run a pipe from the steps drain hole straight to the main bilge sump?   Snip

 

See my comment about muck being washed through the hole in the step. I think the hose would probably block, even a large bore one eventually. It will also require welding a pipe stub under the step or fitting a skin fitting. In the later case water would pool on the stem because of the skin fitting flange,

[magnetman]

A second pump directing the water to the main bilge is what I would do. 

 

I really don't think bilge rust is a big issue unless allowed to get out of hand. It will take many many years to ever get anywhere near rusting through the 6mm sides. As for the 10mm that's going to take a while ! 

 

Regarding the PRV on the calorifier I wonder if it might have some scale holding it ever so slightly open allowing a tiny leak. 

[Tony Brooks]

4 minutes ago, magnetman said:

A second pump directing the water to the main bilge is what I would do. 

 

I really don't think bilge rust is a big issue unless allowed to get out of hand. It will take many many years to ever get anywhere near rusting through the 6mm sides. As for the 10mm that's going to take a while ! 

 

Regarding the PRV on the calorifier I wonder if it might have some scale holding it ever so slightly open allowing a tiny leak. 

 

That is why I said try twisting the knob on the PRV. However we don't know if the second source is the PRV, I speculated that it might be because I can't see how the central heating would have an overflow into the engine room - unless he persistently overfills its header tank. In view of the persistent leak from the cooling system overflow it is a possibility. However this is all speculation because we don't know his systems.

Edited January 13, 2023 by Tony Brooks