Bilge Pump Advice

[Dutch01527]

I stumbled across this very informative real life story of a sail boat which developed a serious leak

.

It prompted me to think about my own pumping arrangements, especially as I have a Cardiff to Dartmouth trip in May. I have a 1984 28 foot Dehler.

The only bilge pump I have on board is a bulkhead mounted, manual gusher. I often sail with only my wife onboard or solo and in the event of a serious leak I can not see how this would cope. I would need to try and locate the leak and stop the flow. She would not have the strength to pump for very long.

That led me to thinking about a automatic electric pump, however, reading up on the usual small bore type, they are only designed for minor drip type leaks. A more major issue would overwhelm them. Larger 12v emergency electric pumps are available. A 14,000 litre / hour runs at 15 amps and costs about £300. That is doable but it would be dependant on battery capacity and availability.

I have a 1000w suitcase generator and a 900w dirty water sump pump which pumps c. 15,000 litres per hour which could be used free standing.

I thought about changing my wife for a younger, fitter one but she pointed out how expensive that would be. My plan is:

1) buy a battery powered water sensor alarm for about £30 to get early warning of an issue
2) take the generator / 240v pump with me for big trips
3) fit a large capacity emergency 12v pump with a automatic switch as a permanent fixture

Have I missed anything or is my thinking flawed?

 

[Boater Sam]

You can sink on little trips just as easily as on big trips -----------------------

Get a standby younger fitter mistress?????????????????????

 

[ghostlymoron]

You can't install sufficient capacity to cope with any eventuality. The best you can do is install a small submersible at low level to cope with ,say, a dripping stern gland and a larger capacity mounted a bit higher to deal with , say, a blown off skin fitting or two. This would hopefully give you enough time to staunch the flow somehow (wooden bung for example). It's recommended that you also have a manual pump but of course if your constantly pumping you can't locate and fix the problem if on your own.

 

[RupertW]

When we had a serious leak 2 days out into the Atlantic (turned out to be a complicated siphon due to getting an internal seized 2 way valve replaced over Winter), the electric bilge pump could not cope.

Standard Jabsco pump with with a small pipe (12mm?) running at least 10 metres with a 2m rise the flow was too slow and secondly all the dry crud from every hidden part of the bilge kept clogging the filter so it was a full time job stopping the pump and clearing it again and again. The manual larger bore cleared the bilges much more rapidly with no filter and deliberately set 4 inches above the bottom of the sump.

So I’m now thinking about a more powerful electric pump but more importantly a large bore and much shorter run to a new hull exit - probably amidships. The main issue with amidships is that the exit would be under water if heeled over that way.

 

[rib]

What about a engine driven pump

 

[jwilson]

Rather than lugging around a genset and big pump I'd look for causes of major leaks: skinfittings the most common, and make sure they are all sound. As other have said, virtually no normal on board pump will cope with a really big leak, and you will have to deal with it somehow - bungs, wedging towels into holes, or fothering with a spinnaker or similar.

 

[TernVI]

Of the tiny number of reasonably sound GRP boats which sink in a decade, how many might have been saved by bigger pumps?I think the number is either 'none' or 'virtually none'.

The OP's Dehler has let's guess, 7m lwl? 2m beam at the wl? .7m freeboard?
So you can probably put more than 3 tons of water in it before it sinks.

Holes in boats mostly come in two sorts: Broken skin fittings and other plumbing, and crash damage.
Proper crash damage will let water in, at a rate of 'tons/minute'. Nothing short of a very serious fire pump is going to make much difference.
Broken skin fittings run up to tens of litres a minute. It takes a lot of minutes to sink a boat at that rate.
The trick is to know the plumbing on your boat and be able to access and plug the likely holes.
The oldschool racing 'rules' of having softwood plugs taped to every skin fitting might be better prep than buying another plastic gadget from the chandler.
Time spent getting to know the boat's systems is also valuable, most people who've had this kind of trauma seem to end up saying things like ' I didn't know that fitting was there' or ' I didn't realise it was connected that way'. Or 'who the @@@ fitted that?'

Be aware that the nominal GPH of a pump is at zero lift through a very short hose. It's often reduced by big factors lifting water a short distance, and another big factor by flowing through a hose. The typical centrifugal pumps are actually quite poor at getting water from the bilge sump in the middle of a yacht to the transom.

I suggest the OP should spend time with his wife getting to know all the skin fittings and checking everything thoroughly before going to sea.

 

[Deleted member 36384]

If you want independent pumps, think about and engine driven pump. However, they have their issues: mounting needs to be strong, belt drive needs to be strong and maintenance needs a bit thought. This latter point is relatively important as they just sit there doing nothing for the majority of their lives. One way around this is to rig the pump to a 2 x way valve and direct the outlet to a strum box or deck wash seacock. Output would still be insufficient if you had a big hole.

There is the Fast Flow bilge pump that clamps onto your propellor shaft and can pump at very high flow rates. However, on most yachts the shaft arrangement will be at to low and angle and too short meaning that the engine will have water sloshing about it before this can be used. For motorboats with long shafts and good lower elevation compared to the engine, this could be a good idea. Fast Flow Pumps | Bilge Pumps I think there are other makes of this type of pump.

As the video suggests, battery elevation needs to be considered. You only need to mount the engine start battery higher up. My own view is the time taken to get the suit case genny out and the electric bilge pump hooked up is a negative.

As others have stated, there are better things that you can do to reduce the risk of water ingress. However, not having all your eggs in one basket is a good idea and manual bilge pumps probably addresses that. At least store the handle beside the pump! Also fit a bilge alarm, they do not need to be connected to the bilge pump, just a level warning audible alarm, low cost early warning.

 

[oldmanofthehills]

I have had bilges fill with water 3 times. The first was headsea breaking over the bows removing the forehatch and filling the cockpit - which the previous owner had arranged to drain straight into engine compartment - (idiot). The electric bilge pump didnt work due to further idiocy but you might be surprised how much this old fellow and wife could shift with humble saucepans. Over 1 ton of water needed getting rid of and she was handling very very sluggish for the size of waves. The joy of a delivery run!

On both other occasions it was due to engine cooling systems. Firstly the exhaust cooling pipe broke and exhaust box melted so all cooling water ended up straight in bilges as did the exhaust smoke- new auto electric pump fine plus occasional manual pump and left engine hatch open - we had a large stout bucket too but didnt need it. Much coughing and swearing as no wind but no other issues.

The second one was the water inlet hose cracking so no engine cooling and boat filling up rapidly. This later boat had two electric pumps, one auto so despite water everywhere it soon cleared, though used the manual pump as well initially. Obviously in neither the first nor third scenario would an engine driven pump be of any certain use.

Many fishing boat sinkings are due to engine cooling or deck drain issues. IMHO yachts are often better constructed or serviced but yachtsmen can still get caught by these issues, and not fun to manage in bad weather

So make sure sure drains and pumps actually go out to sea, have wooden bungs available for minor holes and have a liferaft handy if you get a massive collision hole

 

[pvb]

There is the Fast Flow bilge pump that clamps onto your propellor shaft and can pump at very high flow rates. However, on most yachts the shaft arrangement will be at to low and angle and too short meaning that the engine will have water sloshing about it before this can be used. For motorboats with long shafts and good lower elevation compared to the engine, this could be a good idea. Fast Flow Pumps | Bilge Pumps I think there are other makes of this type of pump.

These things have been suggested on here for many years. But they are essentially useless for most leisure boats. Firstly, as you've said, there needs to be water above the pump aperture if it's going to work - this means the water would be perhaps a foot deep in the cabin before the pump would work. This also means that it won't reduce the water level down to the floor. Secondly, these pumps are big; they may not fit in some boats. But thirdly, and crucially, they need the propshaft to be rotating at about 2000rpm to give their best performance, and that means engine revs of around 4000rpm! The most likely cause of major water ingress is collision. If the boat has a hole in the forward section, and has a foot or so of water inside it, driving flat out forwards isn't going to be either easy or a great idea.

 

[jamie N]

My recently sold RC8D Renault Couach came with a bilge pump running from the engine full time, alongside the usual raw water pump. The pump was engineered to lubricate the bilge pump if and when the bilges were dry. It worked extremely well, and served as a 'fitted spare' pump should the engine impeller have ever failed, then it was a simple swap of hoses from the bilge side to overcome the issue.

 

[RogerJolly]

I've got bilge envy.

All I have is just a few hatches in the floor you can pull up to retrieve the gin. No dirty dank evil smelling cavity with an inch of water sloshing about, which I've always taken to be the sign of a proper boat.

The boat came with a manual pump you can work in the cockpit, with yards of hose attached but just coiled up going nowhere. Guess the idea is to just un-coil it as and when and lead it to the leaky bit.

Wondering if this is common (not been on many other boats).

 

[pvb]

Wondering if this is common (not been on many other boats).

I've only got dust in the bilges.

 

[TernVI]

I have had bilges fill with water 3 times. The first was headsea breaking over the bows removing the forehatch and filling the cockpit - which the previous owner had arranged to drain straight into engine compartment - (idiot). The electric bilge pump didnt work due to further idiocy but you might be surprised how much this old fellow and wife could shift with humble saucepans. Over 1 ton of water needed getting rid of and she was handling very very sluggish for the size of waves. The joy of a delivery run!

On both other occasions it was due to engine cooling systems. Firstly the exhaust cooling pipe broke and exhaust box melted so all cooling water ended up straight in bilges as did the exhaust smoke- new auto electric pump fine plus occasional manual pump and left engine hatch open - we had a large stout bucket too but didnt need it. Much coughing and swearing as no wind but no other issues.

The second one was the water inlet hose cracking so no engine cooling and boat filling up rapidly. This later boat had two electric pumps, one auto so despite water everywhere it soon cleared, though used the manual pump as well initially. Obviously in neither the first nor third scenario would an engine driven pump be of any certain use.

Many fishing boat sinkings are due to engine cooling or deck drain issues. IMHO yachts are often better constructed or serviced but yachtsmen can still get caught by these issues, and not fun to manage in bad weather

So make sure sure drains and pumps actually go out to sea, have wooden bungs available for minor holes and have a liferaft handy if you get a massive collision hole

I've filled the bilges with water 3 times in a Wednesday night race before now. It's not uncommon when racing open dayboats like XOD or Dragons. It's a design flaw of not having a lid or a self draining cockpit. It is good to be able to pump and steer at the same time, and at least our systems are 'tested'.

 

[RupertW]

Of the tiny number of reasonably sound GRP boats which sink in a decade, how many might have been saved by bigger pumps?I think the number is either 'none' or 'virtually none'.

The OP's Dehler has let's guess, 7m lwl? 2m beam at the wl? .7m freeboard?
So you can probably put more than 3 tons of water in it before it sinks.

Holes in boats mostly come in two sorts: Broken skin fittings and other plumbing, and crash damage.
Proper crash damage will let water in, at a rate of 'tons/minute'. Nothing short of a very serious fire pump is going to make much difference.
Broken skin fittings run up to tens of litres a minute. It takes a lot of minutes to sink a boat at that rate.
The trick is to know the plumbing on your boat and be able to access and plug the likely holes.
The oldschool racing 'rules' of having softwood plugs taped to every skin fitting might be better prep than buying another plastic gadget from the chandler.
Time spent getting to know the boat's systems is also valuable, most people who've had this kind of trauma seem to end up saying things like ' I didn't know that fitting was there' or ' I didn't realise it was connected that way'. Or 'who the @@@ fitted that?'

Be aware that the nominal GPH of a pump is at zero lift through a very short hose. It's often reduced by big factors lifting water a short distance, and another big factor by flowing through a hose. The typical centrifugal pumps are actually quite poor at getting water from the bilge sump in the middle of a yacht to the transom.

I suggest the OP should spend time with his wife getting to know all the skin fittings and checking everything thoroughly before going to sea.

Having suffered a serious but not crash style leak I am sure that I want a solution that is better than the useless electric bilge pump - at least as good as a quickly and continuously pumped hand pump and preferably a lot better.

There are quirks in boat plumbing that even owning a boat for 10 years can catch you out. In our case I checked all the skin fittings again and again while the bilges kept refilling. I followed the pipes back as far as I could see and nothing - plus stern gland, hatches and everything else in unpleasantly roughish conditions and no harbours within a couple of days which concentrated the mind. Having run out of any ability to fix the leak or to stop the water rising further then the obvious step was to get the boat upright by turning from a beat to slowly downwind which fixed it while we got some rest. I was weirdly stubborn when tired about closing all the seacocks as they weren’t leaking at all but did do so at the same time we turned downwind.

But I would defy anybody to work it out - the only way I did was instead to think about what work we had done over Winter. Solar panels, no, cable deck fittings, no, engine service, no, hull-cooled fridge with new integrated seacock, maybe but already checked to the compressor and no leaks or mispiping so no, seized 2 way valve above new seacock replaced - ahh! 2 way valve wasn’t leaking but was in the position opposite to the one that it appeared to have been seized in since we bought the boat. So sea-water sink foot pump was now in the valve position to drain the fridge instead.

 

[RupertW]

I've only got dust in the bilges.

You would soon find out - as we did - that if you get a serious leak it’s all the things bigger than dust which have never been picked up by water in all the nooks and crannies that find their way to the sump and block the filter. There is something tempting about filling the bilges to the brim now and again with water and seeing what appears.

 

[oldmanofthehills]

I've only got dust in the bilges.

Some boats have dry bilge. Ours has minor leak from stern gland collecting in adequate sump Others like our old one are wet: Our Westerly had level bilge the length of boat with no sump so completely impossible for pump to keep dry. Many good boats especially wooden ones are wet. Its when it rises above the lounge sole that one has to worry

 

[Gary Fox]

Ok you can at least improve your electric bilge pumping arrangements.

Fit a bigger pump, and mount it in a strum box.
The mesh size should be a bit smaller than anything which can jam the bilge pump itself.

Use something better than a crude float switch for automatic arrangement, they can get jammed by debris, both on and off.

Make sure the wiring is robust and waterproof and even if you don't normally use tinned cable, here it is more important.
Personally my auto bilge pump is hard wired to the battery, so it can't accidentally be switched off or blow a fuse.

Consider multiple, fore and aft, bilge pumps; imagine if your pump is aft under the engine, but you hit a tree trunk while sailing fast at night. In that case, the boat might quickly go down by the head, then the pump would be useless.

A pump you can use in the cockpit, while sailing with your other hand, used to be de rigeur when yachts had tillers and were made of wood. There is no harm in operating the manual bilge pump at change of watch to see what comes out, another habit which is dying out.

Test your pumps regularly..with water! My big cockpit hand pump, a real comfort for last-ditch sinking scenarios, got tested regularly for years, by operating the handle. When it was opened for a check, the diaphragm was found to be in pieces..

Keep the bilges clean. In the early days of ships with engine rooms, the greasers had to sign their rags out from the store, and sign them back in, because of the possible consequences of a rag in a pump suction.

 

[madabouttheboat]

I see an electric pump as a helper, rather than the solution. In this regard its best to fit the biggest and most powerful one that you can. None are likely to keep the boat afloat on their own, but the more they deal with, the easier it will be for me to keep on top via the manual pump or simply by bailing with a bucket.

IMHO the best bilge pump on my boat is the twin 150hp inboard diesels. I don't know how many litres of water they get through per minute, but I guarantee it's more than anything else on the boat can shift. For that reason I am tempted to have a diverter valve that allows me to take cooling water from inside the boat. It will need careful monitoring of course, to make sure they don't run dry, but if I'm sinking my attention will be on little else anyway. With two engines and a full range of revs to work with I have a huge option to vary the amount being sucked from inside. So, unless it was a catastrophic leak, I could probably find a level that is just right to keep on top of the ingress while I motor to safety at whatever speed that gives me.

Has anyone done this, I've never seen it before?

 

[Gary Fox]

I see an electric pump as a helper, rather than the solution. In this regard its best to fit the biggest and most powerful one that you can. None are likely to keep the boat afloat on their own, but the more they deal with, the easier it will be for me to keep on top via the manual pump or simply by bailing with a bucket.

IMHO the best bilge pump on my boat is the twin 150hp inboard diesels. I don't know how many litres of water they get through per minute, but I guarantee it's more than anything else on the boat can shift. For that reason I am tempted to have a diverter valve that allows me to take cooling water from inside the boat. It will need careful monitoring of course, to make sure they don't run dry, but if I'm sinking my attention will be on little else anyway. With two engines and a full range of revs to work with I have a huge option to vary the amount being sucked from inside. So, unless it was a catastrophic leak, I could probably find a level that is just right to keep on top of the ingress while I motor to safety at whatever speed that gives me.

Has anyone done this, I've never seen it before?

It has been standard practice on the various smallish ships I've crewed on and delivered: the 'Bilge Ejection' valve allows the main engine SW pump to suck from the bilges; normally seized solid due to lack of exercise...
The concept needs careful thought on a yacht with small, easily obstucted impeller pumps and very expensive and delicate engines..ideally you would have a man down there, constantly monitoring the water level..I would say dedicated strum boxes would be a good idea.