Bilge Pump Advice

Gary Fox said:
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.
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I can see some pitfalls with the idea, but I'm thinking if the boat is going down, which it will be if the electric and manual pump can't keep up, will I be worried about possible damage to the impeller, or even the engine? It's going to be at the bottom of the sea anyway. On my boat it would be a very easy and cheap think to do. As a last resort it could be the difference between staying afloat or not. Of course having two engines does make the whole thing a bit more flexible as I could use one or both. If one gets blocked, I still have another working while I sort it. If one engine dies, the second will continue do its best etc etc
 
Gary Fox said:
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.
Click to expand...

The flow rate of seawater through a typical yacht engine is pitifully low - it wouldn't do much to reduce water level.
 
One problem, and fishing boats get caught by it, is that once the rising water gets to engine then any engine driven pump stops. Batteries are usually a bit higher and will even run underwater if sealed though the electrics will short eventually.

Anyone who does not have bucket and good capacity manual pump on board, is ill prepared. My manual pump far outperforms my electric pumps though of course attending to pump while single handed and doing other stuff is a challenge
 
madabouttheboat said:
I suspect you may be right, but every little helps I guess. I wonder if I can find out the flow through mine. Being bigger units, and having two of them, it's got to be a reasonably decent amount.
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Although it could be argued that if you want to use the running engines for emptying the bilges, belt driven dedicated pumps might be better.
 
Figures are very hard to come by it seems. Quite a few small yacht engines seem to have been tested with results in the 20-30 litre per minute range. Converting to bilge pump terminology, that like having an extra circa 400gph bilge pump. Probbaly worthwhile.

WIth regards to mine, the figure appears to be more like 100 lpm and with two of them running they may well shift around 2500gph. My engine room bilge pump is quite big (compared to what is fitted by boat builders typically) at 1500gph. With the head and restrictions taken into account this probably equates to less than 1000gph, so engine pumping could make a huge difference.
 
The heads pump is another possibility to use as a bilge pump, with a changeover valve, depending on what type you have.
 
oldmanofthehills said:
One problem, and fishing boats get caught by it, is that once the rising water gets to engine then any engine driven pump stops. Batteries are usually a bit higher and will even run underwater if sealed though the electrics will short eventually.

Anyone who does not have bucket and good capacity manual pump on board, is ill prepared. My manual pump far outperforms my electric pumps though of course attending to pump while single handed and doing other stuff is a challenge
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Once water levels hits the engines and they quit, despite electric bilge pumps, a manual bilge pump and potentially two huge diesel driven pumps, I think it was always going to be a losing battle anyway. You can't win em all.

I have used a manual pump to extract bilge water, not under a sinking scenario where adrenalin would be a huge help, but I found it very tiring, very quickly.
 
I would suggest a “smaller” bilge pump to clear the odd drip.

A manual one as extra ooomph.

A bucket.

Some might consider a crash pump. Ie a larger pump that can shift 2000gph or more with free pipework.

These will only buy you time with a bigger hole!
 
gregcope said:
I would suggest a “smaller” bilge pump to clear the odd drip.

A manual one as extra ooomph.

A bucket.

Some might consider a crash pump. Ie a larger pump that can shift 2000gph or more with free pipework.

These will only buy you time with a bigger hole!
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Exactly.
People need to face the fact that in the very unlikely event of making a big hole in your boat, it will sink.

The reality is it's very, very rare.

When was the last sinking which would have been prevented by a 10,000 gph bilge pump?
GRP boats only please! I know enough bar-room tales of leaky wooden boats.

We do carry a portable so-called 2400 gph pump, it's great for deck washing and emptying the rain from the dinghy.
It's mounted on a 5ft length of plastic rigid waste pipe, with a couple of metres of flay flat hose on the end.
There's also the shower drain pump, which pumps the rain which runs down the mast.
 
RupertW said:
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.
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It worries me that owners don't make the effort to understand the plumbing on their boats, that boatbuilders don't keep it simple or document things properly and some tradesmen have strange ideas.
I was once on a sailing school yacht. decent school, with 4 yachtmasters (inc 2 instructors I think) and the owner.
The yacht had recently had a holding tank fitted. I owned up to not understanding the cypto-ikea style labelling of the valves, the guy who claimed 'it's obvious' was wrong, he got showered in somethng which caused him to jump over the side.
 
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