Are manual bilge pumps useless?

bedouin said:
But it has issues on a small boat like mine. .....
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We probably all agree that there are multiple solutions for shifting water out a boat which have to be considered for each type of boat, the likely distance from rescue, the type of conditions that one is likely to use the boat in. Questions like the OPs do make as all think about this type of thing, which is healthy.
 
Kelpie said:
Well there is the 'Evo': https://www.machinemart.co.uk/p/evo...UAt50mLO9X3NYupNxyuGOJ__bi0zMqLxoCLpsQAvD_BwE
Which is an engine that comes with different attachments- generator, pressure washer, or water pump.
In theory a useful thing to have aboard, but it's pretty agricultural and hard to see how you could integrate it into a boat easily as an emergency pump.
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It would be interesting if the attachments could be fitted to the main engine say the front pulley crankshaft nut as an attachment.
 
Didn't we see sad pictures of a boat sinking off the Needles where she settled very much bow down and there may never have been enough water round the prop-shaft for a shaft-mounted pump to work.
 
A good capacity electric pump assisted by a Henderson mark 4 (if you have crew) can buy you enough time to hammer in a softwood plug or stuff a cushion in a hole before digging out the liferaft.
 
bedouin said:
Yes - that would save the boat - or at least buy you a lot of time. And note that has a 6.5HP engine to power it. You are not going to get that sort of power from your batteries or even by a belt drive from your main engines.

Every time I have looked into this I have come to the conclusion the best approach, short of that, is a fairly large electric pump with decent plumbing. I don't see any real benefit from an engine-driven one, If you want redundancy or more capacity fit another, and another
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That's what we have. Five electric pumps in total. Big battery bank in watertight enclosure vrntilated to dorado box. Generator mounted high in engine room
 
Early warning is crucial and bilge alarms are not fitted often enough, mandatory on decked commercial boats. Simple, cheap, my last one was a reed type float switch, about £8, and a led sounder/light, £2.02. Wired with the neg running through the bilge switch, so no current floating about in the damp. I had one for each section of bilge.
 
Bilge alarms are useful, but they do need replaced frequently in my experience. It's not unheard of for them to be disabled rather than replaced, and this has contributed to the sinking of a least one boat that I can think of.
 
William_H said:
Well much depends on your size of boat. If we are talking 20 ft class with no through hulls and outboard engine. Self righting and self draining cockpit then you are pretty safe with just a bucket.
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I disagree with much of your analysis. Why restrict yourself to a bucket, when you could have a bucket and a manual pump (or two) for little money, and an additional electric pump for not a huge amount? Or to look at it the other way around, you're pretty safe even without the bucket!

A small boat is, in my experience, much more vulnerable to waves and swell than a larger boat, and once any amount of water is aboard will be more affected by it swilling about inside. You mention 'self-righting', but once righted the boat will have an awful lot of water aboard. The cockpit drains of few boats can cope with a pooping, and in a small boat that is more likely to happen (because of the low freeboard), the relative weight of a cockpit full of water will make it very unstable, even if it doesn't pull the transom (and outboard) underwater. The weight of an outboard high up on the stern doesn't help stability at the best of times. The increased number of through hulls in a larger boat are only one of the risks (and a very low one).

No pump, manual or electric, will 'solve' a swamping on a small (or any) boat, but the more, and different, tools you have at your disposal the better able you are likely to be to tackle the situation.
 
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Manual bilge pumps useless? (No...)

Perhaps I missed something in this thread, but the most important duty of a pump is not to just somehow empty out water, but to slow or make some headway against the inflow while a crew person finds and plugs/slows the leak.
That is the reason that offshore racing boats (and well equipped cruisers) will have a "category one" manual pump accessible from the helm position. The idea is that the driver can evacuate water while someone slows or stops the leak. (Single handers will not this option, I do realize.) :(

Our boat was built with a stock Whale Gusher at the helm, and two Jabsco electric bilge pumps, each with separate float switches and hose runs. No way would this combo keep up with a major hull breach, but it could handle a single broken bilge hose or broken thru hull until I could pound in a plug, or so goes the theory I hope to never test.

As for the wonderfulness of really big gas pumps, right on! Not something to carry around on most boats under about 50 or 60 feet LOA, but I can certify that I did stop a 37 foot keel boat from sinking, in its slip when it was found to have a foot of freeboard left. That big centrifugal pump with it's Honda motor was a bear to prime - or I was too nervous - but it threw a Lot of water fast and stopped/reversed the settling.
With a phone call we soon had a salvor on hand with two more high capacity pumps and quickly dried it out. We found out later that an ancient out-of-sight-and-mind thru hull hose had let go late at night.

Also, that same boat did not have a functioning electric pump for some reason.

I know that most electric bilge pumps will not keep up with any hose entry over about 3/4", but they will give you a chance, again, to find the source.

As with a lot of safety stuff, you need to overhaul, service it, and test it regularly. And then try not to need it!

One other thing, while you may certainly tire of hand-pumping water, at least your "energy source' (you) will not be suddenly shorted out by a bit of salt water like your electric pumps. :)
 
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fisherman said:
Wired with the neg running through the bilge switch, so no current floating about in the damp. I had one for each section of bilge.
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A bit of thread drift - would you expand on what you mean? I don't understand the signficance of the wiring
 
Minn said:
If you have got enough water in the boat to use a bucket in the cabin your cockpit floor will be submerged. Feel free to try it...
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The cockpit may be flooded but this doesn't mean the drains aren't working. The surface of the sea inside the cockpit is connected to the surface outside, so it doesn't matter where the water gets chucked.
 
bedouin said:
A bit of thread drift - would you expand on what you mean? I don't understand the signficance of the wiring
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The light/sounder is wired to a power supply, interrupted by the float switch, you can interrupt the pos or neg, makes no difference. If you interrupt the pos then the pos current is down to the switch in the bilge, where it could leak if damp, eg to the engine/drive train which may be connected to neg in some cases. Trying to avoid wires corroding and going green, and stray current in the bilge. These switches always come with a short wire attched so a connection has to be made in the bilge, mine was a trailer connection block in a box.
 
Kelpie said:
Bilge alarms are useful, but they do need replaced frequently in my experience. It's not unheard of for them to be disabled rather than replaced, and this has contributed to the sinking of a least one boat that I can think of.
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Once in 26 years for me. Given this was a dirty old F/V that's quite good, and i tested it every time I checked the engine/seacocks etc. Why anyone would disable it I can't get, unless it was sounding all the time. Who admitted to disabling an alarm allowing his boat to sink?
 
fisherman said:
The light/sounder is wired to a power supply, interrupted by the float switch, you can interrupt the pos or neg, makes no difference. If you interrupt the pos then the pos current is down to the switch in the bilge, where it could leak if damp, eg to the engine/drive train which may be connected to neg in some cases. Trying to avoid wires corroding and going green, and stray current in the bilge. These switches always come with a short wire attched so a connection has to be made in the bilge, mine was a trailer connection block in a box.
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But surely whereever it is in the circuit, the switch (when open) will have to have 12V across it? Or does it only matter when current is flowing?

This is an aspect of bilge wiring that I hadn't considered until recently
 
Much better to use waterproof connections in the bilge than to worry about whether you use the positive or negative. There will have to be a positive connection somewhere, for the pump.
 
bedouin said:
But surely whereever it is in the circuit, the switch (when open) will have to have 12V across it? Or does it only matter when current is flowing?

This is an aspect of bilge wiring that I hadn't considered until recently
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Fishermans point is, if the switch is connected to he positive part of the circuit and any of that wiring comes into contact with 12v negative (which down in the bilges could be engine, shaft etc) directly or indirectly, you have a short circuit. Wired to the negative it wouldn't matter if the wiring touched the engine, other than the fact that (depending which side of the switch touched) you could have the pump running all of the time, dry.

Glue lined, heatshrink, crimps are a good solution to wiring in damp places.
 
PaulRainbow said:
Fishermans point is, if the switch is connected to he positive part of the circuit and any of that wiring comes into contact with 12v negative (which down in the bilges could be engine, shaft etc) directly or indirectly, you have a short circuit. Wired to the negative it wouldn't matter if the wiring touched the engine, other than the fact that (depending which side of the switch touched) you could have the pump running all of the time, dry.

Glue lined, heatshrink, crimps are a good solution to wiring in damp places.
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But the corollary is that if you switch the negative then the pump and all its wiring will be at 12V (unless it is running). Switch the positive and it is only the switch itself (and its connections) that are at 12V

Since I am just about to rewire my bilge pump I am keen to get this right.

At the moment I have two positives from the switch panel, one for automatic and the other for manual, the manual is connected to the pump supply and the automatic switch connects the automatic and manual together. I intend to add waterproof connectors (or put Waco type in a gel box).
 
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