Bilge pump advice

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samwise

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During the continuing voyage of discovery within the vitals of our Westerly Storm, we have found pipework and a skin fitting for a bilge pump. However, no pump or wiring.
There is a substantial cockpit mounted hand pump hosed up to a strum box in one of the bilge compartments and I have to say that -- on the basis of our first full season last year, the boat has remained commendably dry.

We are now planning a series of longer voyages, including one down to the Med and -- thinking the worst -- I got to thinking about a situation in which the hand pump could not cope. So, the question is, if I were to fit an electric pump, what make is best, what sort of output in gph shoudl I be looking for and are automatic / float switch actuated pumps a good idea? I guess I am targeting an all-in budget for pump, switchgear and/or float switch at just under £100. Any ideas or experiences welcomed.
 
My own thought is that batteries are soon flooded when leaks get to be really bad, so a big manual pump is best. Having tried the old 'frightened man with a bucket' routine I can advise that it's total b*ll*cks. Lifting buckets full of water over the companionway is exhausting in a very short time.

My solution is a 1.5 inch pump that can be mounted on the companionway steps so that the legs and back can be used to drive it. The discharge goes by flexible hose into the cockpit and the suction via a strum box permanently attached to lowest part of the bilge, again with a flexible hose to the pump. I have never tried this in anger but have emptied some big buckets with it and am confident that we could pump out for some time if necessary. The cockpit pump is also 1.5 inches bore so we should be able to operate both for a while.
 
When I am frightend I become very short of breath and energy without doing anything! I think Vyv's idea sounds jolly good. In my present boat I have a hand operated diaphragm pump operated in the cockpit, sucking from the bilge, and an electric operated diaphragm pump sucking from the deepest part of the bilge. Neither of these are of great output but are less likely to block than some other kinds of pump. The electric pump is operated by a bilge buddy no-float electrode set up (it can of course also be operated by a by-pass switch). Early in my ownership of this boat and before I had investigated the stern gland seriously I was awoken one morning by the sound of the electric pump cutting in; investigation showed that there was about six inches of water in the bilge and the stern gland weeping quite a lot of water. The pump would probably have kept up with the flow until the batteries ran down. So an automatically operated bilge pump may be a useful early warning device! I also have a hand operated large stirrup pump type complete with hoses for roving pumping.
 
the only downside to a float switch is that if you get a gas leak and a water leak...bang.
Thats the most common courses of gas explosions.
 
at the end of the day if the boat sinks in the marina, it's not your life at risk is it....rather have a manual switch and manual pump
 
I wondered how many "frightened man with bucket" quotes I would get. I think Vyv is right when he points out that said frightened bloke can do the business for a short while but bucketing is very tiring and you would soon be overwhelmed. What concerns me is the speed of inflow of water from a comparatively small hole in the hull ( there is a frightening experiment chronicled by Nigel Calder in his Boatowners Electrical and Mechanical .. book) Another worry is the possibility of an undetected leak developing suddenly from a skin fitting or similar that may not be noticed if everyone is upstairs and it is not until the navigator goes below for a plot that he notices the bunk cushions floating, by which time the situation is irretrievable.
 
For a contrasting view - I'd fit the biggest electrical pump you can afford, as well as having a manual pump. My boat came fitted with an Attwood pump, which was probably about 4 years old when I can to move it, on moving it the plastic failed (it had become brittle), not sure why but I was a little less than impressed.

The comment about sparks from float switches needs further investigation - as I recall some float switches are switched via a phial of mercury - no risk of sparks. When considering flow rates do remember they fall off rapidly if you are asking the pump to extract water from a deep bilge (hence fit the biggest one you can...).

The unexpected discharging of an automatically switched pump will probably be the first indication that you have that something is amiss below the water line, long before the 'we descended below to find the floorboards floating' situation. That early warning might just give you time to do something about the situation other than inflating the liferaft.

have a look at:
http://www.powerboat-reports.com/sample/bilge.html
 
I have a bilge pump fitted below the saloon cabin seat with a long input and output hose tucked away under the seat. I have also have the normal set in the cockpit. If I have a problem the oulet hose stretches into the cockpit which allows two frightened men to pump at the same time.
 
Petrol engined boats have float switches in the bilge so I assume they are ignition protected and don't give off sparks.
 
The best thing about an electric pump is that you can switch it on and get on with repairing the hull damage. It won't shift as much as a good manual pump but it requires no physical effort.

All good float switches are no spark. Only the very cheap ones spark.

Put an alarm on the float switch circuit (computer alarm speaker from maplin is about £1.50) and it will sound when the flost is tripped, that way you get a lot of warning. Relying on a manual pump tells you nothing until the cabin sole is covered in water!

The drain is quite high on an electric pump, about 7amps for a decent one so you will want top start the engine if (God forbid) you ever have to use it for an extended period of time.

Help can sometimes be a long time coming, an electric pump may buy you some time and save the boat but it will only shift the water from a small hole, it certainly won't keep pace with a failed skin fitting. Therefore preparing all the gear to plug a hole is at least as important as carrying good pumps.
 
Yes, I did write no-float electrode, not float switch, however most electric pumps cutting in may cause a spark. My pump motor is, of course, set higher than the gas detector which may be a slight help in the unlikely event of the boat suffering a water and gas leak simultaneously.
 
I've survived with nothing more than a substantial hand pump for more than 20 years, but I have often thought that an emergency electric pump would be a good idea. It would want to be as big as possible - tho' not so as to deplete the batteries in less than 12 hours - because as has been alluded to, once the water gets over the battery terminals it's liferaft time.
Going off on and extended cruise or offshore for any period would certainly be a trigger to fitting such an item, if I were you I'd fit one. As to getting a budget model, just imagine yourself with a hole in the bows, 100 miles off Ushant, wishing you'd bought the £200 pump before you make a final decision. A 2" hole 2' below the waterline will, I think, let in something like 66 gallons per minute.
 
Every pump i've seen advertised is 'spark free'. There may be some Poundshop versions out there designed to spark on power up, but I think I am right in saying that anything CE marked must be spark free. I think it has been recognised for some time now that this could be an issue!
 
I was under the impression that bilge pumps are basically for nuisance water and none are really man enough to cope with a flooding situations.
 
I had a bilge alarm/pump switch which used a tube in the bilge with a washing machine pressure switch at the top. Mount it anywhere, no wires in the water. I always avoided leaving the boat with an auto pump because of problems with residual current in all the electrics, but this could be overcome by fitting dipole battery isolation switches.
 
Have a go at all of them, not much added cost

Softwood plugs for all holes. Cheap

Spare softwood plugs for new holes not previously built into the hull. Cheap

Sheet of sail material and lines to drape cloth over hole in hull from outside. Cheap

Available sleeping bag or blanket to stuff in the hole, with oar jammed in hole against ceiling or similar. (done this with 2 inch hole, and it slowed panic a lot). Cheap

Manual bilge pump with strum. Operated from cockpit. Should be standard. Cheap

Stirrup pump. Operate standing in bilge water. Cheap

2 Electric Bilge pumps with float switch and alarm. Start engine. Buy what you can afford, but one big one and one smaller one.

Use engine cooling water system with valve to block sea water intake and switch over to pumping bilge water out. Start engine. Cheap.

Engine mounted pump to be engaged in emergency. Start engine. Expensive of course.
 
I remember a pump that fitted onto the prop shaft that could pump phenomenal amount of water, somthing like 2,000 litres a minute. Only worked when underwater, the rest of the time it worked as an extractor fan. I think it was called the Ericson Safety Pump.
 
I would have thought that if there was any danger that gas could get near the lectricky bits of your pump or switch innards and cause a bang, then so could water (although a smaller bang......).
 
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Use engine cooling water system with valve to block sea water intake and switch over to pumping bilge water out. Start engine. Cheap.


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Now that's one I hadn't thought of, will be fitting extra bits asap.
Cheers jimdew.
 
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