Bilge Pump System Ideas

[AJ_n_Audrey]

I searched the forum for a comprehensive bilge pump system article, and found none (though I did find some good info on sealing electrical connections in the bilge), so I'm starting this thread.

I have a boat with a deep bilge, with a single Rule 2000gph automatic pump. I learned how insufficient this was when traveling down the ICW in FL and discovering my pump and associated fuse was fried. Replaced fuse, and it blew again. Ultimately, I replaced the bilge pump and solved the electrical issue at my next stop. Nothing scary, there was no water coming in, but it got me thinking, since I was headed to the Bahamas. That one bilge pump, and my manual pump (which works) are my only two means to keep water out. I decided I needed something better, so here's my (tentative) plan:

Rule 2000 automatic at the bottom of the bilge. (Spare pump on hand)
Rule 4000 pump about 6 inches higher in bilge
Ultra Safety Systems UPS-01 Float switched connected to Rule 4000
Ultra Safety Systems high water alarm connected to Rule 4000

External "crash pump" that can be dropped into the bilge. I'm looking at a recommendation from John Harries of Attainable Adventure Cruising on that one; an industrial electric sump pump rated 2900gph that we can plug into cabin outlets. AAC is a great site, fyi.

Also, I recommend David Pascoe's article on Bilge pumps at:

ALL ABOUT BILGE PUMPS - Boats, Yachts Maintenance and Troubleshooting

By his rule of thumb, I should have 6000 gph of pump capacity in the bilge.

The very good point that David Pascoe makes is that even though an electric pump is rated, say 2000 gph, with a three to four foot lift, that nominal 2000 is probably 1500, and maybe less, and that's before you factor in resistance in the exhaust hose. So you subtract about a third from all nominal ratings. With a 2000 & 4000 Rule pumps, I have nominal 6000, but really about 4000. So the crash pump gets me back to 6000, but what if a pump dies after running continuously for an hour (a very real possibility)? Or what if electrical power is lost for whatever reason?

That's where a small Honda pump comes in. I happen to own a Honda WX10T pump for other reasons, and it is rated at 2200 gph. Also, the small lift (maybe 5 feet) from bilge to overboard with the Honda makes almost no difference to performance - 5% decrease maybe; gas pumps are just that much more powerful. So my thought is shrinkwrap it, and keep some pure fuel available (the key to getting it to start easily).

I realize all the above sounds very belt-and-suspenders, but, I'm spending $500ish for the additional Rule 4000 + float switch + high water alarm. Another $450ish if I buy the crash pump. I already own the Honda pump. In the grand scheme of things, this is peanuts, and invaluable if it keeps the boat from sinking.

Also, for those of you with many thousands more miles under the keel than I have, the above may all sound very obvious, but it wasn't obvious to me until I lost my one and only installed electric bilge pump.

Comments and advice are welcome before I pull the trigger on all this, and I hope my thought process will be useful to some other people. I've told my wife that a bilge pump under the Christmas tree would be a welcome gift.....;-)

[Cheechako]

If you have room the Honda is a good idea for a last ditch emergency. The small ones seem powerful for the size too. The one I used was smaller than a basketball and shot a 1" stream of water out with force. But I have often wondered; when you have a "water in the boat" problem, rough weather is likely to go along with that problem. What do you do with a running gas pump when the boat is rocking and rolling, pitching and wallowing and there are lines all over the cockpit that may tangle in an engine or melt on the exhaust?

[brantleychuck]

I think your ideas are sound and provide some" peace of mind". Those of us who think about this kind of stuff often go for worse case scenarios.

[mike d.]

Why would you put a big pump down low to diminish it's capacity. If you have left over water in the lower bilge a small pump should handle that!

[brantleychuck]

Oops hit send to soon....
The situations that seem to sink more boats are the slow and moderate water intrusions into the hull. Just read of a boat that made a pacific crossing and then almost sink at a anchor while crew was onshore for dinner. The article seemed to indicate the crew was aware of a possible problem but........
With deep bilges you will want to be able to service the small primary pump easily, also a means of testing operation. Best way to do a real world test is with a water hose filling the bilge ,triggering the system.
A high water alarm just a couple inches above the maintenance pump switch to let you know there is a problem is imperative I believe and missing on many boats. Mine was hooked to a siren that could. Or be ignored . After that at least one more large rule type pump on a float switch. I did carry a 110 volt submersible pump with a collapsible hose rolled up and ready to go. This would be powered by my Honda 2000.
I have only used that pump one time and it was to help a old boat bum de water his floating home.

[AJ_n_Audrey]

Originally Posted by mike d.

Why would you put a big pump down low to diminish it's capacity. If you have left over water in the lower bilge a small pump should handle that!

Maybe I didn't describe it correctly. I'm talking about a Rule 2000 at the bottom of the bilge, and then a 4000 as high in the bilge as I can attach it. I am a bit limited on space because the V-drive, drive shaft, and prop shaft are directly above the bilge.

[micah719]

The pumps are just one item in the "Remain Surfaced" subroutine. How many compartments, how large, how well can they be sealed, minimum buoyancy at maximum load, what emergency repair gear and techniques and how long do they take in adverse conditions, etc. Look up Roger Taylor and his MingMing test....

[AJ_n_Audrey]

Originally Posted by Cheechako

If you have room the Honda is a good idea for a last ditch emergency. The small ones seem powerful for the size too. The one I used was smaller than a basketball and shot a 1" stream of water out with force. But I have often wondered; when you have a "water in the boat" problem, rough weather is likely to go along with that problem. What do you do with a running gas pump when the boat is rocking and rolling, pitching and wallowing and there are lines all over the cockpit that may tangle in an engine or melt on the exhaust?

I figure if I ever get so desperate than I need the Honda, and it's rough, I'll be okay screwing it down to some surface to hold it in place. Holes in fiberglass can be repaired. But I also might be able to clamp it down with a sea-clamp. Anyway, it's a good point - I need to know where it will be positioned. Possibly floor of cockpit sole all the way forward against the bridge deck.

[AJ_n_Audrey]

Originally Posted by micah719

The pumps are just one item in the "Remain Surfaced" subroutine. How many compartments, how large, how well can they be sealed, minimum buoyancy at maximum load, what emergency repair gear and techniques and how long do they take in adverse conditions, etc. Look up Roger Taylor and his MingMing test....

Yes, I'm also thinking about those things, because obviously you have to stop the water coming in. Only one sealed compartment: freshwater tank under the V-berth - well two if you count the portside freshwater tank - where the freshwater tank is. I haven't done the math, but I'm pretty sure those will not keep me afloat. Thanks for the Roger Taylor reference.

[John_Trusty]

Originally Posted by AJ_n_Audrey

Maybe I didn't describe it correctly. I'm talking about a Rule 2000 at the bottom of the bilge, and then a 4000 as high in the bilge as I can attach it. I am a bit limited on space because the V-drive, drive shaft, and prop shaft are directly above the bilge.

Just to clarify, it does not matter how high you put the pump intake - for safety put it as low as you can. What matters for sequentially activated pumping is the relative heights of the sensor switches. If you want the smaller pump to take all the load and wear of the frequent pumping from small drips, which is reasonable, put that sensor low and put the sensor for the large emergency pump and alarm higher. I'd mount the pump base or intake as low as you can for both to avoid sucking air when they are activated.

[AJ_n_Audrey]

Thanks John Trusty - now that you say it, that's makes perfect sense, but I'm not sure I would have thought of it.

[stormalong]

If you are a live aboard all you need is a second float switch a foot above the pump connected to an audio alarm. A simple pizeo(sp?) alarm will wake the dead. Test it occasionally by lifting the float switch. Connect it to a separate fuse off your main breaker so it is independent of the bilge pump circuit.

Unless you have other issues that should be all you need.

[Blue Stocking]

Bluestocking has narrow deep bilges, in which I can stand, with the cabin sole above my waist ( I am 5' 7 " ).
70% of the below floor volume is filled with well-mounted water tanks, and therefore will not contain a large gallonage of free bilge water. My W46 deisel and batteries are above sole height.
Centrifugal immersion pumps lose efficiency % quickly as head pressure increases.

My M.O. is planned to let the water reach the underside of the cabin sole, where a 4000 pump is tray mounted, with the resulting shortest lift/head to an opening port or the cockpit for drainage.
A pair of #8s are permanently attached to the pump with a twist/lock feed from the batteries.
A rotary ON/OFF switch can throw 100 amps from 2 combined alternators to this service at less than 1500 RPM.

A totally unrestricted 4000gp hour pump is only removing about 66 gpminute. That's equivalent to 25 of 1/2 full 5 gal buckets. That's a lot of water.

This BTW, is all totally independent of my 1" belt driven standard automatic pump, activated by a rule switch mounted at the cabin sole, activated by a vertical travelling rod/float device.

[TrentePieds]

This pops up every so often. If your thinking proceeds from a departure point that posits ALREADY having a gazillion gallons of water in the bilge, you need to roll your thinking backs further: "HOW did the water get there?" is the crucial question. You can construct dozens of scenarios for that. And each scenario will lead you to a different conclusion about the proper way for you to react to it and about the needed capacity of the pump(s).


If you are rolled over by a breaker, you will have far greater problems to think about than getting your pump going, and the likelihood is that you'll sink whatever you do. So be a good skipper and don't get into a situation where you'll get rolled over - or even broached :-) The residual risk of screwing up and getting into such a situation is one that we must all bear. That's part of skippering, but no amount of pumping capacity can compensate for such a screw-up.


If you take green water over the deck or get pooped and fill your cockpit, the scuppers should clear it, and no water should get below. If you've been a good boat-keeper and made sure your scuppers are clear and the hatches are tight and secure. there will be no question of the pump(s) having to deal with it.


If you burst a hose, say from a sink, just close the seacock! You've exercised them all regularly, of course so you KNOW they are functioning correctly :-)? Thereafter you'll have all day to bail out the water that came in. It's not likely that you'll not have noticed the problem before you have to wear scuba gear to get at the seacock, is it ;-)?


If a seacock breaks off its mount (how could that possibly happen?), you'll smack in the conical bung that you've ensured that you have on a lanyard next to the seacock, won't you? Then you'll have all day to clear your bilge.


If you smack into a half-tide rock at seven knots, you are gonna bounce some, and you'll likely CRACK the hull, but it is unlikely that you will wind up with a gaping hole. There may or may not be "weepage" through the cracks, but what would you predict the rate of ingress to be in gallons per minute?


Well, you can continue to construct scenarios. There must be thousands of them and the ones are apposite are related to the kind of sailing you do.


As far as I'm concerned a bilge pump is a housekeeping device, not a safety device. Safety is a function of skippering.


TP

[Hunky Dory]

Interesting! A thought on pump location. Have you thought about placing your pumps mounted on a stainless steel removable loose plate placed in the bilge as low as possible and accessible for maintenance and service . By having a long enough cord and hose you can bring the pump up above the floor to work on it rather than standing on your head. I have this method of mounting so I can move the pumps and clean under also. The pumps are then connected to float switches mounted remote at whatever height you want. By placing pumps down low you will not have short cycling as the water level drops quickly with the top pump installed your way.