Bilge Pumps, employment, care and feeding.

[s/v Faith]

Bilge pumps

After a good storm on the Chesapeake last week, I was reminded of the value of a good bilge pumping system. 

Of course we know there is no better bilge pump then a scared Sailor with a bucket, but I am not a huge fan of that system since it is tough to sail and bail at the same time.

The boat I was on had a small (500 GPH) electric pump in the bilge, and a manual pump mounted where it could be operated from the cockpit.  The leak was not a big one, but when I discovered it the floor boards were floating, so there was a fair amount of water to get rid of.

Issue 1). Electronic switches.
The electric pump's automatic switch was one of the fancy 'solid state' ones.  It of course failed.  It was the second failure of one of these 'foolproof' solid state switches I have personally delt with in the last month.  The first was on an Alberg 30 I have been keeping an eye on.  For my boat there will be nothing but good old mercury float switches.

Issue 2). Redundant redundancy.
The smallish electronic bilge pump was not able to remove the water fast enough for my liking.  I have a similar sized pump on my boat, and it works fine for normal underway splashes that wind up in the bilge, but it was out of it's league.  Even if it were larger, the manual switch had taken it out of the running.  It also eventually clogged while clearing the bilge (you just have to turn it off, and the backflow of water mostly clears it).  The manual bilge pump, a Bosworth Guzzler, (400 I think) had nearly cleared the bilge when the flapper valve either failed or was jammed with debris.  The 'thirsty mate' slide type pump then had to be used to finish clearing the bilge.

The Guzzler is a good pump, but like anything else it can (and will) fail when you need it.

I was glad that the thirsty mate pump worked, since it would be hard to get a bucket into the narrow bilge access.

The plan for my boat was to be set up like this one had been.  I have now decided add another pump (triple redundancy, quadruple if you count the thirsty mate pump).  I will keep my < 500 GPH pump at the lowest point of my bilge.  I will also add a >1000 GPH pump at a higher place in the bilge to take over if the first pump becomes clogged, overwhelmed or fails.  I have already purchased a 'plastimo 925' manual pump that I will mount in the cockpit.

If you have an inboard, you might look at using the cooling pump as an extra means of removing water.  Consider this carefully though, as running your motor dry, or sucking debris into the cooling system might complicate your situation.

Issue 3).  Bilge hygiene.
Both of the pump failures I experienced were the result of trash in the bilge.  I hose my bilge out regularly on 'Faith' but it is easier to keep clean since it is well glassed and accessible.   

Issue 4).  Awareness. 
Of course this would not have been as pressing a problem if I had known earlier that the bilge was filling.  This boat had a high bilge water alarm, but it failed.   I plan to wire an extra float switch to the 'test' button of a smoke detector, to notify me if the water rises.  The smoke alarm will still function, so it will do double duty.  It should also be loud enough that if it went on while the boat was at the dock and I was not present, someone might hear it and know something was wrong.

It would also work to keep the bilge access open if you are in bad wx, but that might present a hazard to crew going below. 



  I know this is a long post, but floating floor boards are enough to ruin your whole day.  My First mate did great through the storm, the waves and wind did not seem to phase her, even the lightning did not bother her all that much.  Looking below and seeing all that water was a bit much, and I will admit it is something I would rather not repeat myself.  Maybe this will remind someone to re-visit your dewatering system.

[AdriftAtSea]

For bilge pump switches, I prefer the design my friend came up with... it is a thin rod with a big foam float on the bottom in a thin PVC pipe.  At the top of the pipe is a switch, which is activated when the big float rises and pushes the rod up—which pushes the switch.   This way, the electronics of the switch are far above the water.

Most people vastly overestimate how effective a bilge pump will be.   Most pumps are rated in gallons per hour.  If you consider that even a relatively small hole can let in a gallon a second, then you have to realize a pump that is rated for 400 GPH is hopelessly outclassed.  This is even more important on smaller boats, which generally have less freeboard, and are effected more readily by water coming aboard—fifty gallons may not mean much to a 100' boat, but on a 20' boat, we have a serious problem.  Having several good bilge pumps, including a very effective, high-capacity manual pump that is located in the cockpit makes a lot of sense.

s/v Faith's idea of having a very high capacity pump in case the level rises above what the lower capacity, primary bilge pumps can handle is also an excellent idea.  The use of the engine's cooling system is another good alternative, but has some serious risks that must be considered.

Keeping the bilge clean of the debris and junk that can clog a bilge pump is also essential.  The labels on canned foods are often a source of much of the gunk that clogs a bilge pump.

The idea of a bilge high-water alarm and using a carbon monoxide or smoke alarm test button as a backup is also good.  One other thing I recommend is a bilge pump cycle counter... that can tell you if a leak is chronic, and whether it is increasing or decreasing in rate.

[Captain Smollett]

Most people vastly overestimate how effective a bilge pump will be.   Most pumps are rated in gallons per hour.  If you consider that even a relatively small hole can let in a gallon a second, then you have to realize a pump that is rated for 400 GPH is hopelessly outclassed.

Just to put a number on this, for those playing at home, 1 gallon per second = 3600 gallons per hour.  "Hopelessly outclassed" is an understatement.

wire an extra float switch to the 'test' button of a smoke detector, to notify me if the water rises.  The smoke alarm will still function, so it will do double duty.

Excellent Idea.  I love it.  I loathe single-use equipment (with few exceptions), and anything that can be made multi-use has multiplied its value exponentially.  One might also consider the use of a propane or LPG alarm if the boat is so equipped.

Great Post, Craig.  Don't sweat the length - it was information dense!  :)

[Pixie Dust]

Good Post Craig.  That is the one thing that worries me on a regular basis.  I have the bilge pump with the float switch and a high water bilge alarm.  The alarm is not very loud and is barely audible, especially if the engine is running.  I have had to replace the float switch x2 in the last 3 yrs.  I also have a manual in the cockpit and it is the Guzzler 400, however, just in testing it out and using it every so often to make sure it still works and is not clogged, I realized how tiring it gets pumping it.  It does not take long for the arms to say, OK, I am done having fun.  :P  I have often thought about how difficult it would be if you had to keep doing that as your only resort.  My bilge area is small, so I am not even sure placing a second pump in there would be an option.   Compac also placed the Auto/Manual switch at the galley right below the sink.  This makes it a prime target for bumping against and turning it off.  I am constantly double checking that.  Definitely good info Craig!  Thanks for taking the time to post.

[s/v Faith]

Here is a link to a good article.  Never mind the title of the magazine that sponsored it (stinkpot-reports), this article;

20 Electric Bilge Pumps Tested in 'Power  boat-reports.com'

has some good information.

It asked;

There are three basic questions about 12-volt bilge pumps:

• Do they move as much water as the manufacturers claim?
• Which one moves the greatest volume of water in a given period of time?
• Which one moves the most water for the electrical power used?

  It also had this quote;

Like manual bilge pumps, electric pumps will not save a holed boat. A 1" hole 5' below the waterline will admit 44 gallons of water a minute. The biggest pump (the Rule 3700) will just about stem that tide—until the battery runs out. Running the engine to charge the batteries may be critical.

However, any of these pumps may give you time to find and fix the problem.

[AdriftAtSea]

GCompac also placed the Auto/Manual switch at the galley right below the sink.  This makes it a prime target for bumping against and turning it off.  I am constantly double checking that. 

Connie-

Might want to see about putting a cage over the switch, so that you can't bump it accidentally.  Also, might want to use the elevated float switch design I mentioned above.  If you have questions about it...let me know. 

BTW, a small bilge shouldn't be a deterrent to installing a second bilge pump.  In fact, the smaller the bilge, the greater the need for it IMHO.

If you want some specific advice, drop me a note, and I'll see what I can come up with for ya.  :D

Dan

[s/v Faith]

Here is another article on bilge pumps;

  David Pascoe's write up in yachtsurvey.com

  He takes a systematic aproach to clearing the bilge, and as a surveyor has seen many of the issues / problems that people (or builders) cause when they install pumps.

  Ok, I will stop posting articles on this subject now (I am sure that there are dozens of others out there floating around on the web).

  Like I posted above this issue has been more on my mind as of late, ever since that day on the Chesapeake.

Having spent many years investigating why they sank, I think I have a pretty good idea why. Its the casual attitude of both boat builders and boat owners toward bilge pumps.

Sail boaters are the absolute worst in this regard. For some strange reason, many of them just don't think that bilge pumps are important. Somehow they rationalize the idea that nothing is ever going to cause their hulls to suddenly flood, so a minimal pumping system is all that is really needed. As in just one pump. I never ceased to be amazed at the number of sailors who argue with me that one pump is enough. After all, the builder built it that way, and they have that nifty manual pump back there in the cockpit and that can really pump a lot of water. More about that later. FYI: Proportionately more sailboats flounder at sea even though powerboats outnumber them 8:1.....So why the widespread lack of concern? Well, its the same old problem of lack of experience; its not until they have a problem that they become convinced of the seriousness of it. Its mainly the people who've had their hulls flooded or even sunk that take the matter of bilge pumps seriously. Its called learning the hard way.

  Here is to not learning the hard way.   ;D

[AdriftAtSea]

Part of the problem is that most sailboats have a large weight attached to them, which makes any holes in them all that more important to fix, and any water that comes in all that more important to get rid of.  Most powerboats don't have this problem.   

Also, most sailboats have a deeper draft than do most powerboats.  This causes two problems: 1) they have more things they can hit...2) when the do hit something, the hole is often deeper in the water, and has more pressure pushing water into the boat.   

A good example of this is the speed transducer on a boat.  Take it out of a stinkpot or a multihull, and replace it with a dummy plug and see how high the water sprays.  Do the same on a deep draft full keel boat and see what happens. 

The deeper the hole, the faster the water comes in.  The bigger the hole, the faster the water comes in.  Sailboats have the worst of boat often.

BTW, boats don't flounder...they founder... :D  flounder is a big fish... founder is to sink.

[Pixie Dust]

This thread has offered some great advice and info!

Dan, the cage over the switch on the galley sink is a great idea. It would sure look better than duct tape.  ;)
I have been thinking about puttting in a secondary bilge pump and trying to figure out a good location, size, float switch location etc.  I think I can make some modifications and get another one in there.  I very well might seek some advice from the panel of experts we have here!  ;)

Craig, Dave Pascoe's write up was very informative.  Site has been saved for future reference.

[Captain Smollett]

Another thought on bilge pumps:

I was reading this article on Ocean Navigator dot com and noticed the author's comments about where the pump intakes are located possibly being a problem when heeling in a high winds.

Something to think about.

(Incidentally, I pump from the athwartships center, at the lowest part of the bilge...I see his point while heeling).

[GordMay]

When calculating desired Bilge Pump capacity, it might be wise to consider how quickly in-flooding water could sink your boat.  Remember, a given volume of water will sink a smaller boat more quickly than it would a larger vessel.

Approximate Flooding Rates, for smooth holes at selected depths, are calculated using the formula:

Flooding Rate in gpm ('Q') = 20 x d x square-root of h

where:
d = diameter of hole in inches
h = depth of hole underwater in feet (head)

Hence, for a 2" dia hole at 3 Ft depth:
Q = 20 x 2" x root 3 = 20 x 2 x 1.73 = 69.2 gpm (4,152 Gal per Hour)
then
69.2 / 60 = 1.15 gal per second, or 2.3 gal in two seconds

The actual flow rate ('Q') will be slightly less than calculated above, due to frictional & turbulence losses at the aperture.

Could your Bilge Pump(s) handle over 4,000 GPH of in-flooding, if a thru-hull lets go? How long will your batteries keep up* with the demand?
* Battery capacity (Amp/Hours) and height above internal waterline.

As posted at:
http://www.cruisersforum.com/forums/showthread.php?t=4016

[Joe Pyrat]

The system I like consits of two electric pumps and a couple of manual backups.  Pump number one is a small nuisance water pump located in the bottom of the bilge on a float switch for nuisance water.  Pump number two is a 4000+ GPH pump located slightly above the nuisance  water pump n a manual switch.  This pump is for use in a emergency where a lot of water is entering the boat, like a failed through hull, etc.  I also have a Lavac head which uses a Henderson manual pump which can be rerouted as a bilge pump and a second, backup Henderson which can be used in the cockpit to supplement or replace the the electrical pumps.  This system is based on a suggestion in Don Casey's book, Good Old Boat.

[AdriftAtSea]

The other question is where are your batteries located?  If they're fairly low in the boat, as they usually are, then the chance of the boat flooding past the height of the batteries is very likely, in which case your electric bilge pumps are gonna be toast.

The fastest electric bilge pump without a battery is a paperweight.

[CharlieJ]

Been there , done that. Had a bilge pump through hull go underwater and back siphon the pump. Flooded the bilge- three times before we figured out what was happening. Had to dump the battery cause it got saltwater in it and was outgassing chlorine gas :o

Now the battery is installed higher. Plus there is a Whale Gusher 10 mounted so it can be operated from the cockpit without opening any hatches. That thing will move a large amount of water- out put is a 1 1/2 inch hose.

There is also a small electric monted in the bilge with a switch- no float. It's for nuisance water, and since we have zero through hulls or other openings below waterline I really don't feel the need for a float switch.

[Captain Smollett]

The fastest electric bilge pump without a battery is a paperweight.

That's why we all carry at least one manual pump AND a bucket, right.  Right?

Saw the sig on the cruisers forum that went somthing like "the fastest bilge pump is a scared sailor with a bucket."

Also, if you are dealing with a large inflow of water, isn't the FIRST course of action to try to stop the flow?

Busted thru-hull...well, that's what those pointy little wooden plugs we carry are for, right?
We can fother with a sail, clothing or for larger holes, stuff in a pfd or a cushion.

In short, STOP (or at least greatly slow) the flow, THEN pump the water out.  There's no way, as indicated numerous times in this thread, that any ordinary pump is going to gain on a large 'leak.'

Food for thought. 

[Captain Smollett]

we have zero through hulls or other openings below waterline

Our sink drain leads to a through hull just under the waterline.  It's got a valve on it that stays closed and truthfully I've never used that sink for anything but to hold some papertowels and small pieces of handy spare line, etc.  The 'faucet' does not even work.

But just out of curiosity, how do you drain your sink?  Does it drain, or do you always use a bucket or tub to dump manually.

What about the drain for your ice box?

Sorry, you've probably answered these questions 100 times here and elsewhere, I just don't remember reading these specifics.

[CharlieJ]

The sink lifts out and we dump it overboard. Has no drain. It started life as a steam table tray, stainless steel. We carry a spare because it dawned on us one day that IF we dropped it ;D ;D



The icebox also has no drain- we use a small hand pump and pump it every other day or as needed. Usually every other day works well.

[Captain Smollett]

Thanks.  :) :)

I did always think a hull without holes was better than one with 'em. ;D

[s/v Faith]

Charlie,

  I can just picturethe confused looks on the face of your guests (Um, hey Charlie, uh... where is the drain?).   ;D

[AdriftAtSea]

The sink also makes a nice bucket to bail with in a pinch... ;)