Emergency dewatering pump

Well, I just bought, and hope to install next week this emergency dewatering pump

https://www.grainger.com/product/DAYTON-1-2-HP-Residential-Dewatering-11C687

80 GPM, 120 volt

I'll be using a poly cam and groove fitting and a dedicated 1.5" through hull.
Using the cam and groove fitting because I want the pump to be quickly relocatable in case I need it somewhere else, or to help someone.
I bought a spare flat hose for just that use.

I'll either be running a dedicated 120 volt circuit so that I can turn it on from the main panel, or purchasing a float switch for it, not sure yet. I'm leaning towards the manual option but I can see a good argument to make the unit automatic, as many floodings occur when the boat s not occupied.

Very nice. If you go automatic, I think you should, mount it a little higher in the bilge than your regular bilge pumps. You probably only want it to kick on if your other pumps can't handle the flooding.

If you can, wire it with an auto / manual selection switch.

A lot of boats sink at the dock while unattended. A small leak over a long period of time will eventually kill your DC pumps. Then this one would kick in and buy you more time to discover the problem.

On the subject of emergency pumps, have you considered using your engine cooling water pump? I can pump my bilge by opening one valve and closing the seacock.

I second Parks method. On our present boat we also have a changeover valve in the engine cooling water intake line with a hose and strainer in the bilge.
I fitted it for safety because I had a problem with a shaft seal on our previous boat. I later fitted a PSS seal and have never had a problem since.
Its comforting to know I have a backup to the 2 bilge pumps 'just in case'.

That looks like a good pump. I want to do the same but haven't decided what to get. The specs on your pump will put out 4980 gph at 5 feet of lift. I would like to get more output. Rule had an 8000 gph pump made up of two 4000 gph pumps. It put out 5500 gph at 8 feet. Problem is I cant find them anywhere.
https://www.walmart.com/ip/RULE-EVACUATOR-8000-GPH-HIGH-CAPACITY-DEWATERING-PUMP/50937104

ksanders said:

Well, I just bought, and hope to install next week this emergency dewatering pump

https://www.grainger.com/product/DAYTON-1-2-HP-Residential-Dewatering-11C687

80 GPM, 120 volt

I'll be using a poly cam and groove fitting and a dedicated 1.5" through hull.
Using the cam and groove fitting because I want the pump to be quickly relocatable in case I need it somewhere else, or to help someone.
I bought a spare flat hose for just that use.

I'll either be running a dedicated 120 volt circuit so that I can turn it on from the main panel, or purchasing a float switch for it, not sure yet. I'm leaning towards the manual option but I can see a good argument to make the unit automatic, as many floodings occur when the boat s not occupied.

Click to expand...

You might consider using this setup as an emergency fire fighting setup as well. A three way valve that allows pickup from a thru hull with an output to a firehose attachment is something I included in Delfin's design. Needless to say, it has never been used, but the capacity is there to play fireman if needed.

I like the plan. Consider fabricating a box about the size of a milk crate of wire mesh. If you hole your boat and there is a lot of water to clear, all sorts of things inside the flooded area will start moving toward the pump and will block the slots, reducing the flow. A larger screened box can make a big difference in keeping the pump clear.

Ted

I have carried a 120 volt submersible pump on board for years. Fortunately have never needed it for the emergency purpose for which it was bought.

However to my great joy I have used it to bail out my dinghy and those of a number of friends when the dinghies have been filled with rain water. While no payment was expected I have received a number of beers as a result and met a couple of good people.

fryedaze said:

That looks like a good pump. I want to do the same but haven't decided what to get. The specs on your pump will put out 4980 gph at 5 feet of lift. I would like to get more output. Rule had an 8000 gph pump made up of two 4000 gph pumps. It put out 5500 gph at 8 feet. Problem is I cant find them anywhere.
https://www.walmart.com/ip/RULE-EVACUATOR-8000-GPH-HIGH-CAPACITY-DEWATERING-PUMP/50937104

Click to expand...

Got one at my local store, was going to get it, but the design is for a 3"outlet ive got 1.5" so passed.

That Rule 8000 is actually two of their 4000 pumps manifolded together. Ive never seen one in action but I bet it's impressive.

HopCar said:

That Rule 8000 is actually two of their 4000 pumps manifolded together. Ive never seen one in action but I bet it's impressive.

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Not really....

Like most electrical centrifugal pumps..any restriction in the discharge line kills them.

Have one on the assistance towboat, compared to the 2 inch honda trash pump... it is david and goliath.

The problem with using your engine raw water pump to bail out your boat is it doesn't really have all that much flow and if you plug the intake with a bilge ferret the engine will overheat and you will fail anyway.

Xsbank said:

The problem with using your engine raw water pump to bail out your boat is it doesn't really have all that much flow and if you plug the intake with a bilge ferret the engine will overheat and you will fail anyway.

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Every time I mention using my engine pump in an emergency someone warns me that I will overheat my engine and ruin it. I don't think so and I'm willing to risk it.

If I open that valve, there is a real danger of the boat sinking. If the boat sinks, the engine is ruined anyway.

Your comment that it doesn't move much water is some what valid. I'd rather have a larger belt driven pump but I just don't have the room. My pump is an 1-1/4" pump that should move better than a thousand gallons per hour. On my little boat that's a significant amount of water.

I was once on about a forty foot sportfish that was sinking. It only had the two Rule 1500 pumps that the builder installed. I kept looking at those two big Jabscos on the engines and thinking how much help they would be if I could get the hose off the seacock. Luckily the Coasties arrived with their 3" crash pump and saved the day.

HopCar said:

Every time I mention using my engine pump in an emergency someone warns me that I will overheat my engine and ruin it. I don't think so and I'm willing to risk it.

If I open that valve, there is a real danger of the boat sinking. If the boat sinks, the engine is ruined anyway.

Your comment that it doesn't move much water is some what valid. I'd rather have a larger belt driven pump but I just don't have the room. My pump is an 1-1/4" pump that should move better than a thousand gallons per hour. On my little boat that's a significant amount of water.

I was once on about a forty foot sportfish that was sinking. It only had the two Rule 1500 pumps that the builder installed. I kept looking at those two big Jabscos on the engines and thinking how much help they would be if I could get the hose off the seacock. Luckily the Coasties arrived with their 3" crash pump and saved the day.

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That's exactly what happened last summer when a 55 ft Sea Ray hit an obstruction off shore and pushed the strut up into the boat. Damaged shaft and prop. The delivery captain used the engine raw water pump to keep the boat afloat and limped into the marina where pumps and travel lift where on stand by. Pretty impressive after seeing the damage first hand.

I went with this particular 120 volt pump Vs the other options for several reasons.

I for one think using the engine pump is not a bad idea, it's just not the route I chose.

One of the reasons is speed to depoly. On my boat the through hulls are aft, in a area that would be fairly slow to reach if water is slopping around. My main breaker panel is right next to the helm. It would be very easy and fast to just turn on a breaker and have the pump running without having to hop down into the engine room, and crawl aft, then open and shut valves in the same area that is flooding.

Capacity. At 5' head this is a 80 gpm continous duty pump. While I apreciate the capacity of my Cummins seawater pumps, I don't think they are that large. I thought about high capacity 12 volt pumps but I am very skeptical. The reason is that 80 gpm at a 5' head requires a 1/2 HP pump. This pump draws 11 amps AC which is about right for a 1/2 horsepower motor. That same power in watts would take 110 amps at 12V DC. Yet I see the argest Rule pump claiming 3700GPM and being able to do so draswing only 15.5 amps at 12V DC. Something is not adding up here.

Versatility. The pump is portable with a standard power cord. I am using quick disconnect fittings, and have a separate discharge hose available. That means that if I need to use the pump in another part of the boat I can (my boat has a watertight bulkhead at the foreward side of the engine room). I can also use the pump to assist someone else, or for any other use (such as dewatering a skiff like larry mentioned).

Having a separate pump from the main propultion system to me makes better sense. If you use the main engine pump and you are any distance from help your boat will either A become overwhelmed, or B the pump will be faster than the water ingress which will cause impeller failure of your engine resulting in both pump and engine faiure.

Hi Parks, I meant that your engine would overheat if it picked up something that was floating in the bilge and blocked the intake. The flow from your raw water pump isnt that great - just look at the overflow out the back while running normally? I used to think a simple diverter valve would do but I am now convinced a serious, dedicated pump that will move a lot of water without revving the engine high or using that silly idea of running it off a shaft. I would rent or buy a Honda trash pump for use in remote areas, like the Broughtons) where there is little help available. I am currently installing another dedicated electric pump (I now have three) which will keep the lump aftoat until we can make it safely into the dinghy or run it up on a rock.

Capt. Sanders, do you have a 120 volt source that will continue to work with the batteries, genset or inverter flooded?

I planned a 3" camlock on the rear deck with a permanently deployed suction hose so I could connect the pump to the camlock and not have to go below. A trash pump will not burn out if run dry and it will do about 16,000 gals/hr. The gas engine will run an hour and a half on a tank. I will either have the leak fixed by then or be long gone!

Xsbank said:

Capt. Sanders, do you have a 120 volt source that will continue to work with the batteries, genset or inverter flooded?

I planned a 3" camlock on the rear deck with a permanently deployed suction hose so I could connect the pump to the camlock and not have to go below. A trash pump will not burn out if run dry and it will do about 16,000 gals/hr. The gas engine will run an hour and a half on a tank. I will either have the leak fixed by then or be long gone!

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Well...

The lowest electrical thing is probably the 12 volt starter on my main engines.

The batterys are tall, and the inverter is above the batteries. The base of the batteries and generator are several inches above the main enginroom level. I suspect that if the water gets deep enough to fault out anything then the boat will be unrecoverable.

The key here is early detection and fast deployment. I have two separate dedicated high bilge water alarms, along with a indicator light on the dash if the regular bilge pump is active, along with a engine room camera that is up on a laptop while underway.

I am a firm beleiver that if you have to do much to deploy your emergency pump you will not likely get it operational in an emergency.

Like mentioned above I too have hit a log in one of my previos boats, a 34 footer while over 50 miles offshore, and doing 27 knots. $40,000 in damage and we almost lost the boat. Fortunately we were able to make it to port using the two main bilge pumps, and go directly into a travel lift sling that was standing by on overtime.

Because of this I know from first hand experience how fast things can happen in an emergency.

BTW I like your idea of a permenantly mounted suction line and a trash pump. The only qualifier is that the trash pump needs to be accessable, and like any engine ran regularly. In my boat I just do not have the deck space for a trash pump, nor the quick means of getting one down to the cockpit where it is needed.

what is a trash pump ?? ( thanks in advance )

Benthic2 said:

what is a trash pump ?? ( thanks in advance )

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A trash pump is generally a low pressure, high volume pump capable of passing large diameter solids.

They are normally driven by a gasoline powered engine.

A trash pump can move allot of water. I saved my home and several others from a forest fire 21 years ago this month using nothing but a chain saw and a trash pump, sucking water from a lake.

"80 GPM, 120 volt"

At 2 ft below the water how big a hole allows 80gpm to enter?

FF said:

"80 GPM, 120 volt"

At 2 ft below the water how big a hole allows 80gpm to enter?

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A 2 inch hole, 2 feet below the waterline will allow 111 gallons per minute of water in your boat.

This is relevant because many of us have 2" piping for our seawater cooled engines.

Another valid example is your generator, watermaker, or salt water washdown seacock, or hose failure.

A 1" hole, 2 feet below the waterline will let in 27.8 gallons per minute.

"A 2 inch hole, 2 feet below the waterline will allow 111 gallons per minute of water in your boat.
This is relevant because many of us have 2" piping for our seawater cooled engines."

Sounds like a bit bigger pump might be a good investment ?