Crash Pumps?

[CharlieJ]

In my opinion pumps only buy you time to find the source of the flooding and eliminate or at least mitigate it.

A 2" hole 3' below the waterline will flood 139 gpm > 8,340 gph.

[DeepFrz]

In my opinion pumps only buy you time to find the source of the flooding and eliminate or at least mitigate it.

And time is a good thing.

[hpeer]

FWIW,

#1 - our boat has 1/4" steel plate
#2 - most of the keel is either filled with concrete/steel, or fresh water, or diesel. Only a small, aft section of keel is not essentially a double hull.
#3 - have a small bilge pump forward, a larger Johnson in the main bilge, in bottom of keel.
#4 - a variety of manual or low capacity electrical pumps.
#5 - bought one of these Harbor Freight pumps.
1 Horsepower Submersible Dirty Water Pump with Float
Yeah, I know Harbor Freight. But, for the money what do I have to loose. I can power it off of my batteries via a inverter, or I can run it off the Honda genset.

While there may be much to criticize it for being Harbor Freight for the money and size is is a no brainer. When I have more money I may do more. It is still more than 95% of boats have.

The 33'er has an electrical bilge pump and a manual pump, and a manual on a board. It is harder to find a real good solution for the smaller boat.

BTW, when we bought the 44' boat, the manual seemed to be working, the aft bilge pump was mounted under the muffler and had disintegrated, the forward pump discharged into the sink drain. Neither surveyor noted any bilge pump problems.

[Andrew Troup]

I get a funny feeling in my water whenever anyone uses "12v" and "emergency equipment" in the same sentence, at least regarding any boat not equipped and wired to something like US Coastguard or National Lifeboat Association rescue vessel standards.

Salt water is a conductor. How many battery isolators, changeover switches, and equipment switches are immersion-proof to IP6x standards....

and of the tiny fraction which are, how many will retain that rating indefinitely under marine conditions?

This applies to all switches on the boat: if any of them go closed-circuit, any relays or loads they switch may come on, including things like windlasses and thrusters, which is likely to flatten the battery in short order, even if the battery itself is sealed.

Furthermore 12V is a low potential, far from ideal for highly adverse conditions, because it takes very little resistance to restrict the high current flows due to the "I squared x R" law for resistance losses (aka copper losses).

Salt water (even salt air), plus connections, adds up to resistance; halving the voltage means that the same resistance will result in four times the losses.

Serious marine installations in the past would routinely use 24V or 36V DC for any critical roles for these reasons.
The reasons haven't gone away but the practice is no longer routine.

Perhaps a more throwaway mentality means the average installation gets rewired a lot more often, averting connection resistance buildup.

It doesn't help in the situation where salt water is sloshing around the interior, though .....

[estarzinger]

"Coast Guard Vice Adm. Robert Parker, Operational Commander for the Atlantic Area, told ABC's Good Morning America that at the time of the distress call, the ship was taking on 2 feet of water an hour. It had about 10 feet of water when the crew abandoned the ship."

I make that to very roughly be 100' x 30' x 2' = 6000 cu ft/h = 44,880 gph = 748 gpm. That's a lot of water . . . . but . . . .

A 10.7hp crash pump (98kg, 4" intake) can push 555gpm. That might be reduced by 50% pushing against a big head, so lets say 280 gpm in the real world. (there are bigger ones - particularly if you are willing to go diesel rather than gas)

So, if the 2 feet per hour is correct, the vessel might well have been saved with 3 operational crash pumps (or perhaps only 2 if the head pressure is not so large)

The USCG helos have a standard crash pump they drop to vessels, but (I believe) its 'only' a 4hp 150gpm model.

---------------------------
On another aspect. They had two 25 man life rafts. The story is a bit confusing, but one set of reports says that the USCG helo counted the full complement (16) of IR images in the rafts and then the rafts overturned and they lost two. Thats a reminder from safety training that over large rafts are NOT safer, and in fact are more likely to capsize as they are designed for 'human ballast'

[Krogensailor]

We had a stuffing box shear it's bolt's thanks to the one person I let work on my boat. He put larger than called for packing in. Locked the shaft sheared the bolts and rolled the gland. We were east of frying pan shoals. I managed to get to the gland, (Cheoy Lee offshore 33) not alot of room in there. Used some wood I always carry to shore it up. Wrapped rags, didn't help much. fired up every pump, 3, cut the engine feed water hose to take water from the bilge and the wife and I on manuel whale pumps and motor sailed for Cape Fear. Appropriate name. One issue was keeping enough water in the bilge to cool the engine. I think a three way would be a good idea there. I'm here, so we got in. Jabsco used to make a trash pump the was permanently mounted to an engine pulley. Looked like it had a crank to engage. Would love to find one. Mallet , and plugs tied to each TH. Crash bulkhead. And then I try to enjoy sailing the boat. (A spoonful of vodka helps the Valium go down.)

[HopCar]

Krogansailor, Is this the type of Jabsco pump you're talking about?

Flow rate: Nominal 23 USgallons/min (87 Litres/min) at 1750rpm
Self-priming from dry up to 2.4m (7.8ft)



Model No.: 6590 Series

• Constructed from marine quality bronze and stainless steel for ruggedness and reliability.
• Easy to service and maintain.
• Inexpensive to buy and operate.
• Will tolerate abrasive wear (this may affect performance - seek advice from your distributer).
• Handles hard and soft solids without clogging.
• Can pump in either direction.
• Will not airlock.

This one should sell for around $900.00. They make larger and smaller ones as well.

[Krogensailor]

That's the one. I saw one years ago on my Dads boat. Is it avail at Hopkins? Thanks

[HopCar]

I don't have it in stock but I'd be glad to order it for you. Jabsco takes two or three weeks to get stuff to me. The price would be $886.90 plus what ever the shipping to you from Miami is.

[Nicholson58]

We have one (JABSCO) on our Camper & Nicholson 58 ketch with Westerbeke 115 HP. The pulley is free0wheeling and there is a manual clutch to engage. I believe it is 6000 gph. It is a very large rubber impeller of the same fashion as the main water pump. Sorry the photo is not great. Looking from aft starboard. The pump is the solid bronze item forward starboard. I hope I never need it.

BTW; my engine intake through-hull port valve has a manually removable port. It allows the valve to be closed and the port plug removed so the engine intake is from the bilge.

[HopCar]

Nicholson58, That's a serious pump system. How big is your engine cooling pump?
Sounds like your intake is a Groco Safety Seacock. They have the plug you describe. You can also use it to fresh water flush the engine or winterize it, what ever that is.

[Capt Phil]

Originally Posted by Captain Jeffry

Great discussion. All ears! Anyone ever heard or tried the main engine raw water intake hose for dewatering assist? Urban legend?

Good point, Capt Jeff... a boat I drive regularly for the owner has twin Detroit 8V71's and with the switch of one valve can switch from raw water cooling to bilge water pickup cooling on each engine. Not sure what the out put is GPM but I would guess at 1800 RPM it would be one hell of a lot! When he was doing a complete rebuild on the boat several years ago, I suggested it to him as his wife was worried about hitting something big in the middle of the night and sinking. Never had enough bilge water to try out the system as there are 4 other 12 volt pumps to handle any water intrusion which has been minimal for nearly 10 years. As a matter of fact, before any cruise, I dry the bilges with a towel and disinfectant with simple green to keep the boat smelling sweet. cheers, Phil

[HopCar]

There have been several discussions about using the engine cooling pump as an emergency bilge pump.
Those who are against it say that there is too much danger of damaging the engine and that they don't move enough water to make much difference.

I say that if the boat sinks the engine is pretty much shot anyway. I also don't buy the theory that bilge water will damage the engine. The water has to pass through the strainer and anything big enough to cause damage will be caught there.

As to them being too small to move enough water to be effective, even the smallest will move 400 or 500 gallons per hour. My engine has an 1-1/4" pump that will move over a 1000 gph.

It shouldn't cost more than about $50 to rig a way to easily use your engine as a bilge pump. I think it's a good investment.

[tbodine88]

Originally Posted by Dockhead

So now my thinking is to buy an electrically powered trash pump, like this one: Honda Pumps: WSP100 Submersible Water Pump

Looks like what we used in the navy for dewatering spaces. I like it, won't fit on my little boat though. Bildge too shallow & no AC source.

[Nicholson58]

Originally Posted by Capt Phil

Good point, Capt Jeff... a boat I drive regularly for the owner has twin Detroit 8V71's and with the switch of one valve can switch from raw water cooling to bilge water pickup cooling on each engine. Not sure what the out put is GPM but I would guess at 1800 RPM it would be one hell of a lot! When he was doing a complete rebuild on the boat several years ago, I suggested it to him as his wife was worried about hitting something big in the middle of the night and sinking. Never had enough bilge water to try out the system as there are 4 other 12 volt pumps to handle any water intrusion which has been minimal for nearly 10 years. As a matter of fact, before any cruise, I dry the bilges with a towel and disinfectant with simple green to keep the boat smelling sweet. cheers, Phil

Found another picture of the engine driven bronze pump with manual clutch. Below that you can see the main cooling pump (cover removed). Engine is Westerbeke 6-cyl diesel 115 HP. The cooling water lines are 1 inch, 1-1/2 & 2. Bilge lines are 2".

WOW! you clean your bilge with a powder-puff? The view down in front of the engine, below the companionway steps is the access to the bilge. It is the aft end of the partial full keel and is a triangular, 35 gallon well about 5 feet deep from the cabin sole. I can assure you there is not a dwarf on the planet small enough to stuff down that hole.