Emergency actions when you hole your boat

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
CharlieO. said:
I am actually planning on doing a real world test of my bilge pumps capacity on my boat. I plan to catch and measure the water the comes out the thru hull. I am just interested in what my 800 gpm and 3400 gpm pumps actually discharge. I also want to measure how much water is pumped out on a single cycle of the float switch.
Click to expand...
GPM or GPH?
 
CharlieO. said:
I am actually planning on doing a real world test of my bilge pumps capacity on my boat. I plan to catch and measure the water the comes out the thru hull. I am just interested in what my 800 gpm and 3400 gpm pumps actually discharge. I also want to measure how much water is pumped out on a single cycle of the float switch.
Click to expand...

I hope that's GPH not GPM otherwise you'll need some big tanks to catch all that water! But in the end, not sure what you are trying to accomplish. Let's say they each discharge 75% of rating. Whether that's good or bad doesn't matter too much if your boat is holed and sinking. I guess it would still be good to know that it's not 10%. Let us know what you find.

Also, reagrding the float switch cycle, doesn't it matter how long the cycle is? If it's a 1 sec cycle, not too much. 10 sec cycle probably 10X. How do you intend to implement this test? Not being critical, but just curious what you have in mind for these tests.
 
CharlieO. said:
I am actually planning on doing a real world test of my bilge pumps capacity on my boat. I plan to catch and measure the water the comes out the thru hull. I am just interested in what my 800 gpm and 3400 gpm pumps actually discharge. I also want to measure how much water is pumped out on a single cycle of the float switch.
Click to expand...
Here's an idea that may be easier.

- Purchase one of these https://www.amazon.com/Save-a-Drop-...1679503884&sprefix=water+meter,aps,464&sr=8-5
- Pump your bilge as dry as your pumps normallly keep it
- Block the float switch(s)
- Fill the bilge as high as you dare without risking damaging anything using the dock hose with the water meter attached
- Release the float switch(s) and time the event until the bilge is dry again.
- Consider turning off all charging sources to make it as real world emergency as possible.

Not only might it be easier on your back it will probably be more realistic because the bilge pump will be functioning as installed
 
When doing previous repair work I had actually pulled a bit of the concrete ballast out of the bilge and refiberglassed so I had sort of a sump where all the water naturally drained to. now my bilge water pools up in the sump to be pumped out rather than the long shallow bilge holding the water for a lot longer and more spread out in the bilge area.

Not sure if that is making sense to other people.

Both of my bilge pumps are at the same level with the float switch for the bigger pump set 3/4" higher than my primary pump.
 
CharlieO. said:
When doing previous repair work I had actually pulled a bit of the concrete ballast out of the bilge and refiberglassed so I had sort of a sump where all the water naturally drained to. now my bilge water pools up in the sump to be pumped out rather than the long shallow bilge holding the water for a lot longer and more spread out in the bilge area.

Not sure if that is making sense to other people.

Both of my bilge pumps are at the same level with the float switch for the bigger pump set 3/4" higher than my primary pump.
Click to expand...

Why is the pump chosen to be set higher, why not the bilge float switch?
 
Has anyone bought a trash/dewatering pump as an emergency bilge pump? A few years back I looked into this topic and bought a Tsurumi 140 GPM (8400 GPH) 120vac trash/dewatering pump ($600). It can run off my inverter, though in practice I'd rather run a genset for it. It' submersible,and has a 50' long, 3" diameter outflow hose. If my bilge pumps, plugs, tarp, tape, epoxy, etc. don't work, I'm hoping it will.
Does anyone have something similar? Anyone ever tried it out?
 
In survival situations/emergency ones too..... you never know what might help and what may not work when needed or isn't doing the job.

I have known quite a few that have gas powered ones aboard because their volume is way more than the average electric ones....not latter the "specs" many pumps claim.

One sailor I knew who crossed the Atlantic frequently pointed to his gas trash pump.... he said insurance was half the price of his boat and the pump was cheap...and more likely to save his life than an insurance policy.
 
MV Dirona had a good write up regarding dewatering with a high capacity pump during a knockdown. They are no longer doing the boat thing but were a very astute cruising couple who have been there and done that. I haven't read it in a few years, but here it is if anyone is interested.

https://mvdirona.com/2014/09/69-1-degrees/
 
A gasoline trash pump may move more water, but as long as either an inverter or genset is still usable, I'd count on an electric pump to work. A gas pump will need careful storage and periodic exercise to have any confidence it'll start when needed.
 
Another way to evacuate water is to disconnect the engine intake hose quickly while engine is running and let the engine do some of the pumping. Actually got rid of a foot of water while underway and had an exchanger end cap leak into boat.
 
rslifkin said:
A gasoline trash pump may move more water, but as long as either an inverter or genset is still usable, I'd count on an electric pump to work. A gas pump will need careful storage and periodic exercise to have any confidence it'll start when needed.
Click to expand...

True..... but my experience in salvage operations has gas/diesel pumps in a whole different class than all but massive electric pumps.

If I was venturing way offshore, mitigating the TINY risk of having a gas pump aboard would definitely be worth it. The maintenance isn't that big of a deal and worth every penny/effort if you ever need it. It is also independent of your electrical system and a huge addition to what electric pumps you already have.

Gasoline and associated fumes are dangerous to the uninformed and/or operator error....
 
SteveK said:
Another way to evacuate water is to disconnect the engine intake hose quickly while engine is running and let the engine do some of the pumping. Actually got rid of a foot of water while underway and had an exchanger end cap leak into boat.
Click to expand...

If you are going to seriously consider that practice, you need to find a way to get some sort of screen over the open intake hose, or you will find yourself truly "hosed" when that errant rag or piece of clothing or whatever gets sucked into the engine's cooling pump.

I would never be able to disconnect the heavy wire reinforced hose between the sea strainer and the pump. However, there is a tee in that hose for flushing the engine on freshwater which I could use but only in a limited capacity.
 
rgano said:
If you are going to seriously consider that practice, you need to find a way to get some sort of screen over the open intake hose, or you will find yourself truly "hosed" when that errant rag or piece of clothing or whatever gets sucked into the engine's cooling pump.

I would never be able to disconnect the heavy wire reinforced hose between the sea strainer and the pump. However, there is a tee in that hose for flushing the engine on freshwater which I could use but only in a limited capacity.
Click to expand...

Don't worry, the rags were already stuck to the bilge pump grills, so not a concern. ;)
 
Unless you have a large engine(s) and planning on running hard, better check the average pump flow on that engine pump. Sure it may help, but don't just arbitrarily think it's a lot of water being moved.
 
psneeld said:
Unless you have a large engine(s) and planning on running hard, better check the average pump flow on that engine pump. Sure it may help, but don't just arbitrarily think it's a lot of water being moved.
Click to expand...
Good grief, offer a suggestion that actually worked in real life and get the third degree responses.
 
SteveK said:
Good grief, offer a suggestion that actually worked in real life and get the third degree responses.
Click to expand...

You think you are the only one with real world experience?

I have done the math rather than lucked out in one boating outing.

I am just suggesting others do the same than take some internet offhand experience.

Never said it was a bad idea, just do one's due diligence.
 
SteveK said:
Good grief, offer a suggestion that actually worked in real life and get the third degree responses.
Click to expand...

It works OK, but some common sense enter too. BTW. my engine can pump 35 gallons a minute.
 
Psneeld is right. Some engines can move a huge amount of water with the seawater pump. Others don't. My engines can move 30 gal/min, but only at high rpm. So depending on the situation it may be helpful, but I wouldn't count on it as a primary dewatering method. Especially as it needs careful monitoring to avoid running dry and killing an impeller.
 
rgano said:
It works OK, but some common sense enter too. BTW. my engine can pump 35 gallons a minute.
Click to expand...
That sounds right and why it will work, not at idle but at modest RPM, the boat can be in or out of gear as the impeller cannot tell the difference. Some people have actually done a T with screen and Y valve to be at ready for this event.
Now imagine twins.
 
If you can’t source the leak by the time floorboards start floating it’s time to activate the abandon ship plan. Stepping into unseeable holes in a hull full of rising water to switch valves you risk breaking an ankle or getting stuck and drowning.

We carry a gas powered 160 gpm dewatering pump on deck with a 50’ hose on a strumbox. This is in addition to the pair of 150 gpm hydraulic driven pumps in the two bilges which are activated via a momentary switch in the pilothouse. On deck there is a life raft and a cat 1 epirb. A second raft is stored inside in a valise case with two additional cat 2 epirbs. An on deck dunnage box contains mres, water jugs, tarps, line, and the majority of the solas signaling devices, as well as the dry suits (not Gumby’s), batteries and radios.

Having seen what happens when a transducer pops into a hull from its 2” hole 4 feet below the waterline I know haw fast things can get out of hand. 5 minutes wasted below trying to find or fix a problem might be better spent getting ready for a night or two in the water.
 
I have two 3700 GPH pumps and two 2000 GPH bilge pumps. Will probably not change anything as I have a dry bilge and it's getting late in the game.

If I were going to do it again or decided to add more capacity, I don't think I would go for the large trash pump. My inclination would be to add two to four 3700 pumps. I would be less concerned with 120 VAC or 12 VDC as long as I have the capacity to electrically support all the pumps at the same time. I'm not even sure they would be permanently mounted. Lot to be said for a portable pump with a soft rolled up hose, long enough to stick out a window. My logic for not wanting one big pump is that it's all or nothing. I'd rather have several in case one fails. The final part if you watch actual film from a sinking boat, there's a lot of debris gathering around the pump strainers. There is a significant likelihood of having to stop the pump to clear the debris. I'd rather turn off 25% of my capacity as opposed to 100%.

Ted
 
psneeld said:
Unless you have a large engine(s) and planning on running hard, better check the average pump flow on that engine pump. Sure it may help, but don't just arbitrarily think it's a lot of water being moved.
Click to expand...

I agree - check the table for your raw water pump!
 
I, too, like the idea of a 110V trash pump. Does anyone have a good one they can recommend? I see 1 to 1-1/2hp pumps for $80 - $120 on Amazon. I am thinking of buying a couple of 1HP pumps - seems like cheap insurance (in addition to my 2000 and 3700GPH 12V pumps).

Can one use flat hose (fire hose style) or does that cause excessive back pressure?
 
Juliet 15 said:
Has anyone bought a trash/dewatering pump as an emergency bilge pump? A few years back I looked into this topic and bought a Tsurumi 140 GPM (8400 GPH) 120vac trash/dewatering pump ($600). It can run off my inverter, though in practice I'd rather run a genset for it. It' submersible,and has a 50' long, 3" diameter outflow hose. If my bilge pumps, plugs, tarp, tape, epoxy, etc. don't work, I'm hoping it will.
Does anyone have something similar? Anyone ever tried it out?
Click to expand...

Post 25
 
2” Honda wt 20 starts first pull and weighs in around 100 pounds. Only used it a few times in reverse to repel boarders at the Columbus Day regatta. Done nothing other than start and run it a couple of times per year.
 
Fletcher500 said:
MV Dirona had a good write up regarding dewatering with a high capacity pump during a knockdown. They are no longer doing the boat thing but were a very astute cruising couple who have been there and done that. I haven't read it in a few years, but here it is if anyone is interested.



https://mvdirona.com/2014/09/69-1-degrees/
Click to expand...
Thanks for posting this. Author spends a lot of time discussing engine room vent location, something I too have praised in Nordhavns. What's interesting is author spends more time thinking about how water enters than de-watering. It's a package deal that includes a life raft as final fallback in the way the mid-Pacific sailboat did.

The hydraulic dewatering pump on Nordhavns is a thing of beauty. Routed out the stem, also serves as an anchor washdown that can damn near remove galvanizing coating.

Peter
 
You must log in or register to reply here.

Similar threads

P
need to install a cable gland
2 3
Replies
88
Views
4K
paulga
P
M
Aquila SureShade Issues - WATER!
Replies
1
Views
381
mhockett
M
PennBruce
Portland Pudgy Compass Question
Replies
4
Views
389
tiltrider1
tiltrider1
T
Name for stainless steel screw Fasteners?
Replies
12
Views
1K
Duke 239
D
C
Would You?
Replies
10
Views
639
Lepke
Lepke

Latest posts

Back
Top Bottom