Crash Pumps

[Bertellini]

I have recently run across the concept of using an engine's raw water intake as an emergency high capacity bilge pump should a major hull breach occur. Most of the recommendations call for rigging up a Y splitter in the line with ball valves to control the path of flow. Has anyone installed or, unfortunately, used such a system? Obvious down sides seem to be clogging the intake by sucking up engine room debris, overcoming the rate of flooding and running the engine dry, and having to wade in to a potentially dark and quickly filling ER to locate and turn the valves.

All in all this seems to be an interesting proposition. Clearly this is a dire emergency oriented setup, which seems to outweigh the aforementioned drawbacks. Thoughts?

 

[MikeP]

I can't see how this would be useful in real life for boats like ours...

Using our 53 as an example...the engine rooms don't seem likely to be the spot for a holed hull to occur. I think that would be more likely further toward the bow. The connection from the forward bilge areas to the eng room is a rather small limber hole/tube - about 1" ID. There is no way enough water can pass through that hole to overwhelm even the standard eng room bilge pump. The same is true from the aft end of the boat - just a small limber tube.

OTOH, if you had a prop shaft break loose/disconnect from the coupler and it exited the boat, you WOULD have a fairly large hole in the hull at the engine room but that's not a difficult hole to plug. (You DO have wooden plugs of that size in the ER, right? )

I guess what I'm saying is that the design of the Hatteras boats and the small opening between bilge areas makes it impossible for enough water to get into the eng room bilge from another compartment to actually give the engine's RW intake much of anything to deal with. Obviously, if something struck the boat from the side at the eng room hard enough to punch a fair sized hole in the hull, then maybe in that specific case, it would be a useful thing. It just seems totally unlikely to me.

In a boat with a common bilge, I can see the use in it. But with the poor "communication? between the Hatteras bilges, I can't see how it could really be helpful. IMO, that's why Hatt installed 4 separtate bilge pumps - one in each bilge area.

 

[Pascal]

The problem with using the engine raw water pump to dewater a bilge is that you need someone there manning the valve, in a possibly challenging environment

As a last resort float or sink measure, I guess it s an option.

If I was spending a lot of time offshore where help is journey away, I d rather carry a real crash pump (gas powered) like what the USCG or the towers use. On the downside, you have to test then regularly to make sure the fuel is fresh and that they ll start, and also find storage space.

 

[rwappleton]

We seriously considered this option while in the yard this time. After looking at the layout that Mike has articulated very well here combined with the cost of the valves and the pipe( Holy Mackerel that stuff is expensive) We decided for our use of the boat (read ditch queen) and the cost was not worth the expense. We did upgrade our bilge pumps

 

[Jaxfishgyd]

I bought two 4000 gph Rule pumps from a boater who was selling his boat and 'stuff' a few years ago for $50 each... I hard wired them (with fuses) to the battery banks and have them set 6" above the other ones,(I have seven 1500 gph bilge pumps plus two 1100 gph in the shower sumps).. along with high water alarms....
I figure if they can't keep up with the water, it's time to abandon ship !!

 

[Genesis]

I considered a suitably-sized 240V electric motor coupled to a TRASH pump head (usually intended for use with a gas engine) wired to be powered by the genset, with a pickup valve arrangement allowing selection of the engine room space, the aft bilge or the forward bilge spaces.

It would of course only work if your genset was operational but those can run with partial immersion without burning up (that is, you can't run them entirely dry but if they get ahead of the water it's ok) and having the selectable intake would mean you could cover any compartment that got holed.

I decided against it as the odds of needing it and the necessity of maintenance (if it doesn't work when you need it of course it's worth zero) didn't seem to come down on the right side of the equation....

 

[Bob Bradley]

I have three things to handle a problem like that:

1: Good liferaft
2: EPIRB packed in liferaft
3: Paid up insurance policy

 

[bobk]

Interesting discussion. My 1981 48MY has a cash pump set up on the raw water side of the port 6V92. I always assumed it was OEM, but maybe not. Hope to never need it.

Bobk

 

[captainwjm]

My 8V92s have them, one for each engine, original equipment on the Viking. I agree that they could only be operated in extremis.

 

[jim rosenthal]

I seem to recall seeing an emergency pump that mounts to the propshaft and just freewheels all the time until water gets up to it. Has anyone seen this?

 

[dastahl]

Interesting discussion. My 1981 48MY has a cash pump set up on the raw water side of the port 6V92. I always assumed it was OEM, but maybe not. Hope to never need it.

Bobk

OK Bob thats funny a cash pump. Skooch is a cash pump too, outboard only.
Some of the LRCs (like mine) have crash pumps on the front of the 6 or 4 71s. Mine will not work and most have been removed over the years. I think a system as others have described with portable electric or even gas trash pumps would be better and cheaper.
BTW make me an offer the pump is brass on the port engine and will weigh in around 50 lbs.

Skooch 58 LRC
Wye River MD

 

[saltshaker]

I seem to recall seeing an emergency pump that mounts to the propshaft and just freewheels all the time until water gets up to it. Has anyone seen this?

I believe Edson made that pump. I remember seeing a video of an open boat with a 2-3 inch hole in it that was able to run and stay afloat with one of their crash pumps. I have an engine mounted crash pump with a clutch. I have a length of 3in hose attached to it so it can reach just about anywhere in the ER. I believe it was standard equipment so SAMs could offer more insight as to cost and availability.

 

[jim rosenthal]

Thanks. That would be worth having, I am going to see if they are still around.

 

[jim rosenthal]

It's Ericson Safety Pump, in Tarpon Springs. I'm still trying to track them down. Can't find a web page for them, but still looking.

 

[TopHattandTails]

I think it makes more sense for a SF than a MY. 1 large ER... I've seen this set up on a lot of Vikings, never used it but its there. I agree that you have to man someone there to turn the Y valve on and off as water rises falls.

 

[Boatsb]

Ripped a shaft log loose 50 miles offshore once and made it back on the engine pump and 5 gallon bucket. never needed to turn it off but glad I had it. Its great to have if you go offshore

 

[bobk]

OK Bob thats funny a cash pump. Skooch is a cash pump too, outboard only.
Some of the LRCs (like mine) have crash pumps on the front of the 6 or 4 71s. Mine will not work and most have been removed over the years. I think a system as others have described with portable electric or even gas trash pumps would be better and cheaper.
BTW make me an offer the pump is brass on the port engine and will weigh in around 50 lbs.

Skooch 58 LRC
Wye River MD

Yes, this is a combination CASH and crash pump. Both go through the engine before being discharged overboard. Good catch Dave.

 

[captddis]

The factory "crash pumps" [I prefer emergency pump] that I have seen have a dedicated permanently mounted pump with a clutch that runs off one of the engines. There is a manifold with hoses going to fwd, rear and engine rooms.

I have also seen pump outs on the intakes[ before sea strainer] that have a long hose to access other areas.
A lot of the intake mounted pump outs use gate valves and they need to be excersized. Almost all I check are frozen. Likewise the impeller in the pumps need to be rotated and replaced regularly.

 

[34Hatt]

When I re-powered I added the tees and valve to my intakes with a hose that goes into the lower part of the bilge. One other good thing is when I winterize it makes life easy and you also exercise the valves as Dave pointed out.

What I find funny is many here don't have them and comment about a lot of $$$ worth of parts and a lot of work to install a system which ever one you may chose but many here worry about a fresh water line sinking their boat
A shaft, rudder or thru-hull letting goes is a lot more water than a 1-2" to 3/4" line with 35 psi behind it!

 

[Boatsb]

Hell if you have a big detriot you can probably get home with a 3" hole in the boat.

The cost is minimal.