Flooding Emergency -- Checklist

[unclemack]

Originally Posted by Dockhead

Clogging is a huge problem which most people don't expect.

No matter how dry and clean your bilges are, all kinds of carp will appear in the bilge water, as soon as the level gets above normal. It's amazing how much comes out. It's because s*** famously rolls downhill, so all kinds of debris ends up in the bilge and you will never see and clean it all, and lots of it ends up in places too high to be washed out in normal circumstances.

I found this out almost by accident and now intentionally get my bilge level up quite high from time to time (with fresh water) just to flush this stuff out.

Figure on cleaning off the screen regularly during an emergency. My large 24v pumps are on plastic pipes (very deep bilge; not possible to reach to the bottom of it) so they can be pulled out and cleaned.


The trash pump is a macerating one and will deal with solids up to 3" in diameter, so no screen to clean.


I bet plenty of boats have been sunk by clogged bilge pumps.


Cockpit discharge no good for my boat, as my boat has terrible cockpit drains. A rare design flaw in the work of a designer known for attention to detail (Bill Dixon), but he screwed the pooch on the cockpit drains. I've had bathtubs which drain better than my cockpit.

Haven't actually proved it by experiment but I think a thin plastic shopping bag or a piece of cling-film will probably stop even a macerating pump.
That stuff gets amazingly strong when stretched - like around a motor shaft.

I'd still want a good big strum box



.

[Cheechako]

Originally Posted by jackdale

Years ago I saw a suggestion to tee a hose (with a ball valve) off the raw water inlet hose to the bilge. In case of flooding open the valve and close the raw water intake. Keep the engine running. Instant bilge pump.

I have not seen any installation that was like this.

Yes I have seen that also. I suspect the dewatering value would be very minimal compared with another bilge pump though. Those engine impellors don't seem to move much water.

[jackdale]

Originally Posted by Cheechako

Yes I have seen that also. I suspect the dewatering value would be very minimal compared with another bilge pump though. Those engine impellors don't seem to move much water.

One more pump.

[On The Water]

Originally Posted by Dockhead

Clogging is a huge problem which most people don't expect.

No matter how dry and clean your bilges are, all kinds of carp will appear in the bilge water, as soon as the level gets above normal. It's amazing how much comes out. It's because s*** famously rolls downhill, so all kinds of debris ends up in the bilge and you will never see and clean it all, and lots of it ends up in places too high to be washed out in normal circumstances.

I bet plenty of boats have been sunk by clogged bilge pumps.

Cockpit discharge no good for my boat, as my boat has terrible cockpit drains. A rare design flaw in the work of a designer known for attention to detail (Bill Dixon), but he screwed the pooch on the cockpit drains. I've had bathtubs which drain better than my cockpit.

Your pumps are huge, way 2 big for almost any cockpit to handle.

I am with you totally on the "No matter how dry and clean your bilges are, all kinds of carp will appear in the bilge water, as soon as the level gets above normal. "

I appreciate the effort you have done and explained here, something of great interest to me as just sold my nightmare of a boat, and at the same time fully retired and am looking to make one more long passage with a ready made boat so will definitely incorporate some of your ideas.

I once tried hard to work around that on one boat, a custom 33' I had, a total "eggshell" construction, all sofas, nav table sides, galley sides, everything was laminated to the hull, each other, bulkheads or the deck, there was not one opening to the floors or bilge apart from a 10 mm internal d drain tube from every one of the numerous "boxes" into the "bilge".
The spaces between 3x3 inch foam filled frames where sprayed with PU sanded and glassed over, basically the only interior parts (apart from fittings) that had screws or bolts where hinges for watertight doors and the chart table top.
The floor was also sprayed in and glassed leaving only the keel stump as a bilge and anything wanting to get into the bilge had only one way to get there, through 3 holes in the locked in place bilge "cover" only the length of the keel and about 2" wide, still stuff was found there, what could get there through a 1" drain holes, mainly dry dog food and dirt, it only housed the bilge pumps and a fisherman's anchor.
In case of a bigger breach the actual "bilge" would have been in the interior to the height of the settee sides calculated to be above WL even when filled ie float in calm or even a small swell if locker tops stayed closed, deck was also glassed in and designed to hold the weight of the boat as it had a quite some flotation incorporated into it.