Taking on water

We were sailing our '87 E-34 from Atlantic City to Sandy Hook, New Jersey yesterday when an alarming situation arose, the cabin sole on the starboard side of the boat had 2 to 3 inches of water across it and both bilge pumps were running. I inspected all the through hulls from bow to stern to no avail, and then I recalled a predicament that a friend of mine experienced on a crossing to the Azores. We were on a port tack all the way up the coast, causing the through hulls for the bilge pumps to submerge, when the pumps ended their cycle and shut off the resulting back flow caused a siphon effect, emptying gallons and gallons of water into the shower sump, and main bilge.
After realizing what was happenning we turned up wind to flatten out the boat and bring the through hulls out of the water, after the pumps had finished the backflow of water they sucked in air, stopping the pumps from syphoning again.
Our bilge hose has a loop in it over the aft bulk head, however this did not stop the water from back flowing into the boat. I will be installing check valves on all my through hulls immediatley, I don't want to think of what may have happened if we were sailing overnight and coming down below less frequently.
E-34 owners should be aware of this and make efforts to avoid this situation happening to you.
If anyone has a better idea than check valve I would like to hear them.
Thanks

Factory stock electric bilge pumps in my '88 boat are Jabsco 37000 series diaphragm pumps. This design should never back flow, as I understand the design, because the chambers act as check valves.

What kind of bilge pumps (make or model) are in your boat?

Loren

Bilge pump issues

Hi everyone,
This bilge pump problem is common with centrifigal bilge pumps. Rule, Attwood etc. I first encountered this problem about 35 years ago on a then not-to-old woodie I was sailing on. First thought it was the garboard plank leaking on one tack!. I think the best solution is an anti siphon valve. Although non return valves will work, they can and do fail. Other problems with centrifigal pumps are dips in the exit line which can air lock the flow out. Also all diaphram pumps should have strainers. a small piece of debris will render a diapham pump useless. I have installed strainers as big as engine sea water strainers on some larger boats. If your bilge is dirty, all kinds of junk floats around when there is a lot of water in the boat. Another good thing is to keep the ever handy bucket around. Longer passages on a beat often show up through hull position problems; sink drains, showers sumps, toilets etc. If you can exit your bilge pumps out the transom this is often the best place with the fewest problems.

Best regards,
Dal Farias
E39 "Stillwater" Bellingham, WA

Bilge pump choices.

Dear Mr. Sassy, Like Loren, I too have a diaphragm pump, not one that came with the boat new from Ericson. It's an ITT belt driven model similar to the one shown in this link http://www.boatersland.com/itt346000010.html. Please note that I have bought several of them over the years and never paid an amount even close to the new price. I typically pay between $25 and $40 for used ones at a nearby chandlery, Minney's. The already stated advantage is that they won't allow water to syphon back into the bilge. Think of the old finger on the straw filled with Coke trick and you have the idea. I combine that pump with an electronic water-sensing bilge switch attached to the vinyl pick up hose with a strainer at the end. As well, I have an in-line ITT fine screen strainer that traps little bits of debris, etc and saves the diaphragms from getting clogged. I have the pump mounted well above the water on a small shelf in the port lazarette. This all sounds way more complicated than it really is and I never have to worry about sinking the boat on a particular point of sail and other advantages. Hope this helps, Glyn Judson, E31 hull #55, Marina del Rey, CA

On my 87 E-34 I installed a siphon break in the bilge pump hose at the top of the transom. End of problem.

I am not a fan of check valves in bilge pump hoses.

siphon break

Tom: you wouldn't happen to have a photo of your siphon break handy would you? Is it like a vented loop, attached?

Actually yes & no. I took the siphon break out of a vented loop and put it into a plumbing tee. Hose barbs on each end installed in the bilge line where it is run under the cap rail.

No pics - this precedes my having a digital camera.

Gotta run, leaving on a power boat delivery. No I am not going over to the dark side.

I agree with Tom here. I would add that I like check valves in the intake side of the bilge pump near teh pick up so the water between the pick up and the pump does not drain back when the pump turns off. This helps get the bilge that much drier.